Central Visual Impairment, Low Vision, Macular Degeneration
Conditions
Brief summary
Central vision loss from macular degeneration creates blind spots that impair reading, face recognition, and navigation. Individuals must learn to use peripheral vision, requiring retraining of eye movements. Our preliminary research using high-speed eye tracking demonstrated that people with larger scotomas have impaired eye movement control, and that single-session visual feedback training showed limited immediate benefit, though combining feedback types showed promise. This study will evaluate whether extended binocular training (5 weekly sessions) with multimodal feedback improves eye movement control in 8-15 participants with bilateral central vision loss. Unlike conventional monocular rehabilitation systems, our approach trains both eyes simultaneously using real-time visual and auditory feedback during saccadic and smooth pursuit tasks. Participants will receive gaze-contingent scotoma awareness feedback, preferred retinal locus feedback, and auditory cues while performing eye tracking exercises. Primary outcomes include saccadic accuracy (latency, landing error, amplitude) and smooth pursuit parameters (gain, tracking accuracy). Secondary outcomes include contrast sensitivity and self-reported visual function. Success could establish an evidence base for accessible home-based training using virtual reality technology, potentially benefiting millions with macular degeneration.
Interventions
BEHAVIORALeccentric viewing training with biofeedback
Participants will complete 5 weekly training sessions (approximately 60 minutes each) performing eye movement exercises while receiving real-time multimodal feedback. Training includes: Saccadic Training: Visually-guided saccades to targets appearing at randomized locations with instructions to use peripheral (inferior) retinal locus. Targets shift horizontally, vertically, and obliquely to train all saccadic directions. Smooth Pursuit Training: Circular pursuit of moving targets at 2.6°/s in randomized directions with instructions to maintain peripheral gaze above the target. Feedback Modalities (systematically varied across sessions):Scotoma Awareness: Gaze-contingent black circle overlay representing participant's blind spot; Preferred Retinal Locus (PRL) Feedback: Dynamic gaze-contingent ring showing real-time fixation location; Auditory Feedback: Tone modulation indicating fixation stability, PRL accuracy, and target acquisition success; Combined multimodal feedback
Sponsors
New England College of Optometry
H. Eric Cushing Foundation
Northeastern University, Department of Psychology
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE
Intervention model description
The study explores a rehabilative approach for individuals with central vision loss.
Eligibility
Sex/Gender
ALL
Age
14 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Bilateral central scotomas confirmed via computerized tangent screen Visual acuity between 20/60 and 20/200 (0.5 - 1.00 logMAR) in either eye Stable central vision loss (no change in visual acuity \>0.2 logMAR in past 6 months) Age 14 years or older, with diagnosis of macular disease Normal cognitive function (Mini-Mental State Examination score ≥24) Ability to provide informed consent and complete study visits No major hearing loss Fluent in English
Exclusion criteria
Unstable ocular disease (e.g., ongoing treatments and/or injections) Peripheral vision loss of less than 40 degrees Conditions affecting oculomotor control independent of CVL
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Saccadic Accuracy (Landing Error) | At First study visit - Baseline, At each training visit (week 1, week 2, week 3, week 4, week 5, and post training (week 11 ) | Mean distance in degrees between saccade landing position and target location, measured using binocular eye tracking during visually-guided saccade tasks. Lower values indicate better accuracy. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Saccadic Latency | At First study visit - Baseline, At each training visit (week 1, week 2, week 3, week 4, week 5, and post training (week 11 ) | Time in milliseconds from target appearance to saccade initiation, measured using binocular eye tracking. Faster latencies indicate improved oculomotor response. |
| Change in Smooth Pursuit Gain | At First study visit - Baseline, At each training visit (week 1, week 2, week 3, week 4, week 5, and post training (week 11 ) | Ratio of eye velocity to target velocity during smooth pursuit tasks (optimal gain = 1.0). Higher gain values indicate better pursuit tracking accuracy. |
| Change in Number of Catch-up Saccades During Pursuit | At First study visit - Baseline, At each training visit (week 1, week 2, week 3, week 4, week 5, and post training (week 11 ) | Mean number of corrective saccades per trial during smooth pursuit tasks. Fewer catch-up saccades indicate smoother, more accurate pursuit performance. |
| Change in Contrast Sensitivity Function | Baseline, Post-training (Week 6) | Area under the log contrast sensitivity function (AULCSF) measured using adaptive Gabor presentations during eye movement tasks. Higher values indicate better contrast sensitivity. |
| Change in Fixation Stability | Baseline, Post-training (Week 6) | Area of the bivariate contour ellipse at 95% confidence interval of fixation positions during stationary target fixation tasks, measured in square degrees. Smaller ellipse area indicates more stable fixation. |
| Change in Vision Related Quality of Life | At First study visit - Baseline, at last training session - week 5, and post training (week 11 ) | Baseline, Post-training (Week 6) |
Countries
United States
Contacts
CONTACTNicole C Ross, OD
CONTACTCecilia Idman-Rait, MPH
Outcome results
None listed