Neuroretinal structure changes in infantile nephropathic cystinosis

Cystinosis leads to pronounced crystal accumulation in the optic disc in early stages of the disease. This accumulation occurs in concomitance with the well-described cystine crystal deposits in the cornea, which have previously been considered the foremost ocular sign of cystinosis. The pearl-string appearance of crystal deposition suggests a primarily glial localization. A significantly thicker pRNFL and a higher rate of positive prelaminar depth was observed in the OCT scans of cystinosis patients, explaining the clinical impression of a crowded optic disc. Additionally, retinal neurodegeneration was significant in patients with cystinosis if compared to healthy controls. The optic disc crowding may result from the dense deposition of cystine crystals in the optic nerve head and the GCL thinning could be due to metabolically induced ganglion cell atrophy. However, the exact reason for these changes remains to be elucidated.