Treatment of corneal cystine crystal accumulation in patients with cystinosis

Abstract

Cystinosis is a rare autosomal recessive disorder characterized by the accumulation of cystine within the cells of different organs. Infantile nephropathic cystinosis is the most common and severe phenotype. With the success of renal transplantation, these patients are now living longer and thus more long-term complications within different organs are becoming apparent. Ophthalmic manifestations range from corneal deposits of cystine crystals to pigmentary retinopathy. With increasing age, more severe ocular complications have been reported. Photophobia is a prominent symptom for patients. With prolonged survival and increasing age, this symptom, along with corneal erosions and blepharospasm, can become debilitating. This review revisits the basic pathogenesis of cystinosis, the ocular manifestations of the disease, and the treatment of corneal crystals.

Efficacy of topical cysteamine in nephropathic cystinosis

“…In addition to corneal involvement, crystal accumulation within the conjunctiva, iris, ciliary body, choroid, fundus and optic nerve have been reported 3 4 6 7. Among our patients, cystine deposits were also found in the conjunctiva in 27(84%) patients.…”

“…The most commonly encountered ocular symptoms of corneal cystinosis include photophobia, foreign body sensation and pain 3 4. In our study, 18 (56%) patients had photophobia at presentation.…”

“…There is progressive accumulation of corneal crystals with increasing age. By the age of 12 years, most affected corneas demonstrate marked crystal deposits 3 4. Corneal cystine crystals begin in infancy and can be identified on slit-lamp examination in all nephropathic cystinosis patients by 16 months of age.…”

“…Corneal cystine crystals begin in infancy and can be identified on slit-lamp examination in all nephropathic cystinosis patients by 16 months of age. The majority of affected corneas demonstrate marked crystal formation by the age of 12 years 3 4…”

Selenosulfides Tethered to gem‐Dimethyl Esters: A Robust and Highly Versatile Framework for H2S Probe Development

“…Our proposed mechanism for H 2 S detection by AL1 is depicted in Scheme . We hypothesized that an initial exchange reaction between H 2 S and AL1 would quickly generate 2 and N ‐acetylcysteamine as an innocuous byproduct (note: cysteamine is a prescribed therapeutic for the treatment of corneal cystinosis given its low toxicity and superb antioxidant activity) . With selenium's heightened electrophilic character, nucleophiles will typically attack at selenium much more rapidly than at sulfur .…”