FR2620329A1 - INTRAOCULAR LENS TO CORRECT AMETROPY - Google Patents

Abstract

The invention relates to an intraocular lens for correcting ametropia. According to the invention, it comprises an optical part 1 and support elements 2 and 3; the optical part 1 in the form of a cylinder 4, the diameter of which corresponds to that of the central optical part of the eye, this cylinder having a lateral projection 5; the end surfaces 6, 7 of cylinder 4 are spherical; the support elements 2 and 3 have the shape of two diametrically opposed sectors extending the surface 7. The invention applies in particular to ophthalmology.

Description

The present invention relates to medicine, ophthalmology and more

especially a lens

  intraocular to correct ametropia.

  The present invention can be used to correct any type of ametropia such as myopia, hypermea

tropie, astigmatism.

  There is an intraocular lens to correct

  ametropia, which includes an optical part and

  support, which can be implanted in the anterior chamber

  back of the eye (review "Ophthalmology" August 1982, page 148, model 20, 20A). In this lens, the optical part is in the form of a disk and the supporting elements

  arched filiforms are made of an elastic material.

  At the implantation of the known intraocular lens, these

  support elements abut against the corners of the anterior chamber

  of the patient's eye, which is traumatic because the contact of the lens support elements with the corneal epithelium and with the trabecular area of the

  of the anterior chamber of the eye may cause

  epythelial-endothelial trophy of the cornea.

  There is also an intraocular lens to correct ametropia, which has an optical part

  and supporting elements, which is intended to be

  in the posterior chamber of the eye, directly on the anterior capsule of the natural lens of the eye

(US, A, 4585456).

  In the known intraocular lens, the optical part is a disc whose thickness is less than the depth of the posterior chamber of the eye, a surface of the disc cooperates with the anterior surface of the artificial lens, the support elements are arched , diametrically

  opposed and made of an elastic material. However, the

  planting the entire intraocular lens in the chamber

  posterior position of the eye, with its provision on the

  anterior surface of the natural lens can cause, in the postoperative period, a decentering of the intraocular lens, decubituses and tears of the capsule

anterior of the natural crystalline lens.

  The object of the invention is to improve the structure

  intraocular lens to correct myopia so as to exclude off-centering of the lens during

  postoperative period and to reduce the number of complica-

  postoperative interventions through reduced trauma

  tissues of the eye through the intraocular lens.

  The problem is solved by the fact that in a

  intraocular lens to correct ametropia, which

  carries an optical part and support elements, according to the invention, the optical part has the shape of a cylinder

  having a lateral annular projection according to the circumference

  of one of its end surfaces, the diameter of the cy-

  lint corresponds to the diameter of the optical central part of the eye, the height exceeds the depth of the posterior chamber of the eye, the projecting end surface is spherical and its radius of curvature is chosen from the condition of ensure correction of the ametropia of the eye, the other end surface is also spherical

  with a radius of curvature corresponding to that of the sur-

  anterior surface of the natural crystalline lens, while the

  The support elements have the shape of two diametrically opposite sectors, exceeding the limits of the spherical surface of

  the second surface at the end of the cylinder and extending it.

  It is useful to make the end surface with projection of the cylinder with areas where the radius of curvature is selected from the correction condition of the cylinder.

the astigmatism of the eye.

  It is desirable to make the optical part

  and the support elements in one piece.

  As a rule, the diameter of the circumference

  limiting the support elements is 10 to 10.5 mm, the di-

  meter of the lateral annular protrusion is 0.38 to 0.59, its thickness, from 0.1 to 0.11, the height of the cylinder, from 0.03 to 0.05, the thickness of the bearing elements , from 0.01 to 0.05 and the radius of curvature of the surface of the second

  cylinder is 1.0 to 1.1 times the diameter of the circumference

  limiting the support elements.

  The intraocular lens made according to the present invention excludes any possibility of decentering

  because the part of its lens with the elements of ap-

  It is located in the posterior chamber of the eye while the end surface with lateral annular projection, which is the useful optical surface, is carried in the area of the pupil. The considered lens structure excludes a risk of decubitus and tearing of the natural lens capsule, which makes it less traumatic

  during the postoperative period.

  The invention will be better understood and other purposes, details and advantages thereof will become more apparent in the

  light of the following explanatory description of a

  embodiment given only as a non-exemplary example

  limiting, with reference to non-limiting drawings

nexes in which:

  FIG. 1 represents an intraocular lens

  to correct ametropia, according to the invention, seen from above; FIG. 2 shows the same lens as in FIG. 1, in longitudinal section; and FIG. 3 diagrammatically represents an eye in which an intraocular lens is implanted to correct

ametropia, according to the invention.

  The intraocular lens to correct the ametero-

  1 and 2 comprises an optical part 1 and bearing elements 2 and 3. The optical part 1 has the shape of a cylinder 4 having an annular protrusion

  side of the circumference of one of its extremities

  mites, whose end surface 6 is spherical and serves as a useful optical surface of the intraocular lens. The radius of curvature R of the useful surface 6 is chosen in

  from the condition of ensuring the correction of

  tropie of the eye. The diameter d of cylinder 4 corresponds to that of the central optical zone of the eye, the height

  h cylinder 4 exceeds the depth of the post-chamber

  in the eye. The opposite end surface 7 of the cylinder

  4 is also spherical and its radius of curvature R1 cor-

  corresponds to that of the anterior surface of the natural crystalline lens.

  rel. Support elements 2 and 3 have the shape of two sec-

  diametrically opposed, exceeding the limits of the

  spherical surface 7 and extending it.

  The diameter D of the circumference limiting the support elements 2 and 3 is defined by the distance between the points a and b (FIG. 3) of fixation of a crystalline lens.

  nature 8, to note, one chooses D <ab.

  The support elements 2 and 3 may have the form of separate parts which are attached to the optical part 1

  during the manufacture of the intraocular lens.

  Support elements 2 and 3 can make a whole

  with the optical part 1 in a biologically transparent material

  inert, such as silicone.

  The intraocular lens being the subject of

  vention is symmetrical with respect to the axis of rotation of the

cylinder 4.

  The useful spherical surface 6 may have a curvature

  variable part: with a part whose radius is chosen starting from the condition of ensuring the correction of astigmatism, the remaining part of the spherical surface

  6 having a radius of curvature chosen from the condition

  to correct myopia or hypermea-

tropie of the eye.

  The diameter D of the circumference limiting the support elements 2 and 3 is generally chosen equal to -10.5 mm. In this case, the outer diameter d1 of the projection is between 0.38 and 0.59 D, the thickness of the projection 5 is between 0.1 and 0.11 D, the height h of the cylinder 4 is included 0.03 and 0.05 D, the thickness of the support elements 2 and 3 is between 0.01 and 0.05D and the radius of curvature R1 of the surface is between 1.0 and 1.1 D As a result of a large number of experiments,

  It turned out that with a choice of the parameters of the

  intraocular cavity smaller than the lowest values indicated, according to the invention, a reversal of

  curvature of the implanted lens was possible.

  In the case where one chooses the parameters of the intraocular lens higher than the highest values indicated, according to the invention, there appears a risk of trauma to the tissues of the eye surrounding the intraocular lens. Implantation of the intraocular lens according to

  the invention is carried out as follows.

  Under local anesthesia, through a section following the limb, is introduced into the eye cavity, the intraocular lens so that the bearing elements 2 and 3 pass through the pupil area and are placed on the anterior surface of the natural lens 8

  (FIG. 3) and that the useful optical surface 6 with the

  5 remains in the anterior chamber of the eye, in the

pupil area.

  Then we make, on the cut, two or three cuts

  tures. As the diameter d of cylinder 4 corresponds to that

  of the central zone of the eye while the external diameter

  the protrusion 5 exceeds somewhat of the diameter of the optical central zone and the height h of the cylinder 4 exceeds the depth of the posterior chamber of the eye,

  the intraocular lens according to the invention is coaxial

  to the optical axis of the eye, which excludes any possibility of

  ease of decentering. Thanks to the realization of the surface

  spherical material having a radius of curvature R1 corresponding to

  spanning the radius of curvature of the anterior surface of the natural lens 8 and the fact that the diameter

  D <ab, the lens slowly sets in place, which ex-

  the possibility of trauma to the tissues and anterior surface of the natural lens and

  its fixing by the support elements 2 and 3.

  Concrete examples of

  implantation of the intraocular lens according to the invention

tion. Example 1

  K, 32, is hospitalized with a diagnosis of

  tic of myopia of high degree of the right eye. OD = D 0,01 sph. - 17.0 = 0.4. Retinal visual acuity is between 0.8 and 1.0. Surgery is performed with implantation of an intraocular lens

  according to the invention, corresponding diopter (for the

  concrete lade). The parameters of the lens are the following

  diameter: D = 10.5 mm, diameter d1 = 0.38D, protrusion thickness 5 = O, ID, height h = 0.03D, thickness of support elements 2 and 3 = O, 01D and radius of curvature R1 = D.

  The postoperative period was uncomplicated.

  At the exit of the hospital, the third day, seen OD = 0.7 without correction; the seventh day, seen OD = 0.8 to 1.0. The eye is calm, the positioning of the lens is correct, the natural lens is transparent. At the end

  of one year, seen OD = 08 to 1.0 without correction.

Example 2

  Sick V., 41 years old. Diagnosis: hyperopia of D

  high degree right eye. OD visualization = 0.06 sph. + 9.0 = 0.3.

  The retinal visual acuity is 0.5 and 0.63.

  Intervention: Implantation of an intraocular lens

  eyepiece according to the invention, corresponding to the diopter of

  this patient. The parameters of the lens are the following

  : diameter D = 10.5 mm, d 1 = 0.45D, thickness of the

  projection 5 = 0.06D, height h = 0.04D, thickness of the elements

  2 and 3 = 0.03D, radius R1 = 1.1D. Postoperative period without complications. At the exit of the hospital, visual OD = 0.3 without correction. At the observation for 8 months, seen OD = 0.5 to 0.6 without correction, the eye is calm, the positioning of the lens is correct. The

natural crystalline is transparent.

Example 3

  Sick N., 29 years old. Diagnosis: high degree of myopia, myopic astigmatism. Visus before surgery: OS = 0.01 sph. - 14.0 cyl. 4.0 = ax 50 = 0.3. The acuteness

  visual retinal is equal to 0.63.

  Intervention: Implantation of an intraocular lens

  eyepiece, according to the invention, corresponding diopter.

  The parameters of the lens are as follows: diameter D = 10 mm, diameter d1 = 0.045D, protrusion thickness = 0.06D, h = 0.04D, thickness of the support elements 2 and 3 =

  0.03D and radius R1 = 1.1D. Postoperative period without

  plications. At the exit of the hospital, visual OD = 0.4 to 0.5 without correction. At the observation during 8 months, seen OD = 0.63 without correction. The eye is calm, positioning

  of the lens is correct, the natural lens is trans-

  parent. At the implantation of the intraocular lens in 30 cases, no complication or

  side of the lens or the side of the surrounding tissue.

8 2620329

Claims (4)

R E V E N D I C A T I 0 N S   1. Intraocular lens to correct ametero   of the type having an optical part and bearing elements, characterized in that the optical part (1) has   the shape of a cylinder (4) with a lateral annular projection   rale (5) along the circumference of one of its ends, the diameter of the cylinder (4) corresponding to the diameter of the central optical zone of the eye, the height exceeding the depth of the posterior chamber of the eye, a surface at the end (6) with a projection (5) being spherical and having a radius of curvature chosen starting from the condition of ensuring the correction of the ametropia of the eye, the second end surface (7) being also spherical with a radius of curvature corresponding to that of the anterior surface of the natural lens (8), the support elements (2 and 3)   being made in the form of two diametrical sectors   opposed to each other exceeding the limits of the frontal surface   spherical section (7) of the second end of the cylinder (4) and the   along. 2. Lens according to claim 1, characterized in that the end surface (6) of the cylinder (4) with its projection (5) has areas where the radius of curvature is   chosen from the condition of correcting the astigmatic of the eye.   3. A lens according to any one of the claims   previously characterized in that the optical part   (1) and the support elements (2 and 3) make a whole.   4. Lens according to claim 1, characterized   in that the diameter D of the circumference limiting the elements   (2 and 3) is between 10 and 10.5 mm, the di-   meter d1 of the lateral annular projection (5) is between 0.38 and 0, 59D, its thickness between 0.1 and 0.11D, the height h of the cylinder (4) between 0.03 and 0.05D, the thickness of the support elements (2 and 3) between 0.01 and 0.05D and the radius R of curvature of the front surface (7) of the second end of the cylinder (4) is between 1 and 1, 1 second end of the cylinder (4) is between 1.0 and 1.1 times the diameter D of the circumference limiting the support elements (2 and 3).