Traditional Chinese Patent Medicine Qizhijiangtang Capsule for Non- Proliferative Diabetic Retinopathy: Study Protocol for a Randomized Controlled Trial

Background: Diabetic retinopathy remains a leading cause of vision loss globally. Here, we investigated the efficacy and safety of Qizhijiangtang capsule (QZJC), a kind of traditional Chinese patent medicine, for patients with NPDR. Methods: This study is a multi-center, randomized, controlled clinical trial. A total of 100 participants will be randomly assigned in a 1:1 ratio to QZJC group or QZJC placebo group. The treatment duration lasts 24 weeks. The primary outcome is the changes in the degree of retinal microaneurysm lesions assessed by fundus photography and fundus fluorescence angiography before and after treatment. The secondary outcomes include the changes in corrected visual acuity, blood glucose, glycosylated hemoglobin, urinary microalbumin excretion rate, the improvement of TCM syndromes and TCM symptoms. Discussion: We postulate that NPDR patients will benefit from QZJC. If successful, this work will provide preliminary evidence that QZJC could delay the progress of DR. Trial registration: Chinese Clinical Trial Registry no. ChiCTR1900023506. The protocol has registered at http://www.chictr.org.cn/showprojen.aspx?proj=39622. Registered 31 May 2019. Template (preprint statement) : This manuscript has been preprinted [https://doi.org/10.21203/rs.3.rs-596869/v1].