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Omer Trivizki, Eric Moult, Prashanth Iyer, Giovanni Gregori, Fujimoto Fujimoto, Philip J Rosenfeld; The Impact of Non-Exudative Type I Macular Neovascularization on the Growth of Adjacent Geographic Atrophy. Invest. Ophthalmol. Vis. Sci. 2021;62(8):2514.
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© ARVO (1962-2015); The Authors (2016-present)
To determine if the growth of geographic atrophy (GA) is influenced by the presence of adjacent non-exudative type I macular neovascularization (MNV), we investigated local GA growth rates along segments of the GA margin at different distances to the adjacent type I MNV. We quantitatively computed the correlations between the local GA growth rates and their positions relative to the MNV lesions in a cohort of eyes having both type I MNV and GA.
Patients were enrolled into an ongoing institutional review board-approved prospective swept source OCT (SS-OCT) imaging study. Patients selected for this study were diagnosed with non-exudative type I MNV adjacent to an area of GA. Eyes with GA embedded within an area of type I MNV were excluded. The interval between the baseline and follow-up visits was 1 year. SS-OCT angiography (SS-OCTA) 6×6mm scans (PLEX Elite 9000, Carl Zeiss Meditec, Dublin, CA) were acquired centered on the fovea. GA was outlined using hyper-transmission defects identified on an en face structural slab positioned 64-400 µm beneath Bruch’s membrane. MNV was outlined using an en face OCTA image from a slab projected between the RPE and Bruch’s membrane. Regions of interest were manually traced and confirmed by two independent retina specialists. Pearson correlations were computed between the distance to the adjacent type I MNV versus local growth rates along segments of the GA margin, which were estimated using a biophysical GA growth model (Figure 1). P-values associated with the null hypothesis of no Pearson correlation were estimated using a Monte Carlo permutation scheme that incorporated the effects of spatial autocorrelation.
To date, 9 eyes have been imaged and analyzed. In 7 of the eyes, global growth rates were lower than the average known growth rates for GA (Table 1). In 8 of the eyes there was a positive correlation between distance-to-MNV lesion and local GA growth rates; however, in all but 1 eye, correlations were weak (Table 1; Figure 1).
SS-OCT imaging combined with local GA growth analysis enabled measurement of quantitative associations between MNV position and GA growth direction. Our results are consistent with the possibility that there may be a very weak inhibitory effect of non-exudative MNV on the local growth of GA.
This is a 2021 ARVO Annual Meeting abstract.
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