Pediatric cystinosis: Corneal cystine deposits and papilledema in a 4‑year‑old:  A case report

Cystinosis is a rare autosomal recessive lysosomal storage disorder characterized by the accumulation of cystine within lysosomes, leading to multi-systemic complications. The present study describes the case details (the presentation and management) of a 4-year-old female child diagnosed with infantile cystinosis, further complicated by distal renal tubular acidosis and stage 4 chronic kidney disease. The patient exhibited significant ocular manifestations, notably bilateral corneal cystine crystal deposits, observed as a shimmering effect under slit-lamp biomicroscopy and marked papilledema in both eyes. Fundoscopic examination also revealed retinal cystine deposits, indicating systemic involvement. The systemic complications included renal dysfunction requiring ongoing dialysis and bicarbonate supplementation to manage metabolic acidosis, as well as elevated intracranial pressure. Ophthalmological management focused on vision preservation through corrective lenses and topical cysteamine eye drops to reduce corneal cystine accumulation. Regular follow-up appointments were scheduled to monitor corneal clarity and optic nerve health. The case described herein underscores the complexity of cystinosis and the critical need for a multidisciplinary approach involving ophthalmology, nephrology, and neurology. Early diagnosis and timely therapeutic interventions are essential to mitigate the progressive nature of the disease and improve patient outcomes. The present case report also highlights the challenges in managing the condition, including treatment adherence and potential complications, and emphasizes the importance of continued research to develop more effective therapies and improve the quality of life for affected individuals.