1. Assessing the Repeatability of Inner Choroid Flow Deficit Percentage in Intermediate AMD and Controls: A Comparative Study between Different Post-processing Approaches.
- Author
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Romano F, Ding X, Garcia M, Zhao Y, Vingopoulos F, Garg I, Stettler I, Bennett C, Overbey K, Finn M, Ploumi I, Laìns I, Patel NA, Wu DM, Vavvas DG, Husain D, Miller JW, and Miller JB
- Abstract
Purpose: To assess repeatability of macular inner choroid flow deficit percentage (ICFD%) in intermediate age-related macular degeneration (iAMD) and controls employing various post-processing approaches., Methods: Cross-sectional, observational study. We included (1) 22 iAMD and 24 control eyes, with (2) age >50 years, (3) visual acuity >20/32, and (4) no additional ocular and systemic confounders., Participants: underwent four consecutive 6x6-mm OCTA scans (2 acquired at 100-kHz and 2 at 200-kHz speed; PLEX® Elite 9000) for intra-session analysis. Same protocol was repeated after 30 minutes for inter-session analysis. Three slabs of different thicknesses were generated underneath Bruch's membrane (4-14, 4-19, 4-24 µm). All slabs were processed with: (1) binarization-only using Phansalkar method (r=4-15 pixels); (2) compensation+binarization; (3) averaging+binarization; (4) averaging+compensation+binarization. ICFD% was measured within 3- and 5-mm circles, and measurements were repeated after excluding drusen areas.Repeatability was analyzed with generalized linear mixed-effects models, intraclass correlation coefficients (ICC) and Levene's variance test., Results: Most post-processing approaches demonstrated high repeatability (ICC>0.75) with no significant test-retest differences (p>0.05). Compensation+binarization of 15-µm slabs at 200 kHz showed the highest repeatability (ICC: 0.96-0.98). Excluding drusen did not significantly impact ICFD% measurements (p>0.05), showing increased ICCs for 10 µm-thick and binarized-only slabs., Conclusions: Strong repeatability can be achieved with various post-processing methods for assessing ICFD%, especially with compensation+binarization of 15-µm slabs acquired at 200 kHz. Drusen removal does not seem to impact repeatability in iAMD when using a swept-source device, except for specific settings., Competing Interests: Conflict of Interest: no conflicting relationship relevant to this research.
- Published
- 2024
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