New approaches to wet age-related macular degeneration treatment

Nov 13 2007

Two particularly notable research presentations at the American Academy of Ophthalmology's Annual Meeting described new approaches to the treatment of "wet" Age-Related Macular Degeneration (AMD), the most common cause of severe vision loss in the western world in people over age 50.

“Wet” AMD is responsible for the majority of AMD-related vision loss. It is characterized by the abnormal growth of blood vessels under the retina (a sensitive area at the back of the eye). New treatments, that act on “wet” AMD's abnormal blood vessel growth, such as Avastin and Lucentis, have allowed some patients to obtain meaningful and sustained improvements in vision. This type of medication, termed “anti-VEGF”, is sometimes combined with a laser treatment called photodynamic therapy (PDT).

In the United States pharmacotherapies are the most common treatment approach. In the US and internationally, surgical treatment may be used when a patient's “wet” AMD has advanced beyond the point where pharmacotherapies are useful or in situations where they are unavailable.

Milam A Brantley, Jr., MD, PhD, an assistant professor of ophthalmology and visual sciences at Washington University School of Medicine, spoke on how genetic factors may affect the success of Avastin (bevacizumab) treatment; and Zhizhong Ma, MD, described an innovative, intriguing surgical technique for “wet” AMD developed in Peking University Eye Center, Beijing, China, where she is a professor of ophthalmology and deputy director.

Dr. Brantley's study is the first to link genetic factors to patients' response to Avastin treatment for “wet” AMD. Previous studies had found variants in two genes, CFH and LOC387715, to be associated with AMD. Dr. Brantley's study looked at 86 patients to see whether having either of these genetic variants affected their responses to Avastin.

“We found that patients with two copies of the CFH variant faired significantly worse than the others in response to treatment with Avastin,” Dr. Brantley said, “but we saw no differences in treatment response with the LOC387715 variant. We hope that our study and future, similar research might lead to the development of more individualized AMD treatments that will be more effective and economical.”

Adjusting patients' treatments based on genetic tests is also underway or in development in other areas of medicine, such breast cancer.

New surgical approaches to “wet” AMD are being explored by ophthalmologists around the world. The technique developed by Dr. Ma's group advanced the ability to sustain transplant tissue integrity and reduced complications during or after surgery, and vision improved in a majority of patients. This could make a significant difference in AMD treatment in certain population groups.