Cystinosis, Ocular Findings in, Retinal Degeneration

Definition

Cystinosis is a rare autosomal recessive metabolic disorder characterized by the intracellular accumulation of cystine, the disulfide of the amino acid cysteine (Tsilou et al. 2007).

A pigmentary retinopathy has also been seen in cystinosis patients. This finding precedes the appearance of the crystals in the cornea and has been seen as early as 5 weeks of age or even in fetal life. However, pigmentary retinopathy does not appear to be a constant finding in cystinosis (Wong et al. 1967; Tsilou et al. 2007).

Clinical Presentation

The most commonly described ophthalmoscopic findings are pigmentary changes consisting of patches of depigmentation with pigmentary mottling at the periphery of the fundus and the macula. In the early stages the pigmentary abnormality is confined to the periphery, and the changes are more marked in the temporal than the nasal segments and appear bilateral and symmetric. In older patients the changes are seen more posteriorly. However, the macular...