Driving with Central Visual Field Loss II: How Scotomas Affect Hazard Detection in a Driving Simulator

Newswise, September 3, 2015-- Vision researchers in Boston have published the second paper of a study designed to determine if a driver who suffers from loss of central vision is able to detect pedestrians in a timely manner when driving. 

Central visual field loss, a scotoma or blind area in central vision, is found most commonly in patients with age-related macular degeneration (AMD). Patients with AMD may drive provided their visual acuity at least meets the requirements for a restricted license. 

However, the size and location of the blind area are usually not considered when making licensing decisions. The purpose of the study was to evaluate how much these blind areas delayed responses to pedestrian hazards in the safe environment of a driving simulator.

This study was conducted with participants with AMD who drove in a state-of-the-art driving simulator at the Schepens Eye Research Institute of Mass. Eye and Ear. The research was led by Alex Bowers, Ph.D., Eli Peli, O.D. M.Sc., and P. Matthew Bronstad, Ph.D..

The study’s first phase, documented in JAMA Ophthalmology, Mar. 2013 showed that patients with blind areas to the side of where they typically look tend to miss pedestrians coming from that side. 

The results of the current study showed that a blind area located above or below the center of interest will still likely block or delay a driver’s ability to detect pedestrians entering the field of vision from the side of the road. 

These late reactions usually occurred because the pedestrians were entirely or partially obscured by the blind area after the drivers noticed the pedestrian using their peripheral vision, and then tried to look at them directly, causing the blind area to obscure the pedestrian.

Taken together, the results of the two papers suggest that that any binocular central field loss might delay a driver’s ability to detect moving hazards in time for the driver to take safe, corrective action.

“If you are a low-vision patient, you should understand how the condition affects and perhaps limits your ability to drive safely,” said Dr. Bronstad. 

“These data should prove useful to clinicians in advising patients about whether they should continue driving, and may even become a consideration for state agencies responsible for licensing drivers.”

About Massachusetts Eye and Ear and Schepens Eye Research Institute
Mass. Eye and Ear clinicians and scientists are driven by a mission to find cures for blindness, deafness and diseases of the head and neck. 

Now united with Schepens Eye Research Institute, Mass. Eye and Ear is the world's largest vision and hearing research center, developing new treatments and cures through discovery and innovation. 

Mass. Eye and Ear is a Harvard Medical School teaching hospital and trains future medical leaders in ophthalmology and otolaryngology, through residency as well as clinical and research fellowships. Internationally acclaimed since its founding in 1824, Mass. Eye and Ear employs full-time, board-certified physicians who offer high-quality and affordable specialty care that ranges from the routine to the very complex. 

U.S. News & World Report’s “Best Hospitals Survey” has consistently ranked the Mass. Eye and Ear Departments of Otolaryngology and Ophthalmology as top in the nation. For more information about life-changing care and research, or to learn how you can help, please visit MassEyeAndEar.org.

About Harvard Medical School Department of Ophthalmology
The Harvard Medical School (HMS) Department of Ophthalmology (eye.hms.harvard.edu) is one of the leading and largest academic departments of ophthalmology in the nation. 

More than 350 full-time faculty and trainees work at nine HMS affiliate institutions, including Massachusetts Eye and Ear/Schepens Eye Research Institute, Massachusetts General Hospital, Brigham and Women's Hospital, Boston Children's Hospital, Beth Israel Deaconess Medical Center, Joslin Diabetes Center/Beetham Eye Institute, Veterans Affairs Boston Healthcare System, VA Maine Healthcare System, and Cambridge Health Alliance. 

Formally established in 1871, the department has been built upon a strong and rich foundation in medical education, research, and clinical care. 

Through the years, faculty and alumni have profoundly influenced ophthalmic science, medicine, and literature-helping to transform the field of ophthalmology from a branch of surgery into an independent medical specialty at the forefront of science.