AIM: To investigate the relationship between blood biochemical parameters and choroidal thickness(CT)in naïve-treatment of patients with nonproliferative diabetic retinopathy(NPDR).

METHODS: Prospective cross-sectional study. A total of 92 patients(92 eyes)with naïve-treated NPDR were selected in the Affiliated Eye Hospital of Nanchang University from July 2021 to July 2022. All of the patients included in this study were subjected to ophthalmologic examination including enhanced depth imaging optical coherence tomography(EDI-OCT), best corrected visual acuity(BCVA), fundus fluorescence angiography, intraocular pressure, slit lamp and fundus examination. At the same time, they were also underwent hematological examination including blood glucose, glycosylated hemoglobin(HbA1c), serum creatinine, uric acid, urea, β2 microglobulin, high density lipoprotein(HDL), low density lipoprotein(LDL), serum calcium, serum potassium and other tests. According to the glomerular filtration rate(eGFR)and CT, the patients were divided into normal, mild and moderate to severe renal function group, pachychoroid group and the leptochoroid group. The blood biochemical indexes, CT differences and theirs correlation were analyzed in naïve-treated NPDR patients.

RESULTS: A total of 92 cases(92 eyes)were included in this study, with 51 males(51 eyes), 41 females(41 eyes), 45 right eyes and 47 left eyes. There was no significant difference in age, axial length and disease duration among the three groups(all P>0.05). There were significant differences in nasal 0.5, 1.5mm, subfoveal and temporal 0.5, 1.5mm CT among three groups(all P<0.05). There was no statistical significance in age, axial length and the course of disease between the pachychoroid and leptochoroid groups(all P>0.05). There were significant differences in creatinine, eGFR, uric acid, urea, potassium and β2-microglobulin between the pachychoroid group and the leptochoroid group(all P<0.05). There were no significant differences in total cholesterol, triglyceride, HDL, LDL, HbA1c, serum calcium and glucose between the two groups(all P>0.05). CT was negatively correlated with creatinine, urea, uric acid and β2-microglobulin, and positively correlated with eGFR. Multiple regression analysis showed that the thicker the nasal 0.5mm CT, the higher the eGFR(B=0.292, P<0.001). CT affected creatinine, eGFR, urea, uric acid and β2-microglobulin(B=16.5, 64.6, 24.1, 18.1, 20.3; P=0.008, <0.001, <0.001, 0.004, 0.001), while there were no significant effects on total cholesterol, triglyceride, glucose, serum calcium, HDL and LDL(all P>0.05).

CONCLUSION: In patients with naïve-treated NPDR, the thicker the CT, the better the renal function. The decrease of CT in newly diagnosed NPDR patients is an important hint to pay attention to the renal function.