POSTCONFERENCE EDITION

Summaries of

the papers

presented at the

topical meeting

Vision Science and VISION SCIENCE

its Applications AND ITS

APPLICATIONS

February 3-7, 1995 Santa Fe, New Mexico

1995 Technical Digest Series Volume 1

Sponsored by Optical Society of America

In cooperation with The American Academy of Optometry FRIDAY

FEBRUARY 3, 1995

ANASAZ1 SOUTH 1 0:40am FB2 • Computer simulation model for imaging by PALs and its 8:00am-8:05am validation, Peter Baumbach, Optische Werke G. Rodenstock, Ger¬ Remarks Opening many. Imaging performance of progressive power lenses is calcu¬ Charles Campbell, Humphrey Instruments, Inc., General Chair lated by use of a computer simulation method. The results are

8:00am-9:45am compared with subjective visual acuity measurements, (p. 24) FA, Optical Correction: 1 Discussant: Gilles LeSaux, Essilor, France G. Guilino, Optische Werke G. Rodenstock, Germany, Presider 11:05am 8:05am FB3 • Aspherization does not make single vision lenses significantly FA1 • Measurement of progressive addition lenses, Colin W. Fowler, thinner, Fanny Jurkiewiez, Francoise Ahsbahs, Gilles LeSaux, Essilor Aston Univ., Birmingham, UK. Methods for the measurement of pro¬ International, France. Single-vision lens thickness depends on in¬ in to their usefulness gressive addition lenses are discussed relation dex, base curve, aspherization. Aspherization effects are shown to and to the role of standards, for different requirements (p. 2) give no real contribution to thickness. Aspherization goal is acuity, Discussant: Guenther H. Guilino, Optische Werke G. (p. 28) Rodenstock, Germany Discussant: Colin Fowler, Aston University, UK

8:30am 11:30am FA2 • New method for characterizing progressive addition lenses, FB4 • Central and lateral static distortion in ophthalmic lenses, Charles E. Campbell, Humphrey Instruments Inc. The power gradi¬ Pierre Simonet, Univ. Montreal, Canada; Bernard Bourdoncle, Chris¬ ent of the lens is measured in a small area using an automatic tian Miege, Essilor International, France. The magnitude of central lensmeter. This measurement, designated PV, is repeated on selected, static and lateral static distortion at the periphery of ophthalmic the lens separated areas of the lens to create a profile of gradient lenses is determined by ray tracing for various designs of lenses, change on lenses of different designs, (p. 6) (p. 31) Discussant: Colin W. Fowler, Aston University, UK Discussant: David A. Atchison, Queensland University of Australia 8:55am Technology,

FA3 • Interferometric assessment of the surface profile of diffractive 11:55am-1:30pm bifocal contact lenses, Russell L. Woods, Queensland Univ. Tech¬ Lunch nology, Australia. A technique using a Nomarski interferometer and ANASAZI SOUTH a reflectance microscope for measurement of the surface profile of and soft diffractive bifocal contact lenses is described, 10) rigid (p. 1:30pm-3:1 5pm Discussant: Michael Simpson, Alcon Laboratories FC, Cornea R. A. Applegate, University of Texas Health Sciences Center, 9:20am Presider FA4 • Hyperchromatic lenses as potential aids for the presbyope, W. N. Charman, H. D. Whitefoot, UMIST, UK. Experiments show 1:30pm (INVITED) that a correcting lens that enhances the natural longitudinal chro¬ FC1 • Refractive surgery—success and the public health, Leo matic aberration of the eye may increase the ocular depth-of-focus Maguire, Mayo Clinic. Abstract not available, (p. 36) and hence assist presbyopes. (p. 14) 2:00pm Discussant: of Canada Jacob Sivak, University Waterloo, FC2 • Representing corneal shape, S. A. Klein, R. B. Mandell, B. A.

Several new methods for 9:45am-1 0:1 5am Barsky, UC-Berkeley. representing gen¬ Coffee Break eral (not axially symmetric) corneal shapes are compared. The de¬ pendence on choice of axis is made explicit, (p. 37) ANASAZI SOUTH Discussant: John E. Greivenkamp, University ofArizona 10:15am-11:55am 2:25pm Correction: 2 FB, Optical • FC3 Zernike polynomial representations of videokeratoscope W. N. Charman, of Manchester, UK, Presider University height data, Jim Schwiegerling, John E. Greivenkamp, Joseph M. 10:15am Miller, Univ. Arizona. Corneal height data is analyzed by Zernike FB1 • Simplified strategies for the simulation of progressive addi¬ polynomial expansion. Removing low-order terms shows residual tion lenses, Colin W. Fowler, Aston Univ., Birmingham, UK. Three height variations. Applications include clinical feature identifica¬ approaches are described for the simulation of the optical perfor¬ tion and optical modeling, (p. 41) mance of progressive addition spectacle lenses, to be used for teach¬ Discussant: Robert Webb, Massachusetts General Hospital ing purposes, (p. 20) Discussant: P. Baumbach, Optische Werke G. Rodenstock, Germany

V FRIDAY

FEBRUARY 3, 1995

2:50pm 4:40pm FC4 • High and low contrast acuity followingexcimerpho¬ FD3 • Quasielastic light scattering from the aging human lens in torefractive keratectomy, E. J. Casson, W.B. Jackson, G. vivo, George M. Thurston, Douglas L. Hayden, Victor G. Taret, Joel Mintsioulis, Univ. Ottawa, Canada. Comparisons of pre- Kandel, Joyce A. Peetermans, Mark S. Bowen, Oculon Corp; Pendra and post-PRK values reveal a decrease in low-contrast rela¬ Burrows, John I. Clark, Maria Courogen, Univ. Washington; David tive to high-contrast acuity and an increase in variability in Miller, Harvard Medical School; Keith M. Sullivan, Rainer Storb, visual outcome, (p. 45) Univ. Washington School of Medicine; Hal Stern, Harvard Univ.; B. Benedek, Massachusetts Institute of In vivo Discussant: Mark Bullimore, University of California, George Technology. is used to measures Berkeley quasielastic light scattering provide quantitative of the increase in protein association in human lens cell cytoplasm 3:15pm—3:45pm with age. (p. 57) Coffee Break Discussant: Melanie C. Campbell, University of Waterloo, ANASAZI SOUTH Canada

3:45pm-5:30pm 5:05pm FD, Acuity and Visual Performance FD4 • Fiber optic reading magnifiers for the visually impaired, Eli Vasudevan Lakshminarayanan, University of Missouri, St. Peli, Schepens Eye Research Institute; Walter P. Siegmund, Taper Louis, Presider Vision, Inc. Fiber optics reading magnifiers specifically designed for low vision are better economically than existing devices. Low reso¬ (INVITED) 3:45pm lution enables higher contrast and lower cost. (p. 61) FD1 • Vision science in the developing world: challenges, Discussant: Vasudevan of Missouri, opportunities, problems, and example, Jay M. Enoch, UC- Lakshminarayanan, University St. Louis Berkeley. In the developing world, population growth and aging, and limited resources, create major problems. Vi¬ 7:30pm sion scientists can play meaningful roles. Research in such Forum on Ophthalmic Lenses, Especially Progressive settings, with an example given, is discussed, (p. 50) Addition Lenses (PALs) G. Guilino, Optische Werke G. Rodenstock, Germany, Presider 4:1 5pm and FD2 • Aging and the eye's optical performance, Junzhong Organizer Liang, Gerald Westheimer, UC-Berkeley. Objective mea¬ This forum will discuss the topics on experience with progressive surements of and data from tests in light spread stray light addition lenses in cases of anisometropia, and cylindrical correc¬ the same observers were used to construct point-spread tion. Functional monocularity and alternating fixation will also be and older functions of young eyes. (p. 54) covered. The forum is open to all attendees. Discussant: Rafael Navarro, Instituto de Optica, Spain

vi SATURDAY

FEBRUARY 4, 1995

ANASAZI SOUTH 1 0:35am SaB2 • Magnetic resonance images of the ciliary muscle and lens 8:00am-9:40am in presbyopesandnonpresbyopes, Susan Strenk, John L. Semmlow, of the Eye SaA, Optical Quality Rutgers Univ. High resolution magnetic images of the eye, using a Howard C. Howl and, Cornell Presider University, specially designed radio frequency receiver coil in conjunction with software direct evidence of in the 8:00am modifications, provide changes and lens accommodation. In the SaA1 • On the true shape of the optical point spread function in ciliary body during presbyopes, muscle continues to contract even the lens is no the human eye, Rafael Navarro, M. Angeles Losada, Instituto de ciliary though longer Optica, Spain. The ocular point spread function, including the ef¬ capable of shape changes, (p. 88) fect of both even and odd aberrations, can be obtained by two asym¬ Discussant: Jane F. Koretz, Rensselaer Polytechnic Institute media, metric passages of the light through the ocular (p. 66) 11:00am Discussant: W. Neil of Manchester, UK Charman, University • SaB3 Binocular pupil brightness changes in the presence of stra¬

8:25am bismus: predictions from computer modeling, Heidi Leising Hall, SaA2 • Effect of higher order aberrations on image quality in the Joseph M. Miller, John E.Greivenhamp, Univ. Arizona. The simulta¬ neous of the with coaxial illumination in the human eye, Junzhong Liang, David R. Williams, Univ. Rochester. brightness pupils pres¬ ence of ocular is modeled with various amounts of We present new measurements of the eye's wave aberrations that misalignment reveal substantial image degradation from aberrations at a fine spa¬ background CCD camera noise, (p. 92) tial scale in the pupil, (p. 70) Discussant: Tom Cornsweet, University of California, Irvine Discussant: Valdemar Portney, Allergan Medical Optics 11:25am-1:30pm 8:50am Lunch

• Line function and measurements of SaA3 spread glare disability ANASAZI SOUTH cataractous eyes, Peter Magnante, Brookfield Optical Systems; Carmel Noonan, Jeremy Wolfe, Leo Chylack, Brigham and Women's 1:30pm-3:1 0pm Hospital. Line spread function and glare disability measurements SaC, Retinal Imaging are compared in a study of 23 patients with normal eyes and 40 Stanley A. Klein, University of California, Berkeley, Presider patients with early , (p. 74) 1:30pm

Discussant: Alan Medical • J. Lang, Allergan Optics SaC1 Images of the cone mosaic in the living human eye, David R. Don G. Michael Univ. Rochester. We 9:1 5am Williams, Miller, Morris, describe a camera that retinal con¬ • high-resolution acquires images SaA4 Peripheral refractive error: a comparison of retinoscopy with a to that of cones, with a new subjective technique, Yi-Zhong Wang, Larry N. Thibos, taining bright spots spacing corresponding 98) Indiana Univ.; Norberto Lopez, Univ. Murcia, Spain. A new subjec¬ (p. tive refraction technique employing contrast detection shows de¬ Discussant: Stephen Burns, Schepens Eye Research Institute tection acuity in periphery varies significantly with lens power and 1:55pm produces refractive corrections superior to retinoscopy. (p. 78) SaC2 • Reflectometric measurement of human cone photorecep¬ Discussant: Howard C. Howland, tor directionality, Stephen A. Burns, Shuang Wu, Ann E. Eisner, Francois C. Research Institute. We have de¬ 9:40am-1 0:1 0am Delori, Schepens Eye Coffee Break veloped an imaging technique for measuring human cone photore¬ ceptor alignment in vivo. (p. 102) ANASAZI SOUTH Discussant: Vasudevan Lakshminarayanan, University of Missouri, 10:10am-11:25am St. Louis SaB, Physiological Optics 2:20pm Charles E. Presider Campbell, Humphrey Instruments, Inc., • SaC3 Influence of increased intraocular light scatter on the con¬ 10:10am trast in a confocal scanning laser ophthalmoscope image, Claes • Matthew Mario SaB1 Is magnification a cue in defocus-induced ametropia in Beckman, Atkinson, Stargard, Rejean Munger, chicks?]. G. Sivak, T. A. Curry, M. G. Callender, Univ. Waterloo, Melanie Campbell, Univ. Waterloo, Canada. The influence of in¬ Canada; E. L. Irving, Univ. Toronto, Canada. In contrast to the ef¬ creased intraocular light scatter on image quality in a confocal scan¬ fects of convex (or concave) defocussing lenses, afocal magnifiers ning laser ophthalmoscope is quantified through computer do simulations and model (10%) not influence the refractive development of the chick eye. eye experiments, (p. 106) (p. 84) Discussant: Ronald Schuchard, University of Missouri, Kansas Discussant: Howard Howland, Cornell University City

vii SATURDAY

FEBRUARY 4, 1995

2:45pm SaE2 • Scanning laser ophthalmoscope imaging of the papillo- SaC4 • Quantitative topographic and tomographic measurements macular bundle of the nerve fiber layer, David H. Grosof, Wash¬ of the human retina by dual beam partial coherence interferom- ington Univ. School of Medicine; Vasudevan Lakshminarayanan, etry, W. Drexler, C. K. Hitzenberger, A. Baumgartner, H. Sattmann, Univ. Missouri-St. Louis. We illustrate the use of the Rodenstock A. F. Fercher, Univ. Vienna. Dual beam partial coherence interfer- scanning laser ophthalmoscope to image the parafoveal nerve fiber ometry is used for tomographic and quantitative topographic mea¬ layer bundles, (p. 134) surements of the human retina in vivo with a of = 5 urn. precision Discussant: Ann E. Eisner, Schepens Eye Research Institute (p. 110) • SaE3 Modeling the optical properties of the aging human crys¬ Discussant: Charles Campbell, Humphrey Instruments talline lens from computer processed Scheimpflug images in rela¬ 3:1 0pm-3:40pm tion to the lens paradox, Christopher Andrew Cook, Jane F. Koretz, Coffee Break Rensselaer Polytechnic Institute. Models of human eye optics for¬ mulated using geometrical data from computer processed ANASAZI SOUTH Scheimpflug slides are optimized to determine lens optical charac¬ 3:40pm-5:00pm teristics, explaining the lens paradox, (p. 138) SaD, Myopia and Photorefraction Discussant: David A. Atchison, Queensl?^ University of Jacob C. Sivak, University of Waterloo, Canada, Presider Technology, Australia

3:40pm (INVITED) SaE4 • Theoretical MTF performance of intraocular lenses, Rong SaD1 • Local and central visual eye growth control: defocus vs. Sun, Valdemar Portney, Allergan Medical Optics. The theoretical diffuse image degradation, Frank Schaeffel, Univ. Tubingen, Ger¬ effects of posterior intraocular lens shape, material, and diopter Abstract not available, many. (p. 116) power on on-axis modulation transfer function of the eye model suggest that MTF requirement on the intraocular lens optical qual¬ 4:1 0pm should be based on clinical reference, • ity (p. 143) SaD2 Models describing eccentric photorefraction crescents, R. Kusel, Univ. Eye Clinic, Hamburg, Germany. Three methods—ray Discussant: W. Neil Charman, University of Manchester, U.K. and wave optics—are described and tracing, geometrical optics, SaE5 • Ray-tracing computation of spectacle magnification and discussed that allow the computation of eccentric photorefraction eye magnification for single-vision lenses, B. Bourdoncle, Essilor crescents, (p. 117) International, France. Spectacle magnification and eye magnifica¬ Discussant: Anthony Norcia, Smith-Kettlewell Eye Research tion have been computed by ray-tracing for single vision lenses. Institute The useful lens parameters for reducing the magnifications are dis¬ cussed, (p. 147) 4:35pm SaD3 • Retinoscopic patterns: explained by the optics of an ec¬ Discussant: Alan J. Lang, Allergan Medical Optics centric A. W. R. C. Univ. source, Roorda, Bobier, Teske, Waterloo, • SaE6 Influence of combined power error and astigmatism on Canada. A model of is developed that pre¬ geometrical retinoscopy visual acuity, Catherine Fauquier, Thierry Bonnin, Christian Miege, dicts the observed for defocused eyes (myo¬ pupillary light patterns Eric Roland, Essilor International, France. A nonlinear regression pia or hyperopia) and those with monochromatic aberrations, equation links drop in acuity to combined power error and astigma¬ (p. 121) tism. A threshold of tolerable drop in acuity is determined, (p. 151) Discussant: Reinhard Kusel, Clinic, University Eye Germany Discussant: Larry N. Thibos, Indiana University

5:00pm SaE7 • Useful variations of the Badal optometer, David A. Atchison, SaD4 • for the of , S. Hutson Technique optical analysis Queensland Univ. Technology, Australia; Arthur Bradley, Larry N. Phil Reiner, Huntsville, AL. An electro-optical device demon¬ Hay, Thibos, Indiana Univ.; George Smith, Univ. Melbourne, Australia. strates promise as a method to detect, categorize, and track the pro¬ We describe optometer variations to overcome the disadvantages gression of various types of cataracts. Objective optical identification of simple Badal optometers, which include limited negative vergence of cataracts that are 10/60 or worse may be possible, (p. 125) range, need for small targets, and proximal accommodation, (p. 155) Discussant: Austin J. Roorda, University of Waterloo, Canada Discussant: Charles E. Campbell, Humphrey Instruments, Inc. ANASAZI NORTH SaE8 • Relationship between defocused MTF and spatial frequen¬ cies needed for letter Alan Medical 5:30pm-7:00pm recognition, Lang, Allergan Univ. Missouri-St. Louis. Sa£, Poster Session and Conference Reception Optics; Vasudevan Lakshminarayanan, Concurrent measurements of defocused MTF and subjective letter SaE1 • Effect of peripheral optical quality on spatial contrast sen¬ recognition confirm that just recognizable letters are free of spuri¬ J. Coletta, Vineeta Sharma, John Carter, Univ. Hous¬ sitivity, Nancy ous resolution, with a 2.1 cycle/letter recognition, (p. 159) ton. Peripheral optical quality reduces spatial contrast sensitivity, Discussant: Frank Thorn, New England College of Optometry even at low luminance and low spatial frequencies. Improvement in the peripheral optical quality of the eye could enhance the vis¬ ibility of spatial patterns at low luminance, (p. 130) Discussant: W. Neil Charman, University of Manchester, U.K.

viii SATURDAY

FEBRUARY 4, 1995

SaE9 • Eye-movement tracking using compressed video images, SaE13 • Temporal characteristics of the motion aftereffect differ Jeffrey B. Mulligan, Brent R. Beutter, NASA Ames Research Center. in the fovea and periphery, Yue Chen, Srimant P. Tripathy, Harold E. The effects of JPEG image compression on the accuracy of eye-move¬ Bedell, Univ. Houston. A more salient motion aftereffect occurs for ment tracking algorithms are investigated for images of the pupil high temporal frequencies of the adapting stimulus at 12° in the and the fundus, (p. 163) periphery than in the fovea, (p. 179) Discussant: Vasudevan Lakshminarayanan, University of Missouri, Discussant: Ted Maddess, Australian National University St. Louis Australia

SaEW • Human face recognition using wavelets, Vasudevan SaE14 • New techniques to present video-based text to low vision Lakshminarayanan, Sanjiv K. Bhatia, Grant V. Welland, Univ. Mis- readers, Robert Plass, Dean Yager, SUNY-New York; Edward Tarasov, souri-St. Louis; Ashok Samal, Univ. Nebraska-Lincoln. Modified Merlin Vision Industries, Inc. Low vision patients read faster with Haar wavelet transformed stimuli were used in experiments to de¬ two new video-based systems that use high-resolution letters and termine the critical parameters for face recognition. The methodol¬ can eliminate the need for eye movements, (p. 183) and results are 167) ogy presented, (p. Discussant: Ronald Schuchard, University of Missouri Discussant: Jeffrey B. Mulligan, NASA Ames Research Center SaE15 • Stability of target fixation, R. Bolzani, E. C. Campos, Univ. SaE11 • Disability glare with retinal position of the detection stimu¬ Modena, Italy; A. Dickmann, Catholic Univ. Rome, Italy;). M. Enoch, lus and the temporal relations between the glare source and de¬ UC-Berkeley. Fixation stability was measured by the evaluation of tection stimulus as variables, Jeanette Meng, Isabel Cristina Bichao, the number and mean amplitude of saccades during fixation and by Dean Yager, Hong Zhan, SUNY-New York; Janice Cheung, the standard deviation of the eye position signal, (p. 187) School, New York. effects are Stuyvesant High Disability glare greater Discussant: Susana Chung, University of Houston when the detection target is in the periphery of the visual field, and when the glare source has a sudden onset, (p. 171) 7:00pm-8:00pm Carter C. Collins Memorial Lecture Discussant: Vivienne Greenstein, New York University Sponsored by the Smith-Kettlewell Eye Research Institute SaE12 'Role of photon noise in determining visual threshold, Adam Assessment of outcomes for clinical trials: Use of noninvasive tech¬ Reeves, Northeastern Univ.; Shuang Wu, Schepens Eye Research niques, Sheila West, Wilmer Eye Institute, Johns Hopkins Univer¬ Institute. The simplicity of the Weber law for increment thresholds sity. may camouflage two distinct square-root law processes: light (pho¬ ton noise) and retinal gain control, (p. 175) Discussant: Russell Hamer, Smith Kettlewell Eye Research Institute

ix SUNDAY

FEBRUARY 5, I99S

ANASAZI SOUTH 11:30am SuB3 • Dynamic visual acuity during vertical retinal image motion: 8:55am-1 0:1 Oam comparison of normal and low vision, Joseph L. Demer, UC-Los SuA, Imaging Angeles. Telescopic spectacles magnify head movements, destabi¬ William H. Swanson, Retina Foundation of the Southwest, lizing images on the retina. Dynamic visual acuity is less sensitive Presider to image motion in low vision than in normal subjects, (p. 214) 8:55am Discussant: Robert Fendrich, University of California, Sacramento SuA 7 • Advantages of infrared imaging in detecting choroidal new 11:55am vessels, Ann E. Eisner, M. Elizabeth Hartnett, Stephen A. Burns, SuB4 • Reading of dynamically displayed text by low vision ob¬ Schepens Retina Associates; John J. Weiter, Sheldon M. Buzney, servers, Elisabeth M. Fine, Northeastern Univ.; Eli Peli, Angela T. Retina Consultants of Boston. Detection and localization of choroi¬ Labianca, Schepens Eye Research Institute. We compared reading dal new vessels, a major cause of severe vision loss, are improved rates for scrolled and RSVP text. Normally sighted observers read by using infrared imaging with the scanning laser ophthalmoscope, RSVP faster. Low vision observers read both at the same rate, (p. 192) (p. 218) Discussant: Bill Swanson, Retina Foundation of the Southwest Discussant: Robert Plass, State University of New York 9:20am 1 2:20pm-2:00pm SuA2 • Influence of the cardiac cycle on topographic measure¬ Lunch ments of the optic nerve head and peripapillary retina, Balwantray C. Chauhan, Terry A. McCormick, Dalhousie Univ., Canada. The ANASAZI SOUTH cardiac cycle influences topographic measurements made with con- focal scanning laser tomography. Synchronizing image acquisition 2:00pm-3:40pm with the cardiac cycle in routine practice is recommended, (p. 196) SuC, Amblyopia Mark Bullimore, University of California, Berkeley, Presider Discussant: Robert Webb 2:00pm 9:45am SuC1 • Critical period for surgical treatment of dense congenital SuA3 • and in the optic nerve Topographic hemodynamic changes unilateral cataract, Eileen E. Birch, Retina Foundation of the South¬ head in humans subsequent to experimental modulation of the in¬ west; David R. Stager, UT Southwestern Medical Center. Treatment traocularpressure, John V. Lovasik, Helene Kergoat, Pierre Forcier, initiated before 6 weeks of age maximizes the opportunity for nor¬ Robert Wojciechowski, Etty Bitton, Univ. Montreal, Canada. Changes mal or near-normal visual development of a congenitally catarac- in the optic nerve head topography and blood flow were quantified tous eye. (p. 224) in normotensives by laser tomography and Doppler flowmetry dur¬ Discussant: Gunilla Haegerstrom-Portnoy, University of ing a transiently increased IOP. (p. 200) California-Berkeley Discussant: Chris Johnson, University of California-Davis 2:25pm 1 0:1 0am-1 0:40am SuC2 • Neurophysiological evidence for long-range facilitation in Coffee Break normal, but not amblyopic, human visual cortex, Uri Pol at, An¬ ANASAZI SOUTH thony M. Norcia, The Smith-Kettlewell Eye Research Institute. Ab¬ stract not available, (p. 228) 1 0:40am-1 2:20pm Discussant: To be determined SuB, Dynamic Visual Acuity Anthony Norcia, Smith-Kettlewell Eye Research Institute, Presider 2:50pm SuC3 • Methodological and statistical issues in the evaluation of 1 0:40am amblyopia therapy, Merrick J. Moseley,, Mary Irwin, Helen S. Jones, SuB1 • Effect of retinal image motion on visual acuity at low lumi¬ Kenneth D. Cocker, Alistair R. Fielder, Univ. Birmingham, UK; Rose¬ nances in normal observers and congenital nystagmus, Susana T. Auld, The Birmingham and Midland Eye Hospital, UK. In the L. Chung, Harold E. Bedell, Univ. Houston. Prolongation of the in¬ mary context of amblyopia treatment evaluation, we examine vision test tegration period at low luminances is likely to limit visual acuity in reliability, learning effects, adaptation to spectacle wear, and the congenital nystagmus, depending on the duration of foveation peri¬ measurement of occlusion therapy, (p. 232) ods, (p. 206) objective Discussant: Joe Demer, University of California-Los Angeles Discussant: Mark Bullimore, University of California-Berkeley 3:1 11:05am 5pm SuC4 • Economic analysis of screening for amblyopia: influences SuB2 • Individual differences in dynamic visual acuity at low lu¬ of prevalence, test cost, test quality, value of detection, sensitivity minance: velocity and contrast as parameters, Hong Zhan, Dean and specificity, Howard C. Howland, Cornell Univ. The conditions Yager, Jeanette Meng, SUNY-New York. Visual acuity is reduced of test cost and quality, value of detection, sensitivity and specific¬ both by target motion and lowering contrast. Significant individual ity all influence the minimum prevalence for which amblyopia may differences in experimental results may be due to different eye move¬ be economically screened, (p. 236) ment strategies, (p. 210) Discussant: Merrick & Midland Discussant: Nancy Coletta, University of Houston Moseley, Birmingham Eye Hospital, UK

X SUNDAY

FEBRUARY 5, 1995

3:40pm-4:05pm 4:55pm

Coffee Break SuD3 • Measurement of the scattering characteristics of the eye in relation to L. D. F. E. ANASAZI SOUTH pupil size, J. Barbur, Edgar, G. Woodward, UK. City Univ., London, The scattering of light is not uniform over the with the far 4:05pm-5:45pm pupil periphery contributing most. A large propor¬ Visual Performance tion of the measured in SuD, variability the stray-light parameter, k, may Eileen E. Birch, Retina Foundation of the Southwest, Presider be caused by fluctuations in n, the scatter index, without affecting significantly the integral of the scatter function of the We de¬ 4:05pm eye. fine a new index, k1, which shows reduced • significantly variability SuD1 Occupationalpsychophysics: establishingjob-relatedvision and may be of greater clinical use. (p. 250) requirements, Chris A. Johnson, UC-Davis. Vision requirements for Discussant: Dean Sfafe New York different occupations can be established through the use of simula¬ Yager, University tion studies measurements of task under involving performance vary¬ 5:20pm

levels of visual function, 242) • ing (p. SuD4 Stabilized image perimetry: evaluating the influence of Discussant: Howard Howland, Cornell University eye movements on perimetry data, Robert Fendrich, C. Mark Wessinger, David Marshall, Jr., Chris A. Johnson, UC-Davis. Eye 4:30pm movements visual field act as a low filter • during testing pass spatial SuD2 Reliability of visual performance measures in low vision, and degrade the details present in high-resolution perimetric Russell Woods, Jan Lovie-Kitchin, Queensland Univ. map¬ Technology ping of sensitivity, (p. 254) Australia. Low vision subjects had worse repeatability of clinical Discussant: vision measurement than normal vision subjects. The value of indi¬ Balwantary Chauhan, University of Dalhousie, Canada vidual repeatability determination was demonstrated, (p. 246) Discussant: Gary Rubin, Johns Hopkins University

xi MONDAY

FEBRUARY 6, 1995

ANASAZI SOUTH ANASAZI SOUTH

8:30am-1 0:1 Oam 1 0:40am-11:55am MA, Photoreceptor Function MB, S-Cones Michael E. Breton, University of Pennsylvania, Presider Gunilla Haegerstrom-Portnoy, University of California, Berkeley, Presider 8:30am

MA 1 • Photokinetic analysis of primate cone responses implies I 0:40am qualitative differences from rod transduction, Christopher W. Tyler, MB1 • Enhanced S-cone syndrome: testing an explanation for hy¬ Russell D. Hamer, Smith-Kettlewell Eye Research Institute. New cone persensitivity of the S-cone system, Vivienne C. Greenstein, NYU photocurrent modelling based on rod photokinetics mimicks hu¬ Medical Center; Donald C. Hood, Columbia Univ.; Artur V. man cone responses over their full dynamic range, but implies PDE Cideciyan, Samuel G. Jacobson, Bascom Palmer Eye Institute. kinetics different from rods. (p. 260) Psychophysical and electrophysiological data are consistent with the that the retina of the ESCS has more S-cones Discussant: David Pepperberg, University of Illinois, Chicago hypothesis patient than the patient with normal retina, (p. 278) 8:55am Discussant: Alvin Eisner, Neurological Sciences Institute MA2 • Rod phototransduction is altered in proliferative central retinal vein occlusion, Mary A. Johnson, Univ. Maryland; Donald 11:05am C. Hood, Columbia Univ. Rod phototransduction is affected in the MB2 • Pupillometric investigation of an S-cone generated response eyes of patients with central retinal vein occlusion who later de¬ in humans, Eiji Kimura, Rockefeller S. L. Yc^.5, 7exas Tech Univ. S- velop iris neovascularization, (p. 264) cone signals are generally best reflected in the OFF-portion of the as evidenced action obtained Discussant: Stephen Burns, Schepens Eye Institute pupillary response by pupillary spectra on long-wavelength backgrounds, (p. 282) 9:20am Discussant: Marilyn Schneck, Smith-Kettlewell Eye Research MA3 • Light adaptation and post-flash recovery in human rods, David R. Pepperberg, Univ. Illinois-Chicago; Donald C. Hood, 11:30am Columbia Univ.; David G. Birch, Retina Foundation of the South¬ MB3 • Foveal adaptation abnormalities in early normal-tension west. Quantitative correlations with salamander rod photoresponses , Alvin Eisner, Heidi M. K. Campbell, R. S. Dow Neuro¬ suggest that timing changes in light adaptation of human rods can logical Sciences Institute; George A. Cioffi, Legacy Good Samaritan be probed by measuring electroretinographic a-wave saturation Hospital and Medical Center, John R. Samples, Casey Eye Institute. periods, (p. 268) Elevations of SWS cone-mediated threshold following onset of a field are less for normal-tension Discussant: Michael Breton, University of Pennsylvania yellow adapting significantly glau¬ coma subjects than for normal subjects, (p. 286) 9:45am Discussant: Adam Reeves, Northeastern University MA4 • Retinitis pigmentosa affects cone phototransduction as well as postsynaptic cone activity, Donald C. Hood, Columbia Univ.; II ^Sam- David G. Birch, Retina Foundation of the Southwest. Retinitis Free Time pigmentosa alters the activation state of cone transduction. These changes in cone sensitivity do not account for the delays in the cone b-wave. (p. 272) Discussant: Erich Sutter, Smith-Kettlewell Eye Research Institute

10:10am-10:40am Coffee Break

xii TUESDAY

FEBRUARY 7, 1995

ANASAZI SOUTH 11:30am TuB3 • Evidence for My-cell involvement in the spatial frequency 8:55am-1 0:1 Oam doubled illusion as revealed by a multiple region PERG for glau¬ Flicker TuA, coma, A. C. James, T. Maddess, K. Rouhan, S. Bedford, M. Snow¬ Smith-Kettlewell Research Presider Erich Sutter, Eye Institute, ball, Australian National Univ. PERGs obtained with stimuli the 8:55am exhibiting frequency doubled illusion predict glaucomatous well. Evidence is here that such PERGs are domi¬ TuA 1 • Flicker sensitivity in patients with retinitis pigmentosa and damage provided nated good acuity, William H. Swanson, Marilyn Fiedelman, Retina Foun¬ by My-cell activity, (p. 314) dation of the Southwest; Gary E. Fish, Texas Retina Associates. Discussant: Anthony Norcia, Smith-Kettlewell Eye Research Forced-choice flicker thresholds for a 570-nm, 50-td 2° test showed Institute normal timing of the temporal response in patients with retinitis 11:55am pigmentosa and good acuity, (p. 292) TuB4 • Early detection of macular dysfunction in the topography Discussant: W. Smith-Kettlewell Research Christopher Tyler, Eye of the electroretinogram, Marcus A. Bearse, Jr., Erich E. Sutter, The Institute Smith-Kettlewell Eye Research Institute; David N. Smith, Steven J. Univ. RochesterMedical Center. Retinal is 9:20am Rose, dysfunction mapped with the in a case TuA2 • Fourier components of the pupillary response and their high-resolution topographic electroretinogram relationship to temporal characteristics of luminance and chro- study of a patient with suspected central serous retinopathy, (p. 318) maticityprocesses, Lie-Yi Fang, Rockefeller S. L. Young, Texas Tech. Discussant: Kathleen Fitzgerald, Children's Mercy Hospital Univ. Low-frequency, fundamental and second harmonic pupillary 1 2:20pm-1:30pm response components reflect mostly luminance and chromaticity Coffee Break processing, respectively. DC component yields information about the temporal frequency characteristic, (p. 296) ANASAZI SOUTH Discussant: John Barbur, City University London, U.K. 1:30pm-3:1 0pm 9:45am TuC, Visual Acuity TuA3 • Effects of retinal illuminance on a temporal gain control in EvanneJ. Casson, Ottawa General Hospital, Canada, Presider the flicker ERG, Shuang Wu, Stephen A. Burns, Schepens Eye Re¬ 1:30pm search Institute. Retinal illuminance affects the temporal frequency- TuC1 • Letter strokewidth, spacing, and legibility, Aries Arditi, Ron dependent modulation response of the flicker ERG, resulting in an Cagenello, Bradley Jacobs, The Lighthouse, Inc. Using a visual acu¬ adaptation pattern similar to Kelly's results at high but not at low metric, we assess as a function of font strokewidth and modulations, (p. 300) ity legibility letter spacing, (p. 324) Discussant: David G. Birch, Retina Foundation of the Southwest Discussant: Russell Woods, Queensland University of 10:10am-10:40am Technology, Australia Coffee Break 1:55pm ANASAZI SOUTH TuC2 • Monocular vs binocular visual acuity as measures of vision impairment, Gary S. Rubin, Beatriz Munoz, Linda P. Fried, Sheila 10:40am-12:20pm K. West, Johns Hopkins Univ. Monocular acuity is compared with TuB, ERG binocular acuity in 672 older adults. Binocular acuity is nearly Christopher Tyler, Smith-Kettlewell Eye Research Institute, equivalent to monocular acuity in the better eye for the majority of Presider cases, (p. 328) 10:40am Discussant: Marcus A. Bearse, Smith-Kettlewell Eye Research TuB1 • Decline in ERG maximum a-wave and b-wave amplitudes Institute with age, Michael E. Breton, Monica B. Patel, Scheie Eye Institute. ERG a-wave and b-wave maximum amplitudes decline linearly with 2:20pm TuC3 • Binocular preferred retinal loci: relationship of visual fac¬ age, consistent with steady loss with age of rod photoreceptors, but tors to binocular Ronald A. Schuchard, Navin Tekwani, transduction amplification gain does not decline with age. (p. 306) perception, Sidney Hu, Univ. Missouri-Kansas City. Individuals with at least Discussant: Mary Johnson, Johns Hopkins University one central scotoma often have well developed monocular PRLs 11:05am while only using a single PRL in free viewing binocular tasks, TuB2 • Extraction of a ganglion cell component from the corneal (p. 332) response, Erich E. Sutter, Marcus A. Bearse, Smith-Kettlewell Eye Discussant: Eli Peli, Schepens Eye Research Institute Research Institute. Extraction of an electroretinogram component 2:45pm originating from a source at the optic nerve head provides a direct TuC4 • Different can be distin¬ noninvasive measure of local ganglion cell function, (p. 310) fixation-acuity-scotoma patterns guished in age-related , Frans J. Van de Velde, Discussant: Donald Hood, Columbia University Alex E. Jalkh, Schepens Eye Research Institute, Inc. Functional evalu¬ ation of vision in patients with age-related macular degeneration using scanning laser ophthalmoscopy reveals distinct fixation, acu¬ ity and scotoma patterns, (p. 336) Discussant: David Grosof, Washington University

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