Session Title: Free Paper Session 4: AMD II
Session Date/Time: Thursday 07/09/2017 | 11:00-12:30
Paper Time: 12:18
Venue: Room 111
First Author: : J.Providência PORTUGAL
Co Author(s): : I. Lains G. Armstrong J. Miller D. Husain J. Miller R. Silva
Age-related Macular Degeneration (AMD) is the leading cause of blindness in developed countries. The pathophysiology of newly recognized features of the disease, such as subretinal drusenoid deposits (SDD), is still only partially understood. This study aimed to compare choroidal vasculature density and macular choroidal volume in intermediate AMD eyes with and without SDD, using swept-source optical coherence tomography (SS-OCT).
Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal; Associação para Investigação Biomédica e Inovação em Luz e Imagem (AIBILI), Coimbra, Portugal; Faculty of Medicine, University of Coimbra, Coimbra, Portugal; Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
Multicentre, prospective, observational study, including patients with intermediate AMD. All participants underwent complete ophthalmic exam, colour fundus photography (used for AMD staging according to the Age-Related Eye Disease Study system) and spectral-domain OCT (used to evaluate for the presence of SDD by two independent graders). SS-OCT (3D horizontal volume, 12mm x 9mm) en face images of choroidal vasculature were captured (using Bruch’s membrane as reference for flattening) and converted to binary images on ImageJ. Choroidal vascular density was calculated as a percent area occupied by choroidal vessels in a 6-mm diameter circular submacular region centreed on the fovea. Choroidal thickness was obtained using SS-OCT automated software. The submacular choroidal vascular volume was calculated by multiplying the average choroidal vascular density by macular area and choroidal thickness. Multilevel mixed effect linear models (accounting for correlated outcomes between 2 eyes) were used for analyses.
We included 185 eyes of 118 patients with intermediate AMD (113 female, 61.1%). Ninety-two percent (n=171) had classic drusen, 50.3% (n=93) had SDD, and 44.9% (n=83) presented with both. Univariate analysis revealed that increased age was significantly associated with decreased choroidal vascular volume (ß=-0.0004, p<0.001) and mean choroidal density (ß=-0.003 p=0.001). After controlling for age, the presence of SDD was significantly associated with reduced macular choroidal volume (ß=-0.003, p=0.007). Macular choroidal thickness in eyes with SDD (n=93, 0.017 mm ± 0.01) was significantly lower than in eyes without SDD (n=92, 0.019 mm ± 0.01). However, SDD were not correlated with mean choroidal density (p=0.063).
Submacular choroidal vascular volume is reduced in eyes with SDD as compared to eyes without these lesions. Our results are consistent with prior work showing reduced choroidal thickness in AMD patients with SDD, and provide potential evidence of choroidopathy as a factor in the disease pathogenesis.