RESUMO
BACKGROUND: Classic homocystinuria (HCU), or cystathionine beta-synthase (CBS) deficiency, is a rare inborn error of methionine metabolism. Main clinical features may include skeletal and vascular manifestations, developmental delay, intellectual disability and eye disorders. MATERIAL AND METHODS: This is an observational and retrospective study aiming at describing eye abnormalities presented by a cohort of late-diagnosed HCU patients. Data regarding ophthalmological evaluation included visual acuity, refraction, biomicroscopy, Perkins tonometry, fundus examination, retinography, biometry, ocular ultrasound, optical coherence tomography, anterior segment photography and topography. RESULTS: Ten patients with HCU (20 eyes) were included. The most frequent findings were ectopia lentis(n = 20) and myopia (n = 9). Biometry, ultrasound, OCT and topography findings were available for four patients. One patient had keratoconus; one had abnormal retinal pigmentation; and two had lens surgery scars with irregular astigmatism. CONCLUSIONS: Eye abnormalities are very frequent in late-diagnosed HCU patients. The presence of ectopia lentis should always raise the diagnostic hypothesis of HCU.