Featured Research

from universities, journals, and other organizations

Peripheral prism glasses are cheap, effective vision rehab tool

Date:
November 8, 2013
Source:
Massachusetts Eye and Ear Infirmary
Summary:
A multi-center study determined that real peripheral prism glasses are more helpful than sham peripheral prism glasses for patients with hemianopia during every day walking.

Permanent peripheral prism glasses for a patient with left hemianopia, providing about 30 degrees of visual field expansion into the blind left visual field.
Credit: Massachusetts Eye and Ear/Schepens Eye Research Institute

More than a million Americans suffer from hemianopia, or blindness in one half of the visual field in both eyes as the result of strokes, tumors or trauma. People with hemianopia frequently bump into walls, trip over objects, or walk into people on the side where the visual field is missing.

Peripheral prism glasses, invented by Eli Peli, M.Sc., O.D., Professor of Ophthalmology at Harvard Medical School and Senior Scientist at Massachusetts Eye and Ear/Schepens Eye Research Institute, use high power prism segments embedded in a regular spectacle lens to expand the upper and lower visual fields of patients with hemianopia by as much as 30 degrees. The prisms optically shift objects from the blind side of the visual field to the seeing side, thereby alerting people with hemianopia to objects and obstacles not otherwise visible to them.

Although the results of early clinical evaluations of the peripheral prism glasses suggested that they were helpful for obstacle avoidance when walking, the device had never previously been compared to either another rehabilitation intervention for hemianopia or to a sham device. A multi-center study (NCT00494676) led by Alex Bowers, Ph.D., Assistant Professor of Ophthalmology at HMS and Assistant Scientist at Massachusetts Eye and Ear/Schepens Eye Research Institute, set out to determine if real peripheral prism glasses were more helpful than sham peripheral prism glasses for patients with hemianopia during every day walking. Their research is published online in JAMA Ophthalmology.

Patients with hemianopia were recruited at 12 clinics in the United States of America and 1 clinic in the United Kingdom. The study used a "crossover" design in which each participant wore two pairs of glasses: a pair of real peripheral prism glasses, providing about 30 degrees of field expansion, and a pair of sham peripheral prism glasses, identical to the real prism glasses, but providing less than 2 degrees of field expansion. Half of the participants wore the real prism glasses first and the sham prism glasses second, and half wore the sham glasses first and the real glasses second. Each pair of glasses was worn at home for four weeks. The data collector at each clinic was masked and did not know whether a participant was wearing real or sham glasses. Participants were also masked, and were informed that one pair of glasses was a sham only after they had completed the study.

"The main outcome measure was the overall difference between the number of participants who wanted to continue using the real prisms as compared to the number of participants who wanted to continue using the sham prisms," said Dr. Bowers.

Of the 73 people randomized, 61 completed the crossover period. A significantly higher proportion selected the real prisms than the sham prisms (64 percent vs. 36 percent, respectively). Participants who completed the study cited that the main reason for selecting the real prism glasses over the sham prism glasses was that the real glasses were helpful for obstacle avoidance when walking, while the sham glasses were not. By comparison, the main reason for selecting the sham over the real prism glasses was that they were more visually comfortable or had caused fewer difficulties. "These results emphasize the importance of including a control (placebo/sham) condition when evaluating a rehabilitation device," said Dr. Bowers.

Forty-one percent of patients were still wearing the real peripheral prism glasses after six months, reporting that the prism glasses were helpful for obstacle avoidance when walking outdoors, in crowded places, shopping malls and unfamiliar places.

Dr. Bowers concluded: "Peripheral prism glasses provide a simple and inexpensive mobility rehabilitation intervention for hemianopia."


Story Source:

The above story is based on materials provided by Massachusetts Eye and Ear Infirmary. Note: Materials may be edited for content and length.


Journal Reference:

  1. Alex R. Bowers, Karen Keeney, Eli Peli. Randomized Crossover Clinical Trial of Real and Sham Peripheral Prism Glasses for Hemianopia. JAMA Ophthalmology, 2013; DOI: 10.1001/jamaophthalmol.2013.5636

Cite This Page:

Massachusetts Eye and Ear Infirmary. "Peripheral prism glasses are cheap, effective vision rehab tool." ScienceDaily. ScienceDaily, 8 November 2013. <www.sciencedaily.com/releases/2013/11/131108102146.htm>.
Massachusetts Eye and Ear Infirmary. (2013, November 8). Peripheral prism glasses are cheap, effective vision rehab tool. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2013/11/131108102146.htm
Massachusetts Eye and Ear Infirmary. "Peripheral prism glasses are cheap, effective vision rehab tool." ScienceDaily. www.sciencedaily.com/releases/2013/11/131108102146.htm (accessed July 30, 2014).

Share This




More Health & Medicine News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Health Insurers' Profits Slide

Health Insurers' Profits Slide

Reuters - Business Video Online (July 30, 2014) Obamacare-related costs were said to be behind the profit plunge at Wellpoint and Humana, but Wellpoint sees the new exchanges boosting its earnings for the full year. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins