Angela M Brown1, Delwin T Lindsey2, Joanna G Cammenga1, Peter J Giannone3, Michael R Stenger4. 1. College of Optometry, The Ohio State University, Columbus, Ohio, United States. 2. College of Optometry, The Ohio State University, Columbus, Ohio, United States Department of Psychology, The Ohio State University, Mansfield, Columbus, Ohio, United States. 3. College of Medicine, The Ohio State University, Columbus, Ohio, United States Kentucky Children's Hospital, University of Kentucky College of Medicine, Lexington, Kentucky, United States. 4. College of Medicine, The Ohio State University, Columbus, Ohio, United States Nationwide Children's Hospital, Columbus, Ohio, United States.
Abstract
PURPOSE: To measure the binocular contrast sensitivity (CS) of newborn infants using a fixation-and-following card procedure. METHODS: The CS of 119 healthy newborn infants was measured using stimuli printed on cards under the descending method of limits (93 infants) and randomized/masked designs (26 infants). One experienced and one novice adult observer tested the infants using vertical square-wave gratings (0.06 and 0.10 cyc/deg; 20/10,000 and 20/6000 nominal Snellen equivalent); the experienced observer also tested using horizontal gratings (0.10 cyc/deg) and using the Method of Constant Stimuli while being kept unaware of the stimulus values. RESULTS: The CS of the newborn infant was 2.0 (contrast threshold = 0.497; 95% confidence interval: 0.475-0.524) for vertically oriented gratings and 1.74 (threshold = 0.575; 95% confidence interval: 0.523-0.633) for horizontally oriented gratings (P < 0.0006). The standard deviation of infant CS was comparable to that obtained by others on adults using the Pelli-Robson chart. The two observers showed similar practice effects. Randomization of stimulus order and masking of the adult observer had no effect on CS. CONCLUSIONS: The CS of individual newborn human infants can be measured using a fixation-and-following card procedure. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.
PURPOSE: To measure the binocular contrast sensitivity (CS) of newborn infants using a fixation-and-following card procedure. METHODS: The CS of 119 healthy newborn infants was measured using stimuli printed on cards under the descending method of limits (93 infants) and randomized/masked designs (26 infants). One experienced and one novice adult observer tested the infants using vertical square-wave gratings (0.06 and 0.10 cyc/deg; 20/10,000 and 20/6000 nominal Snellen equivalent); the experienced observer also tested using horizontal gratings (0.10 cyc/deg) and using the Method of Constant Stimuli while being kept unaware of the stimulus values. RESULTS: The CS of the newborn infant was 2.0 (contrast threshold = 0.497; 95% confidence interval: 0.475-0.524) for vertically oriented gratings and 1.74 (threshold = 0.575; 95% confidence interval: 0.523-0.633) for horizontally oriented gratings (P < 0.0006). The standard deviation of infant CS was comparable to that obtained by others on adults using the Pelli-Robson chart. The two observers showed similar practice effects. Randomization of stimulus order and masking of the adult observer had no effect on CS. CONCLUSIONS: The CS of individual newborn humaninfants can be measured using a fixation-and-following card procedure. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.