Nancy A. Melville

April 15, 2014

PALM SPRINGS, California — Disorders of binocular vision are associated with a significant increase in the risk for falls and fractures in the elderly, likely exceeding the more commonly recognized risks associated with cataracts and age-related macular degeneration, according to new research.

The study is the first to evaluate the association between fractures and disorders of binocular vision in the Medicare database, the largest and most comprehensive data source of its kind in the United States.

"This association has not been previously explored, and it was unclear whether these disorders had a specific impact on morbidity in the elderly," said lead author Stacy Pineles, MD, assistant professor of ophthalmology at the UCLA Jules Stein Eye Institute in Los Angeles.

"However, it makes sense that the rate is higher. Patients with disordered binocular vision may have more difficulty with depth perception and perceiving obstacles in space if they have double vision," she told Medscape Medical News.

The study was presented here at the American Association for Pediatric Ophthalmology and Strabismus 2014.

Researchers looked at a random sample of 5% of Medicare Part B physician claims for beneficiaries 65 years and older from 2002 to 2011.

Of the 2,196,881 beneficiaries identified, 99,525 (4.5%) had a disorder of binocular vision, including strabismus, amblyopia, diplopia, and nystagmus.

Overall, 1,272,948 (57.94%) patients sustained musculoskeletal injuries, fractures, or falls, and 74,504 (5.85%) had disorders of binocular vision (adjusted odds ratio [OR], 1.27; < .001).

"We found a 27% higher risk of injury in patients with disorders of binocular vision," Dr. Pineles reported. This was seen after adjustment for nearly 50 confounders, including age, sex, race/ethnicity, region of residence, systemic health, and ocular comorbidities.

Diplopia had the strongest association with binocular vision disorders (OR, 1.33; P < .001). "This makes sense because patients with diplopia have poor depth perception, they can have visual confusion, and they have impaired ability to negotiate and avoid obstacles," she explained.

Amblyopia had weakest association, which also makes sense, she said. "Patients with amblyopia have theoretically had it their whole life; they've had time to adapt. This can also include patients with mild amblyopia."

Previous studies of ocular disorders such as cataract and age-related macular degeneration have revealed significant associations with musculoskeletal injuries, but with lower odds ratios than were found for disorders of binocular vision, Dr. Pineles said.

Limitations of the study include the identification of an association but not necessarily causation of falls and fractures. Also, the findings from a Medicare database might not be generalizable to other regions of the world or cultures, Dr. Pineles acknowledged.

Nevertheless, the results suggest that clinicians should keep the potential risks in mind when managing older patients with binocular vision disorders, she said.

"Some primary care providers might think that strabismus is mostly a cosmetic problem in elderly patients but, in reality, it may be contributing to increased injuries in this population," she pointed out.

Educating patients on ways to make their environment safer from falls and other types of injuries could be helpful. "These patients can also be referred to a strabismus specialist who may be able to provide various treatments," Dr. Pineles noted.

Session comoderator Mohamad Jaafar, MD, said he agrees that the findings highlight important ocular risk factors that clinicians should be aware of.

"Because falls and fractures carry significant morbidity and mortality, identifying risk factors, such as disorders of binocular vision, is critical to decrease the risk of injury, improve quality of life of the elderly, and limit the cost of medical care," said Dr. Jaafar, who is professor and chief of ophthalmology at Children's National Medical Center, George Washington University, in Washington, DC.

Disorders of binocular vision can, in fact, result from some neurologic conditions, he told Medscape Medical News.

"We have to bear in mind that some of the strabismus — for instance, paralytic strabismus — in this patient population may have been acquired at an older age due to neurologic disease, such as a fall, stroke, or intracranial tumor. This is usually accompanied by diplopia," he explained. "In other words, the fall may be the cause of the strabismus and diplopia, not the effect."

Either way, awareness of the risks and appropriate treatment of disorders of binocular vision are essential, said Dr. Jaafar.

"Clinicians should look for strabismus and amblyopia in the elderly patient — it's easy and not very time consuming — and make the proper referral to the expert, if needed," he explained.

"They should ensure that their patients' functions and well-being are restored," Dr. Jaafar said.

The study received funding from the National Eye Institute and the American Academy of Ophthalmology. Dr. Pineles and Dr. Jaafar have disclosed no relevant financial relationships.

American Association for Pediatric Ophthalmology and Strabismus (AAPOS) 2014: Abstract 2. Presented April 3, 2014.


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