Abstract
Purpose :
To determine evolution of superficial and deep retinal plexuses (SRP and DRP) in retinal angiomatous proliferation (RAP) undergoing 1-year fixed regimen aflibercept treatment by means of swept-source optical coherence tomography angiography (SS-OCT-A, Topcon Triton).
Methods :
22 patients with RAP lesions were assessed with SS-OCT-A before treatment and 1,3, 12 month after treatment. All patients were treated with aflibercept with initial 3 monthly injections followed by 4 bimonthly injections. Angiotool software (version 0.6a, NIH/NCI, USA) was used to calculate vessel density of SRP and RAP area (vessel percentage area, VPA). Morphologic changes in SRP, DRP as well as on a set of SS-OCT B-scans (12x9 mm) were evaluated by 2 independent graders. BCVA was measured with EDTRS charts on each visit, fundus photos were taken at baseline and in month 12, fluorescein angiography was done at baseline. Wilcoxon pair test was used to determine significance of differences between time points.
Results :
In all patients diagnosis of RAP was established by both graders with SS-OCT and SS-OCT-A data and confirmed with FA. There was no significant change in SRP VPA during treatment (35.2% at baseline vs. 33.5% at month 12, p=0.2). Graders did not observe any significant changes in SRP between baseline and month 12 while reduced hyperreflectivity within RAP at the level of DRP was noticed in 21 cases (95%) but without significant changes in number of vessel junctions. RAP VPA was determined in 17 cases (in patients with monofocal lesion) - 45.3% vs 29.2% between baseline and month 12 (p=0.008). Retinal hemorrhages were present in 21 patients (95%) and hyperreflective retinal foci in 22 (100%) at least during one visit and caused shadowing in OCT images, but in all cases areas outside those changes could be seen and evaluated. Retinal pigment epithelium atrophy was observed in 5 patients (22.7%) at baseline and 11 patients at month 12 (50%). Improvement in BCVA was 7.3 letters (p=0.004).
Conclusions :
SS-OCT-A is a useful tool for assessing RAP. It enables to establish RAP diagnosis and observe its evolution even when retinal hemorrhages are present. Angiotool VPA can be used to quantify reduction in RAP vessels. RAP treatment with aflibercept is effective, but incidence of RPE atrophy increases during treatment.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.