The effect of diabetic retinopathy and blood glucose regulation on corneal biomechanical parameters

PURPOSE: To evaluate the effect of different stages of diabetic retinopathy and metabolic control of blood glucose levels on corneal biomechanical parameters MATERİAL AND METHODS: 141 eyes of 141 patients retrospectively examined. Control group was consisted 40 of 141 patients with no DM. Diabetic patients divided into 3 groups; group 1(no retinopathy ), group 2 (background DR), group 3 (proliferative DR ). We examined and compared corneal biomechanical properties, including CH, CRF, İOPg and İOPcc measured by ORA; CCT measured by pachymeter and IOP measured by tonometer and also the effect of HbA1c values on these parameters . RESULTS: Control group was including 40, group 1, 2 and 3 were including 34, 34 and 33 patients respectively. Compared to diabetic patients those with HbA1c ≥ 7mg/dl and HbA1c <7 mg / dl the mean value of CRF, CCT and IOPg 10.88 ± 1.79, 9.7 ± 1.85 (p = 0.009);546 ± 29, 527 ± 28 μ (p = 0.01) and 17.23 ± 4.06 mmHg, 15.25 ± 2.76 mmHg (p = 0.038) respectively. There was no statistically significant difference in IOPcc, IOPg, CH, CRF, IOP(tonopen) and CCT between the control group and group 1,2 and 3. CRF was 11,21±2,25 in group 1 and 10,01±1,48 in group 3. In group 3, CRF was statistically significant lower than group 1. CONCLUSİON: We think that metabolic control of blood glucose is more important rather than the stage of diabetic retinopathy on corneal biomechanical parameters. KEYWORDS:Diabetic retinopathy, HbA1c,Corneal hysteresis, Corneal resistance factor, ORA