RESUMO
BACKGROUND: High-contrast visual acuity (HCVA) changes with age, yet little is known about pediatric-specific age- and sex-normative values for low-contrast letter acuity (LCLA). We define maturational changes in monocular and binocular HCVA and LCLA in childhood and adolescence. METHODS: Normally sighted youth (ages 5-20 years, without neurologic or ophthalmologic disease and best-corrected HCVA of 20/25 or better in each eye) were recruited. Mean monocular and binocular scores using Early Treatment Diabetic Retinopathy Study (for HCVA) and 2.5% and 1.25% Sloan (for LCLA) charts and the magnitude of binocular summation were calculated using 2-year bins. Relationships between scores and age were explored using scatterplots with Locally Weighted Scatterplot Smoothing (LOWESS) and analysis of variance that accounts for intereye correlation, followed by test of linear trend for age effect. RESULTS: Among 101 (202 eyes) healthy participants (mean age 13 years, 42% males), monocular and binocular scores varied by age, with highest mean scores achieved in the 13 to 14-year age group for both HCVA and LCLA. Between the ages of 5 and 14.9 years, monocular scores increased linearly with age (0.76 letter/year for HCVA, 1.11 letters/year for 2.5% LCLA, and 0.97 letter/year for 1.25% LCLA; all P < 0.0001). Binocular HCVA scores also increased with age between 5 and 14.9 years (0.71 letters/year, P < 0.0001). The magnitude of binocular summation for HCVA or LCLA did not change with age. CONCLUSIONS: HCVA and LCLA abilities mature into adolescence, peak between 13 and 14.9 years of age, and then plateau into adulthood. Evaluation of patients with visual deficits should consider age-expected normal visual acuity.
Assuntos
Envelhecimento/fisiologia , Visão Binocular/fisiologia , Visão Monocular/fisiologia , Acuidade Visual/fisiologia , Percepção Visual/fisiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Valores de Referência , Adulto JovemRESUMO
BACKGROUND AND PURPOSE: Pediatric-onset multiple sclerosis (POMS) is associated with focal inflammatory lesions and the loss of cortical and deep gray matter. Optic neuritis (ON) and white matter (WM) lesions in the visual pathway can directly contribute to visual cortical mantle thinning. We determine the relative contributions of MS insult on anterior and posterior visual pathway integrity. METHODS: High- and low-contrast visual acuity, optical coherence tomography (OCT), and 3T MRI scans were obtained from 20 POMS patients (10 with remote ON) and 22 age- and sex-matched healthy controls. Cortical mantle thickness was measured using FreeSurfer. Fractional anisotropy (FA) and mean diffusivity were calculated for postchiasmal optic radiations (with and without WM lesions). Groups were compared using Student's t-test (adjusted for multiple comparisons), and simple linear regression was used to investigate interrelationships between measures. RESULTS: Mean cortical thickness of the whole brain was reduced in patients (2.49 mm) versus controls (2.58 mm, P = .0432) and in the visual cortex (2.07 mm vs. 2.17 mm, P = .0059), although the foveal confluence was spared. Mean FA of the optic radiations was reduced in POMS (.40) versus controls (.43, P = .0042) and correlated with visual cortical mantle thickness in POMS (P = .017). Visual acuity, OCT measures, and lesion volumes in the optic radiations were not associated with cortical mantle thickness. CONCLUSIONS: POMS negatively impacts the integrity of the anterior visual pathway, but it is the loss of WM integrity that drives anterograde loss of the cortical mantle. Preserved visual acuity and foveal sparing imply some degree of functional and structural resilience.