In vivo confocal microscopic features of corneal pseudodendritic lesions in tyrosinemia type II

To report the clinical and in vivo confocal microscopic (IVCM) findings of corneal deposits in a patient with tyrosinemia type II.

The pretreatment and 1-month posttreatment slit-lamp examination and IVCM findings of a patient with tyrosinemia type II are described.

A 12-year-old girl diagnosed with tyrosinemia type II was evaluated for photophobia and bilateral ocular discomfort of 1-year duration. The patient had been placed on topical acyclovir treatment with the diagnosis of recurrent bilateral herpetic keratitis during the previous 12 months. Slit-lamp examination revealed bilateral dendritiform epithelial lesions in the central cornea, which stained poorly with fluorescein. IVCM highlighted multiple hyperreflective linear crystalline deposits at the level of superficial epithelium. One month after discontinuation of acyclovir treatment and initiation of a protein-restricted diet therapy, improvement in the patient's symptoms and regression of corneal epithelial lesions was noted. Reduction in the extent of corneal deposits was also confirmed with IVCM.

Corneal involvement, secondary to hereditary tyrosinemia type II, is characterized by pseudodendritic epithelial lesions on slit-lamp examination and hyperreflective linear deposits in the superficial epithelium using IVCM. These lesions may regress expeditiously with a low-protein diet. IVCM may be a useful tool in the differential diagnosis of this disorder by highlighting the crystalline structures in the superficial epithelial layers and also in evaluating the response to the treatment in patients with tyrosinemia type II.