The effects of diclofenac on cryo-induced miosis.

The maintenance of pupil dilation is necessary for the success of scleral buckling procedures and in prophylactic transconjuctival cryopexy. To assess the miotic effect that is induced by cryotherapy and the ability of diclofenac sodium 0.1% (a potent prostaglandin synthetase inhibitor) to overcome such an effect, we conducted a randomized, masked and controlled experiment on 18 rabbits. These were divided into three groups; each group had their eyes treated by cryotherapy in a controlled fashion. Two groups were treated preoperatively with dilating drops: a solution without diclofenac in one group and one with diclofenac drops in the second. Pupil diameters were measured with Castroviejo's calipers by an independent observer at regular intervals. A third group had no drops and were treated as a control. A highly statistical difference was observed in the reduction of the miotic effect of cryotherapy in those eyes treated by diclofenac.