Relationship between Serum Glucose Levels and Intraocular Pressure, a Population-based Cross-sectional Study

Purpose: The purpose of this study is to assess the relationship between serum glucose levels and intraocular pressure (IOP) both in subjects with impaired fasting glucose (IFG) as well as in subjects with diabetes mellitus (DM). Materials and Methods: Data of a cross-sectional sample of 18,406 subjects who underwent routine annual screening at a tertiary medical center in 2000 to 2013 were analyzed. Results: Mean (SD) age of the subjects was 46 (10) years; 68% were male. Mean (95% confidence interval) IOP measured 13.1 (13.0-13.1) mm Hg in subjects with normal glucose levels, 13.7 (13.6-13.8) mm Hg in subjects with IFG, and 14.3 (14.1-14.4) mm Hg in subjects with diabetes. The difference in IOP between subjects with normal and abnormal (DM or IFG) serum glucose levels were significant, even after adjusting for age, body mass index, and hypertension (P<0.0001). There was a positive linear correlation between serum glucose levels and IOP in both men (r=0.12; P<0.0001) and women (r=0.17; P<0.0001). For every 10 mg/dL increase in fasting serum glucose, IOP increased by 0.09 mm Hg in men and by 0.11 mm Hg in women. Conclusions: This study demonstrated that similar to subjects with DM, subjects with IFG also have IOP levels that are higher than those with normal serum glucose. Moreover, there is a direct correlation between fasting serum glucose levels and changes in IOP. These findings highlight another end-organ effect of uncontrolled glucose levels.