Retinal Degeneration in Choroideremia follows an Exponential Decay Function

Fundus autofluorescence (AF) arises from lipofuscin, which is derived from retinoid byproducts of the visual cycle and accumulates within retinal pigment epithelial cells. Alterations in AF pattern are seen in a wide range of retinal degenerations. Choroideremia is an X-linked retinal dystrophy caused by loss-of-function mutations within the CHM gene, encoding Rab escort protein-1.1 It is uniquely characterized by a central “island” of residual AF that undergoes gradual shrinkage with disease progression.