Visual Psychophysics / Physiological Optics - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group – Visual Psychophysics / Physiological Opticslater myopic shift in 3- to 14-year-old children with IET.Methods: Eye length (right eye) was measured with a Haag-StreitLenstar in 40 children with infantile ET. Five measurements wereobtained at the fovea and at 10° and 20° on the temporal retina. Foroff-axis measurements, children fixated a dim mini-LED affixed tothe instrument. Distance refraction (right eye) was obtained for thesame 3 locations with a Grand Seiko binocular autorefractor with thechild fixating letter targets.Results: At 3-4 and 5-6 years old, children with IET had mean±serefractive error of +3.63±0.61D and +3.81±0.43D, respectively, andaxial length of 21.4±0.3mm and 21.2±0.2mm, respectively.Peripheral eye length was 0.2-0.4 mm longer than axial length,consistent with oblate ocular shape. Peripheral refraction was -0.84 to-0.91D more myopic relative to foveal refraction. At 7-8 years, meanhyperopia was lower (+2.66±0.67D) and axial length longer(22.1±0.2mm). In this age group, peripheral eye length was shorterthan axial length by 0.1-0.3 mm; i.e., eyes were less oblate in shape.By 9-14 years, mean hyperopia was again lower at +1.54±0.76D andaxial length longer at 23.1±0.5mm; eyes were even less oblate(peripheral eye length was 0.2-0.4 mm shorter than axial length). Inthe older age groups peripheral refraction remained slightly myopic (-0.1 to -0.2D) relative to foveal refraction.Conclusions: Hyperopia in IET is associated with oblate eye shape.While the putative “stop” signal of relative peripheral myopia ispresent in younger eyes, the older eyes are significantly longer andsignificantly less oblate at 7-14 years of age, just as the childrenexperience a myopic shift. The possibility that some eyes can growrapidly to become less hyperopic despite inhibitory peripheraldefocus requires longitudinal confirmation.Commercial Relationships: Eileen E. Birch, None; Simone Li,None; Sarah E. Morale, None; Reed M. Jost, None; VidhyaSubramanian, None; Donald O. Mutti, NoneSupport: NIH grant EY022313467 Visual Functions in AMDWednesday, May 08, 2013 2:45 PM-4:30 PMExhibit Hall Poster SessionProgram #/Board # Range: 5017-5042/A0179-A0204Organizing Section: Visual Psychophysics / Physiological OpticsProgram Number: 5017 Poster Board Number: A0179Presentation Time: 2:45 PM - 4:30 PMPreliminary assessment of a new device to test potential visualacuity when compared to gold standard PAMElizabeth R. Richter, Jan A. Kylstra. Storm Eye Institute, MedicalUniversity of South Carolina, Charleston, SC.Purpose: Assess a newly-developed potential visual acuity devicecompared with the gold standard Guyton-Minkowski PotentialAcuity Meter (PAM)Methods: The rationale for potential acuity assessment is todetermine if vision loss is due solely to cataract or due to other ocularpathology. The current gold standard is the Guyton-Minkowski PAM.This method has several problems, including high cost and difficultyin use. The physician cannot see the projected chart on the retina andhas to rely on patient cooperation. When this method is unsuccessful,the cause of failure may result from true retinal pathology ordifficulties with equipment use.We have developed a new device (the SCALE) which combinescurrent indirect ophthalmoscopy with a 20 diopter lens andtransparent ETDRS-style eye chart. The virtual image of the retina isformed 5cm in front of the lens, and in this same plane the eye chartis held. This allows the physician to directly project the eye chartonto the patient's retina while the practitioner also views the patient'sretina to make sure the image is directed on the macula. This is thefirst comparison study to determine the ability of visual acuitymeasurement when compared to the current gold standard in 23patients with preoperative cataracts. After conversion to logMARacuity, paired t-test was used to compare differences amongst thedata. The goal of this study was to determine ease of use andcorrelation with other accepted methods.Results: Of 23 eyes, only one patient was unable to see letters oneither device. Another subject was unable to see anything on thePAM device (>20/800), but could see one line (20/252) with theSCALE. Analysis of the other patients yielded a significantdifference between the visual acuities measured by these twopotential acuity methods (t(20)=3.4916, p=0.00230). The mean PAMlogMAR acuity was 0.551 (SD=0.384), while the SCALE showed a0.335 acuity (SD=0.246); this is approximately 2-line increase on theETDRS chart.Conclusions: The SCALE is another method to assess potentialacuity. From preliminary study, it appears to overestimate visualacuity when compared to the gold standard PAM. However, this newdevice may be an excellent and inexpensive addition to the precataracttoolkit to assess retinal function. Further studies are neededto assess post-surgical acuity to determine if this is a good estimatorof prospective surgical outcome.Commercial Relationships: Elizabeth R. Richter, US ProvisionalApplication No. 61/653,171 (P); Jan A. Kylstra, provisional61/653,171 (P)Clinical Trial: 00016836Program Number: 5018 Poster Board Number: A0180Presentation Time: 2:45 PM - 4:30 PMEvaluation of vision auto-testing in patients with AMD using aniPad AppMatthias G. Hartmann. Private Practice, Berlin, Germany.Purpose: Patients with age-related macular degeneration (AMD)need to undergo regular testing of their visual acuity. A tool for selfmeasurementto be run on an iPad was developed to enable patientsto have regular testing by themselves. It is available in German,English, Spanish and Japanese. This project was designed to evaluatewhether iPad-based vision auto-testing is a feasible method forpatients with AMD compared to established instruments.Methods: The project was run in 4 ophthalmologist’s offices. Targetsample size was 100 patients; only patients with an initial vision of atleast 0.05 were included. Patients had to consent to a threepart visiontest every 4 weeks for 6 months. Visual acuity was measured by a)distance vision testing by projection of Landolt rings (EN ISO 8596)b) near vision test charts (Oculus) with Landolt rings and c) automeasurementwith Landolt rings using the iPad App “Eyetest -Control your visual acuity”. Patients were initially advised how touse the iPad App. All tests were performed in the office. Test resultswere defined to be consistent when they differed to a maximum ofone line.Results: 112 patients of 57 to 92 years of age (mean 77.2 yrs) wereincluded. Nearly all patients had never used an iPad before (96% vs.4%). Results for vision tests by projection and iPad were consistent in76% (right eye) and 83% (left eye) of the measurements. Near visiontest charts were used as a control. Results acquired by near vision testcharts frequently differed from projection results by 2 or more lines.At the end of study, patients were asked for their preference. Themajority of patients (81.25%) chose the iPad App as their preferredmethod to test visual acuity, only 12.5% chose the projection method,6.25% preferred near distance test charts.Conclusions: The fact that over 80% of the patients prefer the iPad©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.