Abstract
Purpose :
Detection of qualitative features of neovascular age related macular degeneration (nAMD) using optical coherence tomography (OCT) is used for the diagnosis and management of patients with nAMD using anti-angiogenic agents. Spectral-domain-OCT (SD-OCT) is now a well-established imaging modality but swept-source OCT (SS-OCT) is a more recent development in OCT technology utilizing a tunable frequency light source. The aim of this work was to compare the ability to detect morphological features of nAMD using commercially available SD-OCT (Spectralis, Heidelberg Engineering) and SS-OCT (DRI-OCT-1, Topcon Inc) devices.
Methods :
Thirty-nine eyes of 39 patients with nAMD were included in this prospective, observational clinical study. Each patient underwent a 12 x 9mm DRI-OCT raster scan and a Spectralis SD-OCT enhanced-depth imaging (EDI) mode macular volume scan (512 A scan per 128 B scan) covering 20° x 20°. Individual line scans were manually evaluated for the presence of retinal features of nAMD and putative choroidal features of disease activity. The presence of each individual feature as a percentage of the total number of line scans was compared between the two imaging modalities.
Results :
Mean (±SD) age of each patient was 73.9 (± 7.2) years. There were 24 male and 15 female subjects. This consisted of 21 right and 18 left eyes. 1,911 SD-OCT and 9,984 SS-OCT line scans were analysed. There was no significant difference between SD-OCT and SS-OCT in the percentage of line scans showing subretinal fluid, intraretinal fluid, pigment epithelial detachment and diffuse retinal thickness (all p ≥ 0.05). The detection of both subretinal hyperreflective material (SHRM) (7.59% vs 1.32%, p = 0.03) and high reflectance signals below a PED (2.2% vs 0.1%, p=0.01) was higher using SD-OCT. There was no significant difference in the detection of those choroidal features analysed in this study (choroidal thickening, thinning and depigmentation, p ≥ 0.05).
Conclusions :
This study shows good agreement between SD-OCT and SS-OCT in the detection of features of nAMD in this cohort. SD-OCT appeared to be superior in the detection of SHRM and high reflectance signal below a PED. This may have relevance in the development of novel therapies targeting components of SHRM in nAMD.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.