Abstract
Purpose :
Morphologic alterations in the retina have been shown to influence the functional response to anti-angiogenic therapies in neovascular age-related macular degeneration (AMD) and impact the visual outcomes. We wanted to test and validate a new 3D volumetric tool to quantify some of the critical alterations in a subset of patients enrolled in a prospective Phase 1/2 trial.
Methods :
The initial phase was an open-label, single-ascending dose of increasing single intravitreal (IVT) doses of an anti-VEGF agent, ranging from 0.03mg to 0.6mg, in patients with neovascular AMD (treatment naïve or previously treated with an anti-VEGF therapy). Images of two dose groups at the highest doses (n=5 for each group) were evaluated at 5 visits. OCT scans were obtained from Spectralis (Heidelberg Engineering) and were imported into the novel software (RevAnalyzer, ADCIS). Three independent trained graders measured three types of alterations: Pigment Epithelium Detachment (PED), Subretinal Fluid (SRF) and Intraretinal Cysts (IRC).
Results :
The agreement between graders for PED, SRF and IRC was 97.3%, 94.6% and 96%, respectively. For the volume measurements of all PED, SRF, and IRC, the intraclass correlation between graders was 0.90 (95% CI, 085-0.94), 0.98 (95% CI, 0.98-0.99) and 0.95 (95% CI, 0.92-0.97), respectively. We found that SRF volume was the most sensitive measurement to our novel anti-VEGF therapy as it rapidly decreased after IVT injection (maximal average reduction at 15 days post-IVT, slope of regression line = -6.40) and, for some cases, quickly re-appeared before any changes in central retinal thickness. When responsive, the IRC volume also rapidly decreased upon treatment (volume was completely absent at Day 15). By contrast, PED volume slowly decreased upon anti-VEGF treatment (slope of regression line= -2.95) but was responsible for the maximal reduction of the central retinal thickness (correlation r2=0.525).
Conclusions :
The semi-automated quantification of PED, SRF and IRC volumes was found to be very reproducible between graders. This innovative software is a valuable tool that allows exquisite visualization of retinal fluid and the refined correlation of sub-types of retinal alterations with retinal thickness and BCVA, as it enables a reproducible measurement of a global volume compared to qualitative assessment or point measurement of each morphologic parameter.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.