Long-Term Effects of Topical Anti-Glaucoma Medications on Conjunctival Cell Morphology by Impression Cytology

Abstract

Background: Glaucoma is a major cause of irreversible blindness worldwide. Reduction of intraocular-pressure (IOP) using topical anti-glaucoma medications remains the mainstay of treatment. However, prolonged use of these medications may induce adverse effects on the ocular surface.
Methodology: This cross-sectional observational study, conducted at the B.P. Koirala Lions Centre for Ophthalmic Studies, Maharjgunj Medical Campus from February 2023 to August 2024. Patients of primary open angle glaucoma receiving topical anti-glaucoma medications for at least three months were enrolled. Conjunctival- Impression Cytology samples were obtained and graded according to Nelson’s grading system. Data analysis was done using SPSS version 16. A p-value <0.05 was considered statistically significant.
Results: 128 eyes from 128 glaucoma patients were analyzed, including 54 males (42.2%) and 74 females (57.8%), with mean age of 58.16 ± 14.44 years. Patients using prostaglandin-analogues demonstrated 39.3% Grade-2 and 27.3% Grade-3 changes. Duration of medication use exceeding three years was significantly associated with higher Nelson grades (p < 0.05). Older patients, particularly those aged 61–70 years, exhibited greater cytological changes (p = 0.005). A significant positive correlation was observed between duration of medication use and severity of conjunctival changes (r = 0.597, p < 0.001). Males exhibited more severe conjunctival changes than females (p = 0.009).
Conclusions: Prostaglandin-analogues showed most severe conjunctival cytological alterations. Longer duration of medication use, advancing age, and male gender were significantly associated with conjunctival changes.
Keywords: Anti glaucoma medications; conjunctival morphology; impression cytology, ocular surface disorder.