Visual Psychophysics / Physiological Optics - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group – Visual Psychophysics / Physiological OpticsProgram Number: 2331 Poster Board Number: B0290Presentation Time: 2:45 PM - 4:30 PMEffects of Eyeglass Correction on Oral Reading Fluency inElementary and Middle School ChildrenIrene Campus 1 , Mabel Crescioni 1 , Tina K. Green 1 , John D. Twelker 1,2 , Joseph M. Miller 1, 2 , Erin M. Harvey 1, 2 . 1 Ophthalmology andVision Science, University of Arizona, Tucson, AZ; 2 College ofPublic Health, University of Arizona, Tucson, AZ.Purpose: To examine the influence of eyeglass correction on oralreading fluency.Methods: Eye examinations were conducted on students in grades 2-8 who failed a vision screening test. Exams included cycloplegicrefraction and subjective refinement. Glasses were prescribed forchildren who met the following criteria: Astigmatism ≥ 1.00 D,Myopia ≥ 1.00 D on any meridian, or Hyperopia ≥ 2.50 D sphericalequivalent (SE) in either eye, or anisometropia ≥ 1.50 D SE.Eyeglasses were dispensed at a second testing session several weeksafter the exam for students meeting the criteria for eyeglasscorrection (N=21). DIBELS Oral Reading Fluency (ORF) (astandardized test of accuracy and fluency with connected text) wasmeasured at the eyeglass dispensing session, and children were testedwithout correction (3 passages read). Several weeks later (average6.31 weeks, SD 4.44), after students had adjusted to their eyeglasses,DIBELS ORF was repeated while children were wearing their bestcorrection. Students in 7th and 8th grade completed DIBELS ORFfor the 6th grade level, the highest grade level available. DIBELSORF median raw score was determined for tests conducted whileuncorrected and corrected, and scores were converted to percentilesResults: Most students were prescribed eyeglasses for astigmatism(18) and/or myopia (14), with one meeting the criteria for hyperopia.DIBELS ORF percentile scores increased significantly an average of7.14 (SD 11.49, p < 0.02) with eyeglass correction. Amount ofimprovement was not significantly correlated with time between tests(duration of new eyeglass wear).Conclusions: Students who meet common criteria for eyeglassprescription show rapid improvement in reading fluency througheyeglass wear. Due to the short follow-up interval and the fact thatimprovement was not correlated with time from first to second test, itis likely that this effect is a result of improved visual clarity, asopposed to advances in reading skills resulting from instruction(learning). There may be additional long-term effects on reading as aresult of improved visual clarity, but this study did not measure theseeffects. These results indicate the importance of vision screening inschools with follow-up to eye care professionals as needed.Commercial Relationships: Irene Campus, None; MabelCrescioni, None; Tina K. Green, None; John D. Twelker, None;Joseph M. Miller, None; Erin M. Harvey, NoneSupport: NIH/NEI 13153, Research to Prevent BlindnessProgram Number: 2332 Poster Board Number: B0291Presentation Time: 2:45 PM - 4:30 PMPeripheral photoreceptor activity during accommodation andemmetropizationBrian P. Schmidt 1 , Maureen Neitz 2 , Jay Neitz 2 . 1 Graduate Program inNeurobiology and Behavior, University of Washington, Seattle, WA;2 Ophthalmology, University of Washington, Seattle, WA.Purpose: Myopia results when the eye grows too long for its optics.The importance of the peripheral retina in emmetropization hasrecently been appreciated and our group has argued that the relativeactivity of cone photoreceptors contributes as well. However, therehas not been a systematic analysis of how peripheral photoreceptoractivity might be stimulated by natural images during nearaccommodation over the period of life which emmetropizationoccurs. The present work uses mathematical modeling to develop atheoretical framework of emmetropization based on the observationthat the peripheral retina is often exposed to distant scenes when thefovea is accommodated to near objects.Methods: The OSLO ray tracing software (Lambda Research) wasused to derive modulation transfer functions of a schematic eye(Escudero-Sanz & Navarro 1999 J. Opt. Soc. Am. A. 16:1881-91) forseveral eccentricities and accommodation states. The amplitudespectrum of calibrated natural images (Tkačik et al. 2011 PLoS One6:e20409) were computed with a fast Fourier transform and fit with a1 / f power law. The activity of photoreceptors was modeled as adifference of Gaussians. Finally, the transfer functions, amplitudespectrum and photoreceptor model were combined to obtain theresponse from the peripheral cone photoreceptor mosaic to theaverage natural scene.Results: Accommodation to near objects results in a significant lossof medium and high spatial frequencies for images of distant objectsin the peripheral retina relative to the fovea reducing the relativeactivity of photoreceptors there. This loss of frequency content ispartially ameliorated by accommodative lag that has been observed inyoung children but decreases during emmetropization.Conclusions: Considering the statistical environment and the opticaltransfer functions characteristic of common accommodation states wecompute that the amount of information the peripheral retina receivesabout the visual environment during near accommodation to smallcentrally fixated targets changes systematically duringemmetropization. This change may regulate the signals that controleye growth. The reason near work contributes to myopia may bebecause the spatial frequency content of the images produced in theperiphery during such activity simulates the normal signals producedby natural scenes in peripheral retina of a young hyperopic eye.Commercial Relationships: Brian P. Schmidt, None; MaureenNeitz, Genzyme (F), Alcon (F), Alcon (P); Jay Neitz, Alcon (F),Alcon (P)Program Number: 2333 Poster Board Number: B0292Presentation Time: 2:45 PM - 4:30 PMRelation between refractive astigmatism and change in sphericalequivalent with age in a sample of Native American children age3 to 18 years of ageErin M. Harvey 1, 2 , John D. Twelker 1, 2 , Joseph M. Miller 1, 2 .1 Ophthalmology and Vision Science, University of Arizona, Tucson,AZ; 2 College of Public Health, University of Arizona, Tucson, AZ.Purpose: To determine if presence of refractive astigmatism isassociated with change in spherical equivalent (SE) refractive error inchildren age 3 to 18 years of age.Methods: Subjects were participants one or more NIH/NEI fundedstudies of visual development in Tohono O’odham children(“Collaborative Longitudinal Evaluation of Ethnicity and RefractiveError” (CLEERE, Tucson Site), “Astigmatism and AmblyopiaAmong Native American Children”, “Amblyopia in AstigmaticChildren: Development and Treatment”). Previous research hasdocumented a high prevalence of with-the-rule astigmatism in thispopulation. A baseline exam was conducted and follow-up examswere attempted at least yearly for each study. Data was combinedacross studies. Cycloplegic autorefraction (Retinomax Autorefractor(KPlus or KPlus2, Nikon Inc., Tokyo Japan)) was conducted at eachstudy exam. Subject exams that met the following criteria wereincluded in analyses: age 3 to < 19 years, right eye autorefractionconfidence ≥ 8. Only subjects with at least two study exams and aminimum interval of 1 year between first and last exam wereincluded in analyses. Analyses included only right eye data, and onlydata from each child’s baseline and final study exams. Linear©2013, Copyright by the Association for Research in Vision and Ophthalmology, Inc., all rights reserved. Go to iovs.org to access the version of record. For permissionto reproduce any abstract, contact the ARVO Office at arvo@arvo.org.