AIM:To investigate the correlation between severity of diabetic retinopathy(DR)and corneal sub-basal nerve plexus(SNP)changes.

METHODS: There were 132 patients with 132 eyes in type 2 diabetes(T2DM)and 80 patients with 80 eyes in age-related cataract selected in our hospital from January 2018 to May 2021, among them, there were 52 non-diabetic retinopathy(NDR)patients with 52 eyes, 40 non proliferative diabetic retinopathy(NPDR)patients with 40 eyes and 40 proliferative diabetic retinopathy(PDR)patients with 40 eyes in T2DM. The general data and corneal laser scanning confocal microscopy were analyzed. Spearman rank correlation analysis was used to evaluate the correlation between DR clinical stage and nerve fiber length.

RESULTS: There were no differences in gender and age comparisons among 4 groups(P>0.05). The diabetes duration in PDR group was significantly longer than NPDR group and NDR group(P<0.05). The diabetes duration in NPDR group was significantly longer than NDR group(P<0.05). The levels of fasting blood glucose and glycosylated hemoglobin in age-related cataract group were significantly lower than other three groups(P<0.05). The best corrected visual acuity in PDR group was significantly lower than NPDR group and NDR group(P<0.05). The best corrected visual acuity in NPDR group was significantly lower than NDR group(P<0.05). The length of nerve fibers in age-related cataract group was significantly higher than NDR group, NPDR group and PDR group(P<0.05). The length of nerve fibers in PDR group was significantly shorter than NPDR group(P<0.05). Spearman rank correlation analysis showed that there was a negative correlation between DR stage and nerve fiber length(r_s=-0.347, P<0.001).

CONCLUSION: There was a correlation between the severity of DR and the changes of corneal SNP. The length of nerve fibers in patients with PDR was significantly shorter than patients with NPDR; Both PDR and NPDR have a loss of neural structure and should pay attention to the evaluation and treatment of ocular surface lesions in the treatment of T2DM fundus lesions.