He is currently a Professor of Ophthalmology, and Pathology and Cell Biology at Columbia University Irving Medical Center in New York.
[6] In 2012, Tsang produced long term visual improvement in retinitis pigmentosa mouse models in two experiments, one using induced pluripotent stem cells and the other gene therapy.
[1] In 2016, Tsang's team, in partnership with University of Iowa scientists, used the genome editing tool called CRISPR to repair a mutation that causes retinitis pigmentosa in patient derived stem cells.
[8][9][10] In 2018, Tsang and his team created a new technique for CRISPR, restoring function in the retina of mice affected by retinitis pigmentosa.
[23] Tsang did his residency at Jules Stein Eye Institute/UCLA, and then he studied with Professors Alan C. Bird and Graham E. Holder, researching how to improve care of people suffering from macular degeneration.