Author: Vincenzo Starace (Italy)
Co-authors: Vincenzo Starace, Sacconi Riccardo, Trevisi Marco, Battista Marco, Bandello Francesco, Querques Giuseppe
Recently, we reported in vivo a strong negative correlation between perfusion density (PD) and aging in the choriocapillaris of healthy subjects. However, less is known about the effect of aging on the topographical distribution of the capillaries of retinal plexuses. The aim of the current study is to evaluate the effect of aging on vascular parameters at foveal, parafoveal, and perifoveal region in the superficial capillary plexus (SCP) and deep vascular complex (DVC) of healthy subjects by using optical coherence tomography angiography (OCT-A).
This is a retrospective study of patients enrolled in Medical Retina and Imaging Unit of the Department of Ophthalmology, San Raffaele Scientific Institute in Milan, Italy.
In this observational cross-sectional study, consecutive healthy subjects underwent Swept Source OCT-A (PLEX Elite 9000, Carl Zeiss Meditec Inc., USA). 3x3-mm and 6x6-mm scans centered on the fovea were acquired and analyzed post-processed with thresholding and binarization processes. Main outcome measures included quantitative topographical OCT-A features (PD and vessel length density [VLD]) at the foveal (circle of radius of 0.5 mm), parafoveal (circular annulus around the fovea with radius of 1.5 mm) and parafoveal region (circular annulus around the fovea with radius of 3.0 mm) in both SCP and DVC, and their relationship with aging.
Ninety-four eyes (94 patients, mean age 48.5±20.4 years old, range 19-84) were included. A strong negative correlation was found between PD and aging in the parafoveal area in both 3x3 mm images (r= -0.394, p=<0.001) and 6x6 mm (r= -0.308, p=0.003). In detail, this reduction was driven by the reduction of PD and VLD in the nasal parafoveal subfield (r= -0.339, p<0.001 and r= -0.272, p=0.008, for PD and VLD, respectively). In the analysis of perifoveal area, there was no significant correlation between aging and PD/VLD of both SCP and DVC in the whole area. However, in the topographical subfield analysis, there was a significant correlation of aging with PD and VLD of the perifoveal nasal and temporal areas of SCP (r= -0.311, p=0.002 and r= -0.326, p=0.001, for PD and VLD of the nasal area; r= 0.326, p=0.001 and r= 0.313, p=0.002, for PD and VLD of the temporal area). Furthermore, a significant negative correlation was found between aging and PD of the perifoveal inferior area of the DVC (r= -0.300, p=0.003).
We reported in vivo a strong negative correlation between PD of the retinal vessels and aging of healthy subjects. This reduction seems related to a reduced number of capillaries (i.e. VLD). The age-related changes were higher in the parafoveal area compared to the perifoveal area.