Topical administration of I% Pilocarpine failed to produce pupillary constriction in a patient who had a large, dilated pupil What should be the most probable reason?
Adie's tonic pupil
Diabetic III nerve palsy
Pharmacological blockade
Uncal herniation
Ans. c. Pharmacological blockade (Ref-YANNOFF 3/E PG,1052-1055)Pilocarpine I% is a sufficient miotic dose for any eye, but a sphincter with all its cholinergic receptor blockade by atropine or tropicamide (i.e. eye with pharmacological blockade) does not constrict with pilocarpine 1%.