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Wednesday, April 28, 8:30 - 10:30 AM Hall BC Poster Session Program Number/Board # Range: 4314-4320 / B775-B781 466. Pediatric Refractive Error Organizing Section: VI 4314 - B775 4315 - B776 Variability of Autorefractor Measurement in Infants, Children and Adults:The Welch Allyn SureSight M.Courage, S.M. Drodge, M.E. Mercer, R.J. Adams. Depts. of Psychology & Pediatrics, Faculties of Science & Medicine, Memorial Univ of Newfoundland, St John’s, NF, Canada. Purpose:In recent years, several hand-held, portable and user friendly autorefractors have emerged to provide rapid measurements of spherical and cylindrical refractive error for a wide variety of clinical patients. The Welch Allyn SureSight is perhaps the most flexible and user/patient friendly of these devices as it is targeted for very young pediatric patients and is calibrated for use without cycloplegia. To date, there has been little evaluation of the effectiveness of this device, in particular, the consistency of non-cycloplegic measurements and comparability to those obtained with formal clinical techniques. Methods:Within a single session, we used the SureSight to obtain two measurements of the right eye in infants (5-19 mo, n=86), preschoolers (2-5 yr, n=87), school-age children (7-10 yr, n=102) and young adults (19-25 yr, n=112). The adults, (range = -10 to +7.75D sph; 0 to 3.5 cyl) were also tested on two separate occasions over the next month. Adult data were compared to non-cycloplegic measurements obtained with formal clinical autorefractive instrumentation. Results: In general, age and the variability of refractive measurements were inversely related. The mean absolute test-retest difference for sphere was 0.26D (SD=0.21D) for adults compared to 0.40D (SD =0.44D) for school children, 0.61D (SD = 0.66D) for preschoolers and 0.78D (SD = 0.52D) for infants. The trend for cylinder was similar but with less variability within each group (Mean diff. = 0.31D, 0.22D, 0.18D, and 0.12D for infants, preschoolers, school children and adults, respectively). One way ANOVA revealed that for both cylinder and sphere, the developmental trend was significant (both p < 0.01). For adults, measurement variability increased over time (e.g., spherical estimates separated by a month differed by 0.60D compared to 0.26D within a session, p< .001). Finally, comparison with clinical measurements revealed that the autorefractor underestimated sphere by 0.80D and cylinder by 0.24D. Conclusions:The Welch Allyn SureSight autorefractor likely provides reasonable first estimates of refractive error for a broad patient population. However, estimates are much less stable in younger patients, are more variable over sessions in older subjects and appear to underestimate spherical error somewhat. Nonetheless, given these shortcomings (likely due to accommodation-related factors), the SureSight’s efficiency and flexibility make it, for many patients, (e.g. young infants), perhaps the only practical option for estimating refractive error. CR: M. Courage, None; S.M. Drodge, None; M.E. Mercer, None; R.J. Adams, None. Support: NSERC 03-372 Refractive Error and the Early Development of Visual Acuity R.J. Adams, S.M. Drodge, J.R. Drover, S.Dalton, M.L. Courage. Departments of Psychology & Pediatrics, Faculties of Science & Medicine, Memorial Univ of Newfoundland, St John’s, NF, Canada. Purpose: In previous work (ARVO 2001, 2002, 2003) we have reported that among individual infants and young children, there is substantial variation in the development of both spatial vision (visual acuity, contrast sensitivity) and refractive error. However, despite significant scientific and clinical interest, the relationship between early optical error and early visual development is very poorly understood, no doubt due to the methodological and technical difficulties involved in obtaining accurate refractive estimates from individual infants and toddlers. In the present work, we employ newly developed refractive technology in an attempt to better quantify how much the early spatial limitations are accounted for by optical immaturities. Methods: Left eyes from 6-month-old (n=28) and 12-month-old (n=30) infants were refracted twice with the Welch Allyn SureSight autorefractor (without cycloplegia) and within the same session, assessed with the Teller acuity cards. For comparison, left eyes from 3-4-year-old preschoolers (n=56), 7-8-year-old children (n= 44) and young adults (n=59) were refracted, and acuity assessed (uncorrected) with either Snellen letters (adults and children) or LEA symbols (preschoolers). Results: Calculations of total absolute refractive error [|Sph| + |Cyl|], spherical equivalent, and other linear models of aggregate refractive error all revealed consistent results. As expected from traditional work, levels of visual acuity in both adults and school-age children were predicted well from the magnitude of uncorrected refractive error (all r > 0.59, all p < 0.01). However, although preschool children showed the same trend as older subjects, there was absolutely no relationship between visual acuity and refractive error in both groups of infants (range of r = -0.08 to +0.06). Conclusions: Our study is the first to examine systematically, the relationship between spatial vision and refractive error in young infants and preschoolers. In preschool children, like adults and older children, visual acuity is predicted well by optical factors. Conversely, almost none of the variation in visual acuity among individual infants is accounted for by differences in optics. Consistent with current neurological and psychophysical models of early visual development, our results suggest that infants’ spatial vision is constrained almost entirely by photoreceptoral and neural immaturities. CR: R.J. Adams, None; S.M. Drodge, None; J.R. Drover, None; S. Dalton, None; M.L. Courage, None. Support: NSERC 03-372 4316 - B777 4317 - B778 An Evaluation of the Accuracy of Estimation Retinoscopy D.S. Carlin, D.K. Wallace, J.D. Wright. Pediatric Ophthalmology and Strabismus, University of North Carolina, Chapel Hill, NC. Introduction: One of the daily challenges of a pediatric ophthalmology practice is retinoscopy of an uncooperative child. For those children who object most strongly to the placement of lenses in front of their eyes, it would be ideal to obtain an accurate estimate of refractive error without using lenses. One technique of estimation retinoscopy involves sliding the sleeve of the Copeland retinoscope downward until a neutral red reflex is achieved. The purpose of this study was to evaluate the accuracy of this technique by comparing it to results from standard cycloplegic retinoscopy in cooperative children. Methods: A Copeland retinoscope was calibrated using a schematic eye and 3 healthy adult volunteers who received cycloplegic eye drops. A scale was created adjacent to the sleeve of the retinoscope which allowed an estimate of refractive error based on the position of the top of the sleeve. Seventy eyes of 35 children had cycloplegic estimation retinoscopy done by one examiner who was blinded to refractive errors, and accuracy was defined as one diopter within the refractive error obtained by standard retinoscopy with loose lenses. Results: Estimation retinoscopy was accurate in: 34 of 37 eyes (92%) with spherical equivalence between -1.50 D and +1.50 D, 13 of 33 eyes (39%) with spherical equivalence between +1.75 D and +6.00 D, 12 of 13 eyes (92%) with cylindrical power between +1.00 D and +2.00 D, and 3 of 9 eyes (33%) with cylindrical power between +2.25 D and +5.00 D. None of 37 eyes with an estimated spherical equivalent less than +1.50 had an actual spherical equivalent greater than +4.25 D, and one of 26 eyes (4%) with an estimated cylinder power of +1.00 D or less had an actual cylinder power of greater than +2.25 D. Conclusions: The technique of estimation retinoscopy done by sliding the sleeve of the Copeland retinoscope downward is very sensitive for eyes with very mild myopia or hyperopia, but it has poor sensitivity for eyes with higher degrees of hyperopia or astigmatism. However, when this estimation technique indicates a spherical equivalent between -1.50 D and +1.50 D, with +1.00 D of cylinder power or less, the examiner can be assured that an amblyogenic refractive error is almost never present. CR: D.S. Carlin, None; D.K. Wallace, None; J.D. Wright, None. Support: Maximizing Refractive Error Detection in Preschool Vision Screening A.M. Hickson1, P.P. Schmidt2. 1Pediatric Optometry, The Ohio State College of Optometry, Eagan, MN; 2The Ohio State College of Optometry, Columbus, OH. Pur pose: Sig n if icant ref ract ive er ror, hy peropia, an isomet ropia, and astigmatism,in early childhood is the most frequent cause of amblyopia. To compare refracting methods for detect significant refractive error when receiver operating characteristic (ROC) curve analysis is used to maximize performance. Methods: 48 preschool children (Mean Age: 4.4 yrs + 1.0 yr) had refractive error measured in a pre-determined order by cycloplegic (C) retinoscopy, noncycloplegic (NC) retinoscopy (Ret), and autorefraction (Nikon Retinomax K-plus (Retmax) and 2 Welch Allyn (WA) autorefractors [Prototype (WAP) & SureSight (SS) 1.22 Child Mode]). All testers were masked; C retinoscopy was the gold standard. ROC curve analysis was conducted for each refracting method. For each refractive error type, specificity (Sp) levels were set at 0.85, 0.90, and 0.95; sensitivity (Se) and cut points (CP) were determined. Results: Hyperopia- Sp=0.85, Se: 0.42 (WAP) - 1.00 (NC Ret); CP=3.44D, 1.37D. Sp=0.90, Se: 0.62 (NC Retmax) - 1.00 (NC Ret); CP=1.37D, 1.37D. Sp=0.95, Se: 0.17 (WAP) - 0.70 (SS 1.22); CP=3.95D, 3.87D. Anisometriopia- Sp=0.85, Se:0.0 (SS 1.22) - 0.50 (NC Ret); CP=1.13D, 0.62D. Sp=0.90, Se:0.0 (SS 1.22) - 0.50 (NC Ret); CP=1.38D, 0.88D. Sp=0.95, Se: 0.0 (SS 1.22, Retmax) - 0.25 (NC Ret, WAP); CP=1.25D - 2.06D. Astigmatism- Sp=0.85, Se:1.00 for all instruments; CP=0.88D - 1.63D. Sp=0.90, Se:1.00 for all instruments; CP=1.13D - 1.88D. Sp=0.95, Se: 1.00 for all instruments; CP=1.75D - 2.50D. Conclusions: Hyperopic cut points and sensitivity vary across methods. Anisometropia cut points vary; sensitivity is poor. Astigmatic cut points and sensitivity are similar across methods. ROC curve analysis enhances the potential usefulness of NC retinoscopy, Retinomax, and SureSight 1.22 method of screening preschool children for significant refractive error. CR: A.M. Hickson, None; P.P. Schmidt, None. Support: Ruth Morris Fund, Welch Allyn Inc. 4318 - B779 4319 - B780 Hyperopia and the emergent literacy skills of young children S.Shankar1, M.A. Evans2, K.Ball1, J.Saad3, A.Butler1, W.R. Bobier1. 1School of Optometry, University of Waterloo, ON, Canada; 2Psychology, University of Guelph, ON, Canada; 3 University of Western Ontario, London, ON, Canada. Pur pose: To measu re emergent literacy skills in u ncor rected hy peropic child ren. Methods: Eighty one children were recruited from a vision study and tested for visual acuity (VA; Cambridge Crowding cards, single optotypes and crowded letters) and then administered three standardized psychological tests to test phonological awareness, letter and word reading skills, and receptive vocabulary, and an experimental test of visual orthographic skills. Parents completed a survey of family demographics and the child’s home literacy experiences. As dry refractions underestimated hyperopia, results presented are for 27 children with current cycloplegic data. When participants were classified on their cycloplegic refraction as hyperopes (≥ 2D OU; N=9; aged 64.6±11 m) or emmetropes (≤ 1.75 D OU; N=18; aged 57.7±10 m) performance differences in vision testing and literacy were found. This division showed no statistically significant differences between the two groups for age, and family variables that are known to contribute to emergent literacy skills such as birth order, number of children in family, mother’s or father’s education and reading skills, shared reading time, number of children’s books at home, etc. Results: Vision: The crowding effect was larger for hyperopes than for emmetropes for the left eye (χ2 (3) =12.82, p=.005), and approached significance for the right eye (χ 2 (3) =7.18, p=.06). There were no significant differences for VA for single optotypes between hyperopes and emmetropes. Literacy: Hyperopes had lower scores than emmetropes for visual-orthographic discrimination (Mann-Whitney U=43.5, p=0.05), phonological awareness (Mann-Whitney U =35.5, p=0.02) and verbal ability and receptive vocabulary (Mann-Whitney U=40.5, p=0.04). They did not differ in letter and word recognition ability. While 4 of the emmetropes had received professional help for parental concerns (speech/language), only one hyperopes’ parent had speech/language concerns but had not consulted a professional. Conclusions: 1. Children who are hyperopic (≥2D) and have increased crowding effects also show reduced performance on tests of visual-orthographic discrimination, phonological awareness, and verbal ability. 2. Differences between hyperopes and emmetropes may represent developmental deficits in the visuocognitive domain1, but the parental questionnaire revealed no significant concerns for any of the hyperopes. 1 Atkinson, J, Anker, S, Nardini, M, Braddick, O. 2002. Strabismus, 10, 187-98 CR: S. Shankar, None; M.A. Evans, None; K. Ball, None; J. Saad, None; A. Butler, None; W.R. Bobier, None. Support: Canadian Language and Literacy Research Network DEVELOPMENT OF SPHERICAL EQUIVALENT AND ACUITY IN CHILDREN WITH OCULOCUTANEOUS ALBINISM (OCA) N.Couture1A, R.M. Hansen1A, A.Moskowitz1A, A.Gee1A, J.LeMoine1A, B.-L.Wu1B, A.B. Fulton1A. AOphthalmology, BLaboratory Medicine, 1Children’s Hospital, Boston, MA. Purpose: Study the development of spherical equivalent and acuity in infants and young children with OCA. Broad distributions of refractive error and letter acuity are recognized in mature subjects with OCA Methods: Longitudinal measures of refractive error and acuity were obtained in 16 children starting at age 1 month. Each were followed for up to 8 years. Each demonstrated physical features of OCA and had tyrosinase gene and P-gene testing. Before age 3 years, binocular grating acuities were measured with the Teller Acuity Card procedure. At older ages, symbol acuities were obtained using established clinical tests (including LEA, HOTV, EDTRS). Spherical equivalents were derived from results of cycloplegic retinoscopy. Spherical equivalents and grating acuities were compared to the 95% prediction interval (PI) for healthy infants and children. Data within the PI was defined as normal, and outside the PI as abnormal. Results: The course of grating acuity was abnormal in 9 and normal in 7 of the 16 subjects. The course of spherical equivalent was abnormal in 8 and normal in 8 subjects, but no significant association between grating acuity and spherical equivalent was found. The abnormal courses of spherical equivalent were characterized by persistent, moderate (N=2) or high (N=6) hyperopia, or significant myopia that increased until 2 years of age (N=2). Six of the seven subjects with normal grating acuity developed abnormal spherical equivalents and low symbol acuity (20/100 or poorer). Among subjects with normal refractive development and good symbol acuity (20/50 or better), only one had a history of abnormal grating acuity. Genotype did not predict acuities or refraction. Consistent with previous reports, Summer’s indices of ocular hypopigmentation did not predict acuity, nor did the indices predict refractive error. Conclusions: Abnormal refractive development was associated with low symbol acuity in these subjects with OCA. The determinants of refractive development and acuity in OCA remain to be elucidated. CR: N. Couture, None; R.M. Hansen, None; A. Moskowitz, None; A. Gee, None; J. LeMoine, None; B. Wu, None; A.B. Fulton, None. Support: NIH Grant EY10597 Copyright 2004 by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. For permission to reproduce any abstract, contact the ARVO Office at [email protected]. Commercial Relationships are noted at the end of each abstract by “None” or with codes. 4314–4319 Wednesday, April 28, 8:30 - 10:30 AM Hall BC Poster Session Program Number/Board # Range: 4314-4320 / B775-B781 466. Pediatric Refractive Error Organizing Section: VI 4320 - B781 Objective Optical Function Evaluation in a Child with Crystalline Lens Dislocation Using a Point Spread Function Analysis System M.A. Goto1, T.Tachikawa1, M.Matsubara1, M.Shibutani2, K.Kobayashi2, G.Takeuchi2, K.Negishi3, K.Ohnuma4, K.Ohno5, T.Noda5. 1Department of Ophthalmology, Tokyo Women’s Medical University Daini Hospital, Tokyo, Japan; 2Topcon Corporation, Tokyo, Japan; 3Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan; 4 Faculty of Engineering, Chiba University, Chiba, Japan; 5Department of Ophthalmology, National Institute of Sensory Organs, Tokyo, Japan. Purpose: To objectively estimate the optical f unction in a child with crystalline lens dislocation using a new point spread function (PSF) analyzer. Methods: Bilateral visual function in a 6-year-old boy with lens dislocation associated with Marfan’s syndrome was evaluated by PSF analysis. Double-pass PSFs were obtained and the optical status was objectively analyzed. The retinal images were simulated and evaluated objectively by convoluting the PSFs to Landolt’s ring images. Results: The subjective best-corrected visual acuities (BCVAs) were 30/20 (20/15 × sph. -2.00 D, cyl. -2.50 D, ax. 160゚) in the right eye and 20/50 (20/30 × sph. -2.75 D, cyl. -5.00 D, ax. 55゚) in the left eye. Autorefractometry showed 3.75 D of astigmatism in the right eye; the left eye was unmeasurable. Using PSF analysis, the anterior and posterior focal lines in the left eye were identified objectively and the estimated astigmatism was calculated as 9.0 D. Simulated retinal images of Landolt’s rings were synthesized, and it was theorized that astigmatic correction should substantially improve optical function. After prescribing glasses based on PSF analysis data, the BCVA improved to 20/22. In the right eye, although the presumed amount of astigmatism was less than in the left eye, asymmetrical components of aberration were recognized in the aerial images and simulated retinal images that seemed uncorrectable with spectacles. Conclusions: In eyes with lens dislocation, marked oblique astigmatism occurred according to the degree of the dislocation. The PSF analysis system can objectively evaluate the characteristics of the optical function in pediatric eyes in which subjective examinations are difficult to perform. CR: M.A. Goto, None; T. Tachikawa, None; M. Matsubara, None; M. Shibutani, Topcon Corporation E; K. Kobayashi, Topcon Corporation E; G. Takeuchi, Topcon Corporation E; K. Negishi, None; K. Ohnuma, None; K. Ohno, None; T. Noda, None. Support: Copyright 2004 by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. For permission to reproduce any abstract, contact the ARVO Office at [email protected]. Commercial Relationships are noted at the end of each abstract by “None” or with codes. 4320