Comparison of AMD Treatment Trials study shows lower fluid

Key Points

Orlando, FL-The results of the direct comparison of ranibizumab (Lucentis, Genentech) and bevacizumab (Avastin, Genentech) after 1 year of treatment showed that the two drugs administered according to monthly and as-needed protocols produced significant decreases in retinal fluid with small amounts of residual fluid in patients with age-related macular degeneration (AMD).

Glenn J. Jaffe, MD, discussed the anatomic findings of the Comparison of AMD Treatments Trial (CATT) to put them into perspective for use in the clinic setting. He presented the study results on behalf of the CATT Research Group during Retina Subspecialty Day at the annual meeting of the American Academy of Ophthalmology.

On average, at baseline, eyes in this study had a total retinal thickness of about 460 µm and compartments of intraretinal, subretinal, and sub-RPE, fluid. After treatment with ran i biz u mab, the retinal thickness in the eye decreased to a mean of 257 µm. In the eyes treated with bevacizumab, while the retinas were slightly thicker, the average retinal thickness was 297 µm and the morphologic appearance was not that different from eyes treated with ranibizumab, Dr. Jaffe said.

"The [retinas of the] eyes treated with ranibizumab monthly were thinner than normal at the end of the study," he said. "At baseline, the [retinas] in all four treatment groups were an average of about 250 µm thick. At week 52, [retinas in] all groups, except for the ran i biz umab monthly group, were an average of 170 µm thick; [retinas in] the eyes treated with ran i bizu mab monthly were an average of 152 µm thick. Normal thickness is about 180 µm, and we are still exploring this in relation to visual acuity."

A significantly (p < 0.001) larger percentage (43.7%) of eyes treated with ranibizumab monthly had no fluid at 52 weeks compared with eyes treated with ranibizumab as needed (23.9%), bev a ciz u mab monthly (26.0%), and bevacizumab as needed (19.2%). However, considering these percentages, most eyes in all groups still had fluid at the end of the study, which raises a question about the volume of fluid that was present at that time point, Dr. Jaffe noted.

"We are not talking about a great deal of fluid," he said. Typically, only a small cyst was present in the retina.