Study shows a significant association between baseline foveal choroidal thickness and macular atrophy.
Nizar Abdelfattah, MD, and colleagues in the Treat-and-Extend Age-Related Macular Degeneration (TREX-AMD) Study Group compared the enlargement rate of macular atrophy in eyes that received monthly injections of ranibizumab (Lucentis/Roche) with that in eyes that received ranibizumab according to a treat-and-extend (TREX) regimen for neovascular age-related macular degeneration (nAMD).
The study was an 18-month, multicenter, randomized controlled clinical trial that included 60 patients with treatment-naïve nAMD in one eye. Investigators randomly assigned patients in a 1:2 ratio to receive ranibizumab either monthly or according to a TREX regimen. The nAMD-unaffected eyes served as controls.
The investigators used spectral-domain optical coherence tomograms (SD-OCT) and fundus autofluorescence (FAF) images to follow-up eyes for 18 months and quantified areas of macular atrophy on the FAF images by using Heidelberg Region Finder software. They confirmed suspected areas of atrophy with SD-OCT and infrared reflectance imaging.
In eyes without macular atrophy at baseline that developed macular atrophy by the 18-month follow-up visit, the investigators assessed intervening visits to determine the first visit at which macular atrophy appeared so they could define its rate of progression.
At baseline, the investigators also assessed foveal choroidal thickness, subretinal hyperreflective material, and pigment epithelial detachment to determine whether they affected the rate of progression of macular atrophy. However, the main outcome measure of the study was mean enlargement rate of macular atrophy at 18 months.
In the final analysis, the investigators assessed 88 eyes in 3 groups. The monthly treatment group included 19 eyes, the TREX regimen group included 30 eyes, and the control group included 39 fellow eyes.
During 18 months, the mean enlargement rate of macular atrophy was 0.39 ± 0.67 mm2 for the monthly treatment group, 1.1 ± 1.9 mm2 for the TREX regimen group, and 0.49 ± 1 mm2 for the control group (P = 0.12). In the 36 eyes with macular atrophy at baseline (41%), this rate was 0.9 ±1 mm2 for the monthly treatment group, 1.9 ± 2.2 mm2 for the TREX regimen group, and 1 ± 1.3 mm2 for the control group (P = 0.31).
These findings led the investigators to conclude that, whether injected monthly or according to a TREX regimen, ranibizumab did not have a statistically significant effect on the development of new macular atrophy in eyes with nAMD.
However, the investigators found a significant association between baseline foveal choroidal thickness and macular atrophy (P = 0.01). They also found a significant association between baseline subretinal hyperreflective material and macular atrophy (P = 0.02).
Moreover, in eyes without macular atrophy at baseline, they found that statistically significant predictors of the development of new macular atrophy included the presence and thickness of subretinal hyperreflective material, the thickness of the pigment epithelial detachment, and the presence of hemorrhage at baseline.
The report, “Macular atrophy in neovascular age-related macular degeneration with monthly versus treat-and-extend ranibizumab: findings from the TREX-AMD trial,” was published in the November 2016 issue of Ophthalmology.