Abstract
Purpose :
To use optical coherence tomography angiography (OCTA) to answer three questions regarding the relationship between choriocapillaris (CC) impairment and the rate of geographic atrophy (GA) growth: (1) Is global CC impairment correlated with global GA growth rate? (2) Is CC impairment immediately adjacent to the GA margin more correlated with global GA growth rate than is CC impairment farther from the GA margin? (3) Does GA preferentially grow into regions of CC impairment?
Methods :
Eight eyes from 6 patients with GA secondary to age-related macular degeneration (AMD) were imaged with a prototype 400kHz, 1050nm swept-source OCTA system at two visits (mean intervisit time: 8 ± 2.1 months). Of these 8 eyes, 1 eye was excluded from the statistical analysis due to the presence of peripapillary atrophy. For each eye, baseline CC impairment—assessed using flow deficit percentage—was computed using global, zonal, and local perspectives, and then correlated with global and local GA growth rates.
Results :
Global baseline CC impairment was found to be correlated with global GA growth rate (Pearson’s r = 0.83, p = 0.02). Zonal analysis did not support the hypothesis that baseline CC impairment immediately adjacent to the GA margin was more correlated with GA growth rate than was baseline CC impairment farther from the margin. Finally, local analysis did not support the hypothesis that GA lesions preferentially grow into regions of CC impairment (mean Pearson’s r = -0.06).
Conclusions :
Global CC impairment, excluding the region of atrophy, may be a useful predictor of GA growth rates. CC impairment in zones immediately adjacent to the GA margin were not more correlated with GA growth rates than were CC impairment in zones farther from the margin. Furthermore, in general, GA lesions were not found to grow into regions of CC impairment, suggesting that local CC impairment is, in general, not directly causal in local GA growth.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.