Session Title: Imaging I
Session Date/Time: Friday 18/09/2015 | 08:00-09:30
Paper Time: 09:04
First Author: : J.Marques PORTUGAL
Co Author(s): : J. Costa M. Marques M. Cachulo J. Figueira R. Silva
PURPOSE:To assess and describe sequential morphological changes in the choroidal neovascularization (CNV) net using optical coherence tomography angiography (OCTA) in patients with age-related macular degeneration (AMD) undergoing treatment with intravitreal injections of anti-VEGF.
Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra (CHUC), Coimbra, Portugal. Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, Portugal. Faculty of Medicine, University of Coimbra (FMUC), Coimbra, Portugal.
Prospective observational study. Inclusion criteria were: 1) either race or sex; 2) confirmed AMD-related CNV with ancillary multimodal retinal imaging: color fundus photography (CFP), fluorescein angiography (FA), indocyanine green angiography (ICGA) and spectral domain optical coherence tomography (SD-OCT); 3) ability to attend regular follow-up visits and 4) no significant media opacities likely to jeopardize image acquisition. A control group consisting of 10 healthy eyes of 10 age-matched controls was used to establish the standards of a normal OCTA angiogram. OCTA was performed with AngioVue® (Avanti, Optovue, USA). The macular angiography scans covered a 3x3mm area and comprised 200x200x8 A-scans acquired in 3.5 seconds. Flow was detected using the split-spectrum amplitude-decorrelation angiography (SSADA) algorithm. Motion artifacts were removed by 3-dimensional orthogonal registration and merging of 4 scans. OCTA was performed sequentially in the CNV group: before the intravitreal injection (t0), 1h (t1), 1 week (t2) and 1 month after the injection (t3). All images were classified by two independent graders. CNV morphology was categorized into tree-like, glomerular or fragmented and the presence of a fibrovascular capsule and feeder trunk were assessed. In the sequential analysis of the OCTA scans the status of the CNV net and the surrounding choriocapillaris were evaluated.
Ten eyes of 10 consecutive patients with AMD-related CNV were included (8 females), 3 of which were treatment-naive. Mean age was 70.4±19.5 years and all patients completed 1 month of follow-up after inclusion. Location of the CNV in the OCTA scan was confirmed by CFP, FA, ICGA. OCTA provided more distinct vascular network patterns, less obscured by subretinal hemorrhage. In all eyes, the CNV net was discernible under OCTA imaging and originated from regions of severe choriocapillaris alteration when compared with the age-matched control group (mean age 68.9±17.6 years). In the baseline scans (t0), CNV morphology was described as tree-like in 5 eyes, glomerular in 1 and fragmented in 4. The presence of a fibrovascular capsule surrounding the CNV net was found in 4 eyes and a feeder trunk was noticed in 3. No changes in the CNV net were observed at t1 in any of the included subjects. Loss of peripheral capillaries, vessel fragmentation and decreased vessel density were evident in 6 eyes at t2 but CNV capillary density increased in 5 of these cases from t2 to t3. No discernible changes in the CNV net were found through the whole length of follow-up in 4 eyes.
OCTA generates detailed, noninvasive, dyeless angiograms in neovascular AMD. CNV morphology can be assessed comprehensively since it is not obscured by leakage or staining as in FA. The effects of anti-VEGF treatment in the CNV net are not evident 1h after the injection but were clearly discernible in 6 eyes 1 week after treatment, with loss of peripheral capillaries, vessel fragmentation and decreased vessel density. The effect on new vessels regression is, however, temporary since the vascular network is again visible 1 month after the injection. Further studies are needed to assess quantitative changes in OCT angiography in the evaluation and treatment of neovascular AMD.