Author: Serena Fragiotta (Italy)
Co-authors: Solmaz Abdolrahimzadeh, Serena Fragiotta, Chiara Ciancimino, Laura Silva, Mariachiara Di Pippo, Gianluca Scuderi
Purpose
To investigate choroidal vascularity index in eyes with adult-onset foveomacular vitelliform dystrophy (AOFVD), early age-related macular degeneration and age-matched controls
Setting/Venue
Academic medical center - Retina Centre, Ophthalmology Unit, NESMOS Department, University of Rome Sapienza, St. Andrea Hospital, Rome
Methods
Eyes with AOFVD of any stage and early AMD according to the Beckman classification were consecutively enrolled. Age-matched healthy controls served as the control group. Eyes with concomitant ophthalmic disorders, diabetes, prior intraocular surgery, and the presence of subretinal drusenoid deposits (SDD) alone were considered as exclusion criteria. Spectral-domain optical coherence tomography with RTVue XR (RTVue XR Avanti, Optovue, Inc., Fremont, CA; software version 2017.1.0.151) was performed in all cases using a grid pattern. Choroidal thickness (CT) was measured manually using a digital caliper at the fovea, 500 and 1500 µm nasally and temporally to the fovea. The subfoveal horizontal b-scan was imported into Fiji software (version 2.1.0/1.53.c, available at http://fiji.sc) and the central 3 mm was selected and cropped for choroidal vascularity index (CVI) calculation. A polygonal selection was drawn delineating the choroid from the outer retinal pigment epithelium border and the chorioscleral junction. After binarization using the Niblack method, the image was converted to RGB color, and the luminal area was calculated using the threshold tool.
Results
Of 54 patients initially screened, 16 patients (29.6%) were excluded from the analysis for the presence of SSD, macular complications, or not acceptable image quality. A total of 38 eyes of 38 patients, 19 eyes with AOFVD and 19 eyes with conventional drusen (CD), and 16 healthy subjects (16 eyes) were included in the study. The subgroups appeared homogenous for gender (p=0.06) and age (p=0.80). CVI was significantly different among subgroups (ANOVA, p=0.006). On post-hoc Bonferroni analysis, eyes with AOFVD presented a higher CVI (+0.03 ± 0.01, p=0.005) than eyes with CD. No differences in CVI were detected in CD (p=0.81) and AOFVD (p=0.13) when compared with controls. On further analysis, AOFVD eyes accounted for the greatest luminal area, particularly significant in comparison with healthy controls (+0.27 ± 0.11, p=0.04). CT at various locations did not significantly differ among subgroups.
Conlusions
AOFVD eyes present a greater CVI than eyes with CD. The major choroidal involvement is on the luminal component, further corroborating a possible role of the choroidal vasculature in the pathological manifestations of AOFVD disease. It may be hypothesized that choroidal vessels enlarge in the efforts to clear the vitelliform material leading to a secondary choriocapillaris impairment with the development of late-stage complications and the atrophic stage. Further studies with a larger sample would be desirable to understand the cascade of events characterizing the different pathological stages preceding the development of macular complications.
Financial Disclosure
none
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