Visual development

The present paper evaluates the most recent randomized controlled trials assessing the efficacy of n-3 LCPUFA supplementation (with or without n-6 LCPUFA) during pregnancy, lactation, infancy and childhood on visual and cognitive development. Available evidence suggests a beneficial effect of maternal n-3 LCPUFA supplementation during pregnancy and lactation on cognitive development of infants and children, but not for visual development. Evidence for an effect of LCPUFA supplementation of preterm and term infants on cognitive development of infants remains inconclusive. However, supplementing term infants with daily doses of 100 mg docosahexaenoic acid plus 200 mg arachidonic acid improves visual development as measured by electrophysiological tests. Evidence for benefits of n-3 LCPUFA on cognitive development in healthy children older than 2 years of age is too limited to allow a clear conclusion. Taken together, the evidence for potential benefits of LCPUFA supplementation is promising but yet inconclusive.

BACKGROUND: The Illinois College of Optometry's (ICO) Pediatric Outreach Program (POP) provides comprehensive vision care for high-risk children from birth to approximately 5 years of age in partnership with early intervention programs throughout the city of Chicago. Grant funds assisted in the ability to deliver vision services and spectacles to uninsured children. This report describes the structure and organization of the POP and presents the visual data. METHODS: Comprehensive eye examinations were performed on 4,298 children ages birth to approximately 5 years at 76 early intervention program sites. All of the children evaluated were enrolled from early intervention/Head Start programs. Visual acuity determination (by Lea method), assessment of binocular status, stereopsis evaluation, cycloplegic retinoscopy, and ocular health evaluations were performed. As necessary, eyeglasses were prescribed. Amblyogenic risk factors, strabismus, and ocular pathology were identified. RESULTS: Of the 4,298 children examined, 49% were boys and 51% were girls. Two percent were younger than 12 months old, 6% were 1.1 to 2 years old, 12% were 2.1 to 3 years, 30% were 3.1 to 4 years, 35% were 4.1 to 5 years, 14% were 5.1 to 6 years, and 1% were older than 6 years. Hyperopia and emmetropia were the most common refractive classifications among the children examined. Approximately 6.5% had risk factors for isometropic amblyopia, and 2.3% had risk factors for anisometropic amblyopia. Approximately 1% of the children had strabismus. Less than 1% of the children examined were identified with ocular pathology. Spectacles were dispensed to 16.6% of the children examined. CONCLUSIONS: The Pediatric Outreach Program provides early identification and treatment of abnormal visual conditions, ensuring that children have maximal visual acuity and visual function. The educational aspects of the program have also contributed to its successes. Education for parents and early intervention agency staff promote the importance of comprehensive vision examinations for children 5 years of age and younger.

High-density EEG was used to investigate the cortical processing of a rotating visual pattern in 2-, 3-, and 5-month-old infants and in adults. Motion induced ERP in the parietal and the temporal-occipital border regions (OT) was elicited at all ages. The ERP was discernable in the 2-months-olds, significant and unilateral in the 3-month-olds and significantly bilateral in the 5-month-olds and adults. The motion induced ERP in the primary visual area was absent in the 2-month-olds and later than in the OT area for the 3-month-olds indicating that information to OT may be supplied by the V1 bypass at these ages. The results are in agreement with behavioural and psychophysical data in infants.

Interactive metric visualization is a novel approach providing complex, multi-dimensional feedback on the effects of layout changes in user interface designs. A graphical overlay, based on the underlying rationale of quantitative design metrics, provides immediate feedback, continually guiding designers toward improved layouts. Effective visual metaphors, colour coding, and dynamic updating enable designers to interpret and utilize more complex informatioiv than from simple quantitative data or static overlays. This technique is especially suited to accelerated design and development using modern visual development tools. An experimental prototype for this approach is described and initial experience is reported 2 13 0-8186-7525-W96 $05.00 0 1996 IEEE

PURPOSE-To characterize how the mechanisms that produce unilateral form-deprivation amblyopia integrate the effects of normal and abnormal vision over time, the effects of brief daily periods of unrestricted vision on the spatial vision losses produced by monocular form deprivation were investigated in infant monkeys.

PURPOSE. Studies in nonhuman primates show that monocular visual deprivation starting at different ages has different effects on cells in the parvocellular and magnocellular laminae of the lateral geniculate nucleus. The present study used color and luminance contrast sensitivity (CS) measurements to look for differences in parvocellular-and magnocellular-related visual function in human subjects with strabismic amblyopia. METHODS. Fifteen subjects with early-and 14 with late-onset strabismic amblyopia and similar ranges of visual acuity were studied, together with 15 subjects with normal vision. Contrast sensitivities were measured to an equiluminant (L-M conemodulated) grating with slow onset and an achromatic (LϩM cone-modulated) 0.8-cpd grating with rapid onset using an adaptive method. RESULTS. Luminance and color CS were lower in the amblyopic eyes than in the fellow eyes of all amblyopes. For luminance CS, this was due both to an increase in sensitivity of the fellow eye and to a reduction in sensitivity in the amblyopic eye. Color CS was greatly reduced in the amblyopic and fellow eyes of subjects with strabismic amblyopia of early-and late onset compared with subjects with normal vision. The reduction in color CS compared with luminance CS was significantly greater in eyes with late-rather than early-onset amblyopia. CONCLUSIONS. Parvocellular and magnocellular function are differentially affected in the amblyopic and fellow eyes of subjects with strabismic amblyopia. The difference is more marked in late-onset amblyopia than in early-onset amblyopia. (Invest Ophthalmol Vis Sci. 2006;47:4836 -4841)

The functional selectivity of human primary visual cortex (V1) for orientation and motion direction is established by around 3 months of age [1-3], but there have been few studies of the development of extrastriate visual areas that integrate outputs from V1 . We investigated sensitivity and topographical organization for global form and motion with high-density visual event-related potentials (VERPs) in 4-to 5-month-old infants and adults. Responses were measured to transitions between concentrically organized elements (short arc segments for form, dot trajectories for motion) and random arrangements. Adults showed topographically separate responses, with midline motion and more lateral form responses. Of 26 infants, 25 showed significant motion responses but only 13 showed form responses, suggesting more advanced development for extrastriate motion areas than form. Infants' form and motion responses were topographically distinct but contrasted with the corresponding adult topographies, with infants' motion responses more lateral than form responses. These results imply distinct neural sources at both ages and raise the possibility of substantial reorganization of extrastriate networks between infancy and adulthood. We speculate that global motion responses arise from area V5 in infants but are dominated by more medial areas such as V3/V3A and V6 in adults.

To determine the prevalence, nature, and degree of accommodative dysfunction among children with different types and severities of cerebral palsy (CP) in Northern Ireland. METHODS. Ninety subjects with CP (aged 4 -15 years) were recruited through the Northern Ireland CP Register (NICPR). Modified Nott dynamic retinoscopy was used to measure lag and lead of accommodation at three test distances: 25 cm (4 D), 16.7 cm (6 D), and 10 cm (10 D) with the distance correction in place. Accommodative function was also assessed in an age-matched control group (n ϭ 125) for comparison. Each subject's neurologic status was derived from the NICPR. RESULTS. Children with CP demonstrate significantly reduced accommodative responses compared with their neurologically normal peers. Of the subjects with CP, 57.6% demonstrated an accommodative lag outside normal limits at one or more distances. Reduced accommodative responses were significantly associated with more severe motor and intellectual impairments (ANOVA P ϭ 0.001, P Ͻ 0.01, respectively). CONCLUSIONS. Brain injury such as that present in CP has a significant impact on accommodative function. These findings have implications for the optometric care of children with CP and inform our understanding of the impact of early brain injury on visual development. (Invest Ophthalmol Vis Sci.