Effects of hemicholinium-3, a photoreceptor and pigment epithelial toxin, on retinal adhesiveness and subretinal fluid absorption.

Retinal adhesiveness and subretinal fluid absorption was studied in Dutch rabbit eyes given intravitreal injections of hemicholinium-3 (HC-3) which causes loss of photoreceptor outer segments and retinal pigment epithelial (RPE) damage. After HC-3 administration, some areas of the fundus showed pigmentary changes and others appeared normal. Small, non-rhegmatogenous retinal detachments were made in both areas. Within 2-5 days after HC-3 injection, only in the areas of visible damage, subretinal fluid spread laterally to make very flat retinal detachments, and the fluid absorbed very quickly. At later intervals, absorption was slower than normal, presumably because of scarring and RPE metabolic damage. HC-3 provides an experimental technique for transiently weakening retinal adhesiveness in vivo but its use as a model must account for the effects of both outer segment and RPE damage.