Pattern of presentation and risk factors of dry eye disease among glaucoma patients on topical medications in Ahmadu Bello University Teaching Hospital, Zaria

Abstract

INTRODUCTION

Glaucoma is the second leading cause of blindness in the world. Globally, 36 million are blind¹, and of these, 4.5 million (12%) are blind from glaucoma.² There is strong evidence suggesting that glaucoma medications may contribute to ocular surface disease (OSD) and the development of dry eye disease (DED).^3,4

METHODS

This was a hospital-based descriptive, cross-sectional study of 181 adult glaucoma patients seen at the Eye Clinic of Ahmadu Bello University Teaching Hospital, Zaria, Kaduna State, Nigeria. Ethical approval for the study was obtained from the Ethics and Research Committee of the Hospital and informed consent was obtained from the participants.

For the purpose of this study, the diagnosis of dry eye disease was based on the Dry Eye WorkShop Diagnostic Methodology⁵ as follows:

• presence of a positive Ocular Surface Disease Index( score of ≥ 13)⁶ together with either
• an abnormal Schirmer’s 1 test (reading of less than 10mm wetting in 5 minutes)⁷ or
• an abnormal Tear Break Up Time (an appearance of the first randomly distributed dry spot in less than 10 seconds).⁷

Chi-square test and binary logistic regression were used to check for the association of risk factors with DED and statistical significance was set at 95% confidence interval (P≤0.05).                           

RESULTS

A total of 181 participants were studied with a mean age of 54±15.7 years. There were 115 (63.5%) females with a female-to-male ratio of 1.74:1. The prevalence of dry eye disease was found to be 40.9%. Grittiness (51%) and blurring (54%) of vision were the most common presenting symptoms (Table 1). Older age, female gender, longer duration of drug administration and mean deviation were found to be statistically significantly associated with a diagnosis of DED (Table 2).

DISCUSSION

The commonest presenting symptoms of dry eye disease in this study were blurred vision (54 %) and grittiness (51%). This differs from the study by Sarimiye et al⁸ that reported stinging (38%) and burning (25%) as predominant complaints. While Pisella et al⁹ in a multicenter study of 4107 patients in France documented ‘discomfort’ as the most common symptom. There was higher propensity of dry eye disease among those 60-79 years (Odds ratio 4.9) and 80 years and older (Odds ratio: 10) compared to those below 40 years in this study. This finding was corroborated by Fetchner et el⁴ in their study. Gender also had a significant association with DED. This is consistent with other studies.^10,11Duration of treatment of glaucoma with topical antiglaucoma medications was significantly associated with DED and this is corroborated by other studies.^12,13 

CONCLUSION

Dry eye disease is a common association of topical antiglaucoma medications; it predominantly presents with blurred vision and grittiness. Identified risk factors include: Older age, female gender, increased duration of drug use and severity of glaucoma. The assessment and treatment of dry eye disease should be integrated in the management of glaucoma to ensure total ocular care of these patients. The screening for dry eye disease should be periodic to ensure early diagnosis and treatment.