JP2011062325A - Gonioscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact gonioscope for allowing a chamber angle to be observed as an erected image from immediately above a cornea upper surface while a subject looks up. <P>SOLUTION: The gonioscope 10 includes a single reflection contact prism 20 brought into contact with an eyeball 2 and a three-time reflection prism 30 separate from the contact prism 20. The contact prism 20 has: a recessed surface 21 in contact with the cornea of the eyeball; an inner reflection surface 22 for performing inner reflection of light flux incident from the recessed surface 21; and a light emitting surface 23 for emitting the light flux reflected by the inner reflection surface 22. The three-time reflection prism 30 has one inner surface reflection surface 33 and two reflection transparent surfaces 31, 32 which make the light flux from the light emitting surface 23 of the contact prism 20 incident, reflect it three times, and emit it. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a corner observation mirror.

  In diagnosing and treating glaucoma of the eyeball, observation of the corner (the exit of the aqueous humor from the anterior chamber) is very important. Since the light from the corner is totally reflected by the cornea, it is usually impossible to directly observe the corner. Therefore, in order to observe the corner angle, a contact lens (lens or prism that contacts the eyeball) is required to be worn on the corneal surface of the subject (patient) and to relax the total reflection condition on the corneal surface. FIG. 4 shows a general prism-type contact lens 1 used for ophthalmic surgery. The contact lens 1 has a concave surface (spherical surface or pseudo-spherical surface) 1 a that follows the curvature of the cornea 3 of the eyeball 2 and a flat emission surface 1 b, and totally reflects light rays from the corner 4 of the eyeball 2 by the cornea 3. Without being guided from the concave surface 1a into the lens 1, it is emitted from the emission surface 1b and observed. Ideally, the exit surface 1 b is in a relationship orthogonal to the light beam (emitted optical axis) 5 from the corner 4.

  Further, a one-time reflection type angle observation mirror has been proposed as one mainly used in ophthalmic diagnosis (Patent Document 1), and a two-time reflection type angle observation mirror has also been proposed in recent years (Patent Document 1). References 2, 3).

U.S. Patent No. 6767098 US 6976758 U.S. Pat.No. 7,419,262

  The corner observation contact lens 1 in FIG. 4 has a simple structure and is compact, but cannot be observed from directly above with the subject facing upward. During use, it was inconvenient because it was necessary to tilt the subject's posture obliquely upward.

  Since the single reflection type corner observation mirror of Patent Document 1 has reflective surfaces arranged in three or four directions, a wide range of corner angles should be observed from directly above with the subject facing upward. However, there is a problem that the whole is large. For this reason, it is used in ophthalmic diagnosis but is not used in ophthalmic surgery because it obstructs the procedure. Furthermore, there is a problem that the image in each direction becomes a mirror image (back image). Patent Document 2 is an improvement of Patent Document 1 and enables a two-time reflection type to enable an erect image observation, but has a problem that it is larger than the one-time reflection type. In Patent Document 3, a member having two reflecting surfaces is added to the exit side of a prism-type contact lens so that a subject can observe from above as a corner observation mirror used for ophthalmic surgery. The structure is such that the exit optical axis of the contact lens is deflected, but only one corner angle can be observed, and the lateral extension of the additional member in the direction opposite to the observed corner angle is large, and ophthalmic surgery Then, there is a problem that it is easy to interfere with the procedure.

  The present invention is based on the above problem consciousness about the angle observation mirror used in conventional ophthalmologic diagnosis and ophthalmic surgery, and observes the angle of the corner in an erect image from almost right above the upper surface of the cornea with the subject facing upward. The objective is to obtain a compact corner-viewing mirror that can

  The present invention provides a four-time reflection type angle observation mirror by combining a one-time reflection contact prism that is brought into contact with the eyeball and a separate three-time reflection prism. The prism is formed with a concave surface in contact with the cornea of the eyeball, an internal reflection surface that internally reflects the light beam incident from the concave surface, and an output surface (transmission surface) that emits the light beam reflected by the internal reflection surface, The three-time reflecting prism is characterized in that a light beam from the exit surface of the contact prism is incident, and then an inner reflection surface and two reflection / transmission surfaces that are reflected and emitted three times are formed. Both the entrance surface and the exit surface of the three-time reflecting prism are reflection / transmission surfaces that reflect or transmit the light beam according to the incident angle condition of the light beam.

  At the same time, the inner reflection surface of the three-time reflection prism emits from a corner portion different from the corner portion observed by the four-time reflection described above, passes through the concave surface and the emission surface of the contact prism, and transmits the three-time reflection prism. It is possible to construct a one-time reflected light path that reflects the light beam incident on the light beam and then immediately emits the light beam from the light exit surface.

  The corner observation mirror of the present invention can further include an observation object distance adjusting lens for making the apparent observation object distances of the optical path that reflects four times and the optical path that reflects one time substantially coincide.

  According to the corner angle observation mirror of the present invention, the corner angle can be observed as an erect image from almost right above the upper surface of the cornea with the subject facing upward.

(A), (B) is sectional drawing of the mounting | wearing state to an eyeball and the non-wearing state which shows the whole structure of one Embodiment of the angle observation mirror by this invention. It is a perspective view of the corner observation mirror of FIG. FIG. 3 is an optical path diagram showing an optical path length difference between a four-reflection optical path and a one-reflection optical path of the corner observation mirror of FIGS. 1 and 2 and an operation of an observation object distance adjusting lens for observing the optical path length by canceling the optical path length difference. is there. It is a principle diagram of a conventional corner observation mirror.

  1 to 3 show an embodiment of a corner observation mirror 10 according to the present invention. The main corner observation mirror 10 includes a contact prism (contact lens) 20 that is brought into contact with the eyeball, and a three-time reflection prism 30 that is separate from the contact prism 20.

  The contact prism 20 basically has a triangular prism shape, and a concave surface that contacts the cornea 3 with a curvature (concave) substantially the same as the curvature (convexity) of the cornea 3 of the eyeball 2 on one surface of the triangular prism ( Spherical surface) 21 is formed. The other two surfaces of the triangular prism constitute an inner surface reflecting surface 22 for internally reflecting the light beam incident from the concave surface 21 and an exit surface (transmitting surface) 23 for emitting the light beam reflected by the inner surface reflecting surface. The inner reflective surface 22 is provided with a metal coat.

  The three-time reflecting prism 30 includes a first reflecting / transmitting surface 31 facing the emitting surface 23 of the contact prism 20 with an air layer interposed therebetween, and all the light beams transmitted through the emitting surface 23 and the first reflecting / transmitting surface 31. It has a triangular prism shape having a second reflection / transmission surface 32 to be reflected and an inner surface reflection surface 33 that reflects the light beam reflected by the second reflection / transmission surface 32 toward the first reflection / transmission surface 31. The inner reflective surface 33 is provided with a metal coat.

  Assuming that the axis passing through the center of the concave surface 21 of the contact prism 20 and the center of curvature of the concave surface 21 is the optical axis O of the main corner observation mirror 10, the second reflection / transmission surface 32 is arranged so as to be substantially orthogonal to the optical axis O. It is desirable. The angles of the inner reflection surface 22, the emission surface 23, and the inner reflection surface 33 are determined as follows. When it is assumed that the concave surface 21 of the contact prism 20 of the corner observation mirror 10 is along the cornea 3 of the eyeball 2 and the optical axis O is aligned with the central axis of the eyeball 2 (FIG. 1A), the eyeball The light beam emitted from the two corners enters the contact prism 20 from the concave surface 21 without being totally reflected by the cornea 3. The incident light beam is reflected (first reflection) by the inner reflection surface 22, then proceeds in a direction substantially orthogonal to the emission surface 23 (first reflection / transmission surface 31), and is emitted from the emission surface 23 to the first. The light enters the reflecting prism 30 three times from the reflecting / transmitting surface 31. The light beam incident from the first reflection / transmission surface 31 is totally reflected (second reflection) by the second reflection / transmission surface 32, then reflected by the inner reflection surface 33 (third reflection), and further the first The light is totally reflected by the reflection / transmission surface 31 (fourth reflection) and emitted from the second reflection / transmission surface 32 substantially parallel to the optical axis O. By observing the above four-time reflected image with the microscope 50 (FIG. 3) placed on the optical axis O, an erect image with a corner angle of 4 can be observed. This four-time reflected light path is shown by a one-dot chain line in FIG. By performing the reflection four times in this manner, the corner observation mirror 10 disposed above the eyeball 2 is less projected in the lateral direction, and a compact configuration is possible. Note that there are individual differences in the size and shape of the eyeball, and the corner positions are also different. Therefore, the above route is an example when a standard eye is assumed. Depending on the subject, the exit optical path from the reflection / transmission surface 32 may have an inclination of about several degrees from the optical axis O. In this case, it is possible to perform favorable corner observation by adjusting the relative position of the microscope 50 with respect to the corner observation mirror 10.

As an example of a specific angle, the angle formed by the emission surface 23 (first reflection / transmission surface 31) with the optical axis O is α, and the first reflection / transmission surface when the three-time reflection prism 30 is an isosceles triangular prism. When the angle formed by 31 and the second reflection / transmission surface 32 and the inner reflection surface 33 is β, and the angle formed by the first reflection / transmission surface 31 and the second reflection / transmission surface 32 is γ,
α = 42 ° ± 5 ° β = 66 ° ± 5 ° γ = 48 ° ± 5 °. Further, by preparing and using a plurality of contact prisms 20 having the internal reflection surface 22 having different angles with the optical axis O, it is possible to cope with the difference in the position of the corner angle 4 by the subject.

  The material (refractive index n) of the contact prism 20 and the three-time reflecting prism 30 is not particularly limited, but the three-time reflecting prism 30 is n> when γ <48 ° in consideration of the total reflection condition. In the case of 1.50 and γ <45 °, n> 1.55 is desirable. The contact prism 20 and the three-time reflection prism 30 may be formed of the same material or different materials.

  The inner reflection surface 33 of the three-time reflecting prism 30 also constitutes a one-time reflection mirror image observation optical path for observing the corner angle 4 at a position opposite to the corner angle 4 observed by the four-time reflection described above. That is, a light beam that has exited from a corner part different from the corner part observed by four-time reflection, transmitted through the concave surface 21 and the exit surface 23 of the contact prism 20 and incident on the three-time reflecting prism 30 is reflected internally. Immediately after being reflected by the surface 33, the light is emitted from the second reflection / transmission surface 32. This single-reflection mirror image observation optical path is shown by a broken line in FIG.

  When the internal reflection surface 33 is used for the one-time reflection mirror image observation in this way, as shown in FIG. 1A, not only the corner angle 4 observed by the observation light path of the four-time reflection but also the same corner angle 4. It is possible to observe the corner angle 4 of the opposite part. However, since the two optical paths have different distances to the corner observation part, under the observation with a surgical microscope, the focal position of the observation image is deviated, and when one is focused, the other is blurred and simultaneous observation is impossible.

  Therefore, in this embodiment, an observation object distance adjusting lens 40 having a positive power is disposed on the optical path for observing a mirror image with a single reflection as indicated by a broken line, and the apparent observation object distance is set as the observation object distance of the four-time reflection optical path with a dashed line. Adjustments are made to be approximately equal. This allows simultaneous observation of both fields of view at the same focal position.

  FIG. 3 is a schematic diagram for explaining the operation of the object distance adjusting lens 40. In order to simplify the explanation, the contact prism 20 and the three-time reflection prism 30 are shown so that the reflection surfaces are developed and the optical paths are in a straight line. Since the four-reflection optical path has many reflecting surfaces, the substantial optical path lengths of the developed contact prism 20 and the three-time reflection prism 30 are long, and the observation object distance from the surgical microscope objective lens 50 is long. On the other hand, since the optical path of the one-time reflection has a small number of reflection surfaces, the actual optical path length of the developed contact prism 20 and the three-time reflection prism 30 is short, so that the observation object distance becomes short. For this reason, when the focus of the surgical microscope 50 is adjusted to the corner observation site on the four-reflection optical path, the focus observation site on the one-reflection mirror image observation optical path is not focused. Therefore, in the present embodiment, the observation object distance adjustment lens 40 having a positive power is arranged on the one-reflection mirror image observation optical path (broken line in FIG. 1), and the surgical microscope 50 is focused on the four-reflection erect image. When it is adjusted to the corner angle observation part on the observation optical path, it is possible to focus on the corner angle observation part on the mirror image observation optical path that is reflected once. That is, the apparent observation object distance at the corner angle 4 on the one-time reflection mirror image observation optical path is matched with the observation object distance at the corner angle 4 on the four-time reflection erect image observation optical path, and both corner angles 4 are observed simultaneously. I can do it.

2 Eyeball 3 Cornea 4 Corner angle 10 Angle observation mirror 20 Contact prism (contact lens)
21 Concave surface (spherical surface)
22 Internal reflection surface 23 Output surface 30 Three-time reflection prism 31 First reflection / transmission surface 32 Second reflection / transmission surface 33 Inner reflection surface 40 Observation object distance adjustment lens

Claims (4)

The contact prism is in contact with the eyeball, and the contact prism is a separate three-time reflection prism.
The contact prism has a concave surface that comes into contact with the cornea of the eyeball, an inner surface reflecting surface that internally reflects a light beam incident from the concave surface, and an exit surface that emits the light beam reflected by the inner surface reflecting surface,
The three-time reflecting prism has one inner reflection surface and two reflection / transmission surfaces that are reflected and emitted three times after a light beam from the emission surface of the contact prism is incident thereon. Observation mirror.   2. The corner angle observation mirror according to claim 1, wherein an entrance surface and an exit surface of the three-time reflecting prism are the two reflection / transmission surfaces.   3. The corner angle observation mirror according to claim 1, wherein the inner reflection surface of the three-time reflecting prism is emitted from a corner portion different from the corner portion observed by the four-time reflection, and is a concave surface of the contact prism. And a corner observation mirror that constitutes a one-time reflection optical path that reflects the light beam that has passed through the emission surface and entered the three-time reflection prism, and then immediately emits the light from the emission surface.   4. The angle observation mirror according to claim 3, further comprising an observation object distance adjusting lens for substantially matching an apparent observation object distance between the light path that is reflected four times and the light path that is reflected once.

Images