Optical coherence tomography findings in a patient with type 1 sialidosis.

Type 1 sialidosis is a metabolic storage disorder characterised by the accumulation of sialylated oligosaccharides. The condition is also known as macular cherry-red spot and myoclonus syndrome due to the characteristic macular appearance in affected individuals. This case outlines the presentation of a patient with type 1 sialidosis, including ophthalmological assessment with retinal photography and spectral domain optical coherence tomography (OCT). OCT scans showed thickening of the perimacular and peripapillary retinal nerve fibre layer, thought to be due to the abnormal accumulation of metabolic products. The cherry-red spot appearance is due to the normal appearing macula being seen in contrast to the abnormally pale surrounding, thickened retinal nerve fibre layer.