Abstract
Purpose :
Previous analyses of macular atrophy (MA) in the HARBOR trial population examined data from color fundus photography and fluorescein angiography. This analysis studied the development and progression of MA in HARBOR via a longitudinal assessment of monthly SD-OCT scans.
Methods :
This was a retrospective, post hoc analysis of SD-OCT images from the phase 3 HARBOR trial (NCT00891735; N=1097), which evaluated intravitreal ranibizumab (RBZ) for the treatment of neovascular AMD in eyes with CNV. RBZ 0.5 mg or 2.0 mg was administered monthly or PRN after 3 loading doses. Evaluable SD-OCT macular cube scans from patients with 24 months (M) follow-up (N=941) were examined monthly from baseline (BL) to M24 by masked reading center graders. Atrophy diagnosis criteria aligned with those proposed by the Classification of Atrophy Meetings (CAM) group: hypertransmission of light into the choroid, RPE loss, and loss of outer retinal layers. Study arms were compared for time to MA detection (log-rank test) and growth rates (time*arm interaction test).
Results :
At BL, MA rates differed across RBZ study arms (0.5 mg monthly: 19.1%; 0.5 mg PRN: 16.1%; 2.0 mg monthly: 10.5%; 2.0 mg PRN: 10.1%). At M24, new MA (in eyes without preexisting atrophy) was present in 25.7% of eyes. Rates of new MA development were similar across RBZ doses (0.5 mg: 25.9%; 2.0 mg: 25.4%) and treatment regimens (monthly: 26.4%; PRN: 25.0%). There were no significant differences in time to detection of new MA (P=0.840) or growth rate of new atrophy area (square-root transformed, P=0.615) among study arms. Preliminary analysis confirmed BL risk factors for MA development that were identified from previous analyses: presence of intraretinal cysts, atrophy in the fellow eye, and absence of SRF. Type III CNV, as compared with other CNV types, correlated with a higher rate of MA. Presence of PED at BL did not affect rates of MA development.
Conclusions :
This was the first analysis of SD-OCT data from a major nAMD trial (HARBOR) using CAM atrophy criteria for grading images. Over 24M in HARBOR, there were no observed differences in the development or progression rates of new MA among study arms, RBZ doses, or treatment regimens. BL risk factors for development of MA were confirmed from prior analyses: presence of cysts, atrophy in the fellow eye, and absence of SRF. Neither RBZ dose level nor treatment regimen appeared to influence the development or progression of MA.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.