Corneal dellen in the limbal approach to rectus muscle surgery

A retrospective study of 170 cases of horizontal rectus muscle surgery performed during the years 1969 and 1970 at the University of Illinois Eye and Ear Infirmary revealed a 6-5 per cent incidence of dellen with the limbal approach to the muscle and a 2-2 per cent of incidence of dellen with the nonlimbal or direct approach to the muscle. This was significant to the 5 per cent level of confidence by the chi2 test. We feel that this finding of an increased incidence of dellen with the limbal approach complements the current theory of desiccation as the cause of corneal dellen. We do not recommend abandonment of the limbal approach to rectus muscle surgery because of this finding, but suggest that surgeons scrutinize more carefully their postoperative patients for dellen. If dellen do not occur careful trimming of the conjunctiva to avoid bunching and thickening may perhaps eliminate them.