Evolution of ocular manifestations in nephropathic cystinosis: a long-term study of a population treated with cysteamine.

Abstract

Nephropathic cystinosis is characterized by an accumulation of cystine crystals within most body tissues. Renal transplantation and oral cysteamine have improved the general prognosis of the disease, and ocular manifestations are now the most common complication. This long-term follow-up study describes the sequence of ocular manifestations in patients with nephropathic cystinosis treated with oral and topical cysteamine. Data were recorded for all patients with cystinosis examined between 1980 and 2000. For each patient, photophobia and visual acuity were evaluated and slit-lamp and fundus examinations were performed. For some patients, an electroretinogram was also performed. Twenty-nine patients were observed during this period. They received oral and topical cysteamine. Photophobia and loss of visual acuity generally began by 10 years of age but were severe only after 15 years of age. Peripheral corneal epithelial infiltration appeared in the first few years of life. Infiltration evolved toward the depth and center of the cornea during the second decade of life. Retinopathy was present in 51.7% of the patients, with 3 cases of maculopathy and 3 cases of flattening on electroretinogram. Photophobia and corneal infiltration, although generally severe after 15 years of age, could be treated with topical cysteamine and corneal transplantation. Retinal infiltration, previously described as frequent and potentially blinding, is currently observed in only half of these patients, with mild visual impairment. This could be related to the treatment with oral cysteamine reaching the retinal vascularization.