Fundus autofluorescence and optical coherence tomography of a macular cherry-red spot in a case report of sialidosis.

BACKGROUND Sialidosis is a rare lysosomal storage disorder characterized by deficiency of alpha-N-acetyl neuraminidase. The macular cherry-red spot, which could be important for diagnosis, is a distinctive feature of its ocular manifestation. We evaluated the fundus autofluorescence (FAF) and optical coherence tomography (OCT) images of a juvenile patient who presented with vision decrease and was later confirmed with genetic sialidosis. CASE PRESENTATION A 13-year-old Chinese male presented with bilateral decreased vision over the past 2 years before his initial visit. Funduscopic examination revealed a macular cherry-red bilateral spot. FAF showed hyperreflective areas surrounding a central hyporeflective fovea in both eyes. OCT revealed increased reflectivity in the ganglion cell layer in both maculae without a definite boundary between the hyperreflective and normal areas. These findings suggested that lipofuscin had accumulated in the retinal ganglion cells, which is a distinctive ocular feature in metabolic central nervous system (CNS) disorders. He was later confirmed with genetic sialidosis. CONCLUSIONS FAF and OCT images are very sensitive and useful techniques for diagnosing lysosomal storage disease of the CNS, and are helpful in evaluating the extent of damage in retinal ganglion cells.