| Summary: | Thesis (M.Sc.)--Memorial University of Newfoundland, 2000. Psychology Bibliography: leaves 68-82 In a previous study (Adams, Courage, Byars, & McKim, 1994), the Teller Acuity Cards (TAC) were used to assess binocular grating acuity in 349 infants between 2 and 42 months (M = 13.20 months, SD = 11.65). All of these children were at risk for abnormal visual/neurological development due to preterm birth and/or significant perinatal complications (e.g., birth asphyxia, seizures, respiratory distress syndrome). In the present study, 76 of these children were reassessed several years later with the TAC, as well as with a battery of spatial and non-spatial vision tests (M age at follow-up = 78.05 months, SD = 34.37, range: 35-122 months). Results of this assessment showed: (1) Compared to healthy, age-matched control children (n = 61) tested with the same battery of follow-up tests, at-risk children had consistently lower test scores, and a higher incidence of ocular disorders and refractive errors. However, most of these visual deficits were not serious. (2) Non-statistical analyses suggest that children who experienced perinatal seizures, bronchopulmonary dysplasia, pneumothorax or necrotizing enterocolitis had relatively poorer visual outcomes than children with other risk factors. (3) Correlational analyses show that an early measure of grating acuity was unrelated to follow-up grating acuity, nor to any other later measure of spatial or non- spatial vision. However, when both the early and follow-up results were categorized as either "normal" or "abnormal", an early TAC result did have high normal predictive value and specificity, but low abnormal predictive value and sensitivity for identifying children with and without visual disorders. These data imply that children who experienced significant perinatal risk factors are at some risk for mild, long-term visual deficits. However, predictions based upon a single estimate of Teller acuity must be made with caution, even when the initial results are normal.
|
|---|