Anti-VEGF injections may not work for all, new study says

A common treatment for wet age-related macular degeneration (AMD) may need a second thought by doctors of optometry.

A new study suggests, in some cases, that patients' vision worsens due to intravitreal, anti-vascular endothelial growth factor (VEGF) injections. An estimated 288 million people will suffer from wet AMD by 2040.

The role of VEGF and its side effects in treatment of wet AMD was examined in a new study first published online in The Journal of Clinic Investigation on Dec. 5, titled  "VEGF regulates local inhibitory complement proteins in the eye and kidney." Senior co-authors include Martin Friedlander, M.D., Ph.D., professor in the cell and molecular biology department of The Scripps Howard Research Clinic, and Moin Saleem, MBBS, FRCP, Ph.D., professor of human biology at the University of Bristol.

According to the authors, "High concentrations of VEGF contribute to CNV (choroidal neovascularization) development, so wet ARMD is treated with intravitreal anti-VEGF injections. This therapy revolutionized ARMD patient care."

But, apparently, it may not work as well in all patient cases. Not only is there a loss of vision, but there also is damage to cells in the kidneys, researchers say. The treatment may inhibit some patients' capability to make inhibitory complement factor H (CFH), a protective and regulatory molecule, the study says.

Researchers linked VEGF inhibition with a decrease in CFH. "Over 40% have stable or improved visual acuity, but 10 to 30% of patients treated develop reduced visual acuity with regular repeated injections over time," wrote researchers, who noted more research needs to be done on why. "This could be due to the loss of VEGF's trophic effects."

'Needs to be monitored'

Steven G. Ferrucci, O.D., is chief of optometry at Sepulveda VA Medical Center and professor at Southern California College of Optometry at Marshall B. Ketchum University.

The study's results are worth being taken into account by doctors of optometry, Dr. Ferrucci says.

"The point is that researches feel that even the small amount of anti-VEGF injected intravitreally may have effects outside of the eye," Dr. Ferrucci says. "In this study, they seem to show a link between patients who have anti-VEGF injections for AMD and kidney issues, at least in animal models."

He adds, "While this is still not clear in humans, the point is that even minimal amounts of anti-VEGF intravitreally may have other effects in the body, so this needs to be monitored. Also, as the study suggests, if patients are not responding to anti-VEGF, perhaps it makes sense to stop rather than to continue treatment."