Distribution of breaks in aphakic and "Senile" eyes with retinal detachments

Abstract

The distributions of retinal breaks have been compared in two groups of patients: (a) Those with eyes aphakic because of uncomplicated intracapsular operations performed after the age of 50 years in pre-operative emmetropes or hypermetropes who had no other eye disease (e.g. previous significant injury, iridocyclitis) or general diseases (e.g. diabetes mellitus) which could conceivably contribute to retinal detachment. Unfortunately, all cases of vitreous loss during cataract extraction may not have been excluded owing to underreporting. (b) A control sample matched for age, sex, side affected, absence of myopia, absence of history of injury, etc. Compared with the controls, the aphakic eyes tended to show breaks which were more often peripheral, more often inferior, and more often superonasal. Breaks in aphakic detachments appearing less than one year after operation tended to be more often peripheral than those which appeared more than one year after operation. The aphakic and control groups did not differ significantly in the incidence of total detachment or in the mean area of fundus affected by detachment; accordingly, the position of retinal breaks in the two groups would probably appear to be shifted by detachment to a similar extent. The sites of holes were plotted directly from the fundus charts which record exactly what is seen with the ophthalmoscope. Factors biasing an observer towards plotting breaks more posteriorly in aphakic eyes are probably cancelled out by factors which tend in the opposite direction. However, breaks are usually plotted in relation to landmarks, especially the ora serrata in pre-equatorial breaks, so that differing magnification is probably the most important factor; since the distance between breaks and landmarks, especially in the pre-equatorial region, is small, the effect is probably negligible. Although it is admitted that the "aphakic" group must include eyes which would have suffered a retinal detachment even if they had remained " phakic", and must also include eyes which developed a retinal detachment merely because of the precipitation and agravation of such pre-disposing factors a detachment and increased mobility of the vitreous, it is considered that in a significant proportion of aphakic eyes the breaks are produced at the time of the operation by traction on the fibres of the suspensory ligament of the lens which are inserted into the teeth of the ora serrata: since these breaks are situated in front of the usual anterior limit of vitreous detachment, there may be a long period before the detachment occurs.