Ocular Surface Changes with Long-Term Topical Antiglaucoma Medications

Long-term use of topical drugs has clearly been shown to induce toxic immunopathological changes in the ocular surface. Lacunae exist in the knowledge regarding the respective roles of active compounds and preservatives. The preservatives used in topical multidose ophthalmic preparations are responsible for a considerable compromise of ocular surface. In chronic diseases like glaucoma where long-term medical treatment is the mainstay of therapy, drug induced surface toxicity is a matter of concern. Toxicity is dose-dependent and concentration-dependent and generally varies according to the overall health of the eye. For glaucoma patients thought to be at risk for ocular surface damage, choosing medications with either low levels of Benzalkonium chloride, alternative preservatives such as Stabilized oxychloro complex, or preservative-free preparations may reduce side effects and increase tolerability of the therapy. This review, based on a literature search using Medline, attempts to present a comprehensive picture of the effect of various antiglaucoma medications and their preservatives on the health of ocular surface.