Corneal opacities associated with NTBC treatment.
OBJECTIVE
To describe a patient with hereditary tyrosinemia type I (HHT-I) treated with 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) who developed corneal opacities.


METHODS
A 14-month-old patient was diagnosed with HHT-I and began treatment with NTBC. Her serial ocular examinations were normal until age 4 years, when she developed ocular discomfort and was found to have bilateral, linear, branching subepithelial corneal opacities.


RESULTS
Over the next 3 years, the extent of the opacities fluctuated, and increased opacities correlated with periods of poor compliance with a restricted protein diet. Serum tyrosine levels remained elevated at 238 to 602 umol/L (normal 26 to 83) throughout the duration of NTBC treatment.


CONCLUSIONS
Corneal opacities are a potential consequence of NTBC treatment for HHT-I. The lesions probably result from elevated serum and ocular tyrosine levels due to inhibition of the tyrosine catabolic pathway and poor dietary compliance.
Ahmad
Saad
S
Department of Ophthalmology and Visual Sciences (S.A., G.T.L.), Washington University Medical Center and St. Louis Children's Hospital, St. Louis, Missouri 63110, USA
Teckman
Jeffrey H
JH
Lueder
Gregg T
GT
D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000037:antagonists & inhibitors; D002675:Child, Preschool; D003315:Cornea / Q000187:drug effects* / Q000503:physiopathology; D003318:Corneal Opacity / Q000139:chemically induced* / Q000503:physiopathology; D003512:Cyclohexanones / Q000009:adverse effects*; D018753:Diet, Protein-Restricted; D004791:Enzyme Inhibitors / Q000009:adverse effects*; D005260:Female; D006801:Humans; D009579:Nitrobenzoates / Q000009:adverse effects*; D014443:Tyrosine / Q000097:blood; D020176:Tyrosinemias / Q000097:blood / Q000188:drug therapy*
D003512:Cyclohexanones; D004791:Enzyme Inhibitors; D009579:Nitrobenzoates; D014443:Tyrosine; D015111:4-Hydroxyphenylpyruvate Dioxygenase; C077073:nitisinone