Is Diabetes Mellitus a Risk Factor for Open-Angle Glaucoma? The Rotterdam Study

Purpose: To investigate whether diabetes mellitus is a risk factor for open-angle glaucoma (OAG).
Design: Prospective population-based cohort study.
Participants: Participants ages =55 years from the Rotterdam Study, The Netherlands.
Methods: Participants at risk for incident OAG (iOAG) underwent at baseline (1990-1993) and follow-up (1997-1999) the same ophthalmic examination including intraocular pressure (IOP) measurement, visual field testing, and simultaneous stereo optic disc photography. At baseline, diabetes mellitus was defined as the use of antidiabetic medication and/or a random or postload glucose value =11.1 mmol/l. The diagnosis of OAG was made with an algorithm based on optic disc measures and visual fields, independent of the IOP.
Main Outcome Measure: Incident OAG.
Results: In total, 3837 participants without OAG at baseline were reexamined. After a mean follow-up time of 6.5 years, iOAG developed in 87 persons. The relative risk of iOAG associated with baseline diabetes was 0.82 (0.33-2.05). After adjustment for age, gender, follow-up time, IOP, IOP-lowering treatment, body mass index, and systemic hypertension, the relative risk of iOAG was 0.65 (0.25-1.64).
Conclusions: In this prospective population-based study, diabetes mellitus was not a risk factor for OAG.