Description

Retinal detachment is thankfully rare, although it remains one of the most frightening, and potentially devastating ophthalmic diseases. The vast majority that are encountered clinically, are rhegmatogenous, (secondary to retinal breaks), although other types are important and well described in this special issue. Many sight saving treatments for other conditions have been with us for centuries. The Babylonians recorded successful couching for cataract, and the invention of spectacles at least 800 years ago has probably benefited more patients that any other form of treatment. By contrast, successful treatments for retinal detachment only became available in the 1920s. The invention of the ophthalmoscope by Helmholtz in 1851 allowed accurate clinical descriptions of the condition, and retinal breaks were described only two years later. However, they were thought to be the result, rather than the cause of the detachment.

At the beginning of the last century, the lack of a successful therapy resulted in all manner of bizarre approaches, including bed rest, subretinal injections of iodine, and various types of drainage surgery. Von Graefe felt that the subretinal fluid should be drained into the vitreous, and therefore tried making holes in the retina! One unfortunate patient in Germany was kept on strict bed rest for a whole year, after which his retina was in fact re-attached. Sadly,after extended celebrations in honour of his
discharge, the retina detached once more!

This therapeutic confusion was brought to an end by Jules Gonin,a Swiss ophthalmologist, who recognised the importance of the retinal break, and devised a practical treatment, which both closed and sealed the break. Suddenly the success rate for re-attachment jumped from zero to 50%. Despite this significant advance, he was met by considerable scepticism and resistance, and it was many years before his ideas were accepted and refined. Today there are various treatment options suitable for almost all types of rhegmatogenous retinal detachments, and the success rate of surgery is greater than 80% for one operation, and 95% after one or more operations.

Eighty years after Gonin ’s advances, there are two main problems facing those treating retinal detachments today. The first is proliferative vitreoretinopathy (PVR). PVR is essentially wound healing which, unlike most other parts of the body, is not helpful in the eye, with retinal scar tissue pulling more breaks and resulting in re-detachment. PVR is the ultimate cause of failure of re-attachment surgery. It is likely that new drug treatments at the time of surgery will be able to reduce the risk of this serious complication.

The second problem is that successful anatomical re-attachment of the retina is not always associated with improvement in vision. If the macular is involved in the detachment (“macula-off ”), the central vision rarely recovers fully, with reduced acuity and distortion being the common result. We are only in the early stages of understanding the processes involved in this visual loss,a nd it is unlikely that we will see an early breakthrough in improving the visual results for patients with macula-off retinal detachments. Although surgery for macula-on retinal detachments preserves central vision, the majority (52%) of patients with retinal detachment present after their macula has detached.

Given the ocular morbidity associated with otherwise successfully treated patients, much interest has focussed on whether retinal detachment can be prevented rather than cured. There are certainly many predisposing lesions, the presence of which indicates a higher than average risk of developing retinal detachment in the future. These include myopia, lattice degeneration,a nd retinal breaks. Attempts have been made to treat such eyes with prophylactic treatments, in the hope that the risk of subsequent retinal detachment can be reduced. Such treatments include laser, cryotherapy, and even scleral buckling surgery.

Unfortunately,there is currently no evidence to support such treatments for any such lesions, other than the traction retinal tear (the ‘U ’ tear that can follow a posterior vitreous detachment). Certainly patients with lattice degeneration do not require treatment, or indeed examination in the hospital eye service. Which patients, therefore, should the optometrist be concerned about? Patients that can be helped most are those with an acute PVD, since they may also have one or more associated retinal ‘U ’ tears (which give no additional symptoms). These are the patients who will benefit from early detection and treatment of the tears, since if successful, subsequent retinal detachment can be prevented. Most patients who present late with a retinal detachment have had symptoms for several weeks previously, but were not aware of their significance. Optometrists have an important public health role in educating the public, particularly those at higher risk, so that any delay from the onset of symptoms to treatment might be reduced.

Mr G W Aylward
Consultant Vitreoretinal Surgeon and Medical Director
Moorfields Eye Hospital
City Road
London EC1V 2PD