A comparative study of risk factors for corneal infection in diabetic and non-diabetic patients

AIM: To compare the clinical characteristics of infectious keratopathy in type 2 diabetes mellitus (T2DM) and nondiabetes mellitus (NDM) and to investigate risk factors for infectious keratopathy in T2DM patients. METHODS: Totally 230 patients with T2DM and 168 with NDM diagnosed as infectious keratopathy were hospitalized at Qingdao Eye Hospital from 2001 to 2015. Data including sex, age, occupation, season, smoking and alcohol consumption habits, duration between onset and treatments, duration of hospitalization were collected. Initially identified indicators were analyzed with a multivariate logistic regression. Glycosylated hemoglobin A1c (HbA1c) in patients with T2DM was analyzed. The infectious keratopathies in the two groups were categorized and compared. RESULTS: The diabetic group consisted of 146 (63.5%) males and 84 (36.5%) females. The NDM group consisted of 111 (66.1%) males and 57 (33.9%) females. There was no signigicantly difference in sex distribution between the two groups (P>0.05). There were significant differences in age, occupation of patients, season of the onset of diseases, duration between onset and treatment, and durations of hospitalization between the two groups (P<0.05). In most of the patients in the diabetic group, the duration between onset and treatment was <= 3mo, and most was <= 3mo in the NDM group. Multivariate logistic regression analysis revealed that age and season were related to the development of corneal infection in the T2DM group (OR=1.709, 1.706). In the T2DM group, HbA1c was 9.09%+/- 2.12%. There were statistically significant differences in the incidences of bacterial keratitis and herpes simplex keratitis in the two groups (P<0.05), but no significant statistical difference was found between fungal keratitis and amoebic keratitis (P>0.05). CONCLUSION: Advanced age and the summer and winter seasons are identified as risk factors for infectious keratopathy in T2DM patients, and T2DM patients are more prone to bacterial keratitis.