A capsule containing fenretinide may someday be the cure for non-exudative macular degeneration. The most damaging form of dry macular degeneration is called geographic atrophy (GA). It is different from the “wet” form as there are no abnormal leaky blood vessels within the retina. Patients with geographic atrophy experience vision loss due to atrophy, or cell death, of the pigmented layer within the retina.
A small 2 year study has been underway and the 12 month results look promising. Patients were given fenretinide in one of two doses versus placebo.
It is believed that GA is a result of lipofuscin and serum retinol-binding protein (RBP) build up in the retinal pigment epithelium (the layer principally affected in the retina), that is, increased lipofuscin and RBP causes cell death of the RPE layer.
Patients receiving either dose of fenretinide were noted to have a slower rate of progression of the atrophic lesions. Also, while there was an inverse relationship between oral fenretinide and lower RBP, none was noted before the trial started. To state another way, it looks as if the oral fenretinide did indeed lower RBP. It then further implicates RBP to be involved in the chain of events leading to RPE cell death.
Lastly, it also appears that the smaller, and earlier, the lesion are treated, the better the response.
What does this mean? As I learn more and more about the cascade of events leading up to cell death of the RPE, it becomes clearer that we soon will be treating patients with dry/non-exudative ARMD. Especially exciting is the fact that treatment is a simple capsule versus and intraocular injection. The trial will be completed in 2010.
Link to the article.
