Corneal lesion as the initial manifestation of tyrosinemia type II

Tyrosinemia type II (Richner-Han hart syndrome) is a rare autosomal recessive disease with deficiency of tyrosine aminotransferase and subsequently increasing level of serum tyrosine. We report the case of a 2-year-old girl who was referred due to bilateral corneal lesions. Slit-lamp examination showed small granular white deposits arranged in a dendritic pattern in the superficial central cornea of both eyes. Physical examination revealed painful, non-pruritic, hyperkeratotic plaques on the soles, palms and fingertips. Mental evaluation demonstrated developmental delay for her age. Blood examination revealed serum tyrosine level to be 1,868 μM (normal range, 30-110 μM), which decreased to 838 μM with 2-month diet on tyrosine and phenylalanine restriction. The corneal and skin lesions resolved completely. However, the corneal deposits recurred a month later as her mother failed to strictly control the diet because the little girl was losing weight and activity. With specific formula and adjusted diet regimen, the corneal lesions decreased again. Corneal pseudodendritic deposits may be the initial manifestation in patients with tyrosinemia type II. Early diagnosis and intervention with diet control are crucial for preventing permanent visual and developmental deficits. Corneal deposits can be one of the parameters in monitoring the efficacy of diet control.