The influence of diabetes mellitus type 2 on the central corneal thickness

Background/Aim. Complications of diabetes mellitus (DM) in the eye are the leading cause of blindness in the world. Although research on eye complications of DM is mainly focused on retinal damage, changes in the cornea are also associated with DM. Central corneal thickness (CCT) reflects the metabolic status of the cornea and is also affected by DM. Knowledge of CCT changes that occur within DM is important for accurate IOP measurement, diagnosis, and monitoring of patients with glaucoma. The aim of the study was to examine the effect of DM type 2 on the central corneal thickness. Methods. The study was designed as a clinical, cross-sectional, observational study. It consists of 96 patients, divided into two groups. The first group consisted of 49 patients diagnosed with DM type 2. The second group was the control group and consisted of 47 healthy subjects. The DM group was divided into subgroups depending on the status of diabetic retinopathy, the length of DM treatment, and the levels of glycosylated hemoglobin (HbA(1)C). Results. A statistically significant difference in CCT was observed among DM patients and the control group. Analyzing only DM patients, the highest CCT values were observed in patients who had HbA(1C) > 7.0%, as well as those who have treated DM for more than 15 years, with a statistically significant difference in relation to the corresponding patient sub-groups (p = 0.002 and p = 0.037, respectively). No statistically significant difference was observed depending on the status of retinopathy. Intraocular pressure (IOP) was statistically significantly higher in patients with DM compared to the control group. Conclusion. Our research demonstrated that the status of retinopathy had no statistically significant influence on CCT. Knowing that the increase in CCT also affects the measured IOP values, this research will be useful in better understanding and control of the patients who have glaucoma in addition to DM type 2.