Treating neovascular AMD: Best course of treatment still unknown

Following the clinical trials of ranibizumab (Lucentis, Genentech), considerations about the course of treatment in patients with choroidal neovascularization (CNV) arose. Addressing that issue was Neil M. Bressler, MD, chief of the retina service, The Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore.

"Our burden has changed in terms of treating neovascular age-related macular degeneration (AMD)," Dr. Bressler said.

Initially, a laser treatment was performed and although the patients were followed, they were not treated at each follow-up visit. Laser photocoagulation was shown to be beneficial about half the time in confining the lesion and stopping it from affecting the center of the retina. When the less destructive photodynamic therapy was introduced, treatment was required as often as every 3 months and five to six times during a 2-year period based on results of fluorescein angiography.

"The vascular endothelial growth factor (VEGF) drugs resulted in an evolution," he said. "We have not only halted progression of the neovascular lesions but in some cases the vision actually improved."

The change associated with VEGF drugs is that treatment can be administered as often as every 4 weeks. The vision can be preserved at the 20/40 level and sometimes have improved vision, but the question of how often to treat arises.

In the PIER trial of ranibizumab, when the drug was given for 3 months and then every 3 months, the patients lost 15 letters of vision compared with the ANCHOR and MARINA trials in which the patients were injected every month and had improved vision of five to 10 letters. While this appears to be an inferior effect of reduced treatment, the PIER trial cannot be compared directly with the MARINA and ANCHOR trials because of different study populations.

"The optimal duration of treatment remains undetermined," he stated.

In assessing individualized treatment, factors that might be considered when terminating treatment are the normal appearance of the retina and the lack of improvement and sustained symptoms seen over the previous 4-month period.

Dr. Bressler said, "Management of patients with neovascular AMD has evolved, but we are at an impasse when considering the continuation of treatment. There is strong evidence to suggest that monthly treatment should continue. Should treatment be administered less frequently? We don't know. The patient should be informed about the side effects of treating the lesions that are either predominantly classic or minimally classic or occult with no classic component that have had recent disease progression.

"I hope in the future we will learn the best treatment regimen and learn what to do in cases with no progression," he concluded.