International Ophthalmology 22: 31–35, 1998. © 1998 Kluwer Academic Publishers. Printed in the Netherlands. 31 Adverse effects of topical antiglaucomatous medications on the conjunctiva and the lachrymal (Brit. Engl) response R. Nuzzi, C. Finazzo & A. Cerruti Institute of Ophthalmology, University of Turin, Italy Accepted 10 August 1998 Key words: antiglaucomatous medication, conjunctiva, preservative, tear Abstract Background: Increasing evidence indicates that long-term use of topically administered medication can induce changes in the conjunctiva and lachrymal function. Methods: In order to evaluate changes in the conjunctiva and lachrymal response after prolonged use of topically administered antiglaucoma medications and preservatives found in antiglaucomatous medication solutions (benzalkonium chloride), we tested lachrymal function (Schirmer I., Jones, BUT, Ferning tests) and used the conjunctival impression cytology technique. Materials: A group of patients with primary open angle glaucoma (POAG) receiving topical antiglaucomatous medication were recruited. A second group received only preservative instillations while a control group was formed of similarly aged subjects with no eye disease and was given topical or systemic medical therapy. Excluded from the trial were patients with a history of external eye disease or who had received conjunctival surgery. Results: Tear secretion was reduced against that of the control group in those subjects who received protracted administration of antiglaucomatous eyedrops (timolol and/or pilocarpine). A statistically significant degree of conjunctival metaplasia was associated with long-term use of topical medication. The subjective symptoms reported by those patients receiving chronic topical antiglaucomatous therapy and the objective observations on them were found to be proportional to the observed tearing response. Changes were more pronounced in subjects who received only benzalkonium chloride. Conclusion: Our study results suggest that long-term use of antiglaucoma medication induces changes in both tear film and conjunctival surface. Such changes may be related to the medication or the duration of treatment, but may also be due to the preservatives used in the commercial product. Introduction Although topically administered medication remains the norm in POAG, the drugs used are not free from adverse effects, both ocular and systemic. The sympa- thicomimetics, for instance, are frequently found asso- ciated with local effects including subjective irritation, epithelial adrenochrome deposition, reactive hyper- aemia, blepharoconjunctivitis and corneal oedema [1, 2], and evidence is increasing of tear film and conjunc- tival suffering from other medications. Pilocarpine and beta-blockers have been implicated in the aetiology of pseudopemphigus or drug-induced ocular scarring [3, 4]. There is no shortage of evidence suggesting that patients treated with topically administered antiglau- comatous medications experience one or the other or both of conjunctival and ocular surface alterations. Many glaucoma patients complain of dry eye when using their medications, yet their tear production by Schirmer test appears normal. Long-term pilocarpine treatment causes conjunctival goblet cells to be lost and long-term beta-agonist treatment is shown by light and electron microscopy to cause changes to the con- junctiva [5, 6]. In vitro evidence points to the toxicity of many antiglaucoma drugs, and the preservatives used in their formulation, to the conjunctival epithe- lium. In our study, we evaluated the tearing response and conjunctival changes which are found with the long-term use of antiglaucomatous medications and of benzalkonium chloride, by means of the standard tests (Schirmer, Jones, BUT, Ferning) and the conjunctival impression cytology technique.