Central vision field loss (CFL) is caused by inherited and acquired diseases that irreversibly damage the fovea while leaving the peripheral retina relatively intact. CFL results in 1,700,000 legal blindness and low vision (LV) cases in the US. LV rehabilitation is the means of restoring functional abilities modified by CFL so that the patient's quality of life may improve. The current CFL rehabilitation approach is based on the principle of modifying the patient's normal, fovea-centered viewing behavior through eccentric viewing (EV) training so that an intact peripheral retinal location, not the damaged fovea, can be consistently directed to the target of interest. While this EV training approach has been used exclusively in CFL rehabilitation since WWII and has gone through incremental improvements, it is nevertheless difficult and time consuming, and has highly variable outcomes, especially in older patients. Because of the high cost of the specialty required in EV training, comprehensive CFL rehabilitation is not accessible for most CFL patients. We propose that the difficulties of the EV approach lie in its attempt to modify the natural and well-practiced cooperation among the perceptual, cognitive and oculo-motor components. We believe that it is possible to restore functional vision lost to CFL without substantial behavior modification. We hypothesize that a rehabilitation approach that retains the patient's natural viewing behavior can circumvent the difficult EV training, and thus can allow quicker and greater success, and be made accessible to the majority of CFL patients. However, the natural viewing behavior would bring the damaged fovea to the target of interest and render it invisible to the patient. The key component of this innovative approach is a wearable photo-electronic device that instantly senses eye position, determines the gaze direction (normally the direction from the fovea to the target of interest), crops the image of the target of interest, magnifies and enhances it, and displays it at a designated, intact peripheral retinal location. This Gaze-guided, Localized Image Magnification Peripheral Sight Enabler (GLIMPSE) completes the natural viewing routine broken by CFL so that when the patient exercises her natural viewing routine, namely, moving the fovea to the target according to the input from peripheral retina, the target becomes visible again. The purpose of this SBIR Phase I research is to assess the feasibility of the GLIMPSE concept. A team of engineer, clinician and scientist will develop the key GLIMPSE components and will evaluate CFL patients'functional vision with and without the help of the GLIMPSE on a desktop prototype. The primary outcome of interest is the change of functional vision brought about by the GLIMPSE. If successful, the proposed research will lead to the development of a new wearable and marketable LV assistive device, and restoration of functional vision may become as easy as getting a new pair of glasses. The GLIMPSE approach may revolutionize the field of LV rehabilitation and will positively impact the quality of life for millions of LV patients.
The loss of central vision affects millions of people and appropriate rehabilitation may help them to regain ability to perform vision related daily tasks. The conventional rehabilitation approach has been shown to be difficult, time consuming, costly and not always successful, because it attempts to modify the patient's natural way of seeing things. The proposed SBIR Phase I research will test whether a wearable photo-electronic device, in the form of a pair of sunglasses, may help to avoid changing the patient's viewing habit, and thus may make low vision rehabilitation quicker, more likely to succeed, less costly and more accessible.
