|Year : 1983 | Volume
| Issue : 6 | Page : 801-804
Singh's pupillary plane intraocular lens
Department of Ophthalmology, Medical College, Amritsar, India
Department of Ophthalmology, Medical College, Amritsar
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Singh D. Singh's pupillary plane intraocular lens. Indian J Ophthalmol 1983;31:801-4
Copeland lens was popular a few years ago. It has two pairs of legs; one pair is meant to go being the iris and the other pair remains in front, so that the optical portion is at the level of the pupil. The width of the lens is 9 mms in all directions. A dilatation of the pupil by 2 1/2 mms, will cause dislocation of this lens. A dislocation rate of 4 to 8 % has been reported. There is constant need to prevent dislocation, by keeping the pupil small with miotics.
The author has tried to overcome the faults of Copeland lens by a small but important modification. The new lens designed has two long legs 11 mms. long and 2 small legs 9 mms. long. The longer legs are meant to go behind the iris. [Figure - 1].
| Material and methods|| |
This paper present a study of author's 50 pupillary plane lenses with a minimum follow up of 3 months.
Preoperative hypytony and good anaesthesia are mandatory. The pupil is dialated with phenylepherine.
1. Incision: a 10 to 11 mms. incision at the uper lumbus.
2. Anterior capsulotomy: During anterior capsulotomy, the lower part of the anterior capsule is saved to make provision for a capsular bag inferiorly.
3. The extraction of the nucleus and cortex is done as routine.
4. A small air bubble is put into the anterior chamber.
5. The implant is held with a McPherson forceps by one of the longer legs and pushed straight down, so that the lower long leg of the implant goes into the capsular bag. The smaller legs that are right angles will automatically come to lie infront of the iris horizontally. Thuys three legs of the implant come to lie in the desired position without the introduction of the instrument into the eye.
At this stage, about 1/2 mm of the upper leg will be seen lying outside the incision [Figure - 2]. In the next step, this leg has to be put behind the upper part of the iris. This is how it is done:
A curved Hoskin's forceps is passed under the upper leg of the implant to catch the iris near the pupillary margin. The iris is pulled out and is made to pass over the upper legs of the implant, which is at the same time pushed downward and backward by McPherson forceps.
The implantation is complete:
6. The pupil in narrowed by intracameral injkection of 0.025% pilocarpine is lactated ringer.
7. Two peripheral iridectomics are done, one on either side of the upper leg of the implant. The patency of the iridectomies is verified by passing an irrigating cannula through them.
8. The incision line is sealed with multiple steel sutures and the anterior chamber is filled with lactated ringer. [Figure - 3].
First dressing is done after 4 hours. A drop of 2% pilocarpine is instilled. The bandage is discarded and a protective shield is given. Next morning the patient wears sun glasses and he is allowed full mobility. A local patient is allowed to go home.
The postoperative medication includes oral chloramphenicol for three days, predniscolone 40 mgm, by mouth on the first day, which is tapered by 5 mgm. every day so that by the end of 8 days, the steroids are stopped. Local steroid drops are instilled three times a day for 45 days. No miotics are put.
| Obserations|| |
This report concerns 50 eyes of 49 patients. There were 25 females and 25 males.
The age distribution is shown in [Table - 1]
In every case extracapsular was performed. The following problems were noted during surgery:
1. Rupture of posterior capsule : 2%
2. Small bleeding in the anterior chamber at the time of surgery: 6%
Early Postoperative Complications:
Striate keratitis : 2%
Hyphaema : 2%
There was one case of severe postoperative accidental injury that led to iris prolapse. The prolapse was excised, the implant was left inside and the coloboma was repaired with steel sutures. The patient had uneventful recovery.
Late postoperative complications:
After cataract : 10%
Cystoid macular oedema: 2%
There were no cases of chronic uveitis, late hyphaema, glaucoma retinaldetachment or membrane formation behind the lens. Final visual acquity:
Copeland lens is easy to insert?. But this lens is not more talked about. Out of fashion perhaps or fear of complications? A number of disadvantages are inherent with it: Dislocation 8.7%. recurrent uveitis 5.5%, cystow macular oedema 16.6%, membrane formation, behind the lens 9.2%.(2) A number of these complications are related to the lens design and the necessity of keeping the pupil small by miotics for unknown periods: months, years? Copeland lenses have been known to discoocate years after surgery. The reason for dislocation as worked out by the author appears to be as follows: When the pupil dilates by one mm. the lens sags by one mm. A dilation of a 2 and 1/ 2 trims. and a similar amount of sagging will lead to a certain dislocation of the lens. This can happen in states of body excitement, like vomiting etc. To prevent this dislocation the pupil has to be kept constricted. The exact length of time for miotic use is difficult to devine. The use of miotics makes the pupil margin hit the edge of the IOL. This can lead to chronic uveitis, hyphaema and secondary membrane formation etc.
The new design of the lens allows the lower leg to be fixed by the capsular bag, the sagging of the lens is therefore minimized. This prevents the dislocation of the IOL in the event of a moderate pupil dilatation. The new design obviates the use of miotics in the postoperative period. A follow up of over one year has not shown any tendency to dislocate. In case there have been two cases where the patient by mistake put atropine. They came with dilated pupils, but the lenses remained central and did not dislocate. This is not to suggest that we should dilate the pupil with mydriatics early after surgery and unnecessarily expose the patient to the risk of lens dislocatin.
We have not noted any cases of chronic uveitis, late hyphaema, membrance formation on the lens. Only one case of cystoid macula oedema was seen. It seems that these complications have been avoided because no miotics were used.
The new pupillary plane lens appears to be easy to implant. However the surgeon should be expert in doing a good extracapsular extraction.The insertion of the lens is quite demanding, so that one does not strip away the endothelium or rupture the posterior capsule. On the whole, the IOL implantation is easy.
The present series concerns only those cases where extracapsular surgery was done. The author is making studies of the use of this lens after intracapsular extractions. The results will be presented in due course of time.
This study suggests that the papillary plane lens is still alive and kicking and the new design may have a role to play in IOL implanation in India. This lens is made by Biolens Amritsar and is available only to ophthalmoligists who have been trained in it.
[Figure - 1], [Figure - 2], [Figure - 3]
[Table - 1], [Table - 2], [Table - 3]