Reversal of pupillary atonia after removal of an encircling band.

: We describe a patient who developed an atonic pupil after placement of an encircling band during retinal detachment surgery. When the band was removed 18 months later, the pupil signs showed partial recovery demonstrating a degree of reversibility of the parasympathetic paresis. We speculate that in this case mechanical deformation of the sclera by the encircling band had produced a conduction block of the short posterior ciliary nerve fibers as they pass forward in the underlying suprachoroidal space.