A vision scientist walks into a clinic...
Symposium: Friday, May 16, 2025, 8:00 – 10:00 am, Talk Room 2Schedule of Events | Search Abstracts | Symposia | Talk Sessions | Poster Sessions
Organizers: Benjamin Backus1,2; 1Vivid Vision Inc, 2SUNY College of Optometry (emeritus)
Presenters: Geoffrey K. Aguirre, Preeti Verghese, Samantha A. Montoya, Deborah Giaschi, Benjamin T Backus
Three good things can happen when a vision scientist works with patients: (1) helping individual patients preserve their vision or see better, (2) helping to develop a treatment, diagnostic tool, assistive technology, or preventative for a disease or dysfunction, and (3) discovering something about how human vision operates by comparing to typically sighted control observers. These are three very different things, but they all require access to patients. In this symposium, the presenters will describe high quality, clinically-related vision science they’ve done that resulted in one or more of those three good things. We will make the case for clinical work, and share our observations about how to do it. We will keep the talks short to leave time for questions and observations from the audience, including, we hope, ones that cover additional areas of clinically relevant vision science. Questions to be addressed include: What does one need to know about how clinicians see the world, in order to collaborate with them? If you’re a student or early in your career, should you also get an MD or OD along with your PhD? What should you do to be a good scientific colleague to a clinician and what should you look for in a clinician colleague? Under what circumstances can one get clinic floor time? What are the personal rewards from working with patients if you’re not a medical doctor? What are the rewards from working with patient community groups? Geoffrey Aguirre will discuss sensory alteration in migraine, drawing insights from how patients describe their symptoms. Preeti Verghese will describe measuring and improving depth perception in patients with AMD, and will help us understand the role of institutional support. Samantha Montoya and Stephen Engel will discuss visual snow, an understudied and debilitating condition, and factors facing early- and later-career scientists doing clinical work, respectively. Deborah Giaschi will describe how motion perception differs between normal and amblyopic vision, and what this reveals about both. Benjamin Backus will discuss how vision scientists can contribute to improved clinical testing, and what it takes to get a new test into clinical use.
Talk 1
Photoreceptors, Facebook, and sensory alterations in migraine
Geoffrey K. Aguirre1; 1Univeristy of Pennsylvania
A bright or flickering light can be unpleasant for anyone, but people with migraine have markedly increased sensitivity to these stimuli, even in the period between headaches. I will describe our efforts to understand the mechanistic basis of these experiences in a typical population and in people with migraine headaches. To be informative, studies of this kind require control over both stimulus and subject. Photoreceptor targeting with tailored spectral modulations allows us to probe the relative contribution of cone and melanopsin signals to discomfort responses, and to measure how these signals are conveyed in post-retinal ganglion cell pathways. To find subjects to view these uncomfortably bright and flickering stimuli, we use targeted Facebook campaigns to direct candidate participants to automated diagnostic classification tools. In ongoing studies we are testing if migraine produces: 1) a post-retinal amplification of discomfort signals derived from the melanopsin-containing, intrinsically photosensitive retinal ganglion cells; 2) a mis-match between the expectation and experience of temporal modulations in the visual environment. Beyond these planned hypotheses, we have found that large-scale screening of clinical populations can yield its own insights. An analysis of over 300 patient responses has led us to wonder if touch signals from the face interact with the sensation of bright light, and how the natural statistics of flicker might vary across visual eccentricity. We recommend soliciting insights from patients using an open-ended question, which in our case was: “What should scientists study about headache and sensory symptoms?”
Talk 2
Peripheral stereopsis in macular degeneration
Preeti Verghese1; 1The Smith-Kettlewell Eye Research Institute, San Francisco, CA
Individuals with macular degeneration (MD) have vision loss in the central retina that typically involves the fovea and significantly impacts tasks of daily living. The type of functional loss depends on how much the scotomata in the two eyes overlap. When they occur in overlapping locations in the two eyes that include the fovea, the resultant binocular scotoma can significantly impact tasks that require high-acuity vision, such as reading and recognizing faces. Moreover, even when the scotomata in the two eyes do not overlap significantly, individuals experience loss of stereopsis in the part of the visual field that corresponds to a scotoma in either eye. To determine the extent of the stereoblind zone and the potential for intact stereopsis in the periphery, we developed a method to measure local stereopsis across the visual field. Local depth sensitivity was combined to generate a stereopsis map and compared to the union of monocular scotoma maps obtained from microperimetry in each eye. The “union” prediction aligned with the stereo map, showing impaired stereopsis within this region and residual stereopsis beyond. Importantly, the stereoblind region was more extensive than the binocular scotoma defined by the overlap of the scotomata. This explains why individuals with a small binocular scotoma may be severely compromised in tasks that benefit from stereopsis, such as eye–hand coordination and navigation. A big takeaway for individuals with MD is that they can learn to utilize the residual stereopsis in their binocular periphery through training.
Talk 3
Visual snow: Symptomology and mechanisms
Samantha A. Montoya1, Stephen A. Engel1; 1University of Minnesota
Visual snow is a recently isolated and surprisingly common (~2-3% of the population) symptom where people continuously perceive tiny flickering dots covering their entire visual field. When combined with other commonly co-occurring symptoms it can interfere with daily activities. The details of visual snow’s symptomology and its underlying mechanisms are poorly understood, limiting the development of treatments. We recently provided the first detailed measurements of visual snow's appearance: Participants adjusted parameters of a simulation to match their symptom. On average, individual elements were very small and fast, and total contrast was low (~2.5% RMS). We also recently demonstrated that snow is dependent upon spontaneous neural activity in the visual system: In people with visual snow, adapting to high contrast external dynamic noise greatly reduced the strength of the snow (transiently) to the point that it disappeared in most observers, some of whom reported seeing the world without snow for the first time. Adaptation to visual noise reduces neural responsiveness in early visual cortex, suggesting that spiking there is necessary for the snow percept. And because effects were measured while viewing a blank screen, this activity must be spontaneous. Current work uses adaptation to identify precisely where and how the spontaneous activity arises, e.g. visual snow shows a motion aftereffect. Drawing upon expertise from the visual snow community, including one of us, was crucial for developing our experimental paradigms, which may in turn provide a window onto noise suppression processes in normally sighted individuals.
Talk 4
A vision scientist walks into a clinic with the goal of improving treatment outcomes for amblyopia and strabismus
Deborah Giaschi1; 1University of British Columbia
Amblyopia is a common developmental disorder that is defined clinically as impaired visual acuity in a healthy eye that cannot be immediately corrected with lenses. The non-amblyopic eye usually has normal visual acuity, but binocular vision is often disrupted. Treatment options are limited and often not successful, which results in lifelong health, education, and psychosocial effects. We showed that deficits in motion perception are common in children with amblyopia with viewing through either the amblyopic or nonamblyopic eye. This suggests that the current clinical definition of amblyopia is incomplete. Motion perception deficits do not improve with standard patching treatment aimed at improving visual acuity in the amblyopic eye, but they are better ameliorated with emerging binocular treatment approaches aimed at reducing interocular suppression. Strabismus (eye misalignment) is one of the main causes of amblyopia. Surgical realignment of the eyes is a common approach to prevent the development of amblyopia and to potentially restore binocular vision, but reoperation is often necessary. We have shown that presurgical levels of both stereopsis with large binocular disparities and global motion perception predict eye alignment 1 year after surgery. This work revealed a relationship between motion perception and binocular vision that may also be important for understanding healthy vision, and modernizes the definition of amblyopia. It also provides clinicians with a fresh perspective and new tools for making treatment decisions and assessing treatment outcomes. I will share my experience with getting access to patients and interacting effectively with clinicians and their staff.
Talk 5
Visual perimetry: More interesting than you think
Benjamin T Backus1,2; 1Vivid Vision Inc, San Francisco, CA, USA, 2SUNY College of Optometry (emeritus)
What could be more boring than visual field testing, which consists of badly measuring the luminance increment threshold of a small stimulus at each of 54 retinal locations, one eye at a time? Our initial goal was simply to port this test to inexpensive mobile VR headsets. However, the test is difficult to take, as it demands several minutes of steady fixation, unrelenting visual attention, and a fixed internal criterion for responding. Thus, eye doctors keep visual field tests short to avoid fatigue. But visual behavior and cognition are better understood now than in the 1970’s when the conventional test was developed, so we updated the test to make it longer and collect more data. With the Yvonne Ou lab at UCSF, we demonstrated that 20 out of 20 patients with glaucoma were each able to perform ten 18-minute tests at home. 100% adherence to anything done at home is remarkable. The scientific benefit of this approach is that visual sensitivity can be measured with better precision. That in turn makes the test useful for pharmaceutical companies, which are using it in clinical trials of new therapeutics. Precision is also essential for research on the relationship between “structure” (which is measured quickly with OCT) and “function” (which is measured laboriously with visual field tests) which may allow OCT to replace visual field testing. Use of the test in direct patient care remains a goal. Many patients find significant meaning in contributing to research on their condition.