LAUSR

An adolescent girl presented with decreased vision and mild nystagmus since childhood. Best-corrected visual acuity was 20/40 OD and 20/100 OS. She had a history of infantile cystinosis with resulting Fanconi syndrome and renal failure for which she received hemodialysis. She had bilateral corneal haze owing to deposition of cystine crystals that precluded detailed retinal examination (Figure, A). There was no visible pigmentary retinopathy. Spectral-domain optical coherence tomography showed hyperreflective foci throughout the retinal layers and subfoveal lucency (Figure, B). Cystinosis is a rare autosomal recessive disorder of amino acid metabolism characterized by accumulation of cystine within lysosomes. Cystine crystals form in many tissues including the kidneys, bone marrow, pancreas, muscles, brain, and eye.1 Apart from corneal crystals as a main feature of ophthalmic involvement, pigmentary retinopathy, constriction of visual fields, and electroretinogram abnormalities have been reported.2 The infantile form (nephropathic) is the most common phenotype presenting with Fanconi syndrome and is the only form with retinopathy.1