Primary infantile glaucoma: influence of age at onset.

To determine the influence of age at onset of primary infantile glaucoma, 15 patients whose glaucoma was present at birth were compared with 24 children in whom glaucoma developed between birth and age 3 months. Of the 29 eyes investigated in the former group 60% had a corneal diameter more than 1.5 mm greater than normal at the time of diagnosis, and 50% of the 22 eyes reassessed 5 years later had a visual acuity of less than 6/60; an average of 2.0 surgical procedures had been required to control the intraocular pressure. Of the 46 eyes in the latter group only 35% had a corneal diameter more than 1.5 mm greater than normal at the time of diagnosis, and of the 45 eyes reassessed 5 years later only 20% had a visual acuity of less than 6/60; an average of 1.3 operations had been required to control the intraocular pressure. Primary infantile glaucoma should be classified as either present at birth or developing between birth and age 3 months since the prognosis is so closely related to age at onset.