Abstract
Purpose :
Detection of imaging markers in the fellow eye of patients with RAP. Comparison with eyes with early/intermediate AMD, in the absence of history of RAP, and with healthy controls.
Methods :
Study with multimodal cross-sectional evaluation. The included eyes were divided into four study groups: control, fellow eye of RAP, early/intermediate AMD and eyes with RAP. All patients were evaluated with color fundus photography (CFP), spectral-domain optical coherence tomography (SD-OCT) and enhanced depth imaging OCT (EDI-OCT) with Spectralis OCT and optical coherence tomography angiography (OCTA) with CIRRUS 5000 AngioPlex. OCTA images were processed and recorded in size 3mm x 3mm, to generate density maps of the vascular perfusion of the superficial, deep retinal plexus and of the choriocapillaris (SRL, DRL and CL). These maps were based on the area of vessels (Perfusion Density), creating a binary slab that assigns to each pixel a 1 (perfused) or 0 (background); a skeletonized slab was created, based on vessels with a trace of one pixel in width (Vessel Density). The ONL and the choroidal thickness were also measured.
Results :
One hundred and thirty two eyes of 97 patients were included (51 controls, 9 fellow eyes, 30 early/intermediate AMD and 42 RAP). The eyes with RAP and its fellow eyes showed a vascular density of the DRL and of the CL significantly lower than control and AMD groups (all p<0.02). Perfusion density in all studied layers, was significantly lower in fellow eye and in RAP groups, when compared to control or AMD groups (all p<0.02). Additionally, the same fellow eyes showed a nasal ONL significantly thinner than controls and than AMD eyes (all p<0.05). The thickness of the choroid, either in the central region or in the periphery, was also significantly lower in fellow eyes and RAP, when compared with controls and AMD eyes (all p<0.03).
Conclusions :
This is the first study based on the analysis of the fellow eye with OCTA. The lowest thickness of the ONL and the choroid, as well as the reduced perfusion and vessel density, mostly in the DRL and CL in fellow eyes, suggest a distinctive phenotype of the fellow eye that can be associated with the RAP pathogenesis.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.