The study rundown:
Researchers induced photoreceptor cell death by exposing mice to “light injury” which typically causes photoreceptor degeneration. However, mice that were given tamoxifen had better photoreceptor function.
What is tamoxifen?
It’s a medication commonly used to treat breast cancer. You learned about it in ocular disease because it can have ocular side effects like tamoxifen retinopathy.
How did it prevent photoreceptor cell death?
Tamoxifen inhibited microglia, the immune cells in the retina. When retinal cells are injured, microglia can make it worse by producing inflammatory cytokines and contribute to photoreceptor demise.
What’s the catch?
The tamoxifen dose used in the mice was equivalent to eight times the FDA approved dose for breast cancer. Researchers plan to investigate whether the protective effect still holds at lower doses.
The take home: Tamoxifen could potentially be used to help AMD and RP patients and clinical studies may not be far off since tamoxifen is already FDA approved and has a good safety profile.