Restoring Functional 3D Vision in Macular Degeneration

Diagram of two eyes seeing an object in depth

Project Overview

Depth vision is important when reaching for and manipulating objects during everyday tasks. For people with macular degeneration, the brain may begin to favor the “good” eye and ignore the “bad” eye. When this happens, depth perception is lost and individuals may need to slow down to compensate for clumsy movements. Using visual rehabilitation, this project aimed to train the two eyes to work together again, with the goal of restoring depth vision and improving overall quality of life.

Stereopsis, the ability to perceive 3-dimensional depth can be severely impaired in individuals with AMD (Verghese, P. Binocular vision and depth perception in individuals with central vision loss. ARVO 2014). We live in a 3-D world and stereopsis is critical in guiding hand movements, particularly grasp, thus being stereo-blind impacts both depth judgments and eye-hand coordination1 . The goal of this research was to characterize the functional impact of the loss of 3-D depth perception in individuals with AMD. We hypothesized that normally sighted individuals can learn to use the two eyes together more effectively, and patients with AMD can learn to use corresponding areas of their retinae that have not been affected by disease. If successful, the results of this research will provide gains in 3-D depth perception which can result in enhanced eye-hand coordination, as well as improvements in Timed Instrumental Activities of Daily Living (TIADLs). Given the prevalence and consequences of vision impairment in AMD, this research is timely in translating basic research into direct patient eye care.

AIM 1 – Assess and quantify stereopsis in individuals with AMD.

Utilized the Frisby test to measure stereopsis, assess eye alignment using a cover test and eye-tracking, evaluate quality of life measures (VA LV VFQ-48)2 and determine the functional impact on TIADLs. Stereo function was correlated to quality of life and the following TIADLs – a) drink pouring and b) judging which of two small objects is closer by reaching for the closest object. Additionally in AMD, assessed fixation locus and correspondence.

AIM 2 – Developed an age targeted virtual training system for eye alignment and stereo-recovery.

Harnessing gamification technology and drawing on the successful training of amblyopes to recover stereopsis, we developed an analogous procedure for training subjects to use both eyes during video game playing.

AIM 3 – Piloted the implementation of the stereo training program to quantify the impact.

Evaluation was conducted utilizing pre and post measures described in Aim 1. We hypothesized that patients can learn to use corresponding functional areas of their retinae through training and expect to see gains in recovering 3-D depth perception which can result in enhanced eye-hand coordination, quality of life and performance on TIADLs.


Team Members

Laura Walker, PhD (Alumni)
Executive Director (Alumni) Tony Succar, PhD (Alumni)
Envision Postdoctoral Research Fellow (Alumni) Saeideh Ghahghaei, PhD
Research Associate, Smith-Kettlewell Eye Research Institute

References & Publications

  1. McKee, S. (2014). Stereopsis and its Discontents. Journal of Vision, 14(15), 86-86.
  2. Cao, K. Y., & Markowitz, S. N. (2014). Residual stereopsis in age-related macular degeneration patients and its impact on vision-related abilities: A pilot study. Journal of optometry, 7(2), 100-105.