Visually Impaired Persons: Assess and Assist

  • Stephen Sinclair | Sinclair Technologies, GSX Pharma, and the Clear Vision Foundation

Visually Impaired Persons: What must be Understood to Assess and Assist.

Until approximately 10 years ago abnormalities of focus were the primary cause of vision loss and the focus of ophthalmic and optometric clinicians worldwide. However with the improvement in the methods to measure and repair the ocular optics (spectacles, contact lenses, corneal and cataract surgery), the major cause of mild, moderate, and severe vision loss throughout the world has now become macular disease caused by the severe rapid expansion of diabetes as well as the aging population, The difficulties in managing retinal disease are caused by three significant problems: 1)The failure of patients to seek attention of an ophthalmic provider until vision abnormalities interfere sufficiently with daily visual function, most often defined by when the second eye becomes involved because the brain in daily function merges the images of the two eyes to one composite with varying dominance. 2) The physician fails to understand the vision deficit because of the reliance on chart acuity, which fails to measure functional vision. 3)The physician relies upon retinal examination to define the onset of disease. Although current laser coherence tomography imaging can define the structural abnormalities with considerable improvement, the images are typically interpreted with failure to attach digital quantification of the abnormalities, or currently with the use of engineering-derived digital measurements that are poorly associated with defining the function of the retina under conditions of varying luminance and color-contrasts.

This discussion will present a vision of what must be done in order to detect, understand, and predict the course of macular disease in the individual patient so that treatment can be instigated sufficiently early to prevent functional loss.

First the diabetic at first diagnosis and those persons genetically at risk of developing macular degeneration must undergo multi-wavelength, coherence, tomography imaging at regular intervals with the images registered and presented in overlay so that dynamic changes over time can be understood and quantitated.

Second, the monocular and binocular vision of an individual must be measured in the central visual field in a dynamic situation that mimics real world luminance and contrasts of typical photopic or mesopic tasks. The results then must be overlaid upon the retinal structural changes in order to understand the relationships of alterations in photoreceptor, middle nuclear layer, or ganglion cell nuclear pathologies with the vision changes. Once this is done, then we can understand the interactive central field of vision and how it is altered under varying luminance conditions of tasks the person is trying to perform and can understand the effects of the pathology and how to prevent, not reverse this process.

Finally then, this will improve our understanding of how to assist those vision tasks the individual wishes to perform. We must switch from focusing on lenticular magnification to understanding the importance of off-axis illumination and reduction in glare with enhancement of edge contrast perception together with shadows that will improve motion parallax detection and depth perception, whether for the individual sitting and trying to crochet, the surgeon performing endoscopic surgery, or the athlete playing on the field. We must understand the problems the central visual field Swiss cheese produces on reading and change the dynamics of the interaction.

So many of these tasks can be certainly be accomplished better with electronics than optics.

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Speaker Details

A graduate of the University of Pennsylvania in biochemistry, and then a Thouron Scholar to Cambridge University, England in biophysics, he then graduated from Harvard Medical School in 1973, followed by training at Massachusetts Eye and Ear Infirmary and University of Wisconsin. He then practiced in full time academic vitreoretinal surgery for 20 years, first at U of Penn and then at Drexel-Hahnemann Medical School where he developed the department as Professor and Chairman. Since 1998, he has continued in private practice as a vitreoretinal surgeon and served as Adjunct Professor of Ophthalmology at the Drexel-Hahnemann School of Medicine and as Adjunct Professor at the Pennsylvania College of Optometry, Salus University. Dr. Sinclair has taught ophthalmic surgeons around the world through Project Orbis and teaches multiple surgical specialties regarding the enhancement of vision for surgical endoscopic dissection, having developed the first surgical simulator and subsequently consulted with the development of VR Magic, the current ophthalmic surgical simulator. His research continues in the development of many digital devices among which are the laser doppler measurement of retinal blood flow, the measurement of functional resolution visual fields, and the development of ophthalmic image management and annotation systems to transport, view and compare images from multiple ophthalmic imaging and vision testing devices acquired for a patient over time with the intent to develop digital methods to apply AI to ocular imaging. Currently, he is working on enhancement of Ramon hyperspectral imaging to examine external tear production, its constituents and modulation with blinking. He is the founding co-director of Sinclair Technologies, GSX Pharma, and the Clear Vision Foundation. Dr. Sinclair has received Honor and Senior Achievement Awards from the American Academy of Ophthalmology and the American Society of Retinal Specialists and has published more than 80 original scientific papers and holds nearly a dozen device and drug patents.

Series: Microsoft Research Talks