JPH07178125A - Artificial cornea - Google Patents

Abstract

PURPOSE:To enable to give natural color tone in an artificial cornea with an optical part fitted into the hole bored at the center of the holding part made of pure titan or titanium base alloy, by attaching on the surface of such holding part a coating layer mainly composed of titanium oxide. CONSTITUTION:The holding part 2, main body 2c of which is to be inserted between the anterior layer and the posterior layer of the cornea, with a hole 2a bored at its center for fitting an optical part 3 is formed by pure titan or titanium base alloy. The color tone of the natural iris or the desired color tone is given by attaching on the surface of such holding part 2 a coating layer mainly made of 450-1400 angstrom thick titanium oxide. The holding part 2 is, as a whole, in the shape of top-cut dome and is provided with plural penetrating holes 2b on its main body 2c. The optical part 3 is made by single crystal alumina (sapphire) or light penetrating material with no adverse effect on the living body such as PMMA or silicon, with its front side 3a and the back side 3b bent at the optically proper curvatures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an artificial cornea used to replace a cornea whose visual function is deteriorated due to corneal disease and restore the visual function.

[0002]

2. Description of the Related Art Conventionally, a titanium-based metal that is more compatible with the surrounding corneal tissue than an artificial cornea made of a synthetic resin material such as PMMA or silicon, and does not cause a void between the artificial cornea and the natural cornea. Artificial corneas have been proposed in which the support member is made of a metal material having biocompatibility such as.

As an example, an artificial cornea (Kline Oczna 8) proposed by Mr. Aladna Kurkova and others.
4: 379-380 [1982]), the optical member is made of a synthetic resin material such as PMMA or silicon, and the supporting member is made of a biocompatible metal material such as pure titanium, titanium alloy or tantalum. An artificial cornea was used. In such an artificial cornea, a cylindrical optical member A as shown in FIG. 5, a ring C having a central hole C ₁ for fitting the optical member A, and the left and right sides of the ring C are integrally formed. An artificial cornea 20 formed of a support member B formed of flaps D and D, and a cylindrical optical member A in a central hole E ₁ of a shield-shaped support member E as shown in FIG.
There was something like an artificial cornea 30 fitted with. Since the support members B and E of these artificial corneas 20 and 30 are made of the above-mentioned metal materials, they have good compatibility with the corneal tissue and further have excellent workability, so that the thickness of the support members can be made extremely small, and surgical invasion is possible. There was almost no effect.

[0004]

However, since all of the above biocompatible metallic materials have a silver-white metallic luster, there is a large difference from the color tone of the iris, and when mounted on the cornea, the appearance is remarkable. There was something strange.

[0005]

In order to solve the above-mentioned problems, according to the present invention, the support member for the artificial cornea is made of pure titanium or titanium alloy, and the surface thereof has a thickness of 45.
By applying a coating layer containing 0-1400Å titanium oxide as the main component, good bonding with the natural cornea is achieved, and the artificial cornea with a natural iris color tone and an aesthetically superior cornea is also provided. It's something to do with tara.

[0006]

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 is an exploded perspective view of the artificial cornea 1, and 2 is shown in FIG.
The main body 2c is a support member for supporting the optical member 3 fitted in the central hole 2a inserted between the anterior layer F and the posterior layer N of the cornea K, and is made of pure titanium or titanium alloy. By coating the surface with a coating layer composed mainly of titanium oxide having a thickness of 450 to 1400Å, a natural iris or desired color tone is obtained, and the overall shape is as shown in FIG. The body 2c is provided with a plurality of through holes 2b while forming a head dome shape.

The optical member 3 is made of a light-transmitting material such as single crystal alumina (sapphire) or PMMA or silicon which is not harmful to human body. As shown in FIGS. 3 and 4, the front surface 3a and the rear surface 3b are optical. As shown in FIG. 3, the central hole 2 of the support member 2 has a disc shape having an appropriate curvature.
A step portion 3d having a taper that opens rearward is formed along the circumference of the side surface 3c so as to be fitted in a, or a groove 3 for fitting and inserting a part of the support member 2 as shown in FIG.
e was formed.

Since the support member 2 of the artificial cornea 1 constructed as described above is made of biocompatible titanium or titanium alloy, it is well compatible with the corneal tissue and excellent in the bondability with the natural cornea. It does not create a gap between the two and has a truncated dome shape that fits the shape of the cornea K,
Furthermore, by coating the surface with a coating layer consisting mainly of titanium oxide with a thickness of 450 to 1400Å and controlling this thickness appropriately, it is possible to obtain all types of irises found in various races such as gold, brown and blue. It is possible to match the color tone and is aesthetically superior.

Hereinafter, a method of manufacturing the support member 2 will be described. First, a large number of support members 2 on a disk having a central hole 2a and a through hole 2b are formed at once in a sheet-like thin plate made of pure titanium or a titanium alloy by a known photo-etching method. The support member 2 having the curvature R of the cornea K is shaped into a truncated dome-shaped support member 2 by further performing press molding.

Subsequently, the thus-supported support member 2 was ultrasonically cleaned with an organic solvent, immersed in a mixed solution containing hydrofluoric acid, washed with water, and immersed in ethanol, and then dried sufficiently.

The operation using the acid mixed solution containing hydrofluoric acid was carried out in the draft chamber, and these solutions were stored in the draft chamber in the adjusted state.

Following this pretreatment, the anode was stored in a beaker containing a 1% aqueous solution of HPO ₃ stored and cooled in a refrigerator according to a conventional method under the conditions of a voltage of 13.00 to 37.0 V and a liquid temperature similar to room temperature. The surface of the supporting member 2 is oxidized to a thickness of 45
A coat layer containing 0-1400Å titanium oxide as a main component was applied.

Experimental Example According to the above-mentioned method, the supporting member 2 was prepared and molded, and Auger electron photoanalysis was performed using the following apparatus and measuring conditions: [Device] JAMP7100E JEOL Ltd. 5KV ・ Etching rate 1.87Å / sec. Converted to the calibration value using a standard SiO ₂ film ・ Etching cycle 5 sec / cycle ・ Analysis area φ100 μm Sputtering at two points 16% each from the median of the maximum and minimum fluctuation bands of the results. The intermediate time was regarded as the etching time required to remove the film containing oxygen atoms, and this was multiplied by the etching rate to calculate the film thickness. The results are shown in Table 1.

[0014]

[Table 1]

As is apparent from Table 1, when the thickness of the coating layer is 450 to 1400Å, the appearance of the support member 2 is suitable for all color tones of the iris found in various races such as gold, brown and blue. It is a thing. On the other hand, when the thickness is less than 450Å, for example, 360Å, the color tone is grayish yellow, which is largely different from that of the iris.
When it was larger than Å, the color tone was grey-blue, and the difference from the color tone of the iris was also large and it was inappropriate.

[0016]

EFFECT OF THE INVENTION In the artificial cornea of the present invention, the support member is made of pure titanium or a titanium alloy, and the surface thereof is coated with a coat layer containing titanium oxide having a thickness of 450 to 1400Å as a main component. It has a better bondability with the natural cornea, obtains a colorant that meets all the required color tones of the iris found in various races, and is aesthetically superior.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an artificial cornea according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which the artificial cornea of FIG. 1 is transplanted into a cornea.

3 is a central cross-sectional view of the artificial cornea of FIG.

FIG. 4 is a cross-sectional view of an optical member forming the artificial cornea of FIG.

FIG. 5 is a perspective view of a conventional artificial cornea.

FIG. 6 is a perspective view of a conventional artificial cornea.

[Explanation of symbols]

 K cornea F anterior layer N posterior layer 1 artificial cornea 2 support member 3 optical member 2a central hole 2b through hole 2c main body

Claims (1)

[Claims] 1. An optical member made of a translucent material which is used as a substitute cornea during corneal transplantation or which does not harm the body to replace the cornea is provided in a support member made of pure titanium or a titanium alloy. An artificial cornea fitted into a central hole, having a thickness of 450 to 1 on the surface of the supporting member.
An artificial cornea characterized by applying a 400 Å coat layer containing titanium oxide as the main component to give it a natural iris color tone.