domingo, 25 de maio de 2014

New glasses may increase risk of falls in older adults, suggests review

 

May 23 / 2014

Wolters Kluwer Health: Lippincott Williams & Wilkins

Blurred vision contributes to the risk of falling in older adults -— but getting new glasses with a big change in vision prescription may increase the risk rather than decreasing it, according to a new article. Unaccustomed magnification may cause objects to appear closer or farther than they really are, thus affecting the reflexes linking the vestibular (balance) system with eye movements. For older patients who aren't used to bifocals and "progressive" lenses, switching to these types of lenses may cause distortion in peripheral vision.


Blurred vision contributes to the risk of falling in older adults -- but getting new glasses with a big change in vision prescription may increase the risk rather than decreasing it, according to a special article, '2013 Fry Lecture: Blurred Vision, Spectacle Corr & Falls in Older Adults' in the June issue of Optometry and Vision Science, official journal of the American Academy of Optometry.The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.

Optometrists can help to prevent falls by avoiding over-aggressive vision correction in older patients at risk, according to the review by David B. Elliott, PhD, 2013 recipient of the prestigious Glenn A. Fry Lecture Award. "Our 2013 Glenn A. Fry Award winner has been studying the effects of blurred vision and vision correction on falls among the elderly," comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science. "In his Award-winning lecture, he provides some very special insights into how this may happen and how we as a profession may help to minimize falls related to vision loss."

Vision Correction May Actually Increase Risk of Falling

Falls are the major cause of accidental death and nonfatal injuries in elderly US adults. At least one-third of healthy adults aged 65 or older fall at least once a year. For those aged 90 or older, the risk increases to about 60 percent.

But falls in older adults aren't accidents, according to Dr. Elliott. Most of the time, they're related to a wide range of risk factors including older age, disabilities, muscle weakness, and many different medical conditions. "The more risk factors you have, the more likely you are to fall," Dr. Elliott writes.

Reduced vision is one important risk factor, suggesting that interventions to correct vision -- particularly glasses and cataract surgery -- would reduce the risk of falling. Surprisingly, however, most studies have shown little or no reduction in falls among older adults receiving a new vision correction.

Magnification from some new glasses provided in one study may contribute to the increase in risk, Dr. Elliott suggests. "Some of the subjects received large changes in spectacle prescription….Older frail people may have greater difficulty adapting to such changes and be at increased risk of falling during this adaptation period."

New Glasses for Older Patients at Risk of Falls -- 'If It Ain't Broke, Don't Fix It'

Unaccustomed magnification may cause objects to appear closer or farther than they really are, thus affecting the reflexes linking the vestibular (balance) system with eye movements. For older patients who aren't used to bifocals and "progressive" lenses -- with different areas of correction for near and distance vision -- switching to these types of lenses may cause distortion in peripheral vision.

So if maximizing vision correction isn't the answer, what can optometrists do to help prevent the risk of falls in elderly patients? An important first step is to assess risk factors, including history of falls, medical conditions, and medications used.

In addition, Dr. Elliott proposes taking a "conservative" approach to prescribing new glasses for older adults with a history of falls or risk factors for falling. He suggests some changes to the vision prescription for optometrists to consider in this situation. He adds, "Indeed, if a patient reports no problems with vision but simply requests a new frame, 'If it ain't broke don't fix it' is an appropriate clinical maxim."

He also suggests keeping the same type of lens (bifocals, progressive lenses, etc) unless there's a significant reason for change. "Progressive lenses or bifocals should never be prescribed to patients who are used to wearing single-vision glasses and who could be characterized at risk for falls," Dr. Elliott writes. He notes that one randomized controlled trial showed that providing an additional pair of distance vision, single-vision glasses for outdoor mobility use -- as opposed to bifocal or progressive addition lenses -- can reduce falls rate.


Story Source:

The above story is based on materials provided by Wolters Kluwer Health: Lippincott Williams & Wilkins. Note: Materials may be edited for content and length.


Journal Reference:

  1. David B. Elliott. The Glenn A. Fry Award Lecture 2013. Optometry and Vision Science, 2014; 91 (6): 593 DOI: 10.1097/OPX.0000000000000268

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