Vision in Leber congenital amaurosis

To determine if vision changed with age in infants and children with Leber congenital amaurosis.

Grating acuity and dark-adapted visual thresholds were tested in 36 patients with Leber congenital amaurosis. Longitudinal assessments were obtained for 24 patients and analyzed for significant changes over time. Visual acuity and threshold and the courses of visual acuity and threshold were examined for significant associations with hyperopia, fundus appearance, and complicated vs uncomplicated status.

Measurable grating acuities ranged from 0.16 to 6 cycles per degree (median, 1.27 cycles per degree or about 20/500), and dark-adapted visual thresholds were elevated 1.0 to 5.6 log units (median, 2.33 log units). Eighteen patients never had demonstrable grating acuity, and 12 had no light perception. Among those with serial tests, visual acuity improved or remained stable in 10 patients and declined in 4. Dark-adapted visual thresholds were stable in those with improving or stable visual acuities but worsened in 5 patients, including the 4 whose visual acuity worsened. No significant associations of visual acuity, dark-adapted visual threshold, the course of visual acuity, or the course of dark-adapted visual threshold with hyperopia, fundus appearance, or complicated vs uncomplicated status were found.

Visual capabilities varied widely. Vision was stable in the majority by longitudinal measures but increased in a few and deteriorated in others. Neither ocular characteristics nor complicated vs uncomplicated status predicted visual function. Thus, if vision and its course are to be known in a patient with Leber congenital amaurosis, it must be tested.