AIM: To observe the changes of retinal nerve fiber layer(RNFL)and corneal nerve fibers(CNF)in diabetic patients without diabetic retinopathy(DR)retrospectively.

METHODS:Forty eyes of 40 patients with type 2 diabetes mellitus, who were found no diabetic retinopathy, were examined by optical coherence tomography(OCT)and in vivo confocal microscope(IVCM). Forty eyes of 40 healthy participants were only scanned using OCT served as RNFL control group, and another forty eyes of 40 healthy participants were only scanned using IVCM served as CNF control group. The thickness of superior, inferior, nasal, temporal and average RNFL to optic disc were measured using OCT. Corneal nerve fibers length(CNFL)and corneal nerve fibers density(CNFD)were measured using IVCM.

RESULTS: The diabetic patients showed decreased thickness of inferior RNFL when compared to controls(P=0.003).No significant differences were found in the thickness of superior, nasal, temporal and average RNFL(P>0.05). The diabetic patients were also found to have lower CNFL and CNFD(P<0.01). What's more, in diabetes patients, the average RNFL were positively correlated with CNFL and CNFD(r=0.518, P<0.01; r=0.484, P=0.002),and the inferior RNFL were also positively correlated with CNFL and CNFD(r=0.607, P<0.01; r=0.573, P<0.01).

CONCLUSION: RNFL and CNF are early damaged in diabetic patients without DR. RNFL decreases in the inferior quadrant of retina. The loss of RNFL positively correlates with that of CNF significantly.