Efficacy and Safety of Qiming Granule for Nerve Injury Associated with Non-proliferative Diabetic Retinopathy: A Multicenter, Randomized, Non-inferiority, Active-Controlled Clinical Trial.

Objective: To evaluate the efficacy and safety of Qiming Granule as an early treatment for patients with nerve injury associated with non-proliferative diabetic retinopathy (NPDR).

Methods: This was a multicenter, randomized, non-inferiority, active-controlled clinical trial. Patients with NPDR complicated with nerve injury, regardless of whether they presented with fundus abnormalities, were randomly assigned in a 1:1 ratio via a randomized number table to orally receive either 4.5 g of Qiming Granule or 0.5 g of calcium dobesilate (CaD), both 3 times daily for 24 weeks. The primary endpoints were changes in retinal nerve fiber layer (RNFL) thickness and foveal avascular zone (FAZ) area from baseline to week 24. The secondary endpoints included changes in RNFL thickness and FAZ area from baseline to week 12, and visual function questionnaire (NEI-VFQ-25) and health survey questionnaire (SF-36 scale), CM syndrome element scale score and the rates of abnormal full-field electroretinogram (ERG), abnormal dilated fundus, and abnormal visual acuity at treatment of weeks 12 and 24. Adverse drug reactions (ADRs) were detected.

Results: A total of 82 patients were enrolled in the study. Changes in RNFL thickness from baseline to week 24 in the Qiming Granule and CaD groups were -1.53 ± 9.88 µm and -4.61 ± 9.23 µm, respectively (a difference of 3.08 µm [97.5% CI: -2.11 to 8.25]). Changes in FAZ area from baseline to week 24 were -0.08 ± 0.39 mm² and 0.01 ± 0.05 mm², respectively (a difference of -0.09 mm² [97.5% CI: -0.26 to 0.08]). Non-inferiority was achieved for both primary endpoints. There were no significant differences between the two groups in secondary endpoints, including changes in RNFL thickness and FAZ area from baseline to week 12, rates of abnormal ERG, dilated fundus, and visual acuity results at weeks 12 and 24, as well as NEI-VFQ-25, SF-36 scale, and CM syndrome element scale scores at week 24. ADRs were detected in 4 (9.76%) and 1 (2.44%) patients in the Qiming Granule and CaD groups, respectively. No serious ADRs occurred.

Conclusion: Qiming Granule demonstrates non-inferiority in terms of efficacy and safety as an early treatment for nerve injury associated with NPDR. (Registration No. ISRCTN39825773).