A Rare Case Report of Conjunctival Cyst.

A conjunctival cyst is a thin-walled sac or vesicle that contains fluid. This vesicle may develop either on or under the conjunctiva. It develops due to variety of causes such as infection, inflammation, retention cyst and rarely drug induced. The authors aimed to report a case of conjuctival cyst in a 34-year-old male following instillation of anti-allergic topical drugs for over period of one year. Conjuctival cyst developing due to chronic use of anti-allergic topical drugs containing preservatives is one of the complications associated with it. Presence of a preservative in an ocular medication has often been considered in damaging the epithelium. Inclusion of a preservative is equally necessary, especially in multiple-drug therapy in order to protect against dangerous organisms accidentally gaining access during instillation. Benzalkonium chloride (BAK), chlorobutanol, chlorhexidine acetate (CHA) and phenylmercuric nitrate or acetate are some commonly used preservatives in eye drops.