Visual Perceptual Learning Based on Adaptive Contrast Detection Training Enhances Vision and Contrast Sensitivity in Diabetic Retinopathy

Purpose: To evaluate the efficacy of home-based visual perceptual learning (VPL) on visual function and explore the residual visual plasticity in diabetic retinopathy (DR). Methods: Thirty-six DR patients following routine therapies were randomized (1:1). Twenty-eight completed the study (VPL, n = 12; control, n = 16) after excluding eight for poor adherence or incomplete follow-up. The VPL group underwent 3-month home-based grating detection training at individual cutoff spatial frequencies. Best-corrected visual acuity (BCVA), grating acuity (GA), contrast sensitivity to first-order motion stimuli (1stM), optical coherence tomography angiography (OCTA), and Low Vision Quality-of-Life (LVQOL) questionnaire were assessed at baseline, 1 month, and 3 months for the VPL group and at baseline and 3 months for the control group. Results: BCVA improved from 0.36 to 0.26 logMAR (P = 0.003), GA improved from 12.42 to 17.47 cycles per degree (2.96 dB) and 1stM increased from 64.26 to 83.42 (2.27 dB) in the VPL group. A significant group × time interaction was found for GA (F1, 26 = 63.595, P < 0.001, \( \eta_{p}^2 \) = 0.710), 1stM (F1, 26 = 32.663, P < 0.001, \( \eta_{p}^2 \) = 0.557), and BCVA (F1, 26 = 10.872, P = 0.003, \( \eta_{p}^2 \) = 0.295). The LVQOL score increased (+4.33; P < 0.001) and correlated with ΔGA (r = 0.671, P = 0.017). OCTA parameters remained stable in both groups. Conclusions: The results reveal significant plasticity in the visual system in DR and suggest that contrast detection training may extend to motion perception tasks. Our study provides additional support for VPL as a potential treatment for DR.