Navigation Links
Test for visual acuity could aid detection, rehabilitation of AMD
Date:10/29/2007

Rockville, MD A computer-based method for evaluating the eyes ability to distinguish object details and shape in patients with age-related macular degeneration (AMD) could provide a more accurate way to assess the effectiveness of eye surgery or vision rehabilitation interventions with devices and training, according to a Canadian study. The computer method could also vary low-, medium- and high-contrast illumination targets for testing spatial vision, which the authors say might be useful for early detection of AMD.

The tests are described in Computer-Based Test to Measure Optimal Visual Acuity in Age-Related Macular Degeneration, (http://www.iovs.org/cgi/content/full/48/10/4838) published in the October issue of Investigative Ophthalmology and Vision Science, a peer-reviewed monthly publication of the Association for Research in Vision and Ophthalmology (ARVO). The researchers are associated with Toronto Western Hospitals Vision Science Research Program, the Centre for Vision Research at Torontos York University and the Department of Ophthalmology and Vision Sciences at the University of Toronto.

Authors Esther G. Gonzlez, Luminita Tarita-Nistor, Samuel N. Markowitz and Martin J. Steinbach incorporated four features known to improve visual acuity into their computer-based evaluation method: high contrast; white optotypes (symbols, letters or numbers used in vision testing ) on a black background to reduce intraocular scatter; proportional layout to reduce the effects of crowding; and multiple optotypes to minimize the effects of fixation instability and to maximize the likelihood of optotype detection.

They conducted three experiments: the first measured the best-eye acuity of 24 AMD patients using the ETDRS charts and three versions of the Tumbling E acuity test; the second compared two White E optotype tests with the ETDRS in 14 AMD patients; and the third measured probability summation in 20 people with normal vision.

The authors concluded that a multiple-optotype, reversed-polarity test is most effective in estimating a patients optimal visual acuity at baseline before vision rehabilitation interventions or surgery. Comparing the results of subsequent evaluations may help assess rehabilitation progress.

People with AMD rarely read or view things under optimal conditions, so this is not a test of how well they see in daily life. This test is designed to give vision rehabilitation practitioners a measure of the best visual acuity a person is capable of and in this sense it could be a useful tool for assessing rehabilitation progress, said Dr. Gonzlez.

In addition, the authors point out that patients with early AMD may demonstrate reduced function, not for the high-contrast, high-illumination targets of standard clinical acuity tests, but for medium- and low-contrast targets. They conclude that their computer method, which allows testing for targets of varying contrast, might help specialists detect AMD early.

Detection of potential visual acuity in patients with AMD is a crucial step in the clinical practice of vision rehabilitation. The ability to accurately estimate such potential will enhance results from vision rehabilitation interventions said Dr. Markowitz, who is a member of the Vision Rehabilitation Committee of the American Academy of Ophthalmology.


'/>"/>

Contact: Joanne Olson
jolson@arvo.org
Association for Research in Vision and Ophthalmology
Source:Eurekalert

Related medicine news :

1. Visually impaired prefer specially enhanced TV
2. The Cause Of Visual Problems Different From Race To Race
3. Sleepiness May Be Associated With Visual Impairment
4. Patients With Alzheimer’s Need To Be Checked For Visual Clarit
5. Attention! Spells of momentary blindness following visual disturbance
6. ‘Never Say Die’ Spirit of Visually Challenged - Makes Him a Role Modl
7. Debra Winger Wants Indians Abroad To Help Visually Impaired
8. Visualization Found To Be Largely Dependent On The Brain
9. Visual Awareness Is Generated At the Back Of The Brain
10. Visual Signs Attuned To Reading Rather Than Writing
11. A Unique Technique To Visualize How The heart functions Developed
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/20/2017)... ... 20, 2017 , ... ReportingMD, a Population Health Software Company, is pleased to announce a move ... new location will triple the size of the previous location while bringing life back to ... , “We are excited to expand our footprint to better serve our growing ...
(Date:2/20/2017)... ... February 20, 2017 , ... Florida ... purchase a new ultrasound-enhanced thrombolysis machine, a state-of-the-art device that breaks up life-threatening ... by the Pepin Family Foundation. , “We greatly appreciate this gift from Constellation ...
(Date:2/19/2017)... ... 19, 2017 , ... Orbita, Inc., a leading ... Healthwise ® at HIMSS 2017 to showcase a breakthrough in ... education, technology and services, will demonstrate a voice-powered knowedge assistant based on ...
(Date:2/18/2017)... ... , ... Park Cities Pet Sitter President, Joette White, has been featured on ... The episode, which was posted this week, features a 30-minute interview of White ... Cities Pet Sitter’s being awarded the 2017 National Association of Professional Pet Sitter’s Business ...
(Date:2/17/2017)... , ... February 17, 2017 , ... ... foundational and sustainable systems change designed to further positively impact the health and ... of Trustees has long considered it our duty to seriously consider releasing our ...
Breaking Medicine News(10 mins):
(Date:2/19/2017)... , February 18, 2017 Marapharm ... to purchase a Medical Delivery Service with the specific ... transactions between qualified patients and caregivers. The delivery service ... located in the Coachella Valley, California ... Los Angeles area to the West, population ...
(Date:2/17/2017)... -- Cryoablation, Electrical, Endometrial Hydrothermal, Laser/Light, Microwave, Radiofrequency, Ultrasound, ... market is expected to grow at a CAGR of 9.4% from ... to grow at a CAGR of 9.5% from 2017 to 2027. ... 2026. ... report will benefit you Read on to discover how you ...
(Date:2/17/2017)... 2017  Perrigo Company plc (NYSE, TASE: PRGO) today announced ... Drug Administration for hydrocodone bitartrate and homatropine methylbromide oral solution ... Hydrocodone bitartrate and homatropine methylbromide oral solution (syrup), 5 mg/1.5 ... of cough in adults and children 6 years of age ... 2017 were approximately $16 million.   ...
Breaking Medicine Technology: