Retinitis pigmentosa. A, Fundus photograph shows pallor of the optic nerve, retinal arteriolar narrowing, focal depigmentation, and bone-spicule pigmentation in the peripheral fundus. B, Histologically, marked photoreceptor cell loss (between red arrowheads) and RPE migration into the retina in a perivascular distribution (black arrows) are apparent and correspond to the bone-spicule– like pattern seen clinically. The retina is artifactitiously detached from the under lying RPE and choroid (asterisk).