Choroidal Neovascularization Analyzed on Ultra-High Speed Swept Source Optical Coherence Tomography Angiography Compared to Spectral Domain Optical Coherence Tomography Angiography

Abstract

Purpose : Cross-sectional, observational study to compare visualization of choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) using an ultra-high speed swept-source (SS)-optical coherence tomography angiography (OCTA) prototype versus a spectral-domain (SD)-OCTA device.

Methods : Patients were imaged on SD-OCT and SS-OCT devices on the same day. The SD-OCT device employed is the RTVue Avanti that operates at ~840nm wavelength and 70,000 A-scans/second. The SS-OCT device used is an ultra-high speed long-wavelength prototype that operates at ~1050nm wavelength and 400,000 A-scans/second. Two observers independently measured the CNV area on OCTA en face images from the two devices using ImageJ. The non-parametric Wilcoxon signed-rank test was used to compare area measurements.

Results : Fourteen eyes from 13 patients were enrolled. The CNV in 11 eyes (78.6%) were classified as type-1, 2 eyes (14.3%) as type-2, and 1 eye (7.1%) as mixed type. The mean CNV areas measured using SS-OCT and SD-OCT 3mm x 3mm OCTA were 0.949 ± 1.168mm² and 0.340 ± 0.301mm², respectively (p=0.001). For the 6mm x 6mm OCTA the CNV areas using SS-OCT and SD-OCT were 1.218 ± 1.284mm² and 0.604 ± 0.597mm², respectively (p=0.0019). The field of view did not significantly affect the measured CNV area (p=0.19 and p=0.18 for SS-OCT and SD-OCT respectively).

Conclusions : SS-OCTA measurements yielded significantly larger CNV areas than SD-OCTA. It is possible that SS-OCTA is better able to demarcate the full extent of CNV vasculature.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.

 

Multimodal imaging of a left eye with mixed type 1 and type 2 choroidal neovascularization. (A) Color fundus. Retinal pigment epithelium (RPE) clumps and mottling, and subretinal hemorrhage (white arrow) surrounded by hypocromic area and drusen.; (B) and (C) Fluorescein angiography at different stages. Red dashed-line representing the occult component; yellow dashed-line representing the classic component.; (D) Spectral-domain optical coherence tomography angiography (OCTA) image and; (E) Swept-source OCTA image. Red dashed-line representing the type 1 component; yellow dashed-line representing the type 2 component.; (F) Corresponding OCT B-scan. RPE represented as red dashed-line. Type 1 component (red arrow) and type 2 component (yellow arrow).