|Year : 1983 | Volume
| Issue : 6 | Page : 733-734
Anterior keratotomy in myopia
P Siva Reddy
President All India Ophthalmological Society, Adviser in Ophthalmology, Govt. of Andhra Pradesh, Director, Operation Cataract Project Sarojini Devi Eye Hospital, Hyderabad, India
P Siva Reddy
President All India Ophthalmological Society, Adviser in Ophthalmology, Govt. of Andhra Pradesh, Director, Operation Cataract Project Sarojini Devi Eye Hospital, Hyderabad
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Reddy P S. Anterior keratotomy in myopia. Indian J Ophthalmol 1983;31:733-4
Near sighted people have tried ways to get rid of their glasses for centuries.
Since the cornea is responsible for such a large proportion of the refractive power of the eye and since surgery of the cornea has gone through such a great deal of development in the past few decades, attention if focussed on the subject of modification of the refractive index of the cornea.
Few years ago Prof. S.N. Fyodorov of USSR, developed a new surgical technique for correcting myopia. He described his surgical operation as dissection ligamentum circular corna. It is popularly known as "Anterior Keratotomy".
So far I have performed nearly 500 radial keratotomy operations at the Institute of Ophthalmology and Sarojini Devi Eye Hospital and this has ben also published in the American Journal "Ophthalmic Surgery" (Col.11, No. 11,Nov. 1980).
In this paper I like to discuss the objectives of our poroposed study in India so that we can determine the (1) efficiency, (2) safety (3) performance and predictability of a standard radial keratotomy procedure in reducing myopia in our country.
Reasons to perform Radial Keratotomy:
As all of you know, there are three major reasons to perform radial keratotomy (1) to achieve professional goals; for example in pilots, professional dancers, Athelets and other type of workers, who often cannot function properly with glasses or contact lenses. (2) Simple, convenience; some individuals have an intolerence for spectacles or contact lenses and (3) for cosmetic purposes. Previous surgical attempts to correct myopia:
For the last 30 years some direct methods have been employed to eliminate myopia byre-shaping the cornea. These methods are (1) Myopia Keratomileusis, (2) Anterior and Posterior half corneal incisions (3) Orthokeratology and (4) Thermo-keratoplasty. Survey of Radial Keratotomy:
It consists of a series of equally spaced radial spoke like incisions made deeply into the anterior cornea. That leaves a central 3 - 5mm clear optical zone.The normal pressure within eye pushes the weakened peripheral cornea forward so that the central cornea flattens. So far the technique has not been standardised regarding the number of incisions, length and depth of the incision etc. They vary from one eye surgeon to the other eye surgeon.
I like to bring to your notice certain considerations which we have tokeep in our minds regarding this surgery. (1) There is a need for the surgery as large number of myopic individuals would like to avoid wearing glasses or contact lenses. (2) Current evidences indicate that the operations can be safe and effective although the procedure has not been studied according toregorous scientific standards and the long term results are still un-known. (3) Large number of radial keratotomies are being done in India as well as other countries and the procedure is in danger of becoming popular before it can be adequately tested.
In conclusion I strongly recommend that a prospective carefully monitored, multi-centre clinical trials of radial keratotomy, atleast for 5 years durain, should be carried out in humans in our country for the following reasons:
1. There is intensive interest on the part of the ophthalmic community and myopia public.
2. Large number of cases are being done in India and number of surgeons training to do the operations is rapidly increasing.
3. While normal studies in animals can give information about alteration in corneal shape and objective refraction, they cannot give information about subjective response which is extremely important, in terms of quality of visual acuity, patient satisfaction with the level acuity and the patient's reaction to glare and fluctuations in vision.
4. Although some data is available aboutradial keratotomy in human eyes, no long term follow up studies, and the short term studies give information only on refraction and keratometry in broad groups.
5. There is enough experience to humans to justify proceding with a very careful trial, since severe complications are extremely rare and reduction in best corrected preoperative visual acuity occurs infrequently.
6. There are presently, In India, no carefully monitored uniformely designed prospective clinical studies.
As such I suggest in India there can be about 6 yo 8 clinical centres and a coordinating centre. Using multiple surge-ns has the advantage of comparing results of a single technique in the hands of different surgeons with different aims, radial keratotomy experience, a situation simulating with active practice.