Purchase this article with an account.
Woo Jhon Choi, ByungKun Lee, Mehreen Adhi, Nadia K Waheed, Chen D Lu, Jonathan Jaoshin Liu, Benjamin Potsaid, Vijaysekhar Jayaraman, Jay S Duker, James G Fujimoto; OCT Angiography of Retinal Pathologies Using Ultrahigh Speed Swept Source Optical Coherence Tomography. Invest. Ophthalmol. Vis. Sci. 2014;55(13):4538.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We investigate dye-free angiography of the retinal capillary network and choriocapillaris in retinal pathologies using ultrahigh speed swept source OCT (SSOCT).
Measurements were performed with an ultrahigh speed SSOCT prototype instrument at 1µm wavelengths with an A-scan rate of 400kHz. Three age-related macular degeneration (AMD) patients without geographic atrophy (GA) and four nonproliferative/proliferative diabetic retinopathy (NPDR/PDR) patients with or without macular edema (DME) were imaged. OCT angiograms were generated by calculating speckle decorrelation between B-scans acquired from the same location. OCT retinal angiograms were generated by projecting all blood vessels above the Bruch’s membrane (BM). OCT choriocapillaris angiograms were generated by extracting an en face plane below the BM.
Compared to a normal subject (Fig.1(A)), patients with mild NPDR and PDR (Figs.1(B,C)) exhibit capillary dropouts near the foveal avascular zone. The PDR patient also exhibits capillary loops and a sparser capillary density than both the normal and NPDR. Choriocapillaris angiograms require careful interpretation because there is a structural variation dependent on fundus positions (Fig.2(A-C)) as well as between subjects (Fig.2(D,E)). In AMD, there is no obvious correlation between choriocapillaris losses and drusen (Figs.2(F,G)). However, the drusen can be classified according to the cross sectional morphology and RPE integrity. Some drusen show increased light penetration into the RPE, suggesting that the RPE is locally compromised (Fig.2(H,J)). A subset of drusen with increased light penetration also exhibit focal loss of choriocapillaris (Fig.2(I,K)).
Although more extensive studies are required to definitively identify trends, these pilot investigations demonstrate that OCT angiography using ultrahigh speed SSOCT can reveal additional information on retinal pathologies that is not visible using conventional structural OCT.
This PDF is available to Subscribers Only