Comparison between Spectral Domain and Swept Source Optical Coherence Tomography Angiographic Imaging of Choroidal Neovascularization in Age-Related Macular Degeneration

Abstract

Purpose : To compare imaging of type 1 choroidal neovascularization (CNV) in age-related macular degeneration (AMD) using swept source (SS) and spectral domain (SD) optical coherence tomography angiography (OCTA).

Methods : OCTA was performed using a 100-kHz SS-OCT instrument and a 68-kHz SD-OCTA instrument (Carl Zeiss Meditec, Dublin, CA). Both 3X3 mm and 6X6 mm scans were obtained on both instruments. The 3X3 mm SS-OCTA scans consisted of 300 A-scans per B-scan at 300 B-scan positions, and the SD-OCTA scans consisted of 245 A-scans at 245 B-scan positions. The 6X6 mm SS-OCTA scans consisted of 420 A-scans per B-scan at 420 B-scan positions, and the SD-OCTA scans consisted of 350 A-scans and 350-B-scan positions. At each B-scan position, the B-scans were repeated four times in the 3X3 mm scans and twice in the 6X6 mm scans. Neovascular lesions were excluded if not fully contained within the 3X3 mm scans. The same algorithm was used to detect CNV on both instruments. Two graders outlined the neovascular lesions and the lesion areas were compared between instruments.

Results : Twenty-seven consecutive eyes from 23 patients were analyzed. For the 3X3 mm scans, the mean lesion areas for the SS-OCTA and SD-OCTA instruments were 1.17mm² and 1.01mm², respectively (P=0.047). For the 6X6 mm scans, the mean lesion areas for the SS-OCTA and SD-OCTA instruments were 1.24mm² and 0.74mm² (P=0.003).

Conclusions : The areas of the neovascular lesions tended to be larger when imaged with SS-OCTA than with SD-OCTA, and this difference was greater for the 6X6 mm scans.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.