The value of conjunctival biopsy in childhood cystinosis

Abstract

Cystinosis is frequently presented with cystine storage in the cornea and cnnjiinctiva. and the diagnosis can be established by slit-lamp esamination. It can also be confirmed by elcctron microscopy of a conjunctival biopsy . The present paper reports on n 16-nionth-old boy with Fanconi's syndronie. in whoni the slit-lanip examination did not show crystal deposits of cystinc in the conjunctiva. The ~iltrastructurals tudj,o f the conjunctival biopsy demonstruted polygonal crystals within douhle mcmbrane-liniited organelles located in fibrobliists. Similar crystals were subsequently found in a hidney biopsy. We therefore think that conjunctival biopsy is a valuable diagnostic tool prior to pcrforming renal biopsy, even in cases with negativc findings hy ophthalmologic examination.