JP2001346763A - Peripheral part-expanded lens for operation to corpus vitreum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To safely and easily conduct fine procedures in an operation in a lens for observing an eyeground in an operation to a corpus vitreum by finely observing the eyeground at a center part and peripheral parts in the operation to the corpus vitreum. SOLUTION: This lens comprises a bottom surface 2 having a concave surface matching the curvature of a cornea, and an inclined upper surface 3 forming a prism lens, and the upper surface 3 has a convex surface. The eyeground at a center part and peripheral parts can thus be easily observed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peripheral magnifying lens for vitreous surgery, and more particularly to an apparatus for observing a magnified image of a fundus in a region from an intermediate peripheral portion to a peripheral portion in vitreous surgery.

[0002]

2. Description of the Related Art Vitreous surgery is usually performed while observing the affected area of the fundus. In recent years, surgery for diabetic retinopathy and proliferative vitreoretinopathy, which are one of the main causes of blindness in developed countries, has recently been performed. In such a case, detailed observation and fine surgical operation are required not only in the posterior pole fundus but also in the intermediate peripheral part and the peripheral fundus.

Conventionally, for vitreous surgery, various lenses having the shapes shown in FIGS. 5A to 5D have been provided as contact lenses for fundus observation. The lens shown in (A) is formed of a bottom surface having a concave curved surface and an upper surface having a convex curved surface, and is a lens in which flare of reflected light on the upper surface of the lens due to illumination light is small (Japanese Patent Application Laid-Open No. 58-11252)
No. 8). In the lens shown in (B) or (C), the upper surface of the lens is formed to be flat or concave, so that the illumination light is not reflected on the upper surface of the lens and does not hinder the observation, and the fundus can be observed in a wide field of view. (Japanese Patent Laid-Open No. 61-
268231). The lens shown in (D) is a so-called prism lens, the upper surface of which is cut into an inclined plane. This prism lens is said to be suitable for observation of the intermediate peripheral portion and the peripheral fundus.

[0004]

However, the conventional lens described above has the following problems as a magnifying lens for surgery used for vitreous surgery, particularly for detailed observation of the intermediate peripheral area and the peripheral fundus. Was. That is, the lens shown in FIG. 5A is a lens used for observing the posterior pole fundus, and cannot be used for an operation requiring observation of the intermediate peripheral area or peripheral fundus. (B) (C)
Are shown in a wide field of view,
A magnified image could not be obtained, which was insufficient for detailed observation. Similarly, the one shown in (D) was also used for the treatment of the intermediate peripheral part and the peripheral fundus, but it was not possible to obtain a sufficiently magnified image, and it was insufficient for detailed observation. Was. For this reason, conventionally, surgery on the intermediate peripheral portion and the peripheral fundus has been particularly difficult, and has largely depended on the skill, experience and intuition of the surgeon.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and enables a detailed observation of an intermediate peripheral portion and a peripheral fundus during a vitreous surgery, thereby enabling a fine surgical operation in the relevant portion to be performed safely and safely. It is an object to provide a peripheral magnifying lens for vitreous surgery that can be easily performed.

[0006]

A first means of the present invention is as follows.
A lens for observing the fundus during vitreous surgery, comprising a bottom surface having a concave curved surface corresponding to the curvature of the cornea, and an inclined upper surface forming a prism lens, wherein the upper surface has a convex curved surface. It is a peripheral magnifying lens for vitreous surgery.

The second means is a peripheral magnifying lens for vitreous surgery, wherein the convex surface has a radius of curvature of 6 mm or more and 50 mm or less in the first means.

A third means is the peripheral magnifying lens for vitreous surgery, wherein the refractive index of the lens material is not less than 1.35 in the first or second means.

According to the above-described means, it is possible to easily observe the intermediate peripheral portion and the peripheral fundus, and it is possible to obtain an enlarged image and a sense of depth sufficient for performing the observation in detail. Accordingly, a peripheral magnifying lens for vitreous surgery can be provided which enables a detailed observation of the intermediate peripheral region and the peripheral fundus during vitreous surgery and enables a fine surgical operation to be performed safely and easily in the relevant portion. Is achieved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. In addition, between each figure,
The same reference numerals indicate the same or corresponding parts. 1 and 2 each show an embodiment of a peripheral magnifying lens for vitreous surgery according to the present invention. Lens 1 shown in FIG.
Has a bottom surface 2 having a concave surface conforming to the curvature of the cornea, and an inclined upper surface 3 forming a prism lens.
The upper surface 3 has a convex curved surface. Since the lens 1 configured as described above forms a prism lens,
It is possible to have an optical structure that allows easy observation of the intermediate peripheral part and the peripheral fundus, and the upper surface 3 has a convex curved surface, so that it is possible to obtain a sufficient enlargement effect and a sense of depth for performing the observation in detail. it can. The effect of the vitreous surgery peripheral magnifying lens 1 can be further enhanced by configuring each part as follows.

(1) Convex curvature of the upper surface In order for the operator to realize the effect of magnifying the image, it is desirable that the upper surface be cut into an inclined plane and that the lateral magnification be about 20% or more compared to a conventional prism lens. . To do this,
The convex surface radius of curvature of the upper surface 3 is 6 to 50 mm, preferably 12
It is appropriate to set it in the range of 〜25 mm. Here, when an object is viewed through a lens, the square of the lateral magnification, which is an index of the size of the image, is equal to the vertical magnification, which is an index of the stereoscopic effect (depth effect) of the image. This means that an image with a more three-dimensional effect can be obtained. Therefore, the lens 1 of the present invention having the above-described enlargement effect
The use of allows a detailed observation of the intermediate peripheral part and the peripheral fundus and a fine surgical operation.

(2) Concave curvature of the bottom surface A lens for vitreous surgery is usually placed on the cornea via an ophthalmic viscoelastic substance (such as hyaluronic acid), and the curvature of the bottom surface of the lens follows the cornea. Must be in range. Usually, since the radius of curvature of the cornea of an adult is around 8 mm,
Also in the case of the lens 1 of the present invention, the concave surface radius of curvature of the bottom surface 2 is 8
mm is preferable. However, it should be smaller for children.

(3) Lens Material In a prism lens, the effect of refracting light is more remarkable as the refractive index of the material is higher. In order to view the peripheral portion better, the refractive index of the lens material needs to be 1.35 or more, preferably 1.45 or more. As the material of the lens,
Glass such as optical glass or plastic is available. As optical glass, heavy lanthanum flint glass, lanthanum flint glass, heavy flint glass, lanthanum crown glass, heavy barium flint glass, barium flint glass, titanium flint glass, flint glass, flint glass such as light flint glass, lanthanum crown glass, Crown glass and quartz glass such as heavy crown glass, heavy phosphate crown glass, light barium flint glass, barium crown glass, crown flint glass, crown glass, borosilicate crown glass, phosphate crown glass, and fluorophosphate crown glass; Sapphire, ruby and the like can be mentioned. Examples of the plastic include polyalkyl (meth) acrylate represented by polymethyl (meth) acrylate and a copolymer thereof, polystyrene, polycarbonate, styrene acrylonitrile, CR-39, and transparent silicone. Furthermore, the material is not limited to the above materials as long as the material is highly transparent, has very little pulse, and is excellent in homogeneity. The lens 1 of the present invention can also be configured using these materials.

(4) Prism Angle The lens 1 of the present invention forming a prism lens has an upper surface 3
Is inclined at a predetermined angle with respect to the tangent plane of the bottom surface 2, and this inclination angle is the prism angle PA (see FIG. 1 or FIG. 2). The prism angle PA is determined by a site desired to be observed. When the site is in a range extending from the intermediate peripheral portion to the peripheral portion, the prism angle PA is 5 to 70.
Degrees, preferably 10 to 60 degrees, is an appropriate range. If the angle is smaller than 5 degrees, the effect of the prism cannot be sufficiently obtained. On the other hand, when the angle exceeds 70 degrees, the effective optical portion of the lens becomes narrow, and the distortion of the observed image becomes remarkable.

(5) Lens Diameter In vitreous surgery, the pupil is dilated by administering a mydriatic,
Observe the fundus from there. Mydriasis diameter is about 9 mm at the maximum. Therefore, the lens diameter needs to be larger than that, and preferably about 10 to 14 mm.

(6) Lens Height The height of the lens is determined by the above-described constitutions (1) to (5). The height can be adjusted by cutting the upper portion as long as there is no problem in the above.

[0017]

The present invention will be described below in more detail with reference to specific examples. (Example 1) Using a transparent glass material having a refractive index of 1.89,
The radius of curvature of the concave surface at the bottom is 8.0 mm, and the radius of curvature of the convex surface at the top is 2
A prism type lens (FIG. 1) for observing the peripheral fundus was prepared at 0 mm and a prism angle (hereinafter abbreviated as PA) of 15 degrees. When this lens was placed on the cornea and the fundus was observed, it was possible to observe the intermediate peripheral portion, similarly to a conventional prism lens having an inclined plane with a PA of 15 degrees. Further, in the lens of this embodiment, the conventional PA15
Compared with the prism lens, not only the image was observed largely in the horizontal direction, but also the depth sensation in the front-back direction (depth difference sensation) was observed.

(Example 2) Except that PA is 30 degrees,
A fundus observation lens equivalent to that of Example 1 (FIG. 2) was prepared. When this lens was placed on the cornea and the eyeball was tilted to observe the fundus, it was possible to observe the intermediate peripheral portion and the peripheral portion, similarly to the conventional prism lens having an inclined plane with a PA of 30 degrees. Furthermore, in the lens of this example, not only the image was observed to be large in the horizontal direction, but also the depth perception in the front-back direction was observed to be very large compared to the conventional 30-degree PA lens. As a result, it was possible to easily distinguish pigmentation or small hemorrhage and small retinal hiatus seen in the intermediate peripheral region or peripheral region.

(Comparative Example 1) A conventional prism lens for observing the peripheral fundus having a tilt plane of 30 ° (FIG. 5)
(D)) was prepared, placed on the cornea, and the fundus was observed from directly above. As a result, it was possible to observe the peripheral portion, but it was not possible to obtain a sufficiently enlarged image, and it was not sufficient to observe the intermediate peripheral portion or the peripheral portion in detail.

FIGS. 3 and 4 show the results of simulations by the ray tracing method using the values of the LeGrand model eyes, respectively, for estimating the fundus observable part and the image magnification effect. In both figures, the solid line indicates the lens 1 of the present invention in which the inclined upper surface 3 forming the prism lens is a convex curved surface and the ray trajectory thereof, and the broken line indicates that the inclined upper surface 3 'forming the prism lens is a flat surface. Of the conventional lens 1 'and its ray trajectory. In this case, the lens 1 of the present invention indicated by the solid line had a PA of 30 degrees and a convex curvature radius of the upper surface 3 of 20 mm. Further, in the conventional lens 1 'indicated by the broken line, PA was 30 degrees, and the upper surface 3' was flat (no curvature).

FIG. 3 shows the ray trajectory when the above two kinds of lenses 1 and 1 'are placed on the cornea and the fundus is observed from directly above. The observable part and the image magnification of the lens 1 of the present invention can be estimated by the ray trajectory indicated by the solid line, and the observable part and the image magnification of the conventional lens 1 ′ can be estimated by the ray trajectory indicated by the broken line.

FIG. 4 shows the ray trajectory of the two types of lenses 1 and 1 'when they are placed on the cornea and the fundus is observed from an oblique position of 30 degrees. Also in this case, the solid line is the ray trajectory of the lens 1 of the present invention, and the broken line is the conventional lens 1 '.
Are shown respectively.

As can be seen by comparing the ray trajectories (solid line and broken line) of the two lenses 1 and 1 'shown in FIGS. 3 and 4, respectively, the lens 1 of the present invention is similar to the conventional prism lens 1'. In addition, it is possible to observe the intermediate peripheral portion and the fundus of the peripheral portion, and it is possible to obtain an image magnification effect approximately twice as large as that of the conventional lens 1 '. This suggests the results of Examples 1 and 2 and Comparative Example 1.

As described above, a first aspect of the present invention is a lens for observing the fundus during vitreous surgery, which has a bottom surface having a concave surface conforming to the curvature of the cornea and an inclined surface forming a prism lens. A peripheral magnifying lens for vitreous surgery, having an upper surface and the upper surface having a convex curved surface. This makes it easier to observe the intermediate peripheral part and the peripheral fundus, and it is possible to obtain a magnified image and a sense of depth sufficient to perform the observation in detail. Detailed observation of the peripheral fundus is enabled, and a fine surgical operation in the relevant portion can be performed safely and easily.

The second means is a vitreous surgery peripheral magnifying lens according to the first means, wherein the convex upper surface has a radius of curvature of 6 mm or more and 50 mm or less. As a result, it is possible to secure the observable portions of the intermediate peripheral portion and the peripheral fundus, achieve an appropriate magnification of the observation image, and achieve a three-dimensional effect effective for distinguishing details in a well-balanced manner.

A third invention is the peripheral magnifying lens for vitreous surgery according to the first or second invention, wherein the refractive index of the lens material is 1.35 or more.
By setting the refractive index of the lens material to 1.35 or more, the prism angle is made relatively small to ensure the ease of observation. It is easy to achieve both a proper enlargement ratio and a three-dimensional effect effective for distinguishing details in a well-balanced manner.

As described above, the present invention has been described based on the embodiments and the examples. However, the present invention can be implemented in various embodiments or examples other than the above. For example, the curved surface of the bottom surface 2 and / or the top surface 3 of the lens 1 may be formed as a spherical surface or an aspherical surface. Further, when the upper surface 3 is formed as an aspherical surface, it is possible to reduce the distortion of the enlarged image and further enhance the effect of the present invention described above.

[0028]

As is apparent from the above description, the present invention relates to a lens for observing the fundus during vitreous surgery, wherein the bottom has a concave curved surface corresponding to the curvature of the cornea, and the inclined surface forming the prism lens. With the upper surface and the upper surface having a convex curved surface, the intermediate peripheral portion and the peripheral fundus can be easily observed, and an enlarged image and a sense of depth sufficient for performing the observation in detail can be obtained. Accordingly, it is possible to perform detailed observation of the intermediate peripheral portion and the peripheral fundus during vitreous surgery, and to perform a fine surgical operation in the relevant portion safely and easily.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a peripheral magnifying lens for vitreous surgery according to the present invention.

FIG. 2 is a sectional view showing another embodiment of a peripheral magnifying lens for vitreous surgery according to the present invention.

FIG. 3 is a simulation comparison diagram of the lens of the present invention and a conventional lens.

FIG. 4 is a simulation comparison diagram of the lens of the present invention and a conventional lens in different states.

FIG. 5 is a diagram showing a configuration example of a conventional lens for vitreous surgery.

[Explanation of symbols]

 1 Vitreous Surgery Peripheral Part Magnifying Lens (Invention) 1 'Vitreous Surgery Peripheral Part Observation Lens (Conventional) 2 Bottom 3 Top Surface (Invention) 3' Top Surface (Conventional)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Demas Simon F-Line Face Sanger F-term (reference) 2H087 KA23 PA01 PA17 PB01 QA02 QA06 RA41 in Hoya Healthcare Co., 6-5-1, Nishishinjuku, Shinjuku-ku, Tokyo UA01

Claims (3)

[Claims] 1. A lens for observing the fundus during vitreous surgery, comprising a bottom surface having a concave curved surface corresponding to the curvature of the cornea, and an inclined upper surface forming a prism lens.
A peripheral magnifying lens for vitreous surgery, wherein the upper surface has a convex curved surface. 2. The convex surface having a radius of curvature of 6 mm or more and 5 mm or more.
The peripheral magnifying lens for vitreous surgery according to claim 1, wherein the diameter is 0 mm or less. 3. The peripheral magnifying lens for vitreous surgery according to claim 1, wherein the refractive index of the lens material is 1.35 or more.