Cataract Surgery May Decrease Risk for Hip Fractures

Jennifer Garcia

July 31, 2012

July 31, 2012 — Elderly patients who undergo cataract surgery have a lower risk for hip fracture within 1 year after surgery compared with patients with cataract who do not have the surgery, according to a newly published study.

A total of 1,113,640 patients aged 65 years or older with a diagnosis of cataract were included in the study, which was published in the August 1 issue of JAMA. These patients comprised a 5% random sample of US Medicare Part B beneficiaries. Between 2002 and 2009, 410,809 (36.9%) of these patients underwent cataract surgery.

The adjusted odds ratio [OR] of hip fracture within 1 year after cataract surgery was 0.84 (95% confidence interval [CI], 0.81 - 0.87), with an absolute risk difference of 0.20% compared with 1-year hip fracture incidence in patients with cataract who did not have cataract surgery. The overall 1-year fracture incidence was 1.3% for hip fractures.

The researchers adjusted for age, sex, race/ethnicity, region of residence, cataract severity, and the presence of physically limiting conditions. Ocular and systemic comorbidities — including the Charlson Comorbidity Index (CCI) score — were also included in the adjustment.

The researchers found a higher prevalence of osteoporosis, hyperparathyroidism, and all ocular comorbidities among the cataract surgery group compared with the cataract diagnosis group. Additionally, when compared with patients of the same age in the cataract diagnosis group and after adjusting for demographic and comorbidity factors, the researchers found that patients in the cataract surgery group aged between 80 and 84 years had the lowest odds of hip fracture (OR, 0.72; 95% CI, 0.67 - 0.78) after cataract surgery among all other age groups.

"Prior studies have shown that there is an association between visual impairment and fracture risk," author Anne Coleman, MD, PhD, from the Jules Stein Eye Institute, David Geffen School of Medicine, University of California, Los Angeles, said in an interview with Medscape Medical News. "Our study found that the removal of a cataract was associated with a decreased rate of hip fractures in older individuals compared to those whose cataracts were not removed. This means that the increased fracture risk associated with the visual impairment of a cataract can be reduced by removing the cataract," Dr. Coleman said.

The authors acknowledge the study limitations, such as the observational and retrospective design, which may result in bias. They note, however, that patients were matched by a propensity score that would have adjusted for potential bias. Additionally, clinical information such as visual acuity among patients was not evaluated, as it was not included in the administrative data used.

The researchers note several strengths of the study as well, particularly the large number of patients included, which provides the statistical power to accurately detect differences between the 2 groups.

"Cataract surgery was associated with 16% decrease in the adjusted odds of hip fracture 1 year after the procedure in Medicare patients 65 years and older when compared with patients with a diagnosis code for cataract who did not have cataract surgery," the researchers note.

"Importantly from a clinical perspective, individuals should not be regarded as 'too old' or 'too ill' to have a cataract extraction, as we found the reduction of the risk of hip fractures to be largest among individuals 80 - 84 years old and individuals with scores in the highest categories on the [CCI]," Dr. Coleman said.

According to independent commentator Alan N. Carlson, MD, chief of cornea and refractive surgery services at the Department of Ophthalmology, Duke University School of Medicine, North Carolina, "Modern cataract surgery usually corrects refractive error with modern lenses [myopia, astigmatism, hyperopia]. Therefore, there is a period of time between surgical procedures when the two eyes may not be working together leading to confusion.

"While cataract surgery leading to improved vision may ultimately reduce an individual's risk for injury from falling, there remains significant risk in the early postoperative period," Dr. Carlson told Medscape Medical News. "Fall prevention in the perioperative period leading up to surgery and in the early postoperative period is a critical aspect of patient care, as these patients form a high-risk group for fall-related traumatic injury and fracture," Dr. Carlson added.

"Linking the diagnosis of cataract or having cataract surgery with hip fracture or falling or any type of accident is a challenging proposition, as the aging population is heterogeneous as is the spectrum of injury with the more serious form of injury including hip fracture," Dr. Carlson concluded.

Funding for this study was provided by the Center for Eye Epidemiology, Jules Stein Eye Institute, Los Angeles, California. The authors and independent commentator disclosed no relevant financial relationships.

JAMA. 2012;308:493-501. Full Article