Evaluation of the factors affecting peripapillary nerve fiber thickness in diabetic patients by optical coherence tomography

Diabetes mellitus is a chronic disease, characterized with abnormal insulin secretion and increased blood glucose levels which have seen in worldwide with affecting circulation, nervous system, kidneys and eyes(microangiopathy).The most clinically important effect of diabetes-related microangiopathy is on the retina and choroid. Alltough vascular structure changes by diabetes are well known, pathological findings in neurons with diabetic retinopathy are not clear. Quantitative measurement of RNFL thickness with OCT is usefull for early RNFL defects. In this study, we examined relationship between peripapillary RNFL thickness and demographic factors such as systemic hypertension, age, sex, duration of diabetes, diabetic retinopathy, diabetic macular edema, glaucoma, laser treatment. A total of 207 eyes in 104 patients with diabetes were included in the study. Peripapillary retinal nerve fiber layer thickness measurements were evaluted with SD- OCT in both eyes of each cases. RNFL were more thinner under age 60 patients than 60 years and older on superior and inferior quadrants. There is a significant relationship between age and RNFL. The average peripapillary retinal nerve fiber layer in women were more thicker than men have been identified. There is no significant relationship between the average peripapillary retinal nerve fiber layer in four quadrants with the presence of systemic hypertension. Superior peripapillary nerve fiber layer thickness in eyes with glaucoma was significantly decreased than without glaucoma. There were significant relationship with superior quadrant of the peripapillary RNFL thickness and glaucoma. Average peripapillary retinal nerve fiber layer thickness on superior, inferior, and nasal quadrants was significantly decreased in duration of diabetes in patients over 15 years than15 years and under. There were significant relationship with duration of diabetes and peripapillary RNFL. Peripapillary RNFL on temporal quadrant was significantly decreased in without retinopathy than PDR and NPDR eyes. There were no significant relationship between temporal quadrant RNFL thickness and PDR and NPDR eyes. Temporal quadrant RNFL thickness in diabetic macular edema eyes were significantly increased. Peripapillary retinal nerve fiber layer thickness on temporal quadrant was significantly increased in eyes undergoing PRP. There were no significant with peripapillary nerve fiber layer thickness in four quadrants and eyes with focal laser.