Ocular Ochronosis in Alkaptonuria

Abstract

A 60-year-old woman affected by genetically diagnosed alkaptonuria showed sclero-conjunctival pigmentation (ochronosis) in both eyes (Fig A-C): “vermiform” pigment accumulation was visible in the conjunctiva (arrow) and “oil drops” deposits were visible at the corneal limbus (triangle) with bluish-dark bilateral scleral pigmentation near the rectus muscle insertion (Osler’s sign) (asterisk). Alkaptonuria is a rare autosomal recessive disorder, in which the enzyme homogentisic acid oxidase is deficient, causing an accumulation of homogentisate in body tissues and its secretion in urine.