AIM: To explore the differences of corneal biomechanical parameters, serum Leptin and extracellular superoxide dismutase(ecSOD)levels in patients with non-proliferative diabetic retinopathy(NPDR)or proliferative diabetic retinopathy(PDR).

METHODS: This article is a prospective study. A total of 118 patients with type 2 diabetes mellitus(T2DM)and diabetic retinopathy(DR)who were admitted to our hospital from May 2020 to May 2022 were selected, and they were divided into NPDR group(n=57)and PDR group(n=61)according to the degree of lesion. Another 54 patients with T2DM but no retinopathy and 52 healthy individuals were set as NDR group and control group. Then the differences in the corneal biomechanics measured with \〖central corneal thickness(CCT), intraocular pressure(IOP), spherical equivalent(SE), the first applanation time(A1T), the first applanation length(A1L), deformation amplitude(DA)\〗 and serum Leptin and ecSOD levels were analyzed, and multivariate Logistic regression analysis was conducted to analyze the high-risk factors affecting the occurrence of PDR.

RESULTS: The CCT, IOP and A1T in PDR and NPDR groups were higher than those in control and NDR groups, and DA was lower than those in control and NDR groups(all P<0.05), and the CCT, IOP and A1T in the PDR group were higher than those in the NPDR group(all P<0.05). The levels of serum Leptin and ecSOD in PDR group, NPDR group and NDR group were higher than those in the control group(all P<0.05). The course of DM, CCT, IOP, A1T, and serum Leptin and ecSOD levels between NPDR group and PDR group were statistically significant(all P<0.05). Multivariate Logistic regression analysis denoted that DM course, CCT, IOP, A1T, Leptin, and ecSOD are risk factors that affect the occurrence of PDR, while DA is a protective factor that affects the occurrence of PDR(all P<0.05).

CONCLUSION: CCT, IOP and levels of serum Leptin and ecSOD in PDR patients were significantly increased compared to those in the NPDR patients, while DA was significantly reduced. Furthermore, CCT, IOP, A1T and levels of serum Leptin and ecSOD were risk factors affecting the occurrence of PDR, while DA was a protective factor affecting the occurrence of the PDR.