HK1115197A - Silicone hydrogel contact lenses - Google Patents

Abstract

Ophthalmically compatible contact lenses include lens bodies configured for placement on a cornea of an animal or human eye. The lens bodies are made of a hydrophilic silicon-containing polymeric material. The lens bodies have oxygen permeabilities, water content, surface wettabilities, flexibilities, and/or designs to be worn by a lens wearer even during sleep. The present lenses can be worn on a daily basis, including overnight, or can be worn for several days, such as about thirty days, without requiring removal or cleaning.

Description

Silicone hydrogel contact lenses

The inventor: junichi Iwata, Tsuneo Hoki, Seiichirou Ikawa and Arthur Back

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the rights of U.S. provisional application No. 60/604,961, filed on 8/27/2004 and U.S. provisional application No. 60/621,525, filed on 10/22/2004, the contents of which are incorporated herein by reference in their entirety.

Technical Field

The present invention relates to contact lenses that can be worn continuously for extended periods of time. In particular, the present invention relates to flexible, hydrophilic silicon-containing contact lenses having an advantageous combination of properties.

Background

Contact lenses are basically classified into soft type and hard type lenses. Hard contact lenses are literally hard and may be slightly uncomfortable to wear. Soft contact lenses, on the other hand, are comfortable to wear, but are typically removed from the eye at the end of each day. Soft contact lenses are classified as hydrogel lenses and non-hydrogel lenses.

Conventional soft hydrogel contact lenses are typically composed of copolymers of hydrophilic monomers (e.g., hydroxyethyl methacrylate, N-vinyl pyrrolidone, etc.) and can be prepared by lathe cutting methods, spin casting methods, cast molding methods, or combinations thereof, followed by a swelling treatment in physiological saline and/or phosphate buffer solutions to obtain lenses having a water content of about 20% by weight or about 30% to about 80% by weight.

Soft silicon or silicon hydrogel contact lenses have been proposed for continuous wear over extended periods of time. For example, some silicone hydrogel contact lenses are intended to be worn overnight. Some silicone hydrogel contact lenses may be worn continuously for about two weeks, and some silicone hydrogel contact lenses may be worn continuously for about one month or about thirty days. Such continuous-wear lenses have relatively high oxygen permeability to allow oxygen to be available to the cornea during extended wear of such lenses.

Oxygen permeability (Dk) is an important factor in contact lens design in maintaining ocular health of contact lens wearers. As determined by Holden and Mertz in 1984, a minimum of 87X 10 is required for hydrogel contact lenses^-9(cmml O₂) /(sec ml mmHg) to limit nighttime edema to 4% (Holden et al, invest. opttalmol. vis. sci., 25: 1161-1167(1984)). Physical properties such as oxygen flux (j), oxygen permeability (Dk) and oxygen transmissibility (Dk/t) are used to characterize contact lenses. Oxygen flux can be defined as the volume of oxygen that passes through a specified area of a contact lens in a set amount of time. The physical unit of oxygen flux can be described as μ l O₂(cm²sec). Oxygen permeability may be defined as the amount of oxygen that passes through a contact lens material over a set amount of time and pressure differential. The physical unit of oxygen permeability can be described as 1Barrer or 10^-11(cm³O₂cm)/(cm³sec mmHg). Oxygen transmissibility may be defined as the amount of oxygen that passes through a contact lens of a specified thickness over a set amount of time and pressure differential. The physical unit of oxygen transmissibility can be defined as 10^-9(cm ml O₂) /(ml sec mmHg). Oxygen transmissibility relates to the type of lens having a specific thickness. Oxygen permeability is a material specific property that can be calculated from the oxygen transmissibility of the lens.

Oxygen transmissibility is typically measured using polarography and coulometry techniques known to those of ordinary skill in the art. Oxygen permeability can be calculated by multiplying the oxygen transmissibility (Dk/t) of the lens by the average thickness of the measured area. However, polarography techniques do not appear to provide accurate measurements for high Dk silicone hydrogel contact lenses (e.g., silicone hydrogel contact lenses having Dk greater than about 100 barrer). The variability associated with polarography techniques may involve the following issues: for silicone hydrogel lenses having a Dk greater than 100barrer, the measurement tends to stagnate at Dk values greater than 100. The Dk of eyeglasses that are believed to have a Dk greater than 100barrer are often measured using coulombic technology.

Prior art soft silicon-containing hydrophilic contact lenses having higher water contents tend to have reduced or lower oxygen permeability. For example, a silicone hydrogel contact lens available under the trade name Focus Night & Day (available from CIBA vision corporation) has a moisture content of about 24% and a Dk of about 140 barrer. Another silicone hydrogel contact lens available under the trade name O2Optix (available from CIBA Vision Corporation) has a moisture content of about 33% and a Dk of about 110 barrer. Another silicon hydrogel contact lens available under the trade name Acuvue Oasys (available from Johnson & Johnson) has a water content of about 38% and a Dk of about 105 barrer. Another silicone hydrogel contact lens available under the trade name PureVision (available from Bausch & Lomb) has a water content of about 36% and a Dk of about 100 barrer. Another silicon hydrogel contact lens available under the trade name Acuevue Advance (available from Johnson & Johnson) has a water content of about 46-47% and a Dk of about 65 barrer. In contrast, a non-silicone hydrogel contact lens available under the trade name Acuvue2 (available from Johnson & Johnson) has a moisture content of about 58% and a Dk of about 25 barrer.

In addition, existing silicone hydrogel contact lenses have a modulus between about 0.4 to about 1.4 mPa. For example, Focus Night & Day contact lenses have a modulus of about 1.4mPa, PureVision contact lenses have a modulus of about 1.3mPa, O2Optix has a modulus of about 1.0mPa, Advance contact lenses have a modulus of about 0.4mPa, and Oasys contact lenses have a modulus of about 0.7 mPa. Generally, for existing silicone hydrogel contact lenses, as Dk increases, the modulus of the lens increases.

Furthermore, existing silicone hydrogel contact lenses do not have desirable surface wettability. For example, FocusNight & Day contact lenses have a wetting angle of about 67, PureVision contact lenses have a wetting angle of about 99, O2Optix contact lenses have a wetting angle of about 60, and Advance contact lenses have a wetting angle of about 107. In contrast, non-silicone hydrogel contact lenses have a wetting angle of about 30 °.

It is important that contact lenses are comfortable and safe to wear. For example, silicone hydrogel contact lenses should be comfortable and safe to wear for daily use, for overnight wear, and/or for wearing in extended or continuous wear. One problem with extended or continuous wear contact lenses is that the lens adheres to the cornea during lens wear, which can lead to wearer discomfort, eye irritation, corneal staining, and/or other damage to the lens. Although lenses with high water content may be softer and more comfortable to wear, such prior art lenses may not have one or more characteristics suitable for providing comfortable and safe wear of contact lenses. For example, existing contact lenses may not have a desirable Dk, a desirable surface wettability, a desirable modulus, a desirable design, and/or a desirable moisture content. For example, silicone hydrogel contact lenses with high Dk typically have a lower water content. In addition, these lenses are stiffer and less wettable than lenses having higher water content.

In order to alleviate stromal hypoxia during daily wear of contact lenses, it is desirable to produce lenses having an oxygen transmission of at least about 45. Lenses having oxygen transmission greater than 50 (e.g., certain existing silicone hydrogel contact lenses) have been developed to alleviate stromal hypoxia during daily wear.

To help improve the properties of silicone hydrogel contact lenses, lenses have been manufactured that include one or more surface treatments or surface modifications in an attempt to make the lens surface more hydrophilic. Other ophthalmic lenses have been made that comprise an interpenetrating network of polyvinylpyrrolidone and a silicon-containing polymer.

There remains a need for novel silicone hydrogel contact lenses having a combination of advantageous properties, such as enhanced flexibility or less hardness, better wettability, and/or better lens design.

Disclosure of Invention

Novel contact lenses have been invented. For example, contact lenses (e.g., silicone hydrogel contact lenses) have been invented that include hydrophilic silicon-containing polymeric components. The spectacles of the invention may be understood to be associated with one, two or more of the following features: natural wettability (e.g., untreated surface wettability), high Dk, high water content, low modulus, and a design that facilitates wearing contact lenses with reduced discomfort. For example, the present lenses have one or more of the above characteristics as compared to existing silicone hydrogel contact lenses. Alternatively, expressed differently, the present eyewear has one or more of the above characteristics of different values. The characteristics of the lenses of the invention result in reduced discomfort to the lens wearer wearing the lenses of the invention as compared to prior art silicone hydrogel contact lenses.

In certain embodiments, the present silicone hydrogel contact lenses have one or more surfaces that are untreated to become more hydrophilic, have no wetting agent, and/or are associated with low or no protein or lipid deposition.

In certain embodiments, the present silicone hydrogel contact lenses have a relatively higher Dk and a relatively higher water content than, for example, the prior silicone hydrogel contact lenses described herein. For example, the present silicone hydrogel contact lenses may have an equilibrium water content of about 30% to about 60% by weight and a Dk of about 200barrer to about 80 barrer. In one embodiment, the silicone hydrogel contact lens has an equilibrium water content of 20% to 70% by weight and a Dk of 220barrer to 60 barrer. One example of a silicone hydrogel contact lens of the invention has an equilibrium moisture content of about 30% by weight and a Dk of about 200 barrer. In certain embodiments, the lenses of the invention have an equilibrium moisture content of greater than 20% by weight and a Dk of greater than 160 barrer. Another example of a silicone hydrogel contact lens of the invention has a water content of about 60% by weight and a Dk of about 80 barrer. In one embodiment, the silicone hydrogel contact lens has a water content of greater than 50% by weight and a Dk of greater than 70 barrer. Yet another example of a silicone hydrogel contact lens of the invention has a water content of about 48% by weight and a Dk of greater than 100 barrer. Thus, it can be appreciated that the present silicone hydrogel contact lenses can have a higher water content and a higher Dk relative to existing silicone hydrogel contact lenses.

Certain embodiments of the present silicone hydrogel contact lenses have a relatively higher Dk and a relatively lower modulus than prior silicone hydrogel contact lenses as described herein. For example, the present silicone hydrogel contact lenses may have a Dk of about 100 to about 200 barrers and a modulus of about 0.4 to about 1.4 mPa. One example of a silicone hydrogel contact lens has a Dk of greater than 90barrer and a modulus of 0.3mPa to 1.5 mPa. In certain embodiments, the present silicone hydrogel contact lenses have a Dk of about 100 and a modulus of about 0.4 mPa. In other embodiments, the present silicone hydrogel contact lenses have a Dk of about 200 and a modulus of about 1.4. In still other embodiments, the present silicone hydrogel contact lenses have a Dk of about 150barrer and a modulus of about 0.8 mPa. In contrast, the existing Acuvue Advance silicone hydrogel contact lenses have a modulus of about 0.4mPa and a Dk of about 70. Existing FocusNight & Day silicone hydrogel contact lenses have a modulus of about 1.4 and a Dk of about 130. Thus, certain embodiments of the present silicone hydrogel contact lenses have a relatively large Dk, a relatively high water content, and are relatively soft, as compared to existing silicone hydrogel contact lenses.

The present silicone hydrogel contact lenses can include surfaces having greater wettability than existing silicone hydrogel contact lenses, such as those described herein. As is understood by those of ordinary skill in the art, the wettability of a contact lens surface can be determined by measuring the wetting angle using methods such as the sitting drop method. A lower wetting angle corresponds to enhanced surface wettability. For comparison purposes, prior silicone hydrogel contact lenses, such as those described herein, have surfaces that provide a wetting angle of about 60 ° to about 110 °. The present silicone hydrogel contact lenses can include surfaces, such as the anterior and/or posterior surfaces, having a wetting angle of less than 60 °. In certain embodiments, the present silicone hydrogel contact lenses have a surface with a wetting angle of less than about 50 °. In other embodiments, the present silicone hydrogel contact lenses have a surface with a wetting angle of about 30 °. At least one example of a contact lens of the present invention has a surface with a wetting angle of less than 40 °. The present contact lenses having lower wetting angles, and thus enhanced surface wettability, have higher Dk, higher water content, and/or lower modulus than prior silicone hydrogel contact lenses as discussed herein.

The present lenses can provide improvements or enhancements in patient comfort as compared to existing silicone hydrogel contact lenses as discussed herein. For example, only about 15% of patients wearing existing silicone hydrogel contact lenses report satisfactory comfort of wearing lenses, while about 40% of patients wearing the silicone hydrogel contact lenses of the present invention report satisfactory comfort of wearing lenses.

In one particular embodiment, the present contact lenses have a Dk of about 115 to about 149 barrers, a water content of about 48% by weight, and a modulus of about 0.84 mPa. For example, a contact lens may have a Dk of greater than 105barrer, a water content of greater than 45% by weight, and a modulus of greater than 0.8 mPa. In certain embodiments, the present silicone hydrogel contact lenses have a water content of greater than about 50% by weight, a modulus of about 0.3 to about 0.5mPa, and a Dk of about 70 to about 100 barrer. For example, a contact lens may have a water content of greater than 50% by weight, a modulus of 0.2mPa to 0.6mPa, and a Dk of greater than 60 barrer. These embodiments are useful as daily wear silicone hydrogel contact lenses. In additional embodiments, the present silicone hydrogel contact lenses have a Dk of at least about 120 barrers and a water content of at least about 48% by weight. These embodiments are useful as extended or continuous wear silicone hydrogel contact lenses. By way of comparison, as discussed herein, an Acuevue Advance silicone hydrogel contact lens has a Dk of about 105, a water content of about 46% by weight, and a modulus of 0.7 mPa.

The lenses of the invention are hydrophilic and have a unique and advantageous combination of properties as described herein. The combination of characteristics aids in the assessment of appropriate conditions for wearing the lenses of the invention. For example, certain combinations of properties such as high water content, relatively low Dk, and low modulus may be desirable or acceptable for daily wear silicone hydrogel contact lenses (e.g., lenses that can be worn overnight without cleaning but are typically discarded daily). Other combinations of properties, such as high Dk, high water content, and low modulus, may be effective to aid in the use of such eyewear in continuous or extended wear applications (e.g., for more than an overnight period, such as for at least about five days, such as for about two weeks or more or at least about one month). The present contact lenses can be manufactured relatively easily and more cost effectively. The use of such spectacles provides advantages such as vision correction with reduced handling and maintenance of the lenses, continuous or extended wear of contact lenses, while being ophthalmically compatible and providing comfort and safety to the wearer.

In one broad aspect, a contact lens comprises a lens body configured to be placed or disposed on a cornea of an animal eye or a human eye. The lens body includes one or more hydrophilic silicon-containing polymeric materials. The lens body has a Dk or oxygen permeability of greater than about 70barrer or about 80barrer or about 100barrer or about 105barrer or about 110barrer or about 115barrer or about 120barrer or about 125barrer or about 130barrer or about 150barrer or about 180barrer or about 200barrer or more, and an equilibrium water content of greater than about 15% or about 30% or about 35% or about 40% or more by weight. The present contact lenses are ophthalmically compatible and advantageously adapted and configured and/or effective for continuous wear, for example, on the cornea of a human or animal eye for 1 or 5 days or at least about 5 or more days.

In one embodiment, the lens body of the present contact lenses, which is an ophthalmically compatible lens body, for example, has no surface treatment or modification on the anterior and/or posterior side of the lens body, e.g., is manufactured without surface treatment or modification. In some prior art lenses, it is desirable to perform such surface treatments to enhance the wettability of the surface and/or one or more other properties of the lens. The lenses of the invention advantageously have ocular compatibility without the need for such surface treatment or modification. For example, the present lenses can be manufactured by polymerizing a lens precursor composition in a contact lens mold assembly to form a contact lens that can undergo extraction and encapsulation steps without the need for post-polymerization surface modification to remain sufficiently wettable when placed on an individual's eye. Additionally, some embodiments of the present lenses do not require polyvinylpyrrolidone (PVP) (e.g., an interpenetrating network comprising PVP) and/or other additives to achieve the desired wettability of the lenses. In certain embodiments, the lenses of the invention are free of surface modification or surface treatment and do not comprise an interpenetrating network comprising PVP. In other words, the present contact lenses can be made by polymerizing or curing a lens precursor composition in a contact lens mold and extracting and hydrating the polymerized lens. Hydrated lenses manufactured in the mold comprise an anterior surface and/or a posterior surface that are sufficiently wettable so as to be worn on the eye with reduced or no substantial discomfort to the lens wearer and without the need for surface treatment. Thus, the present embodiments can be understood to be silicone hydrogel contact lenses without surface treatment.

In one embodiment, the lens bodies of the present contact lenses can have a combination of properties, including an effective or appropriate ion flux to substantially inhibit or even substantially prevent corneal staining, e.g., more severe corneal staining than surface or moderate corneal staining, from occurring after 8 hours or more (e.g., about 1 day or about 5 days or about 10 days or about 20 days or about 30 days or more) of continuous contact lens wear on the cornea of a human or animal eye for 8 hours or more.

The oxygen permeability of the lenses of the invention can be measured while the contact lens is in a wet or fully hydrated state. The oxygen permeability or Dk is indicated as barrer, which is 10^-10(ml O₂mm)/(cm²sec. mm Hg) or 10^-10ml O₂mm cm^-2sec.^-1mm Hg^-1. Preferably, the mirror has a Dk of at least about 80barrer or about 100barrer or about 105barrer or about 110barrer or about 115barrer or about 120barrer or about 125barrer or about 130barrer or at least about 150barrer or about 180barrer or even at least about 200barrer or greater. The large Dk value of the lens bodies of the present invention is very useful in that the cornea of the eye can acquire sufficient oxygen even when the contact lens is continuously positioned on the cornea for an extended period of time as described herein.

The present lens bodies can have effective or suitable structural or mechanical features (e.g., one or more of modulus, tear strength, elongation, and/or the like) to withstand continuous wear of a contact lens as described herein for extended periods of time or extended periods of time. For example, the present lens bodies can have an effective or appropriate modulus for use as continuous wear contact lenses.

The present contact lenses comprise a lens body comprising a hydrophilic silicon-containing polymeric material. In one embodiment, the polymeric material includes units from a silicon-containing monomer (e.g., from two silicon-containing macromers having different molecular weights and preferably different chemical structures). This embodiment may be particularly useful for continuous-wear silicone hydrogel contact lenses (e.g., silicone hydrogel contact lenses that can be worn for about 30 days in a continuous manner). In another embodiment, the present contact lenses include only one silicon-containing macromer having a relatively high molecular weight. This embodiment (i.e., one that includes a silicon-containing macromer) may be particularly useful for daily wear silicone hydrogel contact lenses that are wearable while sleeping, but are typically discarded daily.

Each feature described herein and each combination of two or more of such features is included within the scope of the present invention provided that the features included in the combination are not mutually compatible. In addition, any feature or combination of features may be specifically excluded from any embodiment of the present invention.

These and other aspects and advantages of the invention will be appreciated from the following detailed description, examples and claims.

Drawings

Is free of

Detailed Description

The present contact lenses have a unique and advantageous combination of properties that facilitate their use for extended contact lens wear by lens wearers. For example, the present eyewear may be worn by a person while sleeping. In certain embodiments, the lenses have properties that facilitate their use for daily wear (which may include overnight wear). In other embodiments, the lenses have properties that facilitate their use in continuous or extended wear applications, such as for more than 5 days (e.g., for about 30 days). The present contact lenses provide advantages such as vision correction with reduced lens handling and maintenance, continuous or extended wear of contact lenses, and are ophthalmically compatible and/or provide comfort and safety to the wearer.

In one broad aspect, the invention provides a silicone hydrogel contact lens comprising a lens body without a surface treatment. The lens body comprises a hydrophilic silicon-containing polymeric material and has at least one of an oxygen permeability, a water content, a surface wettability, a modulus, and a design effective to assist a lens wearer in wearing a contact lens in an ophthalmically compatible manner for at least one day. In certain embodiments, the lens body has two or more of the above features such as oxygen permeability, water content, surface wettability, modulus, and design. In additional embodiments, the mirror body has three or more of the above features. As used herein, ocular compatibility can be understood to mean that the lens wearer wears the present lenses with little or no discomfort, and with little or no occurrence of the features associated with existing silicone hydrogel contact lenses (e.g., lipid or protein deposition, corneal staining, etc.). In certain embodiments, the lens body has all of the above-described characteristics useful in wearing at least one day of eyeglasses, including daily wear eyeglasses. In other embodiments, the lens body has all of the above characteristics useful in wearing lenses for about thirty days, including continuous wear contact lenses.

Certain embodiments of contact lenses, such as the present day-to-day lenses, comprise a hydrophilic silicon-containing polymeric material comprising units derived from a hydrophilic silicon-containing macromer (e.g., a hydrophilic silicon-containing macromer). Other embodiments of contact lenses, such as the continuous wear contact lenses of the invention, include a hydrophilic silicon-containing polymeric material comprising units from two different hydrophilic silicon-containing macromers, each having a different molecular weight.

Embodiments of the present silicone hydrogel contact lenses comprise a lens body having an oxygen permeability of at least about 70barrer, a water content of at least about 30% by weight, a modulus of less than about 1.4mPa, and a contact angle on a surface of the lens body of less than about 60 degrees. In some embodiments, the lens body has an oxygen permeability of greater than about 110 barrers. In some embodiments, the lens body has a water content of greater than about 45% by weight. In some embodiments, the mirror has a modulus of less than about 0.9 mPa. For example, one embodiment of the present silicone hydrogel contact lenses comprises a lens body having an oxygen permeability of at least about 115 barrers, a water content of about 48% by weight, and a modulus of about 0.84 mPa. As another example, one embodiment of the present silicone hydrogel contact lenses comprises a lens body having an oxygen permeability of about 70 barrers to about 100 barrers, a water content of at least about 50% by weight, and a modulus of about 0.3mPa to about 0.5 mPa. These and other features of the eyewear of the present invention are included in the following description and the summary above.

In another broad aspect, the invention relates to a contact lens comprising a lens body configured to be placed or disposed on a cornea of an animal eye or a human eye. The lens body includes one or more hydrophilic silicon-containing polymeric materials. The lens body has a Dk or oxygen permeability of greater than about 70barrer or about 75barrer or about 80barrer or about 85barrer or about 90barrer or about 95barrer or about 100barrer or about 105barrer or about 110barrer or about 115barrer or about 120barrer or about 125barrer or about 130barrer or about 150barrer or about 180barrer or about 200barrer, and an equilibrium moisture content of greater than about 15% or about 30% or about 35% or about 40% by weight. The present contact lenses are ophthalmically compatible as defined herein, and advantageously adapted and configured and/or effective for continuous wear, for example, on the cornea of a human or animal eye for about 1 day or about 5 days or at least about 5 days or about 10 days or about 20 days or about 30 days or more.

As used herein, the term "ocular compatibility" as applied to the present contact lenses and lenses is also understood to mean that such lenses and lenses effectively provide the following features in continuous wear applications: (1) allowing oxygen to reach the cornea of the eye wearing the lens in an amount sufficient to maintain long-term corneal health; (2) does not cause substantial undue corneal swelling or edema in the eye fitted with the lens, e.g., no more than about 5% or about 10% corneal swelling after being worn on the cornea of the eye during nighttime sleep; (3) causing the lens to move sufficiently over the cornea of the eye on which the lens is worn to assist tear flow between the lens and the eye, in other words, without causing the lens to adhere to the eye with sufficient force to prevent substantially normal lens movement; (4) such that the glasses are worn on the eyes without undue or noticeable discomfort and/or irritation and/or pain, e.g., such that the glasses are worn with substantial comfort and/or substantially no irritation and/or substantially no pain; and (5) inhibiting or substantially preventing deposition of lipids and/or proteins sufficient to substantially interfere with functioning during lens wear, e.g., inhibiting or substantially preventing deposition of lipids and/or proteins sufficient to encourage lens removal by a lens wearer due to lipid and/or protein deposition. Advantageously, such an ophthalmically compatible contact lens and lens body additionally inhibits, reduces or even substantially prevents corneal staining after the lens is continuously worn on the cornea of an eye, for example during nighttime sleep.

Corneal staining is a measure of corneal epithelial cell damage or destruction. The corneal epithelium is about 50 microns thick and includes 5-7 layers of cells. The epithelium is constantly regenerating, with the outermost layer of cells sloughed into the tear film with the aid of blinking. The innermost cell layer is pushed forward by the new cell growth underneath, and this layer gradually changes to become the outermost layer after a repeated new growth cycle of about 7 days. Damaged or dead epithelial cells were stained when exposed to sodium fluorescein. Thus, the extent of such staining can be used to measure the extent of cellular damage/deterioration. Some degree of corneal staining typically occurs when conventional daily wear and continuous wear contact lenses are worn, and may even occur when contact lenses are not being worn.

Sodium fluorescein is routinely used in clinical practice to determine the extent of corneal epithelial damage. This is because sodium fluorescein can passively accumulate into damaged cells or pool in regions where cells have been removed. One can determine epithelial damage and thus the clinical significance of its management by assessing the extent of the corneal region exhibiting fluorescein staining and whether fluorescein is able to penetrate and diffuse into the corneal stroma. The faster it takes for the dispersion into the matrix to occur, the greater the number of layers that have been damaged. In addition, the staining pattern is also a key indicator of possible etiologies of corneal staining such as superficial macular keratitis (superior punctatekeratitis), epithelial arcuate lesion (SEAL), foreign body tracking (foreign body tracking), arcuate staining (arcuate staining). Assessment scales have been developed for quantifying corneal staining and are well known. See Terry RL et al, "Standards for success Contact lenses Wear", Optom. Vis. Sci.70 (3): 234-243, 1993.

In one embodiment, the lenses of the invention are constructed and/or have a combination of properties so as to substantially inhibit, even substantially prevent, corneal staining from occurring after continuous wear of the lenses during nighttime sleep or after continuous wear for at least 1 day, or at least 5 days, or at least 10 days, or at least 20 days, or at least 30 days. For example, wearing the lenses of the invention advantageously can result in a incidence of corneal staining (staining evaluation scale of 1.0 or above) of less than about 30% or about 20% or about 10% on a representative population of lens wearers.

In the immediately preceding paragraph, the type of corneal staining considered is corneal dehydration staining. This staining characteristically occurs in the inferior half of the cornea, where the dehydration of the tear film on the anterior surface of the lens is greatest and creates an osmotic gradient drawing water from the contact lens during wear. If the lens is thin enough or the material has a tendency to lose water (e.g., has a relatively high ion flux), the osmotic gradient can be large enough to dehydrate the tear film beneath the contact lens and subsequently dehydrate the corneal epithelium. This epithelial dehydration results in corneal damage and thus staining of the cornea with fluorescein. The staining is usually limited to the superficial 2-3 layers of the epithelium and spreads under the cornea, but if the stimulus is large enough, the damage can be deep and severe, allowing rapid dissemination of fluorescein into the stroma. Staining can occur rapidly within a few hours of lens insertion, but typically takes 4-6 hours or more. Also, once the dehydration stimulus has been removed, epithelial lesions can resolve rapidly within 2-3 hours. The greater the stimulus, the faster the staining will be induced and the longer it will take to heal, but usually the regression will not take more than 4-6 hours.

In one embodiment, the lens bodies of the present contact lenses can have a combination of properties (including being effective or suitable forIon flux) to substantially inhibit or even substantially prevent corneal staining as described above. In one useful embodiment, the inventive mirrors have an ion flux of no greater than about 5, more preferably no greater than about 4 or about 3 (e.g., no greater than about 2 or about 1 or less). The ion flux is indicated as 10^-3mm²/min。

The ophthalmically compatible lens bodies of the present contact lenses can be free of surface treatments or modifications (e.g., can be manufactured without surface treatments or modifications on, for example, the anterior and/or posterior faces of the lens body) to enhance surface wettability and/or one or more other beneficial properties of the lens body. Advantageously, no such surface treatment or modification is provided on either the front or back of the inventive ophthalmically compatible lens bodies. By not having such surface treatments or finishes, the lens manufacturing process is less complex and less expensive and more efficient. Moreover, without such surface treatment/modification, the inventive mirror bodies advantageously have a more reproducible and/or more homogeneous surface. In addition, the lens wearer is not exposed to surface treatments on the lens which may themselves and by themselves cause eye irritation and the like.

The oxygen permeability of the lenses of the invention can be measured while the contact lens is in a wet or fully hydrated state. Oxygen permeability or Dk is indicated as 10^-10(ml O₂mm)/(cm²sec. mm Hg) or barrer. Preferably, the mirror has a Dk of at least about 70barrer or about 75barrer or about 80barrer or about 85barrer or about 90barrer or about 95barrer or about 100barrer or about 105barrer or about 110barrer or about 115barrer or about 120barrer or about 125barrer or about 130barrer or about 150barrer or about 180barrer or even at least about 200barrer or greater. The relatively high Dk values of the present ophthalmically compatible lens bodies are highly advantageous in that the cornea of the eye is sufficiently available for oxygen even when the contact lens is continuously positioned on the cornea for an extended period of time as described herein.

Another mechanical characteristic that can effectively provide the present ophthalmically compatible contact lenses and lens bodies is elongation. The bodies of the invention have sufficient elongation to facilitate lens handling convenience, lens structural integrity, lens wearing comfort, effective movement of the lens over the cornea, and similar benefits. Mirrors with insufficient elongation are often deficient in one or more of these aspects. In a very useful embodiment, the inventive mirror body has an elongation of at least about 90%, or about 100%, or about 120%. Mirrors having an elongation of at least about 180% or about 200% are very useful.

The Dk value of the inventive lens, together with the equilibrium water content and/or relatively low ion flux and/or relatively high elongation of the inventive lens, effectively aids the ocular compatibility of the inventive contact lens and/or the enhanced safety and comfort for the wearer of the inventive contact lens, making continuous wear of such lenses beneficial to the lens wearer.

Furthermore, in addition to the present ophthalmically compatible lenses having useful or effective Dk values and equilibrium water contents, and advantageously having relatively low ion fluxes, such lenses preferably also have sufficient structural or mechanical characteristics, such as one or more of a modulus, tear strength and/or similar mechanical characteristics that reduce lens/eye interactions, e.g., SEAL, Contact Lens Papillary Conjunctivitis (CLPC), to permit or at least contribute to the ability of the lens to withstand continuous contact lens wear over extended periods of time as described herein.

The ophthalmically compatible lens bodies of the present invention have a sufficient modulus to be used as continuous wear contact lenses. In one useful embodiment, the lens body has a modulus of about 1.5mPa, about 1.4mPa or about 1.2mPa or less, preferably about 1.0mPa or less and more preferably about 0.8mPa or less or about 0.5mPa or less or about 0.4mPa or less or about 0.3mPa or less. For example, one embodiment of the present lenses has a modulus of about 0.84 mPa. Another embodiment of the lenses of the invention have a modulus of from about 0.3mPa to about 0.5 mPa. For example, a lens body having a modulus sufficient for use as a continuous-wear contact lens, but having a reduced modulus (e.g., less than 1.0MPa) relative to prior art continuous-wear lenses, is advantageous for the comfort of the wearer of the continuous-wear contact lens.

In a particularly useful aspect of the invention, the present contact lenses comprise a lens body comprising a hydrophilic silicon-containing polymeric material. In one embodiment, the polymeric material comprises units from at least two silicon-containing macromers having different molecular weights and preferably different chemical structures. Advantageously, one of the macromers has a number average molecular weight of greater than about 5,000 or greater than about 8,000 or greater than about 10,000. In another embodiment, the polymeric material includes units from only one silicon-containing macromer. For example, one embodiment of the present lenses comprises units of a silicon-containing macromer having a number average molecular weight of at least about 10,000.

The polymeric material can include units from a silicon-containing macromer having a number average molecular weight of less than about 5,000 (e.g., less than about 3,000 or less than about 2,000).

When units from two silicon-containing macromers are included in the polymeric material, these macromers advantageously have number average molecular weights that differ by at least about 3000 or about 5000, more preferably by at least about 10,000. In one useful embodiment, the units from the high molecular weight silicon-containing macromer are present in the polymeric material in an amount by weight greater than the units of the low molecular weight silicon-containing macromer. For example, the ratio of high molecular weight macromer to low molecular weight macromer used to make the mirrors of the present invention can be in the range of about 1.5 or about 2 to about 5 or about 7.

Without wishing to limit the invention to any particular theory of operation, it is believed that the use of two silicon-containing macromers of different molecular weights to manufacture the lens bodies of the invention is advantageous for providing suitable or effective high oxygen permeability and suitable or effective equilibrium water content and/or relatively low ion flux while providing a lens body that is effective for use in a continuous wear contact lens (e.g., an ophthalmically compatible contact lens that can be worn for about thirty days if desired). The use of silicon-containing macromers of different molecular weights provides compatibility with other ingredients used to make the lenses and can provide a degree of heterogeneity (e.g., at the molecular level) in the lenses of the invention that at least helps provide the lens with a desired combination of physical properties that help the lens to be very advantageously used in a continuous wear contact lens. In other embodiments that include units from a silicon-containing macromer, suitable lens characteristics can be obtained that facilitate daily use of the lens (e.g., overnight wear).

In one useful embodiment, one of the silicon-containing macromers (preferably a low molecular weight macromonomer) is monofunctional, i.e., it includes only one group per molecule that participates in the polymerization reaction to form the silicon-containing polymeric material. Without wishing to limit the present invention to any particular theory of operation, it is believed that the monofunctional macromers aid or enhance compositional compatibility and/or heterogeneity (e.g., at the molecular level) of the polymeric material. That is, it is believed that the morphology of the polymeric material of the mirror is sufficiently heterogeneous or heterogeneous that different phase domains (phase domains) are present in the polymeric material. It is believed that such enhanced heterogeneous morphology enhances ocular compatibility of the polymeric material and/or increases at least one of Dk and equilibrium water content and/or reduces ion flux, while maintaining or even reducing the modulus of the polymeric material, relative to a similar polymeric material comprising units from only one silicon-containing macromer, or relative to a similar polymeric material comprising units from two silicon-containing macromers, both of which have at least two functional groups per molecule.

In any event, it has been found that contact lenses having a unique and advantageous combination of properties that render the present lenses ophthalmically compatible and advantageously very effective for continuous or extended wear can surprisingly be provided by selecting macromers and monomers as described herein and processing them into lens bodies of contact lenses.

There is no limitation on the components of the contact lenses of the invention, so long as the lenses have a combination of properties and/or perform in daily wear applications or continuous or extended wear applications as set forth herein.

In one embodiment, the present contact lenses comprise a polymer comprising units derived from a hydrophilic silicone alkyl methacrylate, said units being represented by formula I:

wherein X₁Is a polymerizable substituent represented by the formula:

wherein R1, R2, R3 and R4 are groups independently selected from hydrocarbyl groups having from 1 to about 12 carbon atoms and siloxane groups (e.g., trimethylsiloxy groups); and structure [ Y1] is a polysiloxane backbone comprising not less than 2 siloxane units; r5 is hydrogen or methyl; z1 is a group selected from the group consisting of-NHCOO-, -NHCONH-, -OCONH-R6-NHCOO-, -NHCONH-R7-NHCONH-and-OCONH-R8-NHCONH-, wherein R6, R7 and R8 are independently selected from the group consisting of hydrocarbyl radicals having from 2 to about 13 carbon atoms; m is an integer from 0 to about 10; n is an integer from about 3 to about 10; p is 0 when m is 0, and p is 1 when m is 1 or more; and q is an integer from 0 to about 20.

In formula I, structural unit Y1 can have the formula:

wherein R9 and R10 are groups selected from hydrocarbyl groups having from 1 to about 12 carbon atoms (e.g., methyl), hydrocarbyl groups substituted with one or more fluorine atoms, trimethylsiloxy groups, and hydrophilic substituents, and may differ from one another in the sequential chain; and r is an integer from about 7 to about 1000.

The use of such hydrophilic silicone alkyl methacrylates of the present invention can provide high oxygen permeability for contact lenses, reduced protein and lipid deposition, excellent or enhanced maintenance of lens water wettability during continuous lens wear, acceptable lens movement on the cornea of the eye, and reduced corneal adhesion.

In one embodiment, at least one of R1, R2, R3, and R4 may be selected from the group consisting of the following formulae (1a), (2a), and (3 a):

-C₃H₆Si(-OSi(CH₃)₃)₃ (1a)

wherein g is an integer from 1 to about 10.

The silicon-containing monomer may contain one or more hydrophilic substituents therein, and the substituents may be selected, for example, from linear or cyclic hydrocarbon groups linked with at least one substituent selected from the group consisting of a hydroxyl group and an oxyalkylene group, such as groups represented by the following formulae (3b) and (4 b):

-R21(OH)_i (3b)，

wherein R21 is a hydrocarbon group having from about 3 to about 12 carbon atoms and may have inserted between the carbon atoms-O-, -CO-, or-COO-groups; with the proviso that the number of hydroxyl groups on the same carbon atom is limited to only one and i is an integer greater than 1;

-R22-(OR23)_j-OZ2 (4b)，

wherein R22 is a hydrocarbon group having from about 3 to about 12 carbon atoms and may have inserted between the carbon atoms-O-, -CO-, or-COO-groups; r23 is a hydrocarbon group having about 2 to about 4 carbon atoms, and the number of carbon atoms may be different from each other when j is not less than 2; j is an integer from 1 to about 200; z2 is a group selected from hydrogen, hydrocarbyl groups having from about 1 to about 12 carbon atoms, and-OOCR 24 wherein R24 is a hydrocarbyl group having from about 1 to about 12 carbon atoms.

Examples of hydrophilic groups include (without limitation): monohydric alcohol substituents, e.g. -C₃H₆OH、-C₈H₁₆OH、-C₃H₆OC₂H₄OH、-C₃H₆OCH₂CH(OH)C₃、-C₂H₄COOC₂H₄OH、-C₂H₄COOCH₂CH(OH)C₂H₅Etc.; polyol substituents, e.g. -C₃H₆OCH₂CH(OH)CH₂OH、-C₂H₄COOCH₂CH(OH)CH₂OH、-C₃H₆OCH₂C(CH₂OH)₃Etc.; and polyoxyalkylene substituents, e.g. -C₃H₆(OC₂H₄)₄OH、-C₃H₆(OC₂H₄)₃₀OH、-C₃H₆(OC₂H₄)₁₀OCH₃、-C₃H₆(OC₂H₄)₁₀、-(OC₃H₆)₁₀OC₄H₉And the like. Among these groups, particularly useful groups include: alcohol substituents, e.g. -C₃H₆OH、-C₃H₆OCH₂CH(OH)CH₂OH and-C₃H₆OC₂H₄OH; and polyoxyethylene substituents, e.g. -C₃H₆(OC₂H₄)_kOH and-C₃H₆(OC₂H₄)_LCH₃Wherein each of k and l is independently an integer of about 2 to about 40, preferably about 3 to about 20, from the viewpoint of excellent hydrophilicity and oxygen permeability.

One or more fluorine-containing substituents provide stain resistance to the polymeric material, but over-substitution may impair hydrophilicity. Hydrocarbon substituents having from 1 to about 12 carbon atoms attached to the fluorine atom are very useful. Such useful fluorine-containing groups include (without limitation): 3, 3, 3-trifluoropropyl group, 1, 2, 2-tetrahydrofluorooctyl group, 1, 2, 2-tetrahydroperfluorodecyl group, and the like. Among these groups, 3, 3, 3-trifluoropropyl group is very useful from the viewpoint of hydrophilicity and oxygen permeability obtained in the resulting lens body.

In addition to the hydrophilic substituent and the fluorine-containing substituent, the substituent attached to the silicon atom may include, without limitation, a hydrocarbon group having 1 to about 12 carbon atoms, a trimethylsiloxy group, and the like, and may be the same as or different from each other. A very useful group is an alkyl group having from 1 to about 3 carbon atoms, and methyl is particularly useful.

In formula I, m is advantageously an integer from 0 to about 4. If m is about 5 or more, the monomer may become too hydrophobic to be compatible with other monomers, resulting in turbidity during polymerization and difficulty in homogeneous mixing of monomers. In formula (3a), if g is greater than about 10, the compatibility of the monomer with other monomers may decrease.

The hydrophilic siloxanyl methacrylate described above may be synthesized by reacting 2-isocyanatoethyl methacrylate with a siloxanyl alkyl alcohol.

The contact lenses of the invention may have an equilibrium water content in the range of about 25-60% by weight, include a hydrophilic silicon-containing polymeric material, and have an oxygen permeability (denoted Dk) of not less than about 80, or about 90, or about 100, or about 110, or about 120. The eyewear may provide one or more (e.g., at least 2 or 3 or more) and advantageously all of the following characteristics: reduced protein and lipid absorption inside the lens, easy lens care, acceptable movement of the lens on the eye, acceptable stability of the lens shape, flexibility and wearing comfort, and therefore can be used in continuous wear applications. In one very useful embodiment, the present contact lenses are sufficiently ophthalmically compatible to be effective for continuous wear for at least 5 days, or at least 10 days, or at least 20 days, or at least 30 days.

By weightA water content of less than 5% or less than 15% is generally undesirable because the lens readily absorbs lipids, which may result in the lens adhering to the cornea of the eye on which the lens is worn. Moisture contents in excess of 60% are generally undesirable because of the resulting low strength of the lens, dehydration of the lens, poor scratch resistance during handling, susceptibility to breakage and high protein absorption. Lenses having oxygen permeabilities less than about 80 Dk are undesirable in continuous wear lenses. Having a thickness of less than about 0.2 x 10⁷Lenses with a tensile modulus of dynes per square centimeter (MPa) are generally undesirable because the lens shape is relatively unstable and there are difficulties in handling the lens. Having a thickness of more than about 1.5X 10⁷Dynes per square centimeter (MPa) or about 2X 10⁷Lenses with a tensile modulus of dynes per square centimeter (MPa) are undesirable, for example, because the movement of the lens over the cornea is significantly reduced and the incidence of adhesion to the cornea is increased, problems with lens flexure, problems with comfort during lens wear, and the like.

Other useful hydrophilic silicon-containing monomers for use in the contact lenses of the invention are those monomers having structures represented by the following formulae Ia and Ib, because lenses made from polymeric materials comprising units of these monomers (for example) as well as units of other silicon-containing monomers provide a suitably balanced combination of properties (including, but not limited to, water content, oxygen permeability and modulus, and less protein and lipid deposition) and are advantageously ophthalmically compatible:

wherein h is an integer of from about 8 to about 70, and R11 is a non-polymerizable or non-functional group, for example, a hydrocarbyl group having from about 1 to about 6 carbon atoms. In a very useful embodiment, R11 is-C₄H₉. In one embodiment, the compounds identified in formula (Ib) may be considered, for example, as macromers having a molecular weight in the range of about 1,000 to about 3,000 or about 5,000. The integer h is selected to provideTo provide a macromer having the desired molecular weight. This macromer is particularly useful in combination with another silicon-containing macromer having a higher molecular weight, as described elsewhere herein.

For example and without limitation, the compound of formula I may be a macromer having a number average molecular weight of at least about 5000 or about 8,000 or about 10,000 to about 25,000 or more, such as by appropriate selection of the value of "r". As described elsewhere herein, such high molecular weight macromers are useful in combination with low molecular weight macromers, for example as illustrated by formula Ib, to produce lens bodies for contact lenses that are sufficiently ophthalmically compatible to be effective in continuous wear applications. In one embodiment, the use of the combination of the high molecular weight and low molecular weight silicon-containing macromers to manufacture contact lens bodies can provide enhanced ocular compatibility and/or enhanced effectiveness in such continuous wear applications relative to substantially identical contact lens bodies manufactured in the absence of one of the high molecular weight macromonomer or the low molecular weight macromonomer.

Any polymer containing units from one or more of the hydrophilic silicon-containing monomers and/or macromers described herein can be used in the contact lenses of the invention. For example, the polymer may comprise a copolymer having the following copolymerizable compounds: acrylic monomers, for example, methyl acrylate, ethyl acrylate, and acrylic acid; methacrylic monomers such as methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate and methacrylic acid; siloxane monomers, for example, tris (trimethylsiloxy) silylpropyl methacrylate, bis (trimethylsiloxy) methylsilylpropyl methacrylate, pentamethyldisiloxane propyl methacrylate, tris (trimethylsiloxy) silylpropoxy ethyl methacrylate and tris (polydimethylsiloxy) silylpropyl methacrylate; fluorosilicone monomers, for example, tris (dimethyltrifluoropropylsilanyloxy) silylpropyl methacrylate; fluoroalkyl monomers such as 2, 2, 2-trifluoroethyl methacrylate, 2, 2, 3, 3, 3-pentafluoropropyl methacrylate, and hexafluoroisopropyl methacrylate; fluoroalkyl and fluoroalkyl ether monomers containing a hydroxyl group, for example, 1, 2, 2-tetrafluoroethoxy-2-hydroxypropyl methacrylate; hydrophilic monomers, such as N-vinylpyrrolidone, N' -dimethylacrylamide and N-vinyl-N-methylacetamide; crosslinkable monomers, for example, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate and tetramethyldisiloxane bis (propyl methacrylate).

Among them, a copolymer formed of a methacrylic siloxane, a fluoroalkyl siloxane methacrylate, a fluoroalkyl ether methacrylate having a hydroxyl group, a hydrophilic monomer, a crosslinkable monomer having two or more unsaturated groups in the molecule, and a siloxane macromonomer having a polymerizable unsaturated group at the molecular end is preferable because of properly balanced physical properties such as oxygen permeability, stain deposition resistance, and mechanical strength. The preferred hydrophilic monomers in the present invention are amide monomers containing an N-vinyl group, and in particular N-vinylpyrrolidone or N-vinyl-N-methylacetamide can provide a contact lens having excellent surface wettability.

An example, without limitation, of such a contact lens includes a polymeric material obtained from about 30% to about 70% or about 80% by weight of a hydrophilic silicon-containing monomer or macromer, about 5% to about 50% by weight of N-vinylpyrrolidone, 0% to about 25% by weight of N-vinyl N-methylacetamide, 0% to about 15% by weight of 2-hydroxybutyl methacrylate, 0 to about 10% by weight of isobornyl methacrylate, 0 to about 15% by weight of methyl methacrylate, and about 0.005% to about 5% by weight of a crosslinker compound.

The present contact lenses can be manufactured by conventional lens manufacturing methods. These methods include, for example and without limitation, a method of lathe cutting and then polishing a bulk polymer, a method of casting a monomer (and macromer) composition into a mold having a corresponding lens shape and then polymerizing, and a method of forming only one side of a lens by a casting method using a polymerization mold and then finishing the other side by a lathe cutting and polishing method, and the like.

Polymeric materials comprising units of hydrophilic polysiloxane monomers represented by the general formula II can be used in the contact lenses of the invention:

wherein R12 is hydrogen or methyl R13, R14, R15, and R16 are each independently selected from the group consisting of hydrocarbyl groups having from 1 to about 12 carbon atoms, and trimethylsiloxy groups; y is selected from the group consisting of the structural units (I ') and (II') shown below, wherein the ratio of structural units (I ') to structural units (II') is from about 1: 10 to about 10: 1, and the total number of structural units (I ') and (II') is from about 7 to about 200 or about 1000; each of a and c is independently an integer from 1 to about 20; d is an integer from 2 to about 30; b is an integer from 0 to about 20; x is a-NHCOO-group or a-OOCNH-R16-NHCOO-group, wherein R16 is a hydrocarbyl group having from about 4 to about 13 carbon atoms:

wherein each of R17 and R18 is independently a hydrocarbon group having from 1 to about 12 carbon atoms or a fluorinated hydrocarbon group having from 1 to about 12 carbon atoms, with the proviso that at least one of R17 and R18 is a fluorinated hydrocarbon group; and each of R19 and R20 is independently a hydrocarbon group or an oxygen-containing group, with the proviso that at least one of R19 and R20 is an oxygen-containing group. Very useful oxygen-containing groups for use as R19 and/or R20 include (without limitation):

-C₃H₆(OC₂H₄)_eOH

and

-C₃H₆(OC₂H₄)_fOCH₃，

wherein e and f are integers from about 2 to about 40, preferably from about 2 to about 20.

The monomers of formula II may be considered macromers, such as difunctional macromers. For example, the molecular weight of the II macromonomer can be controlled by controlling the number of structural units (I ') and (II') in the macromonomer. In one useful embodiment, the macromer of formula II has a relatively high molecular weight, for example, at least about 5000 and preferably in the range of about 10,000 to about 25,000 or more (number average molecular weight). In the present contact lenses, the macromer of formula II can be used alone, i.e., as the only silicon-containing monomer. Advantageously, the high molecular weight macromonomer is used in combination with a low molecular weight macromonomer as described elsewhere herein to form the polymeric material comprised in the lenses or bodies of the invention.

In this embodiment, the units from the monomer or macromer may constitute from about 30% or about 40% to about 40% or about 80% by weight of the polymeric material.

In the case where both high molecular weight and low molecular weight silicon-containing macromers are used, the high molecular weight macromers constitute at least about 20% or about 30% or about 40% by weight of the polymeric material. In one useful embodiment, the units from the combination of high molecular weight macromonomer and low molecular weight macromonomer are at least about 30% or about 40% or about 50% by weight of the polymeric material.

The above monomers or macromers of formula II may be copolymerized with one or more other monomers and/or macromers, for example as described elsewhere herein.

Contact lenses comprising the above-described polysiloxane monomers (macromonomers) as the main component can be manufactured by conventional lens manufacturing methods, such as casting methods, in which the monomer composition is injected into a polymerization mold having a corresponding lens shape and subsequently polymerized. A lens manufactured by using a mold made of a material having a polar group at a mold surface, such as a mold made of ethylene-vinyl alcohol (EVOH) copolymer, polyamide, and polyethylene terephthalate, is preferable. These molds are believed to be effective in helping to form a thick stable hydrophilic layer at the lens body surface, having little or no change in surface characteristics during continuous or extended periods of lens wear, and having substantially stable lens performance (e.g., excellent water wettability and reduced protein and lipid deposition during such wear). Advantageously, lenses manufactured in these molds (including EVOH molds) have the desired surface wettability without the need for surface treatments or surface modifications associated with certain existing silicone hydrogel contact lenses.

In the present specification, the structural units of the formulae [ I ] and [ II ] of the silicon-containing monomer or macromer are represented as block type bonds, but the present invention also includes random bond types.

It is preferable from the viewpoint of polymerization that a polymerizable unsaturated group is attached to the end of the siloxane chain, and the structure of the unsaturated group is acrylate or methacrylate. As the linking group to the Si atom, a hydrocarbon group having a urethane or urea bond is preferable, and it may be linked to the Si atom via an oxyethylene group. Urethane or urea bonds are highly polar and enhance the hydrophilic character and strength of the polymer. Structures having two such groups are formed by reacting a diisocyanate bond with a hydroxyl or amine containing molecule having from about 2 to about 13 carbon atoms, and may be linear, cyclic or aromatic in type.

Various methods of synthesis of hydrophilic silicon-containing monomers (macromers) exist. Many of these methods use reagents and reactions and synthetic strategies and techniques that are conventional and well known in the art (e.g., in the field of silicone polymer chemistry).

An example of a useful synthetic method includes the following steps: a mixture of a cyclic siloxane having hydrosilyl (Si-H), a cyclic siloxane having a hydrocarbon group, and a disiloxane having hydroxyalkyl groups at both ends, and (in some cases) a cyclic siloxane having a fluorine-substituted hydrocarbon group is subjected to ring-opening polymerization using an acidic catalyst such as sulfuric acid, trifluoromethanesulfonic acid, and acidic clay to obtain a hydrosilyl-containing polysiloxane compound having hydroxyl groups at both ends. In this case, siloxane compounds having various degrees of polymerization and introduction ratios of fluorine-containing substituents to hydrosilyl groups can be obtained by changing the feeding ratio of each cyclic siloxane to disiloxane compound used.

The isocyanate-substituted acrylate or isocyanate-substituted methacrylate is then reacted with hydroxyl groups at the end of the polysiloxane to obtain a urethane-containing fluorinated siloxane compound having polymerizable unsaturated groups at both ends.

Conventional and well-known chemical synthesis techniques can be used to make the monofunctional macromonomers that are currently useful. For example, a monofunctional hydroxyl polysiloxane (e.g., a commercially available monofunctional hydroxyl polysiloxane) can be reacted with an isocyanate-substituted acrylate or isocyanate-substituted methacrylate in the presence of a catalyst (e.g., a tin-containing catalyst) under conditions effective to obtain a single-terminal acrylate or methacrylate polysiloxane macromer.

Useful isocyanate-substituted methacrylates include, without limitation, monomers such as methacryloxyethyl isocyanate, methacryloyl isocyanate, and the like, and mixtures thereof. Isocyanate compounds having an acrylate group or a methacrylate group obtained by reacting an acrylate or a methacrylate ester having a hydroxyl group (for example, hydroxyethyl methacrylate and hydroxybutyl acrylate) with various diisocyanate compounds can also be utilized.

The hydrophilic polysiloxane monomer and/or macromer may be obtained by adding an unsaturated hydrocarbon group-containing hydrophilic compound to hydrosilane, using a transition metal catalyst (e.g., chloroplatinic acid, etc.), and utilizing a so-called hydrosilylation reaction. In the hydrosilylation reaction, it is known that if active hydrogen compounds such as hydroxyl groups and carboxylic acids are present, the dehydrogenation reaction occurs as a side reaction. Therefore, if these active hydrogen atoms are present in the hydrophilic compound to be introduced, side reactions should be suppressed by protecting the active hydrogen atoms in advance or adding a buffer. See, for example, USP No. 3907851, the disclosure of which is incorporated herein by reference in its entirety.

Another synthetic route is as follows: after synthesizing a hydrosilyl-containing polysiloxane compound having hydroxyl groups at both ends, hydrophilic groups or moieties are introduced by hydrosilylation in advance, and then polymerizable groups are introduced to both ends of siloxane by reaction with isocyanate-substituted methacrylate or the like.

In this case, if active hydrogen which reacts with isocyanate is present in the hydrophilic compound, it is necessary to prevent side reactions with isocyanate, for example, by introducing a protecting group. Alternatively, silicate derivatives such as dimethoxysilane, diethoxysilane compounds, and the like may be used as the starting raw material in place of the cyclic siloxane, for example. Mixtures of two or more of the hydrophilic polysiloxane monomers thus obtained may also be used.

Any polymer comprising units from one or more hydrophilic silicon-containing monomers and/or macromers described herein can be used in the contact lenses of the invention.

In addition to the hydrophilic silicon-containing monomer or macromer, at least one hydrophilic monomer may be used as a comonomer component. Preferably, amide monomers (e.g., amide monomers containing N-vinyl groups) can be used to obtain excellent transparency, stain resistance, and surface wettability. Without wishing to limit the present invention to any particular theory of operation, it is believed that phase separated structures (at the molecular level) may be formed in the copolymerization with the hydrophilic polysiloxane monomers (macromonomers) disclosed in the present invention, for example because differences in copolymerizability, molecular weight, polarity, etc., between two or more of these monomers result in providing stable stain resistance, enhanced hydrophilicity, and enhanced oxygen permeability and preferably an enhanced degree of ocular compatibility.

The N-vinyl containing amide monomer may be selected from, without limitation, N-vinylformamide, N-vinylacetamide, N-vinylisopropylamide, N-vinyl-N-methylacetamide, N-vinylpyrrolidone, N-vinylcaprolactam, and the like, and mixtures thereof. N-vinyl-N-methylacetamide and N-vinylpyrrolidone are very useful.

Useful polymeric materials of the present invention include copolymers obtained by adding monomers other than hydrophilic polysiloxane monomers and N-vinyl containing amide monomers. Any monomer can be used in the present invention as long as it is a copolymerizable monomer, of which hydrophilic monomers are useful. Useful hydrophilic monomers have good compatibility with hydrophilic polysiloxane monomers and/or macromers and can also further improve the surface wettability of the polymeric material and alter the water content. Useful hydrophilic monomers include, for example and without limitation, monomers containing one or more hydroxyl groups that can improve mechanical properties such as strength, elongation, tear strength, and the like, such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 1-hydroxymethylpropyl methacrylate, 4-hydroxybutyl methacrylate, and glycerol methacrylate; monomers containing fluorine-substituted groups, such as 3- (1, 1, 2, 2-tetrafluoroethoxy) -2-hydroxypropyl methacrylate; and acrylates corresponding to the methacrylates set forth herein. 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate and mixtures thereof are very useful.

Other useful hydrophilic monomers include, for example and without limitation, carboxyl group containing monomers such as methacrylic acid, acrylic acid, and itaconic acid (itaconic acid); monomers containing an alkyl-substituted amino group such as dimethylaminoethyl methacrylate and diethylaminoethyl methacrylate; acrylamide or methacrylamide monomers, such as N, N '-dimethylacrylamide, N' -diethylacrylamide, N-methacrylamide, methylenebisacrylamide and diacetoneacrylamide; oxyalkylene group-containing monomers such as methoxypolyethylene glycol monomethacrylate, polypropylene glycol monomethacrylate, and the like, and mixtures thereof.

For example, silicone alkyl acrylates are suitable comonomers for adjusting oxygen permeability. By way of example, such monomers include, without limitation, tris (trimethylsiloxy) silylpropyl methacrylate, bis (trimethylsiloxy) methylsilylpropyl methacrylate, pentamethyldisiloxanyl methacrylate, and the like, and mixtures thereof. Methacrylate-substituted polymerizable polydimethylsiloxanes and the like and mixtures thereof can also be used for similar purposes.

Other monomers that may be utilized include, without limitation, fluorinated monomers such as fluoroalkyl acrylates and fluoroalkyl methacrylates, e.g., trifluoroethyl acrylate, tetrafluoroethyl acrylate, tetrafluoropropyl acrylate, pentafluoropropyl acrylate, hexafluorobutyl acrylate, hexafluoroisopropyl acrylate, methacrylates corresponding to these acrylates, and the like, and mixtures thereof.

In addition, alkyl acrylate monomers and alkyl methacrylate monomers may also be used, if necessary and/or desired. Including, for example and without limitation, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, stearyl acrylate, methacrylates corresponding to these acrylates, and the like, and mixtures thereof. In addition, monomers with high glass transition temperatures (Tg) such as cyclohexyl methacrylate, t-butyl methacrylate, isobornyl methacrylate, and the like, and mixtures thereof, can also be used to enhance mechanical properties.

Furthermore, crosslinkable monomers other than hydrophilic polysiloxane monomers can be used to improve mechanical properties and stability and adjust the water content. For example, it includes (without limitation) ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, bisphenol a dimethacrylate, vinyl methacrylate; acrylates corresponding to these methacrylates; monomers containing one or more alkyl groups such as, without limitation, triallyl isocyanurate, triallyl cyanurate, triallyl trimellitate, and allyl methacrylate; siloxane derivatives such as 1, 3-bis (3-methacryloxypropyl) tetramethyldisiloxane; and the like and mixtures thereof.

Crosslinkable monomers linked in the urethane group are particularly useful for providing compatibility and hydrophilicity as well as mechanical property improvements. A bifunctional crosslinkable monomer represented by the formula (10b) is useful:

wherein R24 and R26 are independently selected from hydrogen and methyl; z3 is a urethane linkage; r25 is selected from the group consisting of hydrocarbyl radicals having from 2 to about 10 carbon atoms and hydrocarbyl radicals consisting of- (C)₂H₄O)_uC₂H₄-polyoxyethylene groups represented by, wherein u is an integer from 2 to about 40; t is an integer from 0 to about 10; s is 0 when t is 0, and s is 1 when t is 1 or more.

Without wishing to limit the invention to any particular theory of operation, it is believed that the above-described bifunctional compounds have good compatibility and copolymerizability and contribute to strength improvement through intermolecular interactions, since the hydrophilic polysiloxane monomers have similar backbones, e.g., those containing urethane groups. Examples of crosslinkable monomers having a urethane linkage include, without limitation, 2-methacryloylaminoxyethyl methacrylate, 2-2 (2-methacryloyloxycarbamoyloxy) ethyl acrylate, 2- (2-methacryloyloxyethylcarbamoyloxy) propyl methacrylate, 2-methacryloyloxyethylcarbamoyloxy tetraethylene glycol methacrylate, and the like, and mixtures thereof.

Particularly useful crosslinkable monomers represented by formula (11b) are:

these crosslinkable monomers may be used alone or in combination.

To improve the balance of characteristics of hydrophilic polymeric materials (e.g., optical characteristics, oxygen permeability, mechanical strength, deformation recovery, resistance to staining during contact lens wear, dimensional stability during tear, and durability), a blend of these copolymerizable monomers may be used.

An example, without limitation, of such a contact lens includes a polymeric material obtained from about 30% to about 70% or about 80% by weight of a hydrophilic silicon-containing monomer or macromer, about 5% to about 50% by weight of N-vinylpyrrolidone, 0% or about 0.1% to about 25% by weight of N-vinyl N-methylacetamide, 0% or about 0.1% to about 15% by weight of 2-hydroxybutyl methacrylate, 0 or about 0.1% to about 15% by weight of methyl methacrylate, and about 0.005% to about 5% by weight of a crosslinker compound. Various additives may be further added before or after the polymerization, if necessary. Examples of additives include, without limitation, dyes or pigments having various coloring characteristics, UV absorbers, and the like, and mixtures thereof. In addition, when the mold is used to manufacture the lens, a release agent such as a surfactant and the like and mixtures thereof may be added to improve the separation of the lens from the mold.

One embodiment of the present silicone hydrogel contact lenses comprises a material having the United States Adopted Name (USAN) comfilcon A.

The present contact lenses can be manufactured by conventional lens manufacturing methods. For example, these methods include a method of lathe cutting a bulk polymer followed by polishing, a method of casting a monomer (and macromer) composition into a mold having a corresponding lens shape followed by polymerization, and a method of forming only one side of a lens by a casting method using a polymerization mold followed by finishing the other side by a lathe cutting and polishing method, etc.

The polymeric materials for use in the present contact lenses are formed into ophthalmic lenses by a molding process in which a monomer mixture comprising, for example, one or more hydrophilic polysiloxane monomers and an N-vinyl containing amide monomer is filled into a mold followed by free radical polymerization by known methods; or by a spin casting process in which the monomer mixture is fed into a rotatable hemispherical mold followed by polymerization. In these cases, the polymerization degree or the lens swelling ratio can be adjusted by polymerization of the monomer mixture solution added with the solvent in the mold. If a solvent is included, it is advantageous to use a solvent that is effective to dissolve the monomer. Examples include (without limitation) alcohols such as ethanol and isopropanol; ethers such as dimethyl sulfoxide, dimethylformamide, dioxane and tetrahydrofuran; ketones such as methyl ethyl ketone; esters such as ethyl acetate; and the like and mixtures thereof.

Any mold material may be used for the mold polymerization or the casting polymerization as long as it is substantially insoluble in the monomer mixture and the lens can be separated after the polymerization. For example, polyolefin resins such as polypropylene and polyethylene can be used, and a material having a polar group at the surface is preferable. As used herein, a polar group means an atomic group having a strong affinity with water, and it includes a hydroxyl group, a nitrile group, a carboxyl group, a polyoxyethylene group, an amide group, a urethane group, and the like. Very useful mold materials are insoluble in the polymerized monomer composition and have a contact angle with water (by the sitting drop method) of not greater than about 90 °, preferably about 65 ° to about 80 °, at least at the portion used to form one lens surface. Contact lenses formed using mold materials having surface contact angles less than 80 ° exhibit, among other things, particularly good water wettability and stability properties with respect to lipid deposition. Mold materials having a surface contact angle of less than 65 ° are disadvantageous in that they are difficult to separate from the mold after polymerization, resulting in minute surface damage of the lens or breakage at the edge portion of the lens. Mold materials that are soluble in the monomer composition are difficult to use due to difficulties in separating the lens as well as rough lens surfaces and low transparency.

More preferably, the mold material is a resin selected from polyamide, polyethylene terephthalate, ethylene vinyl alcohol copolymer (EVOH), and the like. For example, ethylene vinyl alcohol copolymers are particularly useful from the standpoint of ease of molding, providing a dimensionally stable mold and providing stable water wettability for molded lenses. An example of an ethylene vinyl alcohol copolymer resin product to be used is available as "sorlite" from Japan Synthetic chem, ind, co, ltd or as "EVAL" from Kuraray co. Various grades of EVOH having an ethylene copolymerization ratio of about 25-50% on a molar basis may be used in the present invention.

For initiating polymerization, polymerization may be initiated by UV or visible light irradiation in the presence of a photopolymerization initiator in a monomer mixture using a photopolymerization method, or thermal polymerization may be performed using an azo compound or an organic peroxide using a radical polymerization method. Examples of the photopolymerization initiator include, but are not limited to, benzoin ethyl ether (benzoin ethyl ether), benzyl dimethyl ketal, α' -diethoxyacetophenone, 2, 4, 6-trimethylbenzoyldiphenylphosphine oxide, and the like, and mixtures thereof. Examples of organic peroxides include, without limitation, benzoin peroxide, t-butyl peroxide, and the like, and mixtures thereof. Examples of the azo compound include, without limitation, azobisisobutyronitrile, azobisdimethylvaleronitrile, and the like, and mixtures thereof. Among them, the photopolymerization method is very useful because it provides stable polymerization in a short cycle time.

If desired, the surface of the molded lens can be modified by applying plasma treatment, ozone treatment, corona discharge, graft polymerization, or the like. However, in preferred embodiments, the present contact lenses have a very advantageous combination of properties without the need for any surface treatment or modification.

The evaluation methods of the characteristics of the spectacles in the examples and comparative examples are as follows:

water content

The soft contact lenses were immersed in a Phosphate Buffered Saline (PBS) solution for more than 16 hours at 23 ℃. After removing and quickly wiping the surface water, the glasses were accurately weighed. The lenses were then dried in a vacuum desiccator at 80 ℃ until constant weight. The water content was calculated from the weight change as follows:

water content (weight difference/weight before drying) × 100 (%)

Oxygen permeability (Dk value)

The Dk value is determined by the so-called Mocon method, for example, using a commercially available test instrument under the model name of the Mocon Ox-Tran system. Such a process is described in U.S. patent 5,817,924 to Tuomela et al, the disclosure of which is incorporated herein by reference in its entirety.

Dk value is expressed as barrer or 10^-10(ml O₂mm)/(cm²sec mm Hg)。

Tensile modulus

A test piece having a width of about 3mm was cut out from the central portion of the lens, and the tensile modulus (unit; MPa or 10) was determined from the initial slope of a stress-strain curve obtained by conducting a tensile test at a rate of 100mm/min in a physiological saline solution at 25 ℃ using an autograph (model AGS-50B manufactured by Shimadzu Corp.)⁷Dynes/cm).

Ion flux

Ion flux of a contact lens or lens body is measured using a technique substantially similar to the so-called "ion flux technique" described in U.S. patent 5,849,811 to Nicolson et al, the disclosure of which is incorporated herein by reference in its entirety.

Elongation percentage

The elongation of the contact lens or lens body is measured in the fully hydrated state. Such measurements are made in a substantially conventional/standard manner and involve stretching the sample using an Instron machine.

Other mechanical characteristics

Other mechanical properties such as tensile strength, tear strength, etc. are measured using well known and standardized testing techniques.

Examples of the invention

The following non-limiting examples illustrate various aspects and features of the present invention.

Synthesis example 1

[ Synthesis of polysiloxane diol having hydrosilyl group (A1) ]

A mixture of 150 g of octamethylcyclotetrasiloxane, 22.6 g of 1, 3, 5-trimethyltrifluoropropyl-cyclotrisiloxane, 5.2 g of 1, 3, 5, 7-tetramethyl-cyclotetrasiloxane, 9.8 g of 1, 3-bis (3- (2-hydroxyethoxy) propyl) tetramethyldisiloxane, 200 g of chloroform and 1.5 g of trifluoromethanesulfonic acid was stirred at 25 ℃ for 24 hours, followed by repeated washing with purified water until the pH of the mixture became neutral. After separation of the water, chloroform was distilled off under reduced pressure. The residual liquid was dissolved in acetone (36 g), reprecipitated with methanol (180 g), and then volatile components were removed from the separated liquid under vacuum to provide a transparent viscous liquid. The liquid was a siloxane diol having hydrosilyl group (H3R) represented by the following formula, and the yield was 125 g. Here, although the structural formula of the linking group Y is shown as a block structure composed of each siloxane unit, it actually contains a random structure, and the formula shows only the ratio of each siloxane unit. This is the case in all synthesis examples.

Wherein the content of the first and second substances,

a mixture of 125 g of the above siloxane diol, 40 g of polyethylene glycol allyl methyl ether (average molecular weight 400), 250 g of isopropyl alcohol, 0.12 g of potassium acetate and 25 mg of chloroplatinic acid was charged into a flask equipped with a reflux condenser, and heated under reflux with stirring for 3 hours. The reaction mixture was filtered, followed by distilling off the isopropanol under reduced pressure, followed by washing several times with a methanol/water mixture. The volatile components were further removed under vacuum to provide a clear viscous liquid with a yield of 120 grams. The liquid is a siloxane diol (M3R) having no hydrosilyl group represented by the formula:

wherein the content of the first and second substances,

a mixture of 120 g of the abovementioned siloxane diol (M3R), 9.5 g of methacryloyloxyethyl isocyanate, 120 g of anhydrous 2-butanone and 0.05 g of dibutyltin dilaurate was poured into a brown flask and stirred at 35 ℃ for 5 hours, followed by further stirring after addition of 6 g of methanol. Subsequently, 2-butanone was distilled off under reduced pressure, and the resulting liquid was washed several times with a methanol/water mixture, followed by removal of volatile components under vacuum to give a transparent viscous liquid with a yield of 120 g. The liquid is a polysiloxane-dimethacrylate (M3-U) represented by the formula:

wherein the content of the first and second substances,

this material (identified as M3-U) had a number average molecular weight of about 15,000.

Synthesis example 1A

Synthesis example 1 was repeated, with the amounts and/or conditions of the ingredients used to provide a macromer similar in structure to M3-U, except that Y has the following structure, being appropriately adjusted:

this material (identified as M3-UU) had a number average molecular weight of about 20,000.

Synthesis example 2

A mixture of 50 g of α -butyl- ω - [3- (2' hydroxyethoxy) propyl ] polydimethylsiloxane, 10 g of methacryloxyethyl isocyanate, 150 g of anhydrous n-hexane and 0.2 g of dibutyltin dilaurate was poured into a brown flask and heated under reflux for 2 hours, followed by further stirring after adding 6 g of methanol. Subsequently, the n-hexane was distilled off under reduced pressure, and the resultant liquid was washed several times with methanol (30 g)/water (15 g), followed by removing volatile components under vacuum to provide a transparent viscous liquid, the yield of which was 54 g. The liquid is a polysiloxane-methacrylate (FMM) represented by the formula:

wherein the content of the first and second substances,

this material (identified as FMM) has a number average molecular weight of about 1500.

Example 3

A mixture of 64 parts by weight of polysiloxane M3-U described in synthesis example 1A, 10 parts by weight of N-vinyl-2-pyrrolidone (hereinafter, referred to as NVP), 10 parts by weight of N-vinyl-N-methylacetamide (hereinafter, referred to as "VMA"), 6 parts by weight of isobornyl methacrylate (hereinafter, referred to as "IBM"), 10 parts by weight of methyl methacrylate (hereinafter, referred to as "MMA"), 0.1 parts by weight of triallyl isocyanurate (hereinafter, referred to as "TAIC"), and 0.1 parts by weight of 2, 4, 6-trimethylbenzoyl-diphenylphosphine oxide (hereinafter, referred to as "TPO") (which was finally added to the mixture) was mixed with stirring. The mixture was injected into a mold for forming a contact lens made of ethylene vinyl alcohol resin (hereinafter, referred to as "EVOH resin") (manufactured by Japan Synthetic chem.ind.co., ltd., Soarlite S), followed by irradiation with Ultraviolet (UV) light for 1 hour in an exposure apparatus to provide a lens-shaped polymer. The so obtained lenses were soaked in ethanol for 1.5 hours, followed by another 1.5 hours in fresh ethanol, followed by 0.5 hours in an ethanol/water (1/1) mixture, soaked in deionized water for 3 hours, followed by placement in a PBS solution, and then cooked for 20 minutes at high pressure, so obtained lenses were transparent and flexible, and exhibited good water wettability. The evaluation of the physical properties showed the results set forth in table 1.

Examples 4, 5 and 6

Example 3 was repeated three times, except that the resulting mixture had the composition shown in table 1. Each of the thus obtained glasses was transparent and flexible, and exhibited good water wettability. The evaluation of the physical properties showed the results set forth in table 1.

Examples 7, 8, 9 and 10

Example 3 was repeated four additional times, except that the resulting mixture had the ingredients and components shown in table 1. 10 parts by weight of FMM were included in each of these examples. Thus, each of the mixtures includes one silicon-containing macromer having a molecular weight of about 15,000 and another silicon-containing macromer having a molecular weight of about 1,400. Each of the thus obtained glasses was transparent and flexible, and exhibited good water wettability. The evaluation of the physical properties showed the results set forth in table 1.

Example 11

Lenses were prepared according to example 5.

The hydrated lens was placed into a 2% by weight aqueous solution of glycerol monomethacrylate (GMMA)/Glycerol Dimethacrylate (GDMA) (97/3 by weight). The solution containing the lenses was degassed and purged with nitrogen for 15 minutes. The aqueous solution was gently agitated to maintain hydration. The solution was heated to 70 ℃ for 40 minutes. 2, 2' -azobis (2-amidinopropane) dihydrochloride (Vazo 56) was added to the glasses/solution. Polymerization was allowed to occur for 30 minutes. The lenses were removed and rinsed/soaked repeatedly with deionized water. The lenses thus obtained are transparent and flexible and exhibit good water wettability. The evaluation of the physical properties showed the results set forth in table 1.

Comparative examples 12 and 13

Two commercially available extended wear contact lenses were selected for performance testing. Evaluation of the physical properties of both lenses showed the results set forth in table 1.

TABLE 1

Ingredient determination

Examples of Components (% by mass or relative parts)

Composition (I)	Abbreviations	Description of the invention	3	4	5	6	7	8	9	10	11
														Silicone macromers	M3-U	Polysiloxane-based dimethacrylates MW ═ about 15,000 to impart high Dk	64	64	66	60	42	42	44	44	66
Silicone macromers	FM0411M	Polysiloxane-based dimethacrylate MW about 1500 imparts a high Dk					10	10	10	10
														N-vinyl-2-pyrrolidone	NVP	Hydrophilic monomers	10	10	10	10	30	30	30	40	10
N-vinyl-N-methylacetamide	VMA	Hydrophilic monomers	10	12	18	20	10	10	10	0	18
														2-Hydroxybutyl methacrylate	HOB	Hydrophilic monomers				6	10	10	10	10
Glycerol monomethacrylate	GMMA	Hydrophilic monomers									See text
																(IPN method)
Glycerol dimethyl ester	GDMA	Hydrophilic monomers									See text

Radical acrylic esters
																Cross-linking agent (IPN)
Isobornyl methacrylate	IBM	Hydrophilic monomers	6	6	6		6	6	6	6	6
														Methacrylic acid methyl ester	MMA	Hydrophilic monomers	10	8

Composition (I)	Abbreviations	Description of the invention	3	4	5	6	7	8	9	10	11
														Triallylisocyanurate	TAIC	Crosslinking agent	0.1	0.1	0.1				0.1	0.1	0.1
Tetraethylene glycol dimethacrylate	4ED	Crosslinking agent				4	2	1
Bis (2-ethylhexyl) sodium sulfosuccinate salt	Aerosol OT (AOT)	Non-reactive surfactant (to aid release)	0	0	0.5	0.5	0.5	0.5	0.5	0.5	0.5
Diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide	LucirinTPO	UV photoinitiators	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1	0.1

2, 2' -azobis (2-amidinopropane) dihydrochloride	Vazo 56	The thermal initiator is soluble in water									0.1
																										12	13
														Characteristics of		Unit cell										B&LPureVision	CibaNightandDay
EWC (equilibrium water content)		％	34	37	44	36	36	38	44	42	42	36	24
														Dk		*	199		250	200	278	277	196	188	220	100	140
Modulus of elasticity		MPa	1.0	0.8	0.9	1.2	1.2	1.0	0.6	0.5	0.9	1.0	1.2
														Elongation percentage		％	350	290	220	130	190	251	357	355		193	271
Tear strength		N	69	59	32	23	64	69	83	96		183	163
														Tb (stress at break)		MPa	2.3	1.7	1.6	1.3	1.9	2.2	2.3	2.0		2.0	2.1
Ion flux		10-3mm2/min	0.2	0.3	2.8	1.1	1.1	2.2	3.5	3.0		5.0	0.5

Composition (I)	Abbreviations	Description of the invention	3	4	5	6	7	8	9	10	11
														Surface modification		Yes or no	Whether or not	Whether or not	Whether or not	Whether or not	Whether or not	Whether or not	Whether or not	Whether or not	Whether or not	Is that	Is that

The present contact lenses (i.e., the contact lenses of examples 3-11) have a unique and advantageous combination of physical properties that makes each of these lenses very effective in continuous or extended wear applications, especially when considered as compared to the comparative commercial lenses of examples 12 and 13.

Each of the lenses manufactured in examples 3-11 was placed in a human eye and worn for six (6) hours after appropriate treatment to remove extractable material and hydrate the lens in preparation for wearing in the human eye. After this period, the lenses were removed and the eyes were tested for corneal staining. Each of these lenses resulted in less than about 20% corneal staining.

Each of the lenses of examples 3-11 has a combination of properties, such as including water content, oxygen permeability, modulus, and/or one or more other mechanically-related properties, and ion flux, that provides enhanced performance in continuous wear applications, such as in lens functional effectiveness, wearer comfort, and safety. For example, the combination of physical characteristics of the eyewear of examples 3-11 is not comparable to the competitive eyewear of examples 12 and 13.

The lenses of examples 3 to 11 are ophthalmically compatible during at least about 5 days or about 10 days or about 20 days or about 30 days of continuous wear. For example, such lenses do not adhere to the cornea during said continuous wear.

Briefly, the present contact lenses of examples 3-11 illustrate the important continuous wear advantages of the present embodiments.

In view of the disclosure herein, it can be appreciated that the present contact lenses include one or more features that are different from existing silicone hydrogel contact lenses. In one embodiment of the present lenses, the lens body has a water content of about 50% (e.g., 47% or about 48%) and an ion flux of between about 4 and about 5. In additional embodiments, the mirror body has a Dk greater than 100.

The disclosure of U.S. patent No. 6,867,245 is incorporated herein by reference in its entirety.

A number of publications, patents and patent applications have been cited above. Each of the cited publications, patents, and patent applications is incorporated by reference herein in its entirety.

While the invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited to the examples and embodiments, and that the invention can be practiced otherwise than within the scope of the following claims.

Claims (55)

1. A silicone hydrogel contact lens, comprising a lens body comprising a hydrophilic silicon-containing polymeric material without a surface treatment, the lens body having at least one of an oxygen permeability, a water content, a surface wettability, a modulus, and a design effective to assist a lens wearer in wearing the contact lens in an ophthalmically compatible manner for at least one day.

2. The contact lens of claim 1, wherein the lens body has an oxygen permeability, a water content, a surface wettability, a modulus, and a design effective to assist the lens wearer in ophthalmically compatible wearing of the contact lens for at least one day.

3. The contact lens of claim 1, wherein the lens body has an oxygen permeability, a water content, a surface wettability, a modulus, and a design effective to assist the lens wearer in ophthalmically compatibly wearing the contact lens for about thirty days.

4. The contact lens of claim 1, wherein the polymeric material comprises units from a silicon-containing macromer.

5. The contact lens of claim 1, wherein the polymeric material comprises units from two different silicon-containing macromers, each macromer having a different molecular weight.

6. The contact lens of claim 1, wherein the lens body has an oxygen permeability of at least about 70barrer, a water content of at least about 30% by weight, a modulus of less than about 1.4mPa, and a contact angle on a surface of the lens body of less than about 60 degrees.

7. The contact lens of claim 6, wherein the lens body has an oxygen permeability of greater than about 110 barrers.

8. The contact lens of claim 6, wherein the lens body has a water content of greater than about 45% by weight.

9. The contact lens of claim 6, wherein the lens body has a modulus of less than about 0.9 mPa.

10. The contact lens of claim 6, wherein the lens body has an oxygen permeability of at least about 115 barrers, a water content of about 48% by weight, and a modulus of about 0.84 mPa.

11. The contact lens of claim 6, wherein the lens body has an oxygen permeability of about 70 barrers to about 100 barrers, a water content of at least about 50% by weight, and a modulus of about 0.3mPa to about 0.5 mPa.

12. A contact lens comprising a lens body comprising a hydrophilic silicon-containing polymeric material, the lens body having a Dk of greater than about 110 barrers and an equilibrium water content of greater than about 30% by weight, the contact lens being ophthalmically compatible.

13. The contact lens of claim 1, wherein the lens body has a Dk of at least about 150 barrers.

14. The contact lens of claim 12, wherein the lens body has an equilibrium water content of at least about 35% by weight.

15. The contact lens of claim 12, wherein the lens body has an anterior surface and a posterior surface, and at least one of the anterior surface and the posterior surface is unmodified.

16. The contact lens of claim 15, wherein neither the anterior surface nor the posterior surface is modified.

17. The contact lens of claim 12, wherein the lens body has a modulus of about 1.4mPa or less.

18. The contact lens of claim 12, wherein the lens body has an elongation of at least about 90%.

19. According toThe contact lens of claim 12, wherein the lens body has a thickness of no greater than about 510^-3mm²Ion flux/min.

20. The contact lens of claim 12, wherein the polymeric material comprises units from a silicon-containing macromer.

21. The contact lens of claim 12, wherein the polymeric material comprises units from two silicon-containing macromers having different molecular weights.

22. The contact lens of claim 21, wherein units from a high molecular weight silicon-containing macromer are present in the polymeric material in an amount by weight greater than units from a low molecular weight silicon-containing macromer.

23. The contact lens of claim 21, wherein the polymeric material comprises units from a silicon-containing macromer having a number average molecular weight of at least about 10,000.

24. The contact lens of claim 21, wherein the two silicon-containing macromers have number average molecular weights that differ by at least about 5,000.

25. The contact lens of claim 22, wherein units from the high molecular weight silicon-containing macromer are at least about 40% by weight of the polymeric material.

26. The contact lens of claim 22, wherein units from the high molecular weight silicon-containing macromer and units from the low molecular weight silicon-containing macromer add up to at least about 50% by weight of the polymeric material.

27. The contact lens of claim 21, wherein one of the silicon-containing macromers is a monofunctional monomer.

28. The contact lens of claim 21, wherein the polymeric material comprises units from a plurality of hydrophilic monomers.

29. A contact lens comprising a lens body comprising a hydrophilic silicon-containing polymeric material, the lens body having a Dk of greater than about 70barrer and an equilibrium water content of greater than about 30% by weight, the lens body being manufactured without a surface treatment, the contact lens being ophthalmically compatible.

30. The contact lens of claim 29, wherein the lens body has a Dk of at least about 90 barrers.

31. The contact lens of claim 29, wherein the lens body has an equilibrium water content of at least about 35% by weight.

32. The contact lens of claim 29, wherein the lens body has a modulus of about 1.4mPa or less.

33. The contact lens of claim 29, wherein the lens body has an elongation of at least about 90%.

34. The contact lens of claim 29, wherein the lens body has a power of no greater than about 510^-3mm²Ion flux/min.

35. The contact lens of claim 29, wherein the polymeric material comprises units from a silicon-containing macromer.

36. The contact lens of claim 29, wherein the polymeric material comprises units from two silicon-containing macromers having different molecular weights.

37. The contact lens of claim 36, wherein the polymeric material comprises units from a plurality of hydrophilic monomers.

38. A contact lens comprising a lens body comprising a hydrophilic silicon-containing polymeric material, the lens body having a Dk of greater than 100barrer, an equilibrium water content of greater than about 30% by weight, and not greater than about 510^-3mm²Ion flux/min, said contact lens being ophthalmically compatible.

39. The contact lens of claim 38, wherein the lens body has a Dk of at least about 130 barrers.

40. The contact lens of claim 38, wherein the lens body has an equilibrium water content of at least about 35% by weight.

41. The contact lens of claim 38, wherein the lens body has an anterior surface and a posterior surface, and at least one of the anterior surface and the posterior surface is untreated.

42. The contact lens of claim 41, wherein both the anterior surface and the posterior surface are untreated.

43. The contact lens of claim 38, wherein the lens body has a modulus of about 1.4mPa or less.

44. The contact lens of claim 38, wherein the polymeric material comprises units from two silicon-containing macromers having different molecular weights.

45. The contact lens of claim 38, wherein the polymeric material comprises units from a plurality of hydrophilic monomers.

46. A contact lens comprising a lens body comprising a hydrophilic silicon-containing polymeric material, the lens body having an equilibrium water content of greater than about 15% by weight, the polymeric material comprising units from two silicon-containing macromers having different molecular weights, the contact lens being ophthalmically compatible.

47. The contact lens of claim 46, wherein one of the macromers has a number average molecular weight greater than about 10,000.

48. The contact lens of claim 46, wherein the polymeric material comprises units from a plurality of hydrophilic monomers.

49. The contact lens of claim 46, wherein the lens body has a Dk of at least about 70 barrer.

50. The contact lens of claim 46, wherein the lens body has an equilibrium water content of at least about 30% by weight.

51. The contact lens of claim 46, wherein the lens body has an anterior surface and a posterior surface, and at least one of the anterior surface and the posterior surface is untreated.

52. The contact lens of claim 46, wherein the lens body does not include a surface treatment.

53. The contact lens of claim 46, wherein the lens body has a modulus of about 1.4mPa or less.

54. The contact lens of claim 46, wherein the lens body has a power of not greater than about 510^-3mm²Ion flux/min.

55. The contact lens of claim 46, wherein the lens body has an elongation of at least about 90%.