Abstract

Introduction: Glaucoma is a second cause of blindness worldwide. Diet may potentially contribute to the disease progression. Coffee which contains caffeine is widely consumed globally. The aim of this study was to determine the association between coffee intakes and progression of glaucoma. Method: A cross sectional study was conducted on 91 primary glaucoma patients who were on topical antiglaucoma drugs. Direct face to face questionnaire on the frequency of coffee intake was conducted between December 2011 and May 2012. Ocular examination was performed including intraocular pressure (IOP) measurement and fundus examination. Two consecutive reliable Humphrey visual field (HVF) 24-2 standard analysis was obtained at the recruitment period. Severity and progression was based Hoddap- Parrish- Anderson (HPA) criteria. The progression of primary glaucoma was based on the difference of HVF at the diagnosis and the recruitment. Results: 63 (69%) were coffee drinkers with 68% of them drink coffee daily. 42 of primary glaucoma patients who consumed coffee in their diet developed progression of their disease after 6.6 (SD 4.4) years of follow up. Mean IOP at initial presentation (22.9 SD 8.1mmHg) and at current recruitment period (15.5 SD 2.3mmHg) was slightly lower among coffee drinkers but without significant difference (p=0.538, 0.454 respectively). There was no significant association between coffee drinking and severity of glaucoma (p=0.863). In spite of negative association between coffee drinking and progression of glaucoma (p=0.250), the frequency of coffee drinking was significantly associated (p=0.001) with progression glaucoma. Daily coffee drinking increased the risk of progression 8.1 folds (95% CI 2.5, 26.9) based on multivariate analysis. Conclusion: Drinking coffee daily was associated with glaucoma progression in this small study. Perhaps, glaucoma patient should minimize or avoid coffee intake.