Ocular manifestations in classic homocystinuria

ABSTRACT

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.

KEYWORDS:

• Classic homocystinuria
• CBS deficiency
• eye abnormalities
• ectopialentis

Acknowledgments

We thank Mariana Sbaraini, MD, for providing the photos and assisting with data collection. We also thank FIPE, the Hospital de Clínicas’ financial support for science.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

All phases of this study were supported by the National Council for Scientific and Technological Development (CNPq). Conselho Nacional de Desenvolvimento Científico e Tecnológico.