Retinal nerve fiber layer (RNFL) thickness and optic nerve head (ONH) in diabetic patients with normal tension were analyzed using optical coherence tomography (OCT), which revealed that diabetes induce morphologic changes in optic disc and RNFL thickness.

A total of 192 patients with type 2 diabetes were analyzed with fundus examination and classified as having normal retina, mild - moderate, severe nonproliferative retinopathy (NPDR), or proliferative retinopathy (PDR). These patients were evaluated with OCT and compared with normal control group.

The mean average thickness and nasal average thickness of RNFL in mild-moderate, and severe NPDR groups decreased compared with those of the other groups. There was an increase in the temporal average thickness of RNFL in the PDR group. As the duration of diabetes increased, the mean average and nasal average of RNFL thickness also decreased. The severity of diabetic retinopathy didn't show statistically significant differences in a topographic analysis of the optic nerve head.

The mean average thickness and nasal average of RNFL decreased in NPDR groups. Diabetic changes should be considered when diabetes patients are diagnosed with glaucoma or glaucoma progression.