Purpose:
Several diseases associated with neovascularization deteriorate vision. Detecting alterations of vasculature non-invasively will provide insightful information to investigate diseases. This paper demonstrates non-invasive three-dimensional vascular imaging of human eyes with vascular disease by high-sensitivity Doppler optical coherence angiography (HS-OCA).
Methods:
Seven eyes of 7 subjects (elder than 50 yo: 6, younger than 50 yo: 1) of macular degeneration with choroidal neovascularization (CNV), 2 eyes of 2 subject of pathological myopia with CNV (- 11D and - 16D) and 3 eyes of 3 subjects diagnosed as polypoidal choroidal vasculopathy (PCV) were examined by HS-OCA. High-sensitivity and high-speed blood flow detection in micro-vessels was done by spectral-domain Doppler OCT with dual probing beams of 840 nm wavelength. By using two probing beams, time efficiency is increased and long observation for capturing extremely tiny movement is realized. This system is operated at 27,000 axial scans per second. Three-dimensional blood flow distributions were acquired. Depth-resolved vasculature images were provided from these distributions.
Results:
In 6 of 7 eyes of macular degeneration and 2 of 2 eyes of pathologicalmyopia, the particular pattern in choroidal blood flow images, which is coincident with Indocyanine green angiography (ICGA). In 3 eyes of macular degeneration and 2 eyes of pathological myopia, blood flow signals were observed in outer retina which is co-located with hyper-fluorescence macular degeneration Fluorescein angiography (FA). After the treatment with ranibizumab injection for 1 eye of macular degeneration and 1 eye of pathological myopia, blood flow signals at the outer retina were disappeared or reduced as shown in Figure. In 3 of 3 eyes of PCV, abnormal blood flow signals were observed at some part of the retinal pigment epithelium (RPE) detachment. They were located between the RPE and the Bruch’s membrane.
Conclusions:
HS-OCA can detect three-dimensional location of blood flow in abnormal vessels non-invasively. Comprehensive non-invasive ophthalmic angiography will enable frequent monitoring of the ocular vasculature and/or screening of vascular-related diseases.
Keywords: choroid: neovascularization • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • blood supply