Classification of congenital and early onset retinitis pigmentosa.

We retrospectively studied 36 patients with congenital (Leber's amaurosis) and early onset retinitis pigmentosa (RP) to develop a new schematic classification system based on the age at onset of symptoms, severity of visual loss, and associated nonocular abnormalities. Our four groups were designated as complicated and uncomplicated Leber's congenital amaurosis and juvenile and early onset RP. Criteria for patient selection included an extinguished or barely recordable electroretinogram, well-documented age of onset, and comprehensive ocular and medical examinations before the age of 10 years. Among the congenitally blind, the distinguishing features were the degree of hyperopia and the presence or absence of neurologic abnormalities. Among patients with infantile or juvenile onset of retinal degeneration, the distinguishing features were the severity of visual loss and the age at onset of symptoms. The presence of nystagmus and hyperopia and the severity of central visual loss differentiated congenital from early onset RP.