This healthy 36YO female presented with a long history of bilateral vision loss with night blindness. Family history was negative. Vision was 20/80 bilaterally. Anterior segments were normal.
Fundus imaging shows extensive pigmentary degeneration with subretinal crystalline deposits involving both posterior poles. OCT scanning shows hyperreflective dots overlying the RPE-Bruch’s membrane complex with variable outer retinal and RPE loss. A few areas of outer retinal tubulation are noted temporally OS. Fundus autofluorescence (FAF) shows diffuse hypo-FAF throughout each posterior pole, dense hypo-FAF within areas of discrete atrophy, and dots of more peripheral hyper-FAF.
Learning Points:
Bietti crystalline dystrophy is an autosomal recessive ocular disorder that affects both the anterior and posterior segments. Clinical features include crystalline deposits in the retina, cornea, and rarely the crystalline lens, as well as retinal pigment epithelial clumping and atrophy. Mutations in CYP4V2 that cause dysregulated lipid metabolism have been implicated in its pathogenesis. While there is no definitive treatment, anti-VEGF therapy can be administered for secondary macular neovascularization. See Saatci et al for a recent review (Clinical Ophthalmology 2023;17:953-967).
