Propose: Dry eye is a common disease among glaucoma patient undergoing on topical medication for lowering intraocular pressure. In this study we determine the prevalence and risk factors of dry eye among glaucoma patients.

Methodology: We conducted a prospective cross-sectional study at Kilimanjaro Christian Medical Center (KCMC), Ophthalmology Department, over a period of 8 months, from October 2018 to June of 2019. Purposive sampling technique was used, and patients with POAG aged 18 years and above were consecutively selected. Socio-demographic and clinical data were collected. The main outcome variable was dry eye. The data were summarized using SPSS version 23 and analyzed using the STATA software version 13.

Results: A total of 325 patients were enrolled into the study; 56.6% were male and 43.4% were female. The mean age was 66.1 years (SD11.7). We found that the prevalence of dry eye using OSDI questionnaire was 79.7%; among them evaporative dry eye was found in 36.9% and aqueous deficiency in 43.4%; 87.1% had abnormal TBUT; abnormal ocular surface staining was found in 64.3%; Schirmer test was abnormal in 43.4% and 36.9% had meibomian gland dysfunction. The severity of dry eyes among those using OSDI questionnaire is: mild 22.1%, moderate 16.0% and severe 61.9%. Factors such as use of two or more medication (AOR = 2.55, 95% CI: 1.89 - 3.36), 2 - 5 years of medication (AOR = 1.52, 95% CI: 1.35 - 1.88) were associated with dry eye in patients with glaucoma at KCMC.

Conclusion: Dry eye is highly prevalent in glaucoma patients in our setting, and showed also the high prevalence of signs and symptoms. The use of timolol combined with other medication in our study was shown to be a strong predictor of having dry eye. To be exposed to two or more medication is strongly predictors of having dry eye.