OCT-guided treatment of neovascular AMD preserves drug benefits

The results of the PrONTO Study, an exploratory open-label trial, indicated that intravitreal injection of ranibizumab (Lucentis, Genentech) produces rapid improvements in visual acuity and findings on optical coherence tomography (OCT) in patients treated for neovascular age-related macular degeneration, said Philip Rosenfeld, MD, PhD, during Retina Subspecialty Day.

Forty patients underwent three consecutive monthly injections with 0.5-mg intravitreal ranibizumab during the first year and three patients withdrew during year 2. From months 3 to 24, OCT images were obtained monthly and fluorescein angiography images every 3 months with the goal of determining if OCT-guided regimens could be used over 2 years to maintain visual acuity improvements and OCT outcomes achieved after the three consecutive monthly doses of the drug, according to Dr. Rosenfeld, professor of ophthalmology, Bascom Palmer Eye Institute, University of Miami.

"By day 1 after treatment, we saw about a 50-µm decrease in the central retinal thickness, a 190-µm decrease by 3 months, a 178-µm decrease by 12 months, and a 215-µm decrease by 24 [months]," Dr. Rosenfeld reported.

There was an increase in visual acuity (6 letters) by 14 days after the first treatment that continued to 3 months (11 letters). At 24 months, the mean improvement in visual acuity from baseline was 10.7 letters. The mean number of injections over 24 months was about 10, according to Dr. Rosenfeld.

"The PrONTO Study showed that visual acuity and OCT changes appeared to be rapid after intravitreal ranibizumab," he concluded. "The OCT changes always preceded the visual acuity changes, whether for better or worse. OCT-guided treatment appears to preserve the benefits seen after three monthly doses of ranibizumab. A larger prospective study is necessary."