Abstract
Purpose :
Choroidal reflectivity is a newly proposed factor to assess choroidal structure in various diseases. The purpose of this study was to investigate the choroidal reflectivity in eyes with neovascular age-related macular degeneration (AMD), and evaluate its association with AMD subtype, visual prognosis, and changes after treatment.
Methods :
Patients with neovascular AMD underwent imaging of the macula with enhanced-depth imaging optical coherence tomography. Using Image J software, the inner and outer boundaries of the choroid and retinal pigment epithelium were segmented to allow the reflectivity of the pixels in the choroid, nerve fiber layer (NFL), and overlying vitreous to be quantified. Normalized choroidal reflectivity, with the NFL as the bright reference standard and the vitreous as the dark reference standard, was calculated using the formula: normalized choroidal reflectivity = (choroidal reflectivity-vitreous reflectivity)/NFL reflectivity.
Results :
One hundred and ninety four eyes with neovascular AMD including 94 eyes with polypoidal choroidal vasculopathy (PCV) and 19 eyes with retinal angiomatous proliferation (RAP) were included. Mean choroidal reflectivity was (0.35 ± 0.15) (range; 0.08 – 0.9). Choroidal reflectivity correlated positively with age (P<0.001, r=0.417) and negatively with choroidal thickness (P<0.001, r=0.568). Mean choroidal reflectivity was (0.34 ± 0.15) in typical AMD, (0.35 ± 0.13) in PCV, and (0.41 ± 0.16) in RAP. Mean choroidal reflectivity was significantly greater in eyes with pseudodrusen, compared those without pseudodrusen (0.42 ± 0.14 vs 0.34 ± 0.14, P=0.029). One year after three initial monthly, followed by bimonthly, intravitreous aflibercept injections, mean choroidal reflectivity increased to 0.42 ± 0.16 (P<0.001). Choroidal reflectivity at baseline correlated negatively with best-corrected visual acuity at 1 year (P=0.013, r=0.178).
Conclusions :
Choroidal reflectivity differed among AMD subtype and was greater in eyes with pseudodrusen. Choroidal reflectivity is a significant predictor of visual outcome after fixed-regimen intravitreous aflibercept injections.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.