A recent study found a direct association between high long-term hyperglycemia and increased IOP. Researchers evaluated the intraocular pressure (IOP) of 2,524 diabetes patients from the Singapore Epidemiology Eye Disease Study. Within this group, they found a consistent association between diabetes and higher IOP, as well as between diabetes and thicker central corneal thickness (CCT). The study suggested high serum glucose levels were also significantly associated with IOP elevation. However, “the indirect contribution of CCT to both the diabetes-IOP and high serum glucose-IOP association was small and not significant,” the researchers said.

“Our findings suggest that higher IOP associated with diabetes is not primarily mediated through thicker CCT,” the study authors said. “Therefore, diabetes and poorer long-term glycemic control may potentially place one at a greater risk of glaucoma through non CCT-related mechanisms.”

They conclude that while the physiological mechanism that underlies the association between diabetes and higher IOP remains unclear, elevated IOP in diabetes patients should not be considered an overestimation because of thicker CCT but as an objective measurement that may increase the risk of glaucoma in these patients.