Objective: This study analyze the effect of proprotein conversion enzyme subtilisin type 9 (PCSK 9) inhibitor effect on retinal microvascular changes. Methods: This study is a prospective randomized controlled trial. Group Awere treated with PCSK9 inhibitors with statins, and group B were treated with statins. Retinal microvascular changes will be examined by Optical coherence tomography angiography (OCTA) before and after treatment. Results: The foveal avascular zone (FAZ) showed a significant reduction at 12 months in group A, whereas the FAZ in group B showed a significant expansion. The superficial vessel density (SVD) in every region in group A were significantly higher than those in group B. Deep vessel density (DVD) in every region except foveal DVD in group A were significantly higher than those in group B after treatment. In group B, the downward trend only was found in the parafovea DVD. Conclusion: Intensive lipid-lowering therapy with PCSK9 inhibitor can not only influence atherosclerosis, but also help maintain retinal blood flow stability.