Visual Psychophysics / Physiological Optics - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group – Visual Psychophysics / Physiological OpticsInstitute from the vision rehabilitation unit. Patients without previousexperience of low vision optical aids use underwent a visionrehabilitation program (the IOBA-RRP). Visual (reading speed andduration, visual acuity and magnification) and psychosocialquestionnaire outcomes were recorded before and after undergoingthe 6-week training. Odds ratios (ORs) were calculated to assess thepredictive value of these variables.Results: Contrast sensitivity (OR’s: 2.94, 95% confidence intervals(CI): 0.99-8.33), age (OR’s: 0.21, 95% CI: 0.06-0.74) and GeriatricDepression Scale (GDS) score (OR’s: -2.33, 95% CI: 1.16-4.76) wereassociated with improvement in reading speed.Conclusions: Better contrast sensitivity, older age and lower GDSscores can predict success on reading fluency in CFL patients afterreading rehabilitation training.Commercial Relationships: Salvatore Di Lauro, None; Maria B.Coco, None; Alberto López-Miguel, VISIÓN I+D, SL (E); RubénCuadrado, None; Agustin Mayo, None; José Alberto De Lázaro,None; Miguel J. Maldonado, None; Joaquín Herrera, None;Laura Mena, None; Jose-Carlos Pastor, NoneSupport: RD 12/0034/0001Program Number: 5042 Poster Board Number: A0204Presentation Time: 2:45 PM - 4:30 PMDo Pedestrians Make Safe Street-Crossing Decisions?Shirin E. Hassan. School of Optometry, Indiana University,Bloomington, IN.Purpose: The aim of this study was to determine whether the streetcrossingdecisions of subjects with Age-related MacularDegeneration (AMD) are as safe as those made by young and oldersubjects with normal vision.Methods: Street-crossing decisions and crossing times in 12 AMDsubjects, 20 young and 20 older control subjects with normal visionwere measured along an unsignalized street for nine different gaptime categories. Using their habitual vision and hearing, subjectsobserved an approaching vehicle for two seconds. At the end of thetwo second period, subjects were required to make a crossingdecision of whether or not they thought it was safe to cross the street.Subjects’ crossing decisions were then objectively classified as being“safe” when the measured gap time was longer than the subject’sstreet-crossing time. The converse was true for objectivelyclassifying crossing decisions as being “unsafe”. The proportion ofsafe crossing decisions (ie. subjects reporting it was safe to cross forobjectively safe gap times) and unsafe crossing decisions (ie. subjectsreporting it was safe to cross for objectively unsafe gap times) wasdetermined for each subject group and gap time category. Ahierarchical logistic regression, with repeated measures for subject,was used to determine if the proportion of safe and unsafe decisionschanged as a function of subject group and gap time category.Results: We observed that the older normally-sighted subjects mademore unsafe crossing decisions compared to the AMD subjects forgap times that were between four and one second shorter than thetime they needed to cross the street. However, the differencesbetween these two groups were only marginally significant (p=0.06,p=0.05, p=0.04 and p=0.05 for gap times that were four, three, twoand one second shorter than subjects’ crossing times, respectively).No significant difference in the proportion of unsafe decisions werefound between the young and older normally-sighted subjects(p>0.05) and between the young normally-sighted and AMD subjects(p>0.05). No significant differences in the proportion of safe crossingdecisions were also found between the different subject groups forgap times that were longer than subjects’ crossing times (p>0.05).Conclusions: Our data suggests that older pedestrians with normalvision have a tendency to adopt a more risky crossing strategy thaneither the young normally-sighted or AMD pedestrians.Commercial Relationships: Shirin E. Hassan, None508 Improving Imaging and Ophthalmic InstrumentationThursday, May 09, 2013 8:30 AM-10:15 AMExhibit Hall Poster SessionProgram #/Board # Range: 5543-5554/B0053-B0064Organizing Section: Visual Psychophysics / Physiological OpticsProgram Number: 5543 Poster Board Number: B0053Presentation Time: 8:30 AM - 10:15 AMStabilized cone imaging with adaptive optics optical coherencetomographyOmer P. Kocaoglu 1 , R. D. Ferguson 2 , Zhuolin Liu 1 , Ravi S. Jonnal 1 ,Qiang Wang 1 , Daniel X. Hammer 3 , Donald T. Miller 1 . 1 School ofOptometry, Indiana University, Bloomington, IN; 2 Physical SciencesInc., Andover, MA; 3 Office of Science and Engineering Laboratories,Center for Devices and Radiological Health, Food and DrugAdministration, Silver Spring, MD.Purpose: Cone photoreceptors exhibit a complex optical signaturethat has become increasingly valuable in ophthalmologicexamination. Adaptive optics optical coherence tomography (AO-OCT) is a highly sensitive method that is particularly well suited for3D imaging the cone signature. Like all in vivo retinal imagingmethods, however, AO-OCT suffers from the effects of involuntaryeye movements that blur and distort the image, especially at the conelevel. Compensation of movement can be realized with registrationalgorithms in post processing or dynamic retinal tracking inhardware. Tracking is particularly attractive for AO-OCT as it cancompensate for eye motion larger than the imaging field of view andpermits repeated imaging of the same retinal patch. In light of theseadvantages, this study examines the efficacy of an active retinaltracker integrated into AO-OCT for cone imaging.Methods: The 2nd-generation Indiana AO-OCT system wasintegrated with a customized retina tracker module. Key AO-OCTcomponents included a broadband light source (λc=800nm,Δλ=160nm, bandpassed to Δλ=80nm), an astigmatism-free samplearm, and a high-speed linescan camera operating at 100K Alines/s.The tracker module was designed to stabilize the location of the AO-OCT beam relative to a specific retinal landmark tracked at 1060nm,and to provide a 35° field of view SLO image at 950 nm. Closed-looptracking performance was assessed by comparing cone motion in1.8°x1.8° volume videos acquired with and without dynamic retinaltracking. Videos were obtained at 4° nasal and 3° superior to thefovea of a normal subject (30 yrs). Five sessions of volume videoswere collected, each consisting of five volumes (1 vol/s). En faceprojections of the AO-OCT volumes were assessed for lateral conemotion. To avoid masking tracker performance, no post-processingregistration was applied to the videos.Results: The average maximum cone displacement was 18±5μmwith tracking compared to 150±107μm without tracking, a factor ofeight improvement. The corresponding contrast improvement in theaveraged en face cone image was 38% (p=0.008). Tracking wassufficiently robust to find repeatedly the same cone patch acrosssessions.Conclusions: Dynamic tracking stabilized AO-OCT cone images,sufficiently so for monitoring the same cones over time.Commercial Relationships: Omer P. Kocaoglu, None; R. D.Ferguson, Physical Sciences Inc (E), Physical Sciences Inc (P);Zhuolin Liu, None; Ravi S. Jonnal, 7,364,296 (P); Qiang Wang,©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.