Navigation Links
Prism Glasses Expand the View for Patients with Hemianopia
Date:5/12/2008

Schepens study opens way for high-power permanent version of the glasses

and larger new study

BOSTON, May 12 /PRNewswire/ -- Innovative prism glasses can significantly improve the vision and the daily lives of patients with hemianopia, a condition that blinds half the visual field in both eyes. The peripheral prism glasses, which were invented by Dr. Eli Peli, a Senior Scientist at Schepens Eye Research Institute, were evaluated in the first community-based multi- center trial of such a device, which is published in the May issue of the Archives of Ophthalmology. The study was coordinated by Dr. Alex Bowers, a Senior Scientific Associate at the Institute.

"This is the first real breakthrough in the rehabilitation of patients with this condition," says Peli, a world-renowned low vision expert, the Moakley Scholar in Aging Eye Research at Schepens and a Professor of Ophthalmology at Harvard Medical School. Peli had searched for a solution for his hemianopia patients for many years before designing the peripheral prism glasses, creating a prototype in his laboratory.

More than a million Americans suffer from hemianopia, which blinds the vision in one half of the visual field in both eyes, resulting from damage to the optic pathways in the brain. Most commonly caused by strokes, it can also be the result of brain damage from tumors or trauma. A patient with this condition may be unaware of what he or she cannot see and frequently bumps into walls, trips over objects or walks into people on the side where the visual field is missing.

Peli's goal was to find a way to expand the visual field. He did this by attaching small, specially designed high power prisms on the top and bottom of one spectacle lens, leaving the center of the lens untouched. The prisms pull in images missing from the visual field above and below the line of sight on the side of the vision loss, and alert the patient to the presence of a potential obstacle or hazard. The patient can then move his/her head and eyes to examine the prism-captured image directly through the clear center of the lens.

Prisms by their nature can shift images from one side of the visual field to the other side (e.g., from the right side of the field to the left side). Before Peli's invention, others had tried to develop prism glasses to bring the missing part of the patient's visual field into view. However, these previous techniques placed the prisms in the center of the glasses, which resulted in double vision, which is disturbing and confusing. Peli's solution was to keep the central part prism free and place prisms above and below.

The Archives of Ophthalmology study evaluated the glasses' ability to improve a patient's walking mobility, which includes obstacle avoidance. Forty-three patients were fitted with prism glasses in 15 community-based clinics around the country. The clinicians interviewed them at six weeks and after 12 months. Success was measured by how many patients continued wearing the prism glasses and by their ranking of the prisms' effectiveness in assisting with obstacle avoidance while walking.

Thirty-two participants (74 percent) continued wearing the glasses at week six. At 12 months, 20 (47 percent) were still donning the spectacles eight hours a day and rating them as "very helpful" for obstacle avoidance. These 12-month-plus patients were reporting significant benefits for a variety of obstacle avoidance scenarios (e.g. walking in crowded areas, unfamiliar places, shopping malls). According to Bowers, the first author of the paper, "These results indicate that the glasses have great promise for helping patients resume normal daily life."

Peli partnered with a small optical company in Vermont-Chadwick Optical, Inc. who funded the study in part through a National Institutes for Health (NIH) small business grant. Peli and Karen Keeney, the President of Chadwick Optical, created a permanent version of the prisms with higher optical quality and better durability than the temporary prisms that were fitted at the start of the study. These permanent prisms were provided to 15 of the study patients when they became available.

A new, higher power, version of the permanent prism glasses recently developed by Chadwick Optical should also further expand the visual field and be even more beneficial for patients' mobility, according to Peli. The prototype used in the study expanded the peripheral upper and lower visual fields by 20 degrees without obstructing central vision. The new glasses expand the field by 30 degrees.

A larger community-based multi-center study is currently underway to evaluate the latest model. In addition to the higher power, the new study is also evaluating a novel design for which Dr. Peli just received a patient from the US patent office. Details on the new ongoing study are available at http://www.clinicaltrials.gov (clinical trial NCT00494676).

Schepens Eye Research Institute is an affiliate of Harvard Medical School and the largest independent eye research institute in the nation.


'/>"/>
SOURCE Schepens Eye Research Institute
Copyright©2008 PR Newswire.
All rights reserved

Related medicine technology :

1. New Implantable Lenses Can Reduce the Need for Glasses After Cataract Surgery
2. BiPar Sciences Expands Phase 2 Clinical Trials of BSI-201, a Novel DNA Repair Inhibitor, in Ovarian Cancer
3. CoreSpine Technologies Expands Spinal Disc Site Preparation Efforts
4. Delcath Expands Phase III Trial for Metastatic Melanoma to Include University of Maryland Medical Center
5. FDA Grants NeoVistas Request to Expand CABERNET Trial to 30 Sites in the U.S.
6. Alseres Pharmaceuticals Expands Sites for the First Stage of the ALTROPANE(R) Phase III Clinical Trial Program
7. Senesco Expands on Recently Announced Preclinical Pancreatic Islet Data
8. BiPar Sciences Expands Clinical Program for BSI-201, a Novel DNA Repair Inhibitor, in Brain Cancer
9. PAREXEL Expands Global Clinical Pharmacology Capabilities
10. Medicare Announces Expanded Coverage for Anticoagulation Patients, Opening the Door for More Patients to Test PT/INR at Home
11. Medicare Announces Expanded Coverage for Warfarin Patients Monitoring Clotting Time at Home
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/1/2017)... BELL, Pa. , June 1, 2017 ... (PRN) and Veterinarian Recommended Solutions (VRS), and KD Pharma ... investment in Nutriceutical Holdings by KD Pharma Group. KD ... Holdings with the option to acquire the entire company. ... partner in KD. They are committed to growing the ...
(Date:5/30/2017)... 2017 Therapix Biosciences Ltd. (Nasdaq: TRPX), ... the development of cannabinoid-based drugs, today announced that ... at three upcoming scientific and investor conferences in ... Invitational: ...                     Wednesday, June ...
(Date:5/26/2017)... May 25, 2017  In response to the opioid ... Direct Relief is working with Pfizer to make up ... no cost to community health centers, free and charitable ... "Pfizer has a long-standing commitment to ... ensuring patient safety through educational activities," said Caroline ...
Breaking Medicine Technology:
(Date:6/23/2017)... ... June 23, 2017 , ... Dr. ... New York, has recently begun offering three new minimally invasive procedures to patients ... procedures and reducing downtime, Dr. Rubinstein is excited to bring microneedling, microneedling facials, ...
(Date:6/23/2017)... ... June 23, 2017 , ... The Aesthetic Channel has recently highlighted Dr. ... come up with a proprietary technique that he calls the AuraLyft Facelift. ... For all ages, patients can expect to look refreshed, rejuvenated, and revitalized. , ...
(Date:6/23/2017)... ... June 23, 2017 , ... MD Now Urgent Care opened its ... facility overall and marks the urgent care center's eighth location in Miami-Dade county. , ... Falls shopping mall. The new clinic offers a wide array of services ...
(Date:6/23/2017)... ... June 23, 2017 , ... Ulster University, Magee Campus in ... 9 am to 3 pm to present to graduate students exciting new and innovative ... original curriculum project led by The Health Improvement Service of the Western Health & ...
(Date:6/23/2017)... ... June 23, 2017 , ... Radabaugh & Associates, ... families and business owners in North Central West Virginia, is embarking on a ... differently abled residents in the region. , The Stepping Stones organization offers a ...
Breaking Medicine News(10 mins):