The association between diabetes, level of glycaemic control and eye infection: Cohort database study.

AIM: To examine whether diabetes and the degree of glycaemic control is associated with an increased risk of acute eye infection, and prescribing of ocular antimicrobial agents.

DESIGN AND SETTING: A retrospective cohort study was carried out using the Royal College of General Practitioners Research and Surveillance Centre database (RCGP RSC), a large primary care database in the United Kingdom. We compared ocular infection rates in people aged ≥15 years without diabetes to those with diabetes, both type 1 and type 2. We developed logistic regression models to assess the excess risk in diabetes of: conjunctivitis, blepharitis, stye/chalzion, periorbital cellulitis, keratitis/keratoconjunctivitis, lacrimal gland infection, endopthalmitis, and ocular antimicrobial prescriptions over a six-year period (2010-2015). We also analysed the impact of glycaemic control on infection rates in those with diabetes. All models were adjusted for potential confounders.

RESULTS: We analysed infection risk in 889,856 people without diabetes and 48,584 people with diabetes (3273 type 1, and 45,311 type 2). After adjustment for confounders both type 1 and type 2 were associated with increased incidence of conjunctivitis (OR 1.61; 95% CI 1.38-1.88; p<0.0001 and OR 1.11; 95% CI 1.06-1.16; p<0.0001 respectively). No association was found with blepharitis, stye/chalzion, periorbital cellulitis, keratitis/keratoconjunctivitis, lacrimal gland infection, and endopthalmitis in the whole population. In subgroup analyses blepharitis was more common in those with type 1 diabetes under 50 years old and endopthalmitis in those under 50 with type 2 diabetes. Glycaemic control was not found to be associated with any infection. Diabetes was also associated with an increased incidence of antimicrobial prescriptions (Type 1 OR 1.69; 95% CI 1.51-1.88; p<0.0001 and type 2 OR 1.17; 95% CI 1.13-1.20; p<0.0001).

CONCLUSIONS: Conjunctivitis is recorded more frequently in people with diabetes. However, no substantial increase in recording of other ocular infections was noted. Infection risk was not found to be associated with the degree of glycaemic control.