To analyze choriocapillaris (CC) vessel density (VD) around geographic atrophy (GA) secondary to non-neovascular dry age-related macular degeneration using optical coherence tomography angiography.
We compared CC VD surrounding GA margin (500 μm radius) with control CC (outside GA margin) in a consecutive series of GA patients presenting between August 2016 and February 2017 at the Medical Retina and Imaging Unit of University Vita-Salute, IRCCS Ospedale San Raffaele in Milan. Images were obtained through thresholding and binarization. We also compared the CC VD in a sample area of 500 μm × 500 μm surrounding GA margin rated as hyperautofluorescent on fundus autofluorescence to a similar area rated as isoautofluorescent.
Fifty eyes of 29 patients (19 women and 10 men; mean age 77 ± 6 years) with mean GA area of 9.43 ± 5.08 mm2 and mean subfoveal choroidal thickness of 164 ± 73 μm were included. Choriocapillaris VD surrounding GA margin as detected by optical coherence tomography angiography revealed a significant impairment compared with control CC outside GA margin (0.317 ± 0.083 vs. 0.461 ± 0.054, P < 0.001), which was even greater in patients with foveal involvement (P = 0.013). Furthermore, mean VD in hyperautofluorescent areas was significantly lower compared with isoautofluorescent areas (0.242 ± 0.112 vs. 0.327 ± 0.130, P = 0.001). A positive correlation was disclosed between VD surrounding GA margin and subfoveal choroidal thickness (r = 0.332, P = 0.019).
Optical coherence tomography angiography discloses CC impairment surrounding GA margin. Such CC impairment at GA margin seems to precede retinal pigment epithelium alterations at fundus autofluorescence. Optical coherence tomography angiography could be a new valuable tool for detecting CC alterations and to evaluate potential therapeutic responses in clinical studies.
This study was conduced to evaluate the vessel density of choriocapillaris around geographic atrophy secondary to non-neovascular dry age-related macular degeneration using optical coherence tomography angiography. We found a significant choriocapillaris impairment surrounding geographic atrophy margin, which seems to precede retinal pigment epithelium alterations at fundus autofluorescence.
*Department of Ophthalmology, University Vita-Salute, IRCCS San Raffaele Hospital, Milan, Italy;
†Department of Ophthalmology, University of Verona, Hospital of Verona, Verona, Italy; and
‡Department of Ophthalmology, University of “Magna Graecia,” Catanzaro, Italy.
Reprint requests: Giuseppe Querques, MD, PhD, Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy; e-mail: firstname.lastname@example.org
Presented in part at International Retinal Imaging Symposium (IRIS) Annual Meeting 2017, Los Angeles, CA, March 25, 2017.
None of the authors has any financial/conflicting interests to disclose.