D. Luisa Mayer

Neurodevelopmental Outcome in Survivors of Periventricular Hemorrhagic Infarction

OBJECTIVES. Periventricular hemorrhagic infarction is a serious complication of germinal matrix-intraventricular hemorrhage in premature infants. Our objective was to determine the neurodevelopmental and adaptive outcomes of periventricular hemorrhagic infarction survivors and identify early cranial ultrasound predictors of adverse outcome. METHODS. We retrospectively evaluated all cranial ultrasounds of 30 premature infants with periventricular hemorrhagic infarction and assigned a cranial ultrasound–based periventricular hemorrhagic infarction severity score (range: 0–3) on the basis of whether periventricular hemorrhagic infarction (1) involved ≥2 territories, (2) was bilateral, or (3) caused midline shift. We then performed neuromotor, visual function, and developmental evaluations (Mullen Scales of Early Learning, Vineland Adaptive Behavior Scale). Developmental scores below 2 SD from the mean were defined as abnormal. RESULTS. Median adjusted age at evaluation was 30 months (range: 12–66 months). Eighteen subjects (60%) had abnormal muscle tone, and 7 (26%) had visual field defects. Developmental delays involved gross motor (22 [73%]), fine motor (17 [59%]), visual receptive (13 [46%]), expressive language (11 [38%]), and cognitive (14 [50%]) domains. Impairment in daily living and socialization was documented in 10 (33%) and 6 (20%) infants, respectively. Higher cranial ultrasound–based periventricular hemorrhagic infarction severity scores predicted microcephaly and abnormalities in gross motor, visual receptive, and cognitive function. CONCLUSIONS. In the current era, two thirds of periventricular hemorrhagic infarction survivors develop significant cognitive and/or motor abnormalities, whereas adaptive skills are relatively spared. Higher cranial ultrasound–based periventricular hemorrhagic infarction severity scores predict worse outcome in several modalities and may prove to be a valuable tool for prognostication.

Esotropic children with amblyopia: Effects of patching on acuity

The rates of improvement of acuity in response to full-time occlusion therapy of 30 esotropic patients with amblyopia were determined. The childrens ages at the time of full-time patching ranged from about 3 to 10 years. In keeping with clinical experience, the rate of acuity improvement during patching was slower for older than younger patients. The age-related changes in responsiveness to patching were modeled nonlinearly to provide quantitative guidelines for management of occlusion therapy of esotropic children with amblyopia.

Visual development of infants with severe ocular disorders

Among 11 patients who presented as blind in early infancy, with Lebers congenital amaurosis (5 patients), optic nerve hypoplasia (4 patients), or macular colobomata (2 patients), 8 developed visually guided behavior and measurable grating acuity by age 5 to 46 months. All children with measurable grating acuity demonstrated visually guided mobility. Grating acuity was predictive of later visual performance in 10 of 11 patients by age 12 to 16 months. The best grating acuity attained by 7 months was 1.3 to 3.0 cycles/degrees (20/460 to 20/200) and 0.13 cycles/degrees (20/4700) by month 8. Two patients with Lebers congenital amaurosis and one with optic nerve hypoplasia remained blind. No clinical features existed to differentiate these three patients from the eight whose visual status improved. Posterior visual pathway maturation may underlie the improvement.

Visual acuities and dark-adapted thresholds of children with Bardet-Biedl syndrome

We studied the visual acuities and dark-adapted sensitivities of 12 children with Bardet-Biedl syndrome. All except one child, who was seen only once, were tested serially. In the first decade of life, all visual acuities were within 2 octaves of normal. All but two final visual acuities obtained from patients in their second and third decades were more than 2 octaves poorer than normal. Dark-adapted sensitivities of all patients were, or became, significantly less than normal even in those patients whose period of follow-up was limited to the first decade of life. Of the 11 patients measured serially, seven showed decreases in dark-adapted sensitivities of at least 0.5 log unit during the follow-up period, and the last measured sensitivities of all patients were at least 2 log units less than the normal mean.

Grating Acuity Cards: Validity and Reliability in Studies of Human Visual Development

Publisher Summary This chapter evaluates critically the acuity card procedure (ACP), a preferential looking (PL) measure of grating acuity, which has become a major outcome measure in the studies of the effects of dietary fatty acids on human infant development. It is found that in the studies of normal full-term and healthy preterm infants, in which testers are often familiar with the expected acuity scores for infants of a particular age, knowledge of the spatial frequency of the gratings on the acuity cards could bias the testers judgment concerning acuity threshold, thereby reducing the variability of the acuity results. In a study, in which the standard clinical ACP was used to test acuity in a large population of pediatric ophthalmology patients, mean acuities obtained by three testers showed significant differences for the right eye tests but not left eye tests. It is suggested that that most of the variability in test-retest comparisons is due to biological differences within individual infants and to variability arising from the measurement procedure.

Preferential Looking — Clinical Lessons

Preferential looking-based tests of acuity have been available for over a decade. The authors discuss their use in clinical practice, particularly in three groups in whom acuity could not be quantified by traditional means: normal infants, and young children who are either mentally retarded, or who have visual disorders. Preferential looking (PL) testing has increased our understanding of the natural history of visual pathway disorders and has revealed certain patterns of acuity development. Early acuity development may be normal, delayed, or stationary, while in later infancy and childhood the following abnormal patterns have been identified: asymptotic, parallel, catch-up, or regressing. While this information has introduced a degree of complexity hitherto unknown which, if misunderstood, can lead to test misinterpretation, it offers the clinician invaluable information to improve patient care, and may also offer clues to the fundamental mechanisms of visual development.

Delayed Visual Maturation

Fifty-three infants with delayed visual maturation (DVM) are presented. These have been classified according to their ocular and systemic features into three groups: DVM as an isolated anomaly, in association with mental retardation, and ocular abnormalities accompanied by DVM. The clinical features are discussed, particularly regarding the time and speed of visual improvement in the three groups. Infants with DVM who experienced difficulties in the perinatal period have an increased risk of developing permanent neurological sequelae.

Do preferential looking techniques underestimate infant visual acuity

Abstract Held et al . (1979) Vision Res . 19 , 1377–1379, have recently provided evidence for the existence of non-monotonic psychometric functions in infant acuity testing. We argue that these non-monotonicities are statistically significant in the original report, but are not robust across small variations of stimuli and testing techniques. The existence of such non-monotonicities in some laboratories does not imply that infant acuity has been universally underestimated by all PL techniques, nor does it argue against the general sensitivity of PL techniques as measures of other visual capacities in infants.

Visual fields in young children treated with vigabatrin.

Purpose. To evaluate white sphere kinetic perimetry (WSKP) as a test of the peripheral visual field in young children with a history of epilepsy and treatment with Vigabatrin (VGB). VGB is an antiepileptic medication that is associated with visual field constriction. Methods. Thirty-one VGB patients and 10 control subjects, median age 6 years, were recruited. Visual field extent on the major oblique meridia was tested with a 6° white sphere and WSKP, a method used by Quinn et al. to study field extent in children with retinopathy of prematurity. The same meridia were tested using Goldmann kinetic perimetry (GKP; 1.7° target) in those who were capable. Monocular and binocular tests were conducted. Visual field extent for WSKP and GKP were compared in VGB patients and control subjects. Results. Twenty-eight of 31 VGB patients were testable with binocular WSKP and their median visual field extents were smaller than controls. In 8 of 28 (29%) VGB patients, binocular field extents were smaller than the minimum in the control subjects. Monocular WSKP results did not differ between VGB patients and control subjects. Nine VGB patients were testable with both WSKP and GKP; visual field extents did not differ between tests. Conclusions. WSKP is feasible in VGB patients, even in those with developmental delays. WSKP has the potential to detect visual field constriction associated with VGB use.

Reduced visual resolution acuity and cerebral white matter damage in very-low-birthweight infants

Neonatal cerebral white matter echolucencies predict visual resolution acuity deficits in very-low-birthweight (VLBW) infants. We examined maternal sociodemographic, lifestyle, intrapartum, infant birth/perinatal, and ocular motor/refractive characteristics to determine whether they accounted for this association in infants who were tested once between postnatal age 25 and 56 weeks (corrected for gestational age at birth). Cranial ultrasound scans were read by consensus to identify echolucency in a population of VLBW infants with no known ocular abnormalities. Visual resolution acuity was measured with the Acuity Card Procedure (ACP) in 14 infants with echolucency and compared with that of 81 VLBW infants born in the same hospitals with normal ultrasound scans. In time-oriented logistic regression models, echolucency remained a consistent predictor of abnormal visual resolution acuity after adjustment for covariates in three developmental periods (pre-, peri-, and postnatal). Odds ratios ranged from 19.3 (95% confidence interval, 4.5 to 82.2; p=0.001) to 10.4 (95% confidence interval, 1.3 to 81.9; p=0.03). Reduced visual resolution acuity in VLBW infants appears to be due to cerebral white matter damage.