In two siblings with olivopontocerebellar degeneration, the retinal pigment epithelium or the sensory retinal or both appeared to be damaged first. These layers were markedly involved before secondary changes in the choriocapillaris, the inner retinal layers, or the optic nerve occurred.
Ryan SJ, Knox DL, Green WR, Konigsmark BW. Olivopontocerebellar DegenerationClinicopathologic Correlation of the Associated Retinopathy. Arch Ophthalmol. 1975;93(3):169-172. doi:10.1001/archopht.1975.01010020177001