Norman E. Byer, M.D.
USA

The era of successful treatment of retinal detachment began with the work of Jules Gonin of Lausanne, Switzerland about 75 years ago.  Later it began to be realized that the causative retinal tears often were located near certain abnormal-appearing  areas of retina, and ophthalmologists began to think that perhaps retinal detachments could be prevented by treating these sites before
the onset of a detachment.  Around 1956 the invention of photocoagulation using Xenon, by Meyer-Schwickerath of Germany, provided for the first time a rather easy method of treating these lesions.  His machine was eventually replaced by cryotherapy and then by laser photocoagulation.  It soon became the standard of practice throughout the world to treat visible lesions of the retina “prophylactically” with the hope that this would prevent later retinal detachment. This was especially true in cases of the fellow-eyes of patients who had already had detachments in their first eyes.   The lesions treated consisted mainly of 1) pre-existing retinal breaks, 2) lattice degeneration, 3) cystic retinal tufts, and 4) senile retinoschisis.

This concept of treating these lesions in order to prevent detachment rested on three assumptions which unfortunately had not been substantiated by natural history studies.  These assumptions were that 1) the incidence of fellow-eye detachments was from 20%-50%;  2) these abnormal lesions were the sites at which new retinal breaks were going to occur;  and 3) treatment of these lesions would significantly reduce the incidence of fellow-eye detachments.

Later long term natural history studies revealed that these three assumptions were greatly exaggerated, and in fact not accurate.  The actual facts are that 1) the incidence of fellow-eye detachments is no greater than 5%;  2) in up to 80% of fellow eyes the causative retinal tears occur not at these visible sites, but in areas of the retina which appeared normal;  and 3) the incidence of retinal detachments in fellow eyes is only reduced very slightly, if at all.

It has now been well substantiated that rhegmatogenous retinal detachment cannot be significantly prevented by so-called “prophylactic” treatment of visible pre-existing lesions of the retina.  However many retinal detachments CAN be prevented by a different approach altogether.  This is by the prompt diagnosis of acute posterior vitreous detachment in patients who notice sudden new “floaters” or “light flashes” in their vision.  Such patients should be carefully examined with indirect ophthalmoscopy and scleral indentation, to discover any new tractional retinal tears.  Such tears should be promptly treated with either laser photocoagulation or with cryotherapy. Among this group of patients this treatment can reduce the incidence of detachment from around 35% to less than 5%.  This is now the only proven method of preventing retinal detachment.  Examples of the visible retinal lesions discussed above, which may be associated with retinal detachment, will be shown by actual color photographs taken with scleral indentation.

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