A selected group of patients with hereditary retinal degeneration have been studied by electroretinography and fluorescein fundus photography. At early stages of the diseases, receptor cell damage occurs prior to marked disturbance in choroidal or retinal circulation. In advanced degeneration the fluorescein pattern can be altered by pigment migration within the retina.
Geltzer AI, Berson EL. Fluorescein Angiography of Hereditary Retinal Degenerations. Arch Ophthalmol. 1969;81(6):776-782. doi:10.1001/archopht.1969.00990010778004