Abstract
Purpose :
To determine whether the presence of subretinal hyperreflective material (SHRM) may mask the detection of choroidal neovascular membranes (CNVM) on optical coherence tomography angiography (OCTA).
Methods :
In this prospective observational study, patients diagnosed with neovascular age-related macular degeneration (AMD) with co-existing SHRM and showing signs of activity in the form of intraretinal or subretinal fluid or hemorrhage detected by OCT B scans, were selected to undergo OCTA (Optovue Inc, Fremont, California, USA) imaging and fundus fluorescein angiography (FFA). The software built-in 6x6 mm choriocapillaris slab on OCTA was examined to determine the presence of the presumed CNVM underneath the SHRM. The corresponding area on FFA was correlated, and used as a reference arm to demonstrate the activity of the neovascular frond.
Results :
Fifteen eyes of fifteen patients with SHRM and OCT signs of active neovascular AMD were recruited. All fifteen eyes failed to show a CNVM frond in the choriocapillaris slab of OCTA underneath the areas of SHRM, whereas all of them showed an actively leaking hyperfluorescent CNVM that increased in size and intensity, and showed staining in the late stages of the fluorescein angiogram. In 1 eye, parts of a large neovascular frond existing under the SHRM were invisible due to blocking of the light waves, while parts extending beyond the SHRM were detected on the choriocapillaris en face slab with flow on the corresponding B scan.
Conclusions :
The presence of SHRM may act as a reflecting surface that precludes the passage of light waves in OCTA, thus diminishing its ability to detect underlying CNVMs. The clinical implications of these findings could potentially limit the use of OCTA as a tool for follow up of CNVMs with co-existing SHRM, which may possibly be better followed up using OCT or FFA signs of activity.
This is a 2020 ARVO Annual Meeting abstract.