JP2716060B2 - Intraocular lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrally molded intraocular lens made of polymethyl methacrylate, which is a biocompatible transparent hard resin. More particularly, the present invention relates to an intraocular lens having a flexible support, and an intraocular lens having a flexible and restorable support.

[0002]

2. Description of the Related Art An intraocular lens is used after the lens of the eye is removed, instead of the lens that has lost transparency due to cataract. An intraocular lens generally includes an optical portion and a support portion. The optical portion is made of polymethyl methacrylate (PMMA) in consideration of light transmittance and the like, and the support portion is made of polypropylene (PP) in consideration of flexibility and the like. ) Is often used.

[0003]

The support section made of PP is bonded to the optical section made of PMMA using heat welding or an adhesive. However, this adhesion is not sufficient, and there is a possibility that the support part may be detached from the optical part during the mounting operation or during the mounting in the eye. In addition, the intraocular lens usually has two, and sometimes three or more supports, and the loop shape of the plurality of supports is kept in a desired shape (symmetry and / or balance stability is maintained). Gluing is practically difficult. The symmetry of the loop shape between each support and / or
Or, if the balance stability is poor, positioning of the intraocular lens in the eye may be hindered.

On the other hand, there is also known an intraocular lens in which an optical portion and a support portion are integrally formed of a biocompatible transparent hard resin such as PMMA. In such an integrally formed intraocular lens, since the supporting portion is not bonded, the problems of poor bonding and poor symmetry of the loop shape and / or poor balance stability as described above do not occur.

[0005] However, PMMA and the like are less flexible than PP. For this reason, it is difficult to bend the support portion into the eye, and sometimes the support portion is damaged. In addition, even after being placed in the eye, due to the lack of flexibility, tissue in the eye may be deformed and the pupil may not maintain a perfect circular shape, and in some cases, the optical unit may be maintained at a predetermined position. It can be difficult to keep doing it.

Accordingly, a first object of the present invention is to provide an intraocular lens which is integrally formed of PMMA, which is a biocompatible transparent hard resin, and which has a flexible supporting portion. Is to do. Further, a second object of the present invention is to provide a PMMA which is entirely a biocompatible transparent hard resin.
An object of the present invention is to provide an intraocular lens which is integrally molded with the above and has a support portion which is rich in flexibility and restoring property.

[0007]

According to a first aspect of the present invention, there is provided:
An integrally molded intraocular lens made of polymethyl methacrylate, comprising an optical part, a support part, and a connecting part connecting the optical part and the support part, and both directions of a longest axial length on a plane perpendicular to the optical axis of the intraocular lens Therefore, the compression load when the support portion is compressed so that the shaft length becomes 10 mm is 0.3 to 0.7.
g.

In a second aspect of the present invention, the polymethyl methacrylate integrally formed intraocular lens comprises an optical portion, a support portion, and a connecting portion connecting the optical portion and the support portion. The support portion has a substantially constant width in a range of 80% or more of the entire length of the support portion from the boundary between the support portion and the tip of the support portion, and the ratio of the width to the thickness of the support portion is The present invention relates to an intraocular lens in a range of 0.5 or more to less than 1 and in which this ratio is substantially constant.

Hereinafter, the present invention will be described. 1 and 3 are plan views of an intraocular lens 1 according to an embodiment of the present invention. FIG. 2 shows a side view of the intraocular lens 1 from the direction perpendicular to the axial length direction of the intraocular lens of FIG. The intraocular lens 1 shown in FIGS. 1 and 3 includes an optical unit 2, a support unit 3, and a connection unit 4 located between the optical unit 2 and the support unit 3 and connecting the two. . However, the intraocular lens 1 of FIG.
In FIG. 3, the optical unit 2 is circular, and in the intraocular lens 1 of FIG. 3, the optical unit 2 is elliptical.

The feature of the intraocular lens of the present invention is that the supporting portion is compressed when the supporting portion is compressed so that the axial length becomes 10 mm from both directions of the longest axial length on a plane perpendicular to the optical axis 5 of the intraocular lens. The load is 0.3 to 0.7 g.
Both directions of the longest axis length in which the intraocular lens 1 is compressed are indicated by arrows in FIGS. 1 and 3. When the support 3 of the intraocular lens 1 is compressed so that the axial length is 10 mm, the intraocular lens of the present invention has a length of 0.3 to 0.7 g, preferably 0.3 to 0.7 g.
It has a compression load of 0.6 g. Here, the compressive load when the axial length is compressed to 10 mm is specified because the capsular bag of the human body is usually about 10 mm, and the compressive load when compressed to about 10 mm, that is, the flexibility is important for the performance of the support part. Because it is important. The inventors of the present invention have proposed that an intraocular lens made of polymethyl methacrylate has a PP of 0.3 to 0.7 g at an axial length of 10 mm when the compression load is 0.3 to 0.7 g.
It has been found that an intraocular lens having flexibility equal to or higher than that of an intraocular lens having a support portion made of aluminum can be obtained. The supporting portion of the intraocular lens having a compression load of more than 0.7 g at an axial length of 10 mm lacks flexibility.

Incidentally, the compressive load can be measured by using an apparatus shown in FIG. That is, the intraocular lens 1 is moved to the micro load meter 10 including the load detection unit 11 and the movable moving unit 12 that are linked with the load detector 14, and the longest axial direction of the intraocular lens 1 and the movement of the micro load meter 10 are adjusted. It is set so that the directions match, and the micro load meter 10 is set with the micrometer 13.
The moving unit 12 is moved, and the load at a predetermined moving amount is read from the display of the digital display 15 connected to the load detector 14.

Further, in the intraocular lens of the present invention, the support portion 3 is substantially constant within a range of 80% or more of the entire length of the support portion from the boundary between the support portion 3 and the connecting portion 4 toward the tip of the support portion 3. And the ratio of the width to the thickness of the support portion 3 is in the range of 0.5 or more and less than 1, and the ratio is substantially constant. By satisfying such conditions, P
Flexibility and restorability equal to or higher than that of the P support can be provided. Here, the width is a dimension that appears on the plan view of the intraocular lens, and is, for example, a dimension indicated by an arrow in FIG. The thickness is a dimension that appears on a side view of the intraocular lens, and is, for example, a dimension indicated by an arrow in FIG. 2B. The width and thickness ratio (width / thickness) satisfies this condition as long as it is 80% or more of the entire length of the support portion 3. The thickness width ratio may be 1 or more. The substantially constant width means that a maximum and minimum deviation of a reference value (a desired set value in design) is within 0.02 mm. Also,
The preferred thickness width ratio is 0.6 to 0.9, and more preferably 0.7 to 0.8. The fact that the thickness-width ratio is substantially constant means that the maximum and minimum deviation of the thickness-width ratio is within 0.1. The boundary between the support portion 3 and the connection portion 4 refers to a point at which the position is gradually shifted from the connection portion 4 in the direction of the support portion 3 and the width is measured, and the width starts to become substantially constant. And The intraocular lens of the present invention also includes an intraocular lens in which the connecting portion 4 is small and the boundary between the supporting portion 3 and the connecting portion 4 is almost in contact with the optical portion 2.

[0013] The intraocular lens of the present invention is made of polymethyl methacrylate, which is a biocompatible transparent hard resin. However, in the present invention, polymethyl methacrylate means not only a homopolymer of methyl methacrylate, but also a methyl or methacrylate and a suitable crosslinking agent such as di- or poly- (diol) or polyol (e.g., ethylene glycol dimethacrylate, triethylene glycol dimethacrylate). Crosslinked polymethyl methacrylate which is a copolymer with (meth) acrylate or the like is also meant. If necessary, an ultraviolet absorber and / or a colorant may be added to the polymethyl methacrylate.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
However, the present invention is not limited to these examples.

Example 1 An intraocular lens was formed by the following method so that the optical portion had a circular shape with a diameter of 6.5 mm, an axial length of 13 mm, a width of a support portion of 0.16 mm, and a thickness of 0.12 mm. Was prepared. An intraocular lens precursor, which is a flat plate having a substantially planar shape of an intraocular lens, is obtained by cutting out a flat plate of an acrylic resin (98% of methyl methacrylate, 2% of ethylene glycol dimethacrylate) using a milling machine (milling lathe). I got Next, the upper and lower surfaces are turned on the front and rear surfaces of the intraocular lens using an NC lathe (numerical control lathe), and then tumble polishing (barrel polishing) is performed. Obtained.

The width and thickness of the supporting portion of the obtained intraocular lens were measured at points A to F shown in FIG. Note that point F
Is at the junction, point E is at the boundary between the junction and the support,
Points D, C, B and A are points 30%, 50%, 80% and 98% of the total length of the support from point E, respectively. Table 1 shows the results.

Further, the flexibility of the supporting portion of the intraocular lens was measured using the apparatus shown in FIG. The intraocular lens is set on the micro load meter 10 so that the longest axis direction of the intraocular lens 1 and the moving direction of the micro load meter 10 coincide with each other.
The load was moved at a rate of 10 seconds, and the load (ma) at a predetermined movement amount was read from the display of the load detector 14. FIG. 5 shows the results. The compression load when the axial length of this intraocular lens was 10 mm was 0.35 g.

Further, in order to test the resilience of the support portion of the intraocular lens, the above-mentioned intraocular lens was immersed in a physiological saline solution at 37 ° C. for a certain period of time while being held in a ring holder having a diameter of 10 mm. After taking out from the ring, its longest axial length was measured. FIG. 6 shows the results. In addition, ring holder 2
Intraocular lens 1A held in 0 (assumed to be held in the capsular bag) and in the eye before being held (before insertion surgery, ie, sold as a product) FIG. 7 shows the lens 1B.

Example 2 In the same manner as in Example 1, an intraocular lens having an elliptical optical part having a major axis of 6 mm and a minor axis of 5 mm was produced. The width and thickness of the support portion of the obtained intraocular lens were measured at points A to F shown in FIG. Note that point F is at the connection, point E is at the boundary between the connection and the support, and points D, C, B and A are 30%, 50% and 80% of the total length of the support from point E, respectively. % And 98%. Table 1 shows the results.

Further, the flexibility of the supporting portion of the intraocular lens was measured in the same manner as in Example 1. FIG. 5 shows the results. The compressive load when the axial length of this intraocular lens is 10 mm is 0.73.
g. Further, the restoring property of the supporting portion of the intraocular lens was tested in the same manner as in Example 1, and as a result, almost the same restoring property as in Example 1 was shown (the results are not shown).

Comparative Example 1 An intraocular lens (MC-5TE, manufactured by Hoya Co., Ltd.) having an optical part made of PMMA and a support part made of PP (diameter of optical part:
The flexibility of the support having a size of 6.5 mm, an axial length of 13.5 mm, and a cross section of the support having a circular shape and a diameter of 0.15 mm) was measured in the same manner as in Example 1. FIG. 5 shows the results. The compression load when the axial length of this intraocular lens was 10 mm was 0.50 g. Further, the restoring property of the intraocular lens was measured in the same manner as in Example 1. FIG. 6 shows the results.

Comparative Example 2 An integrated intraocular lens made of PMMA was produced in the same manner as in Example 1 except that the width and thickness of the support portion at points A to F were as shown in Table 1. In addition, similarly to the first embodiment,
Point F is at the junction, point E is at the boundary between the junction and the support, and points D, C, B and A are 30%, 50%, 80% and 30% of the total length of the support from point E, respectively. 98%.

The flexibility of the supporting portion of the intraocular lens was measured in the same manner as in Example 1. FIG. 5 shows the results. The compression load when the axial length of this intraocular lens was 10 mm was 1.13 g. Further, the restoring property of the intraocular lens was measured in the same manner as in Example 1. FIG. 6 shows the results.

[0024]

[Table 1]

As apparent from the above results, Comparative Example 1
The intraocular lens whose support portion is made of PP is inferior in restorability of the support portion, and the intraocular lens of Comparative Example 2 which shows a tendency that the width and thickness ratio of the support portion both increase as the distance from the connection portion increases. When the longest axis length was 10 mm, it greatly exceeded 0.7 g, so that the flexibility was poor.

On the other hand, the intraocular lenses of Examples 1 and 2 both had remarkable flexibility and good resilience. Therefore, the intraocular lens of each embodiment of the present invention can be easily inserted into the eye by the surgeon, has a very low possibility of breakage, and furthermore, is shifted from a predetermined position after the intraocular wearing. This is an intraocular lens that does not cause.

[0027]

According to the first aspect of the present invention, P
It is possible to provide an intraocular lens integrally formed of MMA and having a flexible supporting portion. Further, according to a second aspect of the present invention, a PMM
It is possible to provide an intraocular lens which is integrally molded with A and has a supporting portion which is rich in flexibility and restoring property.

[Brief description of the drawings]

FIG. 1 shows a plan view of an intraocular lens of the present invention in which the optical part is circular.

FIG. 2 shows a side view of the intraocular lens of the present invention in which the optical section shown in FIG. 1 is circular.

FIG. 3 shows a plan view of an intraocular lens according to the invention, in which the optical part is elliptical.

FIG. 4 shows a schematic view of a device for measuring the compression load of an intraocular lens.

FIG. 5 shows the relationship between the compression ratio of the intraocular lens and the compression load.

FIG. 6 shows a test result of restorability of an intraocular lens.

FIG. 7 shows an intraocular lens 1A held in a ring holder 20 and an intraocular lens 1B before being held.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Intraocular lens 2 Optical part 3 Support part 4 Connecting part 5 Optical axis of intraocular lens 10 Micro load meter 11 Load detection part 12 Moving part 13 Micrometer 14 Load detector 15 Digital display 20 Ring holder

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yuichi Ogino 2-7-5 Nakaochiai, Shinjuku-ku, Tokyo Inside of Hoya Co., Ltd. (56) References JP-A-2-5940 (JP, A) JP-A Showa 60-99246 (JP, A)

Claims (2)

(57) [Claims] 1. An integrally formed intraocular lens made of polymethyl methacrylate, comprising an optical part, a support part, and a connecting part connecting the optical part and the support part, on a plane perpendicular to the optical axis of the intraocular lens. The axial length is 10m from both directions of the longest axial length
m, the compressive load when the support portion is compressed is
An intraocular lens weighing 0.3-0.7 g. 2. The support portion has a substantially constant width in a range of 80% or more of the entire length of the support portion from the boundary between the support portion and the connection portion toward the tip of the support portion. is in the range ratio is less than 1 0.5 or more of the width to the thickness of the parts, and claim 1 Symbol this ratio is substantially constant
The placement of the intraocular lens.