JP4916351B2 - Soft intraocular lens - Google Patents

Description

  The present invention relates to a soft intraocular lens made of a single material, foldable and having a structure suitable for insertion into an eye with an injector.

  As the elderly population has increased, the number of senile cataract patients has increased. Treatment of cataracts has been performed by removing the cloudy lens nucleus and cortex, correcting vision with glasses or contact lenses, or inserting an intraocular lens. A method of fixing a lens has been widely implemented.

In recent years, with the spread of ultrasonic emulsification and the like, intraocular lenses that can be inserted from small incisions have been developed and widely used clinically for the purpose of reducing postoperative astigmatism and surgical invasion. This lens is a soft intraocular lens that can be inserted from a small incision by bending its optical part by using a soft material for the optical member material.

  The soft intraocular lens can be broadly classified from the structural aspect: the optical part and the support part are made of different materials, and the optical part and the support part are made of the same material. .

  Intraocular lenses of the type in which the optical part and the support part are made of different materials are generally composed of a substantially circular optical part made of a soft material such as foldable silicon, acrylic resin, hydrogel, and the like. It is composed of a support part made of a hard material such as relatively hard polypropylene or polymethylmethacrylate, which has an open end, and is relatively stable in the eye. It is said that there is a possibility that the cost will be high, or that a defect may occur at the joint between the optical part and the support part.

  As an intraocular lens of a type in which the optical part and the support part are made of the same material, the support part is a disc-shaped type, a closed loop type (see Patent Document 1), and an open loop type (Patent Document 2). However, the present invention relates to a soft intraocular lens having a support portion having an open loop shape.

  On the other hand, various injectors have been developed as instruments for inserting an intraocular lens from a smaller incision in the eyeball. According to these injectors, the folded intraocular lens can be pushed into the eye through the cylindrical insertion tube, so that the incision wound is much smaller than when inserted using a conventional sushi. It became possible to insert an intraocular lens.

Under such circumstances, the functions and properties required for the intraocular lens include not only the optical function of the intraocular lens, but also (a) the intraocular lens (in the lens capsule) being in a stable state. Be kept. (B) When the intraocular lens passes through the injector, it may be folded to be smaller and pass smoothly.
Japanese National Patent Publication No. 10-513099 Special Table 2000-509615

However, in an intraocular lens having a conventional support portion with an open loop shape, it cannot be said that the above functions are sufficiently satisfied. For example, the intraocular lens described in Patent Document 1 may have the following disadvantages. FIG. 6 is a view showing a state in which the intraocular lens 200 of Patent Document 1 is inserted into the injector 300. As shown in FIG. 6, the intraocular lens 200 is folded in two and inserted from the insertion port 301 of the injector 300. In this case, since the length of the support portion 202 of the intraocular lens 200 described in Patent Document 1 is relatively long, the support portion 202 in the front is twisted when the intraocular lens passes through the insertion tube of the injector 300, There is a risk that it cannot be released into the eye. Moreover, although the support part 202 has a hinge structure, since the support part as a whole lacks flexibility, there is a possibility that stress is concentrated locally on the crystalline lens capsule after insertion into the eye.

  Further, the intraocular lens described in Patent Document 2 also has the same problem as described above due to the length of the support part, and the width near the base of the support part is too wide, so that the intraocular lens can be folded small in the injector. There were also problems such as the possibility of clogging in the injector without being possible.

  Furthermore, in addition to the above-described problems, when the support portion is an open loop intraocular lens, the support portion on the rear side in the insertion cylinder is inserted into the injector plunger (extrusion) when the intraocular lens in the injector passes. There is also a risk that the support portion on the front side may be entangled between the optical portion and the inner wall of the insertion cylinder.

  The object of the present invention is to solve these problems, that is, to provide an intraocular lens having a structure that is stably held in the eye after insertion into the eye, and the intraocular lens passes through the injector. An object of the present invention is to provide an intraocular lens having a structure that is sometimes folded smaller and can pass smoothly.

As means for solving the above-mentioned problem, the first means is:
An optical unit, a plurality of support units provided outside the optical unit to hold the optical unit in the eye, and a transition unit provided between the optical unit and the support unit, A foldable intraocular lens in which the optical part, the transition part and the support part are integrally formed of the same material and have an IRHD hardness of 40-60,
The distance L from the optical center axis of the optical part to the reference point of the support part side end of the transition part is between 3.75 mm and 4.50 mm,
An angle θ formed by a surface including the optical center axis and a reference point on the support portion side end of the transition portion and a surface including the optical center axis and in contact with the tip of the support portion is 35 ° to 50 °,
The width of the transition part is wider than the width of the support part, and the width Wm of the transition part between the optical part side end and the support part side end of the transition part is 1.5 to 3 times the width Ws of the support part. It is a soft intraocular lens characterized by being doubled.
The second means is
The soft intraocular lens according to the first means, wherein the transition portion extends substantially outward in the radial direction.
The third means is
In a region between the surface including the optical central axis and the reference point and the surface including the optical central axis and forming a surface of 20 ° with respect to the surface including the optical central axis and the reference point, The soft intraocular lens according to the first or second means, wherein the width Ws of the support portion is substantially constant and is between 0.3 mm and 0.6 mm.
The fourth means is
The soft intraocular lens according to any one of the first to third means, wherein the number of the support portions is two.

According to the above first means, L is set to 3.75 mm to 4.50 mm, and the angle θ
Is 35 ° to 50 °, and at the same time, Wm is 1.5 to 3 times Ws, so that the support portion is twisted or entangled with the injector plunger when passing through the injector, or The support part on the front side does not get caught between the optical part and the inner wall of the insertion tube, and it can be folded small in the injector so that it can pass through the injector smoothly. It has become possible for the first time to obtain an intraocular lens that can be stably held in the eye after insertion into the eye.

  When L is shorter than 3.75 mm, the support portion must be relatively long, so the front support portion is twisted in the injector insertion tube, or the front support portion is the optical portion and the inner wall of the tube. There is a possibility that the rear side support part may be entangled with the plunger. In addition, when L is longer than 4.50 mm, the support portion becomes relatively short, and sufficient contact between the lens capsule and the support portion cannot be obtained, and the stability of the intraocular lens in the lens capsule is poor. It is also possible to become. Moreover, there is a possibility that the centering in the lens capsule may be deteriorated.

  When the angle θ is less than 35 °, sufficient contact between the capsular bag and the support cannot be obtained, and the stability of the intraocular lens in the capsular bag is deteriorated, or the centering in the capsular bag is deteriorated. Or If the angle θ exceeds 50 °, the length of the support portion becomes long, so the front support portion is twisted in the injector insertion tube, or the front support portion is sandwiched between the optical portion and the inner wall of the tube, There is a possibility that the rear side support part may be entangled with the plunger.

  When Wm is less than 1.5 times Ws, the strength of the transition portion becomes weak, the front support portion is twisted in the injector insertion tube, or the front support portion is sandwiched between the optical portion and the inner wall of the tube. There is a possibility of inducing it. When Wm exceeds 3 times Ws, it becomes an obstacle when the intraocular lens passes through the injector insertion cylinder. From the viewpoint of discharge from a small-bore injector, a type having two support portions is particularly preferable.

  According to the second means, since the transition portion extends substantially in the radial direction, the peripheral portion of the intraocular lens and the transition portion interfere with each other when being folded in the insertion tube, and the transition portion may be damaged or defective. Can be reduced.

  According to the third means, the surface including the optical center axis and the reference point, and the surface including the optical center axis and forming a 20 ° with respect to the surface including the optical center axis and the reference point In the region between the two, the support portion width Ws is substantially constant and 0.3 mm to 0.6 mm, so that the support portion can have a substantially uniform and appropriate flexibility over the entire support portion. This makes it possible to reduce the local pressure applied to the lens capsule. Here, the reference point refers to the midpoint of the boundary line between the transition part and the support part, and the boundary line between the transition part and the support part is the width of the support part with the minimum width of the transition part. A straight line indicating the width at equal parts.

  When Ws is narrower than 0.3 mm, the repulsive force from the capsular bag to the support part is weak, and the stability and centering in the eye are deteriorated. When it is larger than 0.6 mm, flexibility cannot be obtained. The local pressure from the support to the lens capsule becomes too great. Moreover, when the said angle is 20 degrees or less, there exists a possibility that the softness | flexibility as the whole support part may fall.

  1 is a plan view of a soft intraocular lens according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II in FIG. 1, FIG. 3 is a partially enlarged view of FIG. It is a figure which shows the intermediate body in the middle of manufacture of a soft intraocular lens, Comprising: FIG. 4 (A) is a top view, FIG.4 (B) is an AA sectional view. Hereinafter, a soft intraocular lens according to an embodiment of the present invention will be described with reference to these drawings.

  As shown in FIG. 1, the soft intraocular lens according to the embodiment is an optical unit 1 and an outer peripheral part of the optical unit 1, and is approximately at a target position around the central axis O of the optical unit 1. Each of the two support portions 2 provided and a transition portion provided between the optical portion 1 and the support portion 2 are provided. The intraocular lens is a so-called one-piece type soft intraocular lens in which the optical part 1, the support part 2, and the transition part 3 are integrally formed of the same soft material.

  The optical unit 1 is composed of a convex lens having a substantially circular shape with a radius r1 in plan view. In plan view, the transition part 3 is raised from the wide base at the outer peripheral part of the optical part 1, that is, from the optical part side end of the transition part toward the outside, and gradually becomes narrower. When the width becomes equal to the width (Ws), that is, the support portion 2 is moved to the support portion side end of the transition portion. The support portion 2 is bent from the vicinity of the support portion side end of the transition portion 3 to the optical portion 1 side, and is extended by a predetermined distance with a constant width (Ws) and thickness (Ts). The width Ws of the support part 2 is preferably equal to or less than the thickness Ts of the support part 2. Thereby, the possibility of twisting of the support portion can be reduced. In addition, the thickness of the transition part 3 is the thinnest thickness Tm at the optical part 1 side end part of the transition part 3, and is substantially the same as the thickness of the support part 2 at the support part 2 side end part of the transition part 3. The same thickness Ts. For a refractive index of 20 diopters, Tm = 0.2 mm and Ts = 0.4 mm.

  Next, the structure of the support part 2 and the transition part 3 is demonstrated in detail, referring FIG. Now, let P1 and P2 be two points where the curve that divides the outline of the transition part 3 in plan view is separated from the circle of radius r1 that outlines the plan view of the optical part 1 at the root of the transition part 3. Then, the two contour lines that divide both widths of the transition portion 3 rise up outwardly with the points P1 and P2 as base points.

  A curve having the point P1 as a base point is a curve having a radius of curvature R1, and the point P3 is an end point thereof. Note that the center of curvature of this curve is outside the optical unit. On the other hand, a curve having the point P2 as a base point is a curve having a curvature radius R2, and the point P4 is an end point thereof. This curve is a curve that is convex toward the curve having the point P1 as a base point. Next, a straight line portion having a point P5 as its end point is formed as a tangent line that touches the curve of the radius of curvature R1 at the point P3, starting from the point P3. In this embodiment, R1 = 0.75 mm and R2 = 2.25 mm.

  Further, the curve has a radius of curvature R3 starting from the point P4 and rises in a tangential direction in contact with the curve of the radius of curvature R2 at the point P4, and the convex direction of the curve of the radius of curvature R2 is opposite to the convex direction. A curve is formed which has a point P6 as its end point. Furthermore, it is a curve having a radius of curvature R4 starting from the point P5, rising at the point P5 in the linear direction of the linear portion, and having the same convex direction as the convex direction of the curve of the radius of curvature R1. Thus, a curve having the point P7 as its end point is formed. In this embodiment, R3 = 0.7 mm and R4 = 0.3 mm.

  Further, the curve has a radius of curvature R5 starting from the point P6 and rises in a tangential direction in contact with the curve of the radius of curvature R3 at the point P6, and the convex direction of the curve of the radius of curvature R3 is the same. And a curve having a point P8 as its end point is formed. Further, the curve has a radius of curvature R6 starting from the point P7 and rises in a tangential direction in contact with the curve of the radius of curvature R4 at the point P7, and the convex direction of the curve of the radius of curvature R4 is the same as the convex direction. And a curve having a point P9 as its end point is formed. And between the point P8 and the point P9, it forms in the smooth curve convex outside. In this embodiment, R5 = 4.75 mm and R6 = 4.35 mm.

Here, the distance between the points P1 and P2 of the transition part 3 is w1, the width of the intermediate part of the transition part 3 is Wm, and the width of the support part 2 is Ws. In this embodiment, Wm = 0.63 mm and Ws = 0.4 mm. Ws is preferably 0.3 mm to 0.6 mm. Further, the Wm is preferably 1.5 to 3 times the width Ws of the support portion. When Wm is less than 1.5 times Ws, the strength of the transition portion becomes weak, the front support portion is twisted in the injector insertion tube, or the front support portion is sandwiched between the optical portion and the inner wall of the tube. There is a possibility of inducing it. When Wm exceeds 3 times Ws, it becomes an obstacle when the intraocular lens passes through the injector insertion cylinder.

  Moreover, the width Wm in the intermediate part of the transition part 3 is determined as follows. That is, first, the optical part side end of the support part 2, in other words, the support part side end of the transition part 3 is where the width of the transition part 3 is Ws. This is because when the point where the straight line connecting the point P4 and the point O4 which is the center of curvature of the curvature radii R3 and R4 and the curve of the curvature radius R4 intersect is defined as K3, the straight line P4K3 is It means that it becomes the support part side end or the transition part side end of the support part 2.

  The midpoint of this straight line P4K3 is set as K, and the point K is set as a reference point at the end of the transition portion 3 on the support portion side. Then, when the radius of a circle centered on the central axis O of the optical unit 1 and passing through the point K is r3, r2 having a relationship of r2 = (r1 + r3) / 2 is set as the radius, and the optical unit 1 A circle centered on the central axis O is assumed. When the points where the circle and the outline of the transition portion 3 intersect are defined as K1 and K2, the length Wm of the straight line K1K2 is the intermediate width of the transition portion 3. In this embodiment, r1 = 3.00 mm, r3 = 4.06 mm, r2 = 3.53 mm, and Wm = 0.63 mm.

  Further, an angle formed by a surface S1 including the central axis O (optical axis) of the optical unit and the point K and a surface S2 including the optical axis and in contact with the point P9 at the tip of the support unit 2 is θ. Then, in this embodiment, θ = 44.9 °. It is preferable that θs ≦ θ ≦ θm. Here, θs = 35.0 ° and θm = 50 °. When θ is less than 35 °, sufficient contact between the capsular bag and the support portion cannot be obtained, and the stability of the intraocular lens in the capsular bag is deteriorated, or the centering in the capsular bag is deteriorated. To do. If θ exceeds 50 °, the front support part is twisted in the injector insertion cylinder, the front support part is sandwiched between the optical part and the cylinder inner wall, or the rear support part is separated from the plunger. There is a possibility of getting stuck.

  Further, the point P8 which is the outer peripheral end of the support portion 2 is configured to be on a circle having a radius r4 with the central axis O (optical axis) of the optical portion 1 as the center. In this embodiment, r4 = 6.25 mm. Further, if the distance between the central axis O of the optical unit 1 and the reference point K at the support side of the transition unit 2 is L, the distance L is equal to the radius r3 described above. L = r3 = 4.50 mm. Here, it is preferable that 3.75 mm ≦ L ≦ 4.25 mm.

  When L is shorter than 3.75 mm, the support portion has to be relatively long. Therefore, the front support portion is twisted in the injector insertion cylinder, or the front support portion is formed between the optical portion and the cylinder inner wall. There is a possibility that it will be sandwiched between them, or the rear support part may be entangled with the plunger. In addition, when L is longer than 4.50 mm, the support portion becomes relatively short, and sufficient contact between the lens capsule and the support portion cannot be obtained, and the stability of the intraocular lens in the lens capsule is poor. Or centering within the capsular bag may worsen.

FIG. 5 is a diagram showing a state in which the intraocular lens 100 according to the embodiment of the present invention is inserted into the injector 300. As shown in FIG. 5, the intraocular lens 100 is folded in two and inserted from the insertion port 301 of the injector 300. In this case, the intraocular lens 1 of the present embodiment
Since the length of the support portion 2 of 00 has an appropriate length, appropriate flexibility, etc., the support portion 2 in the front may be twisted when the intraocular lens passes through the insertion tube of the injector 300. It can pass smoothly and be released into the eye.

  The soft intraocular lens having the above configuration is manufactured as follows. That is, surface forming processing for forming the curved surface forming the optical surface 1, the support portion 2, and the transition portion 3 is performed on the front and back surfaces of the raw material 10 whose plan view is shown in FIG. . FIG. 4B is a cross-sectional view taken along line AA of the raw material 10 after processing. As shown in the figure, the optical part 1 is formed on a curved surface constituting the lens, the concentric circle part constituting the support part 2 is formed flat, and the part constituting the transition part 3 has a thickness in the radial direction. It is formed into a changing curved surface. In addition, it is also possible to make all the said processes into the cast mold manufacturing method, or to use the cast mold manufacturing method until surface formation processing. The disk-shaped raw material 10 processed in this way is cut into a shape of an intraocular lens as shown by a dotted line in FIG. Thereby, a soft intraocular lens is obtained. Further, in order to improve visibility and prevent sticking between the support part and the optical part, the surface of the support part or the surface of the support part and the transition part surface can be processed into a ground glass shape. In addition, as a soft material which comprises the raw material 10, soft acryl, hydrogel, silicone, etc. can be used.

  FIG. 7 is a partially enlarged plan view of a soft intraocular lens according to another embodiment of the present invention. Hereinafter, a soft intraocular lens according to another embodiment of the present invention will be described with reference to FIG. As shown in FIG. 7, the soft intraocular lens according to this embodiment also has an optical part 1, two support parts 2, and a transition part 3, which are integrally formed of the same soft material. Since the main configuration is the same as that of the above-described embodiment, different points will be mainly described below, and description of the same points will be omitted.

  This embodiment differs from the above embodiment in the values of r2 and r3, the specific shapes and dimensions of the support portion 2 and the transition portion 3, and the like. In this embodiment, r2 = 3.50 mm and r3 = 4.00 mm. Further, in the transition part 3, the curvature radius R1 of the curve having the point P1 as the base point and the end point thereof as the end point is R1 = 0.86 mm, the curvature radius of the curve having the point P2 as the base point and the point P4 as the end point thereof. R2 = 0.75 mm.

  The curvature radius R4 of the curved portion starting from the point P3 and ending at the point P5 = 0.40 mm, and the curvature radius R3 = 0.75 mm of the curve starting from the point P4 and ending at the point P6. Here, the curve starting from the point P5 has its end point at the point P10 and its curvature radius R5 = 4.5 mm. The curve starting from the point P5 has an end point P9 and a radius of curvature R6 = 4.10 mm.

  A point P9 is the starting point, rises in a tangential direction in contact with the curve of the radius of curvature R6 at the point P9, and is a curve having the same convex direction as the convex direction of the curve of the radius of curvature R6. A curve having a radius of curvature R7 as an end point is formed. In this embodiment, R7 = 1.50 mm, and further, starting from the point P11, rises in the tangential direction in contact with the curve of the radius of curvature R7 at the point P11, and the convex direction of the curve of the radius of curvature R7 and its direction A curved line R8 is formed that has a convex direction opposite to the point P12. In this embodiment, R8 = 0.40 mm. The point P12 is the tip of the support portion 2 with which the surface including the optical axis 0 comes into contact. An angle θ formed by a plane including the central axis O and passing through the point P12 at the tip and a plane including the central axis O (optical axis) and passing through the reference point K is 44.60 °. A portion on the plane including the optical axis 0 starting from the point P12 and ending at the point P13 is a straight line portion, and a smooth curve convex outward is formed between the point P13 and the point P10. .

The transition part 3 is in an area between a curve P1P2 that partitions the root and a straight line K3K4 that partitions the boundary with the support part 2. The width of the intermediate part of the transition part 3 is such that the length Wm = 0.66 mm of the straight line K1K2 is the width of the intermediate part when K1 and K2 are points where the circle of radius r2 and the left and right contour lines of the transition part intersect. It is. The reference point K is a midpoint of the straight line K1K2 and is a point on a circle with a radius r3. The straight line K3K4 that divides the boundary with the support part 2 is also a straight line indicating the width of the portion where the width of the transition part 3 is the narrowest, and is also the width Ws of the support part 2 closer to the optical part 1 side. The region of the width Ws extends to a region connecting the points P8 and P9, from which the width gradually increases toward the tip, and the maximum width Wn near the tip of the support portion 2 is 0.80 mm. In this case, the plane including the center axis O and passing through the midpoint K5 of the straight line P8P9 and the above-described center axis O (optical axis), the reference point K
Is an angle θn = 25.9 ° with the plane passing through.

  According to this embodiment, in particular, by widening the tip side of the support portion, the support portion is more stably held in the eye after being inserted into the eye, and is supported when the intraocular lens passes through the injector. It is possible to more smoothly pass by reducing the risk of the portion becoming tangled.

  The present invention can be used as an intraocular lens that is inserted into the eye and fixed after the entire lens has been removed.

It is a top view of the soft intraocular lens concerning embodiment of this invention. It is the II sectional view taken on the line in FIG. FIG. 2 is a partially enlarged view of FIG. 1. It is a figure which shows the intermediate body in the middle of manufacture of the soft intraocular lens which concerns on this invention, Comprising: FIG. 4 (A) is a top view and FIG. 4 (B) is an AA sectional view. It is a figure which shows a mode that the intraocular lens 100 which concerns on embodiment of this invention is inserted in the injector. It is a figure which shows a mode that the intraocular lens 200 of patent document 1 is inserted in the injector 300. FIG. It is a partially expanded plan view of a soft intraocular lens according to another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical part 2 Support part 3 Transition part

Claims (4)

An optical unit, a plurality of support units provided outside the optical unit to hold the optical unit in the eye, and a transition unit provided between the optical unit and the support unit, A foldable intraocular lens in which the optical part, the transition part and the support part are integrally formed of the same material and have an IRHD hardness of 40-60,
The distance L from the optical center axis of the optical part to the reference point of the support part side end of the transition part is between 3.75 mm and 4.50 mm,
An angle θ formed by a surface including the optical center axis and a reference point on the support portion side end of the transition portion and a surface including the optical center axis and in contact with the tip of the support portion is 35 ° to 50 °,
The width of the transition part is wider than the width of the support part, and the width Wm of the transition part between the optical part side end and the support part side end of the transition part is 1.5 to 3 times the width Ws of the support part. A soft intraocular lens characterized by being doubled.   The soft intraocular lens according to claim 1, wherein the transition portion extends substantially outward in the radial direction.   In a region between the surface including the optical central axis and the reference point and the surface including the optical central axis and forming a surface of 20 ° with respect to the surface including the optical central axis and the reference point, The flexible intraocular lens according to claim 1 or 2, wherein the width Ws of the support portion is substantially constant and is between 0.3 mm and 0.6 mm.   The flexible intraocular lens according to any one of claims 1 to 3, wherein the number of the support portions is two.

Images