Corneal pseudodendritic lesions masquerading as herpetic keratitis in a patient with tyrosinemia type I

Objective: To describe the clinical findings of a patient with tyrosinemia type I with noncompliance to a protein-restricted diet, treated with 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC). Methods: Clinical findings at the initial examination and after strict compliance to a protein-restricted diet after 4 weeks follow-up are described in a patient with tyrosinemia type I on NTBC treatment, who had been treated with presumed herpetic keratitis. Results: A 10-year-old girl diagnosed with hereditary tyrosinemia type I and on NTBC treatment presented with photophobia and ocular discomfort in both eyes. An ophthalmologic examination demonstrated bilateral dendritiform epithelial lesions in the central cornea, staining faintly with fluorescein. These lesions were subsequently intermittently treated with topical antivirals for presumed herpes simplex virus keratitis and lubricant eye drops for 9 months without resolution; however, when strict compliance with a protein-restricted diet was instituted, nearly a complete resolution of the lesions was noted at the 4-week follow-up. Conclusions: Although type II tyrosinemia is known to have corneal involvement, the natural course of tyrosinemia type I has not been shown to have corneal involvement. Corneal involvement in type I tyrosinemia may be an indicator of dietary noncompliance and may show complete resolution with a strict compliance to protein-restricted diet only.