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Tyrosinemia type II: nine cases of ocular signs and symptoms
M S Macsai1, T L Schwartz, D Hinkle
1Division of Ophthalmology, Evanston Northwestern Healthcare, Northwestern University School of Medicine, 2050 Pfingsten Rd., Glenview, IL 60025, USA. mmacsai@enh.org
Purpose:
To report nine cases of tyrosinemia type II, with ocular signs and symptoms.
Methods:
Participants included nine patients (18 eyes) who were followed for a mean follow-up period of 6.5 years (range, 2 to 8 years). Intervention included dietary restriction of tyrosine and phenylalanine, which led to resolution of ocular and cutaneous lesions, improved behavior in one patient, and may have prevented developmental delay in others. The main outcome measures were visual acuity and serum tyrosine levels to determine the response to dietary therapy. Intelligence testing and developmental screening were performed when appropriate.
Results:
All patients presented with ocular signs and symptoms as the primary manifestation of disease and serve to illustrate the typical ocular findings of this syndrome. Three patients presented with cutaneous manifestations, and one patient had mild mental impairment at the time of diagnosis.
Conclusions:
Recalcitrant pseudodendritic keratitis may be the presenting sign in tyrosinemia type II. Awareness of the presenting signs and symptoms may accelerate the diagnosis and dietary intervention. Initiation of a tyrosine-restricted and phenylalanine-restricted diet in infancy is most effective in preventing cognitive impairment.