Research suggests RVO linked to heart disease, stroke

Meta-analysis finds increase in adverse cardiac events for these patients.

By Robert Stoneback, associate editor

One of the first large-scale analysis of medical research shows a correlation between retinal vein occlusion (RVO) and adverse cardiac events, including heart disease and stroke.

When compared to patients who do not have RVO, according to the study, RVO patients were at an increased risk of stroke (risk ratio [RR] of 1.45), heart attack (RR of 1.26), heart failure (RR of 1.53), peripheral arterial disease (RR of 1.26) and all-cause mortality (RR of 1.36).

The research, conducted by physicians at Mount Sinai and published in Retina, was conducted through analyzing 15 manuscripts that contained data on nearly 475,000 patients. Of these, 60,069 had RVO while 414,397 did not.

The study’s authors recommend that ophthalmologists refer RVO patients to cardiologists and/or neurologists due to the higher risk of cardiovascular disease, instead of referring them to a general practitioner.

“This study suggests that we as retina specialists should probably be far more aggressive in referring our RVO patients out for specifically cardiac and neurological evaluation,” said senior study author Avnish Deobhakta, MD, assistant professor of Ophthalmology at the Icahn School of Medicine at Mount Sinai, via press release. “Ideally, we should be even more communicative with the primary care physician about these sorts of cardiac and neurological risks that these patients face.”

Pravin Dugel, MD, clinical professor of ophthalmology at the USC Roski Eye Institute, Keck School of Medicine in Los Angeles, was more cautious about the results, saying the nature of the study’s methodology meant there were some limits for its practical application.

“Mount Sinai’s research is excellent for a meta-analysis, but meta-analyses also rarely change how physicians treat patients; that is simply due to the fact that it is not a ‘higher level’ of data that shows a direct causal link,” says Dr. Dugel.

In the case of RVO and ailments such as heart disease and stroke, it may be that people with one disease may be more likely to have a second or third, perhaps due to age or sickness, he points out.

While the study “doesn’t change my behavior, I don’t ignore it, either.” OM

Study proposes link between air pollution, AMD

Research examined exposure to nitrogen dioxide and carbon monoxide.

By Robert Stoneback, associate editor

A recent study out of Taiwan suggests a link between increased air pollution and the likelihood of developing AMD.

Conducted by members of Taiwan’s China Medical University and published in the BMJ Journal of Investigative Medicine, the research concluded that chronic exposure to high amounts of nitrogen dioxide (NO2) and carbon monoxide (CO) can significantly increase the risk of AMD.

The study, “Traffic-related air pollutants increase the risk for age-related macular degeneration,” was a longitudinal population-based study that used medical data from 2000 to 2010 provided by the Taiwan National Health Insurance Program.

A total of 39,819 subjects age 50 or older were enrolled from that dataset; of those subjects, all of whom were AMD-free at the time of enrollment, 1,442 developed AMD during the study’s 11-year follow-up.

The annual total exposure to NO2 and CO from 1998 to 2010 for each subject was calculated using the Cox proportional hazard model. The adjusted hazard rate for developing AMD was 1.91 times greater for people in the highest NO2 quartile, and 1.84 times greater for those in the highest CO quartile.

Daniel Su, MD, a retina specialist at Retina-Vitreous Associates Medical Group, in Los Angeles, notes that the findings are consistent with the effects of cigarette smoking on AMD, which is “the single most important modifiable risk factor for AMD”; both CO and NO2 are found in cigarettes.

Dr. Su says that the Taiwanese study did not control for cigarette smoking; however, “despite the lack of causative data, there certainly is a strong association between air pollution and AMD.”

It is still helpful for patients to avoid areas of heavy air pollution, says Dr. Su, as in addition to the risks of lung disease and lung cancer, air pollutants can cause surface eye irritation and dry eye. OM