|Year : 1956 | Volume
| Issue : 4 | Page : 81-87
Intraocular plastic lenses
Eye Hospital, Sitapur, India
|Date of Web Publication||10-May-2008|
J M Pahwa
Eye Hospital, Sitapur
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Pahwa J M. Intraocular plastic lenses. Indian J Ophthalmol 1956;4:81-7
With the advent of proper anaesthesia and akinesia and various corneoscleral stitches etc., cataract surgery has made many, developments and strides during recent years. Looking to the various disadvantages of aphakic patients H. Ridley in 1949 introduced his first plastic lens in retro-iridic space after an extra-capsular cataract extraction. I have already reported seven cases operated by this method. No doubt one of my case had been lucky, because the lens did not dislocate even after an injury sufficient to fracture her both hones of fore arm but on the other hand one of these cases is having recurrent attacks of irido-cyclitis. Due to various complications like dislocation of lens and opacification or wrinkling; of posterior capsule after this operation, it has not become universally popular.
In order to extend its use and achieve better results Prof. Strampelli of Rome and Prof. Schreck of Germany conceived a new idea of inserting the lens in the anterior chamber and evolved new designs for such applications. Dr. Dannheim has still further improved the lens by making it very light (8 to 9 mg) and having a loop of supramit plastic thread on each side of the central optical portion of the lens [Figure - 3].
Indications of this operation are:-
(a) After Intra-capsular extraction.
(b) After extra-capsular extraction.
(c) Aphakia with broad iridectomy and even prolapse of vitreous in the anterior chamber.
2. Anisometropia and unilateral high myopia.
These lenses unlike Ridley lenses are specially made for each individual case after doing the proper refraction of the patient by skiascopy and are of proper size as measured under slit-lamp [Figure - 4]. 'While ordering, the distance of the lens in the trial frame from the anterior corneal surface must be mentioned. These lenses are also well tolerated and even if need be, can be easily removed without any adverse effect on the eye.
The radius of curvature of the non-optical part of the Strampelli lens is 14 mm., as a smaller radius will make the plastic lens too curved which will make its introduction difficult and may also touch the corneal endothelium while larger radius will make the lens too flat and will continuously cause contact with the iris specially when it is placed in non-aphakic cases.
| Serilisation|| |
Alchohol or other solvents and steam should not be used as the material is quickly damaged by them. Thirty minutes immersion in 1% Cetavlon (I.C.I.) or Armil is recommended. If there is any grease etc, it may be dipped in absolute alchohol and quickly removed, but it should be well washed with penicillin solution just before use.
| Operation|| |
The operation is usually done in two stages, the lens being inserted 4 to 8 weeks after a cataract extraction (intra or extra-capsular) or linear extraction in cases of traumatic or unilateral juvenile cataract. In non-aphakic cases like anisometropia or unilateral high-myopia cases, question of a second stage does not arise. [Figure - 5]. Prof. Schreck has devised a special forceps and a spatula for holding and introducing, the lens. Similarly Dr. Dannheim has devised his own forceps for his lens.
The operation is done under local anaesthesia and akinesia as required for a simple case of cataract extraction, but pre-operative miosis is preferred to avoid prolapse.of vitreous in the anterior -chamber specially when an intra-capsular extraction has been done before. A corneal incision is given with keratome and [Figure - 6]A enlarged by Westcott's scissors or with the knife at the external quadrant. The incision must be wide enough to admit the lens without any difficulty. The section should be slightly corneal so that extremities of the lens once put in place do not touch or come in contact with the incision wound. [Figure - 7]
If the lens is introduced by a trans-scleral incision there will always be a danger of the lens projecting through the wound. It should be inserted without exerting any pressure or causing any damage to the corneal endothelium. It must be gradually and gently slided into the anterior chamber across the sphincter papillae without hooking round the pupil (6A-E). When the proximal end of the lens is almost in the angle of the anterior chamber, a little pressure over both caudal ends accompanied by gentle traction of the scleral flap will he enough to - bring the Zeus in correct position with the three ends resting in the chamber angle. The lens is placed in the horizontal position because [Figure - 7]
(1) Introduction is easier.
(2) Movements of the lids do not produce any displacement.
(3) There is no danger of getting the peripheral iridectomy hole blocked by the tips of the lens as otherwise it may produce secondary glaucoma.
(4) It is probably less visible.
In those cases where peripheral iridectorny has not been-done before, it -should, be done now. The incision wound is then closed by one or more fine, silk sutures and sterile air is introduced into the anterior chamber, particularly if the Iris has a tendency to come forward.
Even in eves operated previously for traumatic cataract etc. where one may have been forced to do a broad iridectomv,,the inclusion of lens is not difficult in the second stage because there- is sufficient support for the lens, In those non-aphakic cases where normal lens is in situ (Anisometropia and unilateral high myopia etc.) One has to be very careful. Here incision should he wide in superoexternal quadrant (Rt. eye 8 to 1 and left 11 to 4 o'clock). Lens is again preferably introduced in . the horizontal position. A subconjunctival injection 50,000 units of Penicillin is given as a routine in all cases, before giving a binocular bandage.
| Post-operative Care|| |
It is the same as for any case of cataract operation. Procain Penicillin injections are given for 2-3 days. The first dressing is done on the third day and local atropine and hydro-cortisone linstilled daily thereafter. Diamox may be given for 3-4 days, because it helps in the formation of anterior chamber and also prevents any non-inflammatrv oedema of the cornea. The second eye is opened on the fourth day and movements allowed thereafter. Bandage is removed on the eighth day. Now orthoptic exercises or education with after images in cases of amblyopia can be usefully started after the inclusion of this lens.
| Accidents|| |
1. Imperfect Dimensions of the Lens:-If the lens is big, it will cause deviation of the pupil and there may be hypotony due to small cvclodialvsis caused by the lens edges. It may also be difficult to insert it and will also cause greater surgical trauma. On the other hand, if the lens is small, the lens will change its position with every movement of the eye which can produce micro-trauma in the iris. This can be easily managed if two lenses of the same power but of .5 mm. size difference kept in readiness and one of suitable size inserted.
2. Tearing of the corneal endothelium:--It may be injured if one is not careful.
3. Dragging of the pupil.
4. Loss of vitreous
5. Luxation of lens :-Only possible by brutal force.
| Complications|| |
These again are rare but following may be anticipated :
(1) Glaucoma due to
(a) neuro-vegetative irritation or blockage of the angle.
(b) blockage of the Pupil or of the small peripheral iridectomy hole.
This is easily avoided by placing the lens horizontally and one should be sure
that deepest layer of the iris is also cut.
(2) Irido-cyclitis:-This is not so severe and hydro-cortisone drops locally checks that.
(3) Pigmentary deposits or precipitate on the lens :- These are usually not much, rather few and tine. They usually disappear without treatment.
(4) Traumatic corneal oedema :-This usually disappears and Diamox is also helpful here.
(5) Late oedema of the cornea:-This may be due to endothelial distrophy at the point where the cornea touches the lens.
| Results|| |
During my recent visit to Europe I had the occasion of watching several such operations and seeing many operated cases at Barcelona. Till then (July '56) Dr. Barraquer had done nearly 50 cases and out of these 15 were in non-aphakics (anisometropia and unilateral high myopia) and the oldest one of two years duration. These lenses were well tolerated and no complication was seen in any case except secondary glaucoma which occurred in two cases. These cases were cured by rotating the lens to horizontal position and doing another small iridectomy as in earlier cases the lens was placed invertical position. In the second case cycleo-diathermy was also done as a prophylactic measure. Routine tonometry in all cases after this operation showed a little hypotony which normalised after 15-20 days. Gonioscopy was done in all the cases and it was seen that if the size of the lens was correct, no changes in the angle or any gonio-synechias were seen. Only a small zone of partial iris atrophy may be seen in old cases. If the size of the lens is bigger it might cause a small cyclodialysis or depression of the iris root with secondary pupillary deviation.
In young children as the eye will enlarge with age, the lens can be changed also later on without any adverse effect on the eye. If there is any thickening of posterior capsule or it becomes opacified, capsulotomy can be done through behind the lens without touching or injuring the lens. [Figure - 8]A & B Air injection can be also given in the anterior chamber to prevent prolapse of viterous.
| Case Report|| |
My personal experience consists of only one case which is described here :
Mr. Baij Nath Singh 5o years Hindu male Was admitted on 16th October, 1956 in this hospital for cataract in the left eye and aphakia in the right with broad iridectomy. He was not using his glasses regularly. Strampelli lens was introduced in the right eye on 2oth of October 1956.
Biomicroscopy showed the vitreous to be in the anterior chamber. A superolateral corneal incision was taken as described. The lens was introduced carefully in front of the iris without engaging the iris margin of the broad iridectomy coloboma and was placed in the horizontal position to avoid any chance of secondary glaucoma. Sterile air was injected in the anterior chamber before closing the wound by a fine stitch.
The first dressing was done on the third clay. The cornea was found to be slightly hazy and chamber had not formed yet. Diamox was started now (i tablet every 6 hours.) Cornea became clear with this and with atropine and cortisone drops. The bandage was opened on the 10 th day. He was discharged on 16th of November 1956 and vision was 6/18 with plus 2 cylinder axis 120. Patient came to the hospital on the 9th of December 1956. His vision was 6/12 with - I sph. and +2.5 cylinder axis 1254. Biomicroscopy showed no flare, but there were fine deposits on both the surfaces of the plastic lens. Fundus could be seen and was normal..
From the results, it is clear that this lens is well tolerated even in aphakic eyes with vitreous in the anterior chamber. This type of implant opens up a new and promising future for unilateral anisometropic aphakic cases though we shall have to wait a little longer to gauge the late results.
| References|| |
Barraquer Moner .. Archivos de la Sociedad oftalmologica Hispano-Americana 15 P
..Estudios E Informaciones oftalmologias Vo. VI No. 15.
..Read during the ophthalmic Congress in Oxford in 3rd July 56
Dannheim ..Re during the All German oph. Congress in Heidelburg on 31st Aug. 1956.
Pahwa (1956) .. Indian Medical Review Jan. 1956 Page 1-7.
Strampelli .. An. de ottal e clin ocul A Lxxx No. 2; 11-54.
Schreck .. Read during the oph. Congress-Heidelburg 1955 July.
[Figure - 1], [Figure - 2], [Figure - 3], [Figure - 4], [Figure - 5], [Figure - 6], [Figure - 7], [Figure - 8], [Figure - 9], [Figure - 10]