Squamous metaplasia or epidermalization of the conjunctiva as an adverse reaction to topical medication.

Prolonged topical medication causes epidermalization of the conjunctiva in some patients. Loss of the normal conjunctival goblet cells, direct toxic effects on the corneal epithelium, and disturbance of lid function may combine to produce corneal changes which may be misinterpreted and treated with further potentially toxic compounds. Examples of conjunctival changes caused by miotic and non-miotic antiglaucoma therapy, mydriatics, preservatives, and antiviral compounds are presented.