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Yiwen Li, M.D.

Yiwen Li, M.D.

Yiwen Li, M.D. 

Research Subject

Photoreceptor Cell Biology, Retinal Degeneration, Retinal Neuroprotection, Retinal Vascular Disorders


Photoreceptor Degeneration, Photoreceptor Neuroprotection, Choroidal Neovascularization, and Diabetic Retinopathy

Published Articles


Research Assistant Professor of Ophthalmology




My research is focused on photoreceptor degeneration and retinal vascular disorders. By using experimental models, I hope to have a better understanding of the mechanisms and processes of retinal degenerations, and retinal vascular disorders, including diabetic retinopathy and choroidal neovascularization. Those models are also used to screen potential treatments for pre-clinical evaluation.

Current Research

The ultimate goal is to understand retinal diseases and to develop effective treatments. My research is focused on retinal degeneration, diabetic retinopathy, and choroidal neovascularization.

Photoreceptor outer segment renewal: the molecular mechanisms.
The outer segments (OS) of photoreceptors undergo constant renewal as the OS tips are shed daily and newly synthesized OS are added. Although the OS renewal was known since the late 1960s, the mechanisms underlying the renewal are not understood. A novel technique has been developed in our lab to measure photoreceptor OS turnover. Using this tool, we can determine the OS renewal rates in different animal models, which may shed light on the mechanism of the OS renewal.

Photoreceptor degeneration caused by genetic mutations.
Retinitis pigmentosa (RP) is a group of retinal degenerations caused by different genetic mutations. It affects 1 in 3,500 to 4,000 worldwide. Patients with RP experience progressive loss of vision due to degeneration of rod photoreceptors and eventually total blindness due to secondary cone degeneration. Our studies would lead a better understanding of the disease process and the development of effective treatments. My research is focused on the secondary cone degeneration and potential treatments that would slowdown or stop the degenerative process.

Diabetic retinopathy.
Diabetes is on the rise worldwide and diabetic retinopathy is a leading cause of blindness. The research on diabetic retinopathy is hampered by the lack of adequate rodent models of proliferative diabetic retinopathy. We are attempting to develop a mouse model of diabetic retinopathy with genetic approaches, which hopefully would lead to a better understanding of the disease and to better treatments.

Studies on choroidal neovascularization (CNV).
CNV is the hallmark of extrudate age-related macular degeneration, which can lead to severe vision loss. By using a unique Matrigel CNV model and a novel labeling technology to identify newly developed abnormal blood vessels, we are studying the molecular mechanisms underlying the development of CNV and to evaluate novel treatment strategies that could protect patients from loss of vision.