Abstract
Purpose: :
It is well established that children with fetal alcohol spectrum disorder (FASD) are susceptible to negative effects on the human central nervous system, particularly in regions such as the basal ganglia, hippocampus, corpus callosum and cerebellum, brain areas that control key human motor and cognitive functions. Surprisingly however, very little attention has been paid to the sensory systems that are fundamentally responsible for transmitting basic information into the CNS. Here we provide some of the first data on functional vision in FASD children.
Methods: :
21 children (6 to 13 yr) with diagnosed FASD were subjected to a comprehensive battery of tests designed to assess all major aspects of functional vision, namely spatial contrast sensitivity (FACT chart), visual acuity (Patti-Pics crowded optotypes), stereoacuity (Titmus fly stereotest), color vision (Ishihara plates), refractive error (Welch-Allyn non-cycloplegic autorefraction), and ocular alignment/motility (cover test, fix & follow). Testing was conducted monocularly and with optical correction if prescribed. A control sample of 21 children, matched precisely in age and gender, were also examined with the same test battery.
Results: :
Compared to control children, children with FASD showed significant deficits on visual acuity [M = 20/36 (FASD) vs. 20/22 (control)], stereoacuity (M =188 vs. 92 arcsec), contrast sensitivity (especially at high spatial frequencies), and color vision (primarily mild deuteranopia). Interestingly, FASD and control children showed highly similar levels of refractive error and only one child with FASD had ocular misalignment (monocular esotropia).
Conclusions: :
Children with FASD show substantial vision deficits, especially in visual functions (stereoacuity, contrast sensitivity, visual acuity) that require proper and intricate development of the visual cortex. Although we cannot rule out a retinal origin, it appears that these amblyopia-like deficits do not have an optical or neuromuscular basis, the most common precursors for typical childhood amblyopes.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • clinical (human) or epidemiologic studies: risk factor assessment