We report the case of a 6-year-old child from a consanguineous marriage who consulted the ophthalmology department for photophobia, tearing and sensation of a foreign body. The ophthalmologic examination finds a better-corrected visual acuity of 20/30 in the right eye and 20/40 in the left eye. Slit lamp examination shows conjunctival hyperemia and bilateral deposits of cystine crystals in the cornea. The remainder of the anterior segment exam is normal. The fundus is normal. Cystinosis is a rare genetic disorder characterized by the accumulation of cystine in lysosomes, causing damage in various organs and tissues, especially in the kidneys and eyes. It manifests itself in the eye by the deposition of cystine crystals in the cornea but also in other structures of the eye, anomalies in the pigmentation of the retina and impaired visual acuity. Diagnosis is based on the determination of cystine in leukocytes. cysteamine is the only topical effective treatment for ocular cystinosis.

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Corresponding author
Karima Madbouhi, Université Mohammed V Souissi, Ophtalmologie A, Hôpital des Spécialités, Centre Hospitalier Universitaire Rabat, Rabat, Morocco (karima.madbouhi@gmail.com)