GB2165456A - Intra-occular prosthetic lens - Google Patents

Abstract

An intra-occular prosthetic lens (1) comprises three supporting elements; one of the elements is shaped as a loop (4), while two other elements (3) are shaped as arcuate pieces curved towards each other. These arcuate elements (3) are held in the lens body on the side of it which is diametrically opposite the loop-shaped element (4) and are arranged symmetrically with respect to the plane passing through the mid-point of the lens body and of the loop-shaped element. <IMAGE>

Description

SPECIFICATION Intra-occular prosthetic lens This invention relates generally to medicine and more specifically to opthalmology, having particular reference to an intra-occular prosthetic lens or lenticulus.

According to the invention, there is proposed an intra-occular prosthetic lens, comprising an optical lens body and three supporting elements secured therein, one of which is shaped as a loop, while two other elements are secured to the lens body on the same side of it, which is diametrically opposite to the loop-shaped element, characterised in that the two supporting elements situated on the same side of the lens body are shaped as two arcuate pieces curved towards each other, their free ends being arranged symmetrically with respect to the plane passing through the mid-point of the lens body and of the loop-shaped element, these arcuate pieces being curved towards the posterior surface of the lens body.

The intra-occular prosthetic lens can be so made that the edge of the loop-shaped element and the edges of the arcuate elements furthest from the lens body lie on the same imaginary circumference having its centre at the centre of the lens body, while the portions of the arcuate elements adjacent said edges are additionally curved so as to be parallel to the principal plane of the lens body.

The aforesaid construction is advantageous in that the mutual arrangement of the optical lens body and the support elements makes it possible to provide reliable spatial orientation of an intraoccular prosthetic lens when implanted in the anterior or posterior eye chamber, to attain a full correspondence of the overall dimensions of the intra-occularlenstothose of the anterior and posterior eye chambers, as well as to reduce the incidence of post-operative complications.

Hereinafter the invention is explained by way of example with reference to the accompanying drawings, wherein: Fig. 1 is a plan view of an intra-occular lens implant, according to the invention; Fig. 2 is a side view of the intra-occular lens implant of Fig. 1. adapted for being implanted in the anterior eye chamber; and Fig. 3 is a side view of an intra-occular lens implant substantially similar to that illustrated in Fig. 1 but adapted for being implanted in the posterior eye chamber.

Referring now to Fig. 1 an intra-occular prosthetic lens 1 comprises a lens body 2 of any already known construction, e.g., a bi-convex one, as can best be seen from Figs. 2 and 3, two arcuate supporting elements 3 and a loop-shaped supporting element 4.

The arcuate supporting elements 3 may be made of any elastic material, e.g., Supramide (a proprietary name). As can be seen from Fig. 1,the arcuate elements are situated on the side of the lens body diametrically opposite to the loop-shaped element 4 and are fixed at one of their ends to the lens body 2 by any known technique. The arcuate elements 3 are curved towards each other and their free ends are arranged symmetrically with respect to the plane passing through the mid-point of the lens body 2 and of the loop-shaped element 4. In addition, the arcuate elements 3 are curved somewhat backward towards the posterior surface of the lens body and can be curved further in the course of surgery to suit the radius of the patient's scleral curvature.

Fig. 3 is a side view of an intra-occular lens substantially similar to the lens of Figs. 1 and 2, differing only in that the edge of a loop-shaped element 4' and the furthest edges of the arcuate elements 3' lie on the same imaginary circumference having its centre at the centre of the lens body 2. As is obvious from Fig. 3, portions 5 of the arcuate elements and a portion 6 of the loopshaped element, adjacent said edges, are curved additionally so as to be parallel to the principal plane of the lens body.

In both cases the vacant ends of the arcuate elements have thickened portions 7 aimed at reduced traumatization of the eye tissues.

There is now explained the operative technique to be applied for implantation of the above described intra-occular lens in the anterior eye chamber.

A corneal incision 6 to 7 mm long is made so as to form a 2 to 3 mm wide conjunctival flap.

The intra-occular lens is implanted with the aid of a tenaculum forceps, taking hold of the lens in such a manner that the loop-shaped supporting element 4 faces upwards. Then the effective portion of the forceps carrying the lens is brought into the anterior eye chamber in such a way that the supporting elements 3 rest with their bottom portion upon the inferior angle of the anterior eye chamber, thus causing the lens to move further downwards, the supporting element 4 being brought under the upper edge of the scleral incision and placed in the superior angle of the anterior eye chamber.

Then the wound is hermetically stitched up with five or six intermittent sutures. Next the anterior chamber is restored with physiological saline, and a continuous suture is applied to the conjunctiva.

Given below is an exemplary case report.

A male patient M, aged 31, a locksmith, was admitted to the eye clinic on March 3, 1982, the diagnosis being one of aphakia, absence of the limiting vitreous membrane, liquefaction of the vitreous body in the left eye. A year before he had been operated upon for traumatic cataract of this eye. Visual acuity~0.02 with correction + 11; right eye~0.8. Intra-occular pressure~20 mm Hg. The boundaries of the fields of vision were normal. A scar was present in the supra-exterior corneal portion. The anterior chamber is deeper than that in the right eye, its contents being transparent. The iris retains its colour, the pupil is round,the light reaction is vivid. The anterior limiting membrane of the vitreous body cannot be determined. The vitreous body is liquefied.The occularfundus exhibits no appreciable pathologic changes.

Surgery was carried out on March 6, 1982 implantation of an anterior-chamber intra-occular prosthetic lens according to the technique described above.

Post-operative clinical treatment: Three hours afterthe operation the patient was permitted to walk. Treatment instituted: bactericidal drops, a one per cent scopolamine solution three times a day, and daily injection of a one per cent dexasone solution under the conjunctiva.

Status of the eye operated upon: at the day of surgery- moderately pronounced conjunctival hyperemia. the corneal incision was well adapted.

Inconsiderable folds of the Descemet's membrane.

The anterior chamber was deep, its contents being transparent. The iris was quiet. The optical portion of the intra-occular lens implant was located exactly in front of the pupil, no contact with the cornea was present. The supporting elements of the lens were arranged symmetrically. The pupil is 3.5 mm in diameter. The subjacent eye portions exhibited no perceptible pathologic changes.

Within the initial few days after surgery (from 1 to 5) conjunctival hyperemia disappeared, the symptoms of descemetitis subsided. The intraoccular lens implant assumed a stable position.

At dismissal on March 13, 1982: visual acuity~ 0.8 (non-corrected). On March 20, 1982 the conjunctival suture was removed. Visual acuity~ 0.8 (non-corrected). The left eye was quiet. The intra-occular lens implant assumes a stable position, its optical portion being arranged concentrically with the pupil, the pupillary reaction is not limited. The supporting elements contact the anterior iridal surface.

Gonioscopyfindings: the arcuate elements are situated on the surface of the ciliary body stria. No contact with the elements of the corneoscleral zone is observed.

Tonometryfindings: lOP-2 mm Hg.

The patient regained his professional job. The follow-up period lasted 12 months.

Implantation of the herein-proposed intra-occular prosthetic lens in the posterior eye chamber is performed as follows. After extracapsular cataract extraction, with a moderately dilated pupil (4.5 to 5.0 mm), the lens implant is caught with a tenaculum forceps in such a manner that the loop-shaped supporting element should face downwards, while the arcuate elements should face upwards. Then the lens is brought, with the aid of the forceps, into the anterior eye chamber in such a way that the loopshaped element should pass through the pupil under the inferior portion of the iris. Then the forceps carrying the lens is moved downwards to place the loop-shaped element into the ciliary groove, whereupon the forceps is removed. Further manipulations are carried out with two blunt-ended microtenacula.One of these is used to catch hold of one of the arcuate elements and bend it downwards, while the other microtenaculum is used to pull the iris upwards by its pupillary margin, whereupon the aforesaid arcuate element is brought under the iris.

The other arcuate element is brought behind the iris in a similar way.

The basal irdectomy is performed along the twelve o'clock meridian. The operative incision is hermetically stitched up with intermittent corneoscleral sutures, while a continuous suture is placed on the conjunctiva. The anterior eye chamber is restored by injecting a balanced solution therein.

A case report is hereinafter described by way of example.

A male patient R, aged 40, was admitted to the eye clinic on February 6, 1983, the diagnosis being one of complicated cataract in the right eye. Visual acuity~0.4, non-corrected. On February 8,1983, the patient underwent surgery - extra-capsular cataract extraction followed by implantation of an intra-occular lens in the posterior eye chamber according to the afore-described technique. The operation was uneventful.

Clinical tactics within the post-operative period.

Three hours after the operation of the patient was allowed to stand up. Treatment instituted: eye drops ~1% scopolamine solution, corticosteroids, bactericidal drops-thrice a day, 1% dexasone solution~0.3 under the conjunctiva daily. At the day of surgery- pronounced conjunctival hyperemia, corneal incision well adapted. The anterior eye chamber was of a moderate depth, its contents being transparent. Slight descemetitis was observed. The pupil was moderately dilated, the optical portion of the intra-occular lens being determined in the pupillary zone.

At dismissal on February 14, 1983: a slight conjunctival infection in the anterior portion of the eye operated upon. The cornea was transparent.

The anterior eye chamber was 3 mm deep, its contents being transparent. The pupil was 4.00 mm in diameter, the optical portion of the lens implant was determined centrally within the pupillary zone.

The subjacent portions of the eyeball exhibited no perceptible pathologic changes. The occular fundus was without any pathological changes. IOP-- 19.0 mm Hg. Visual acuity~0.8 (non-corrected). Stable binocular vision. The follow-up period lasted 9 months.

The intra-occular prosthetic lens of the present invention is indicated for implantation in cases of aphakia attended by disturbed intactness of the limiting membrane of the vitreous body, liquefied vitreous, cataract extraction accompanied with vitreoptosis (implantation in the anterior eye lens).

The proposed lens is also indicated for implantation in the case of extra-capsular cataract extraction (implantation in the posterior eye chamber).

Claims (3)

1. An intra-occular prosthetic lens, comprising an optical lens body and three supporting elements secured therein, one of which is shaped as a loop fixed with both its ends in the lens body, the two other elements being secured in the lens body on the same side of it, which is diametrically opposite the loop-shaped element, each of said two other supporting elements being shaped as an arcuate piece fixed with one of its ends in the lens body, the arcuate elements being curved towards each other, and their free ends being arranged symmetrically with respect to the plane passing through the midpoint of the lens body and of the loop-shaped element, the arcuate elements being curved towards the posterior surface of the lens body.

2. An intra-occular prosthetic lens as claimed in Claim 1, wherein the edge of the loop-shaped element and the edges of the arcuate elements furthest from the lens body lie on the same imaginary circumference having its centre at the centre of the lens body, while the portions of the arcuate elements adjacent the said edges are additionally curved so as to be parallel to the principal plane of the lens body.

3. An intra-occular prosthetic lens substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.