[Effects of retinopathy on visual function in type 2 diabetes mellitus]

Objective: To study the influence of the severity of diabetic retinopathy (DR) on the visual function of patients with type 2 diabetes, to provide scientific basis for the early prevention and control of DR. Methods: This study was designed as a cross-sectional study, recruiting already-diagnosed type 2 diabetes patients in four community health service centers in Guizhou Province between February and September 2022. Employing the Chinese version of the Visual Function Index-14 (VF-14), assess the participants' near vision, visual adaptation, subjective visual perception, and stereo vision, with higher scores indicating poorer visual function. Categorize the severity of each eye's damage into no diabetic retinopathy (DR), mild non-proliferative diabetic retinopathy (NPDR), moderate NPDR, severe NPDR, and proliferative diabetic retinopathy (PDR), and use a 5-level DR grading system to evaluate the overall severity of diabetic retinopathy in both eyes. Employing linear regression analysis to investigate the linear relationship between DR and visual function index. Local weighted regression evaluates the nonlinear relationship between the DR composite score and the scores of visual function, with a steeper slope indicating poorer visual function for that level. Results: A total of 542 patients with type 2 diabetes were investigated, including 244 (45.02%) males, 298 (54.98%) females, and 162 (29.89%) patients with DR. After adjusting for confounders, compared with those without DR, patients with binocular DR Had overall scores (β=0.136, P=0.003), near vision (β=0.163, P<0.001), visual adaptation (β=0.092, P=0.042), subjective vision (β=0.120, P=0.009) and stereo vision (β=0.094, P=0.044) were higher than those without DR. There were no differences in visual functions between DR And monocular DR. The local weighted regression curve showed that near vision (slope: 23.78) and overall score (slope: 58.37) increased sharply from mild to moderate NPDR in both eyes. Visual adaptation (slope: 5.37, 7.72), subjective vision (slope: 6.53, 7.93), stereovision (slope: 0.74, 0.91) increased slowly in mild to moderate NPDR in both eyes and in moderate to severe NPDR/PDR in both eyes. Conclusion: Binocular DR is associated with impaired visual function, but there is no difference between monocular DR And non-DR visual function. The early damage of DR To visual function is mainly manifested in near vision. In the prevention and control of DR, more attention should be paid to visual function, especially the change of near vision, and retinal damage should not be assessed solely by visual status.