Ophthalmic features of mucolipidosis type I (sialidosis): a clinical case. Ophthalmology aspects for neurologists and pediatricians

A very rare clinical case of a juvenile form of a storage disease mucolipidosis type I (sialidosis) is presented. Ophthalmic features include a bilateral macular cherry-red spot. Bilateral macular optical coherence tomography (OCT) revealed hyper-reflectivity of the ganglion cell layer. CONCLUSION: A cherry-red spot is specific not only for central retinal artery occlusion but also for storage diseases, such as gangliosidoses (Tay-Sachs disease, Sandhoff disease, etc.), mucolipidoses, etc. Ophthalmological examination may be the only key to identify serious systemic diseases, and timely genetic testing might be crucial for a child to determine the adequate therapy. This case was characterized by a typical ophthalmic presentation of sialidosis type I with unclear neurological symptoms suggestive of Tay-Sachs disease. Ophthalmological examination revealed a cherry-red spot with a slow progressing decrease in best-corrected visual acuity (BCVA) which is typical for sialidosis type I but not for Tay-Sachs disease. A neurologist observed the symptoms more characteristic of Tay-Sachs disease than sialidosis type I; they included unsteady gait, ataxia, and dysarthria. There was no myoclonic activity characteristic of sialidosis type I. Thus, genetic testing to identify NEU1 mutations was the only method to objectively examine the patient and determine possible supportive therapy.