New eye-tracker method shows 'preferred retinal location' in both eyes

July 28, 2015, Wolters Kluwer Health

Eyes with central vision loss adapt by developing a new fixation point in a different part of the retina, called the preferred retinal location (PRL). Now for the first time, a new method makes it possible to identify PRLs in both eyes simultaneously, reports a study in the August issue of Optometry and Vision Science, official journal of the American Academy of Optometry.

The new eye-tracker technique may help in developing visual rehabilitation approaches to improve for the many older adults with central affecting both eyes, according to the new research led by Esther G. González, PhD, of the Vision Science Research Program at Toronto Western Research Institute.

Technique Identifies PRLs in Both Eyes of Patients with Central Vision Loss

Central vision loss results from degeneration of the fovea—the central pit of the retina, where visual acuity is sharpest. The most common cause is age-related macular degeneration, which is also the leading cause of blindness in older adults. "Especially when present in both eyes, loss of central (reading) vision is a major intrusion on quality of life and everyday functioning," explains Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.

Taking advantage of visual plasticity that persists even in old age, the brain and eye can partly compensate for loss of the fovea by developing a PRL—shifting fixation to another nearby spot in the retina. Patients learn to use an area of their peripheral vision to substitute for their lost central vision.

A technique called microperimetry with eye-tracking can precisely identify the PRL, but only in one eye at a time. This may not adequately represent binocular function—vision with both eyes working together. "Understanding binocular vision is important for designing optimal rehabilitation methods for with central vision loss," Dr. González and coauthors write.

They developed a method to establish the PRLs in both eyes, based on the relationship between microperimetry and eye-tracking measurements in healthy eyes. Predicted PRLs in nine with central vision loss were compared with the findings of standard PRL assessments in the two eyes individually.

All patients had at least one PRL fall onto a functional area of retina during binocular viewing. In most cases, the PRLs were found in corresponding locations in the two eyes—that is, in about the same position relative to the center of the retina. The one patient whose PRLs were not in corresponding locations had problems with double vision (diplopia).

Dr. González and colleagues note some important limitations of their "proof-of-principle" study. Further studies will be needed to evaluate the new eye-tracker method in a broader sample of patients with central vision loss.

By enabling simultaneous identification of the PRLs in both eyes, the technique provides important information on binocular function in eyes with low central vision. At least for some patients, the results may help to guide approaches to maximizing binocular vision—for example, through relocation training to help move the PRL to the corresponding location in both eyes.

The -tracker method may be especially valuable for managing the large number of patients with age-related macular degeneration affecting both eyes. Dr Adams comments, "Such an approach not only allows a better understanding of how the eyes and brain deal with binocular loss, but also opens up exploration of new approaches to visual rehabilitation for these individuals."

Explore further: 'Preferred retinal location' may aid rehabilitation in patients with central vision loss

More information: "Identifying Absolute Preferred Retinal Locations during Binocular Viewing" (DOI: 10.1097/OPX.0000000000000641

Related Stories

'Preferred retinal location' may aid rehabilitation in patients with central vision loss

May 28, 2013
Perceptual learning techniques may provide a useful new approach to rehabilitation in patients with central vision loss—taking advantage of visual plasticity that persists even in old age, according to a special article ...

How's your 'twilight vision'? Study suggests new standardized test

April 24, 2015
A simple method of testing "twilight vision" gives reliable results in identifying people who have decreased visual acuity under low light conditions, according to a study in the May issue of Optometry and Vision Science, ...

Researchers link age, general health and antidepressant use with eye disorders

May 1, 2014
Abnormal binocular vision, which involves the way eyes work together as a team, increases dramatically as we age, according to research from the University of Waterloo. The study also found a correlation between this condition, ...

Helping people with vision loss due to age-related macular degeneration

June 18, 2014
(Medical Xpress)—Losing the ability to read is one of the biggest complaints among people suffering from age-related macular degeneration (AMD) – a disease that causes a distorted or blind spot in the centre of a person's ...

Preserving photoreceptor cells following retinal injury

July 22, 2015
Vision researchers at Massachusetts Eye and Ear/Harvard Medical School (HMS) Department of Ophthalmology have taken a first step in solving a vexing problem: how to preserve photoreceptor cells and avoid irreversible vision ...

Human eye movements for vision are remarkably adaptable

August 15, 2013
When something gets in the way of our ability to see, we quickly pick up a new way to look, in much the same way that we would learn to ride a bike, according to a new study published in the journal Current Biology on August ...

Recommended for you

Satellite imaging techniques may help reduce preventable vision loss

May 11, 2018
By adapting pattern recognition techniques used to assess satellite images, scientists have devised a novel way to diagnose blinding eye diseases, such as age-related macular degeneration.

Ophthalmologists link immunotherapy with a serious eye condition

May 7, 2018
New immunotherapy treatments offer a remarkable chance for survival for patients with advanced melanoma and hard-to-treat cancers of the bladder, kidney and lung.

Burnout, depression can affect ophthalmology residents, study finds

May 4, 2018
A new study led by Brown University researchers finds that ophthalmology residents across the U.S. face a substantial burden of burnout and depression, which may affect not only the residents themselves but also the quality ...

AI better than most human experts at detecting cause of preemie blindness

May 3, 2018
An algorithm that uses artificial intelligence can automatically and more accurately diagnose a potentially devastating cause of childhood blindness than most expert physicians, a paper published in JAMA Ophthalmology suggests.

New diagnostic technique picks up the S in vision

May 1, 2018
A new technique that could help improve diagnosis of vision disorders has been successfully tested at the University of Bradford, UK.

A bit of dark chocolate might sweeten your vision

April 26, 2018
It may not replace prescription glasses, but a few bites of dark chocolate might offer a slight and temporary bump up in vision quality, new research suggests.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.