Indocyanine green angiography and optical coherence tomography angiography of choroidal neovascularization in age-related macular degeneration

Abstract Purpose: To compare the capability of indocyanine green angiography (ICGA) and optical coherence tomography angiography (OCTA) in detecting choroidal neovascularization (CNV). Methods: In this prospective study, patients with CNV detected with fluorescein angiography (FA) underwent ICGA and OCTA, spectral domain OCT (SD-OCT), and infrared or fundus color photographs. CNV lesions were outlined on ICGA and OCTA images, and the composition and size of the CNV was documented. Results: One hundred eighty-two eyes were included. With ICGA, well-defined lesions were observed in 37.9%, partly defined in 44.5%, and undefined in 17% of eyes. On OCTA, well-defined, partly defined, and undefined vessels were observed in 53.8%, 27.5%, and 18.7% of eyes, respectively. There was a good correlation between CNV size measured with the two instruments (r = 0.84). However, OCTA underestimated CNV area by about 4.5% (slope coefficient with linear regression: 0.55, 95% confidence interval [CI]: 0.46 to 0.65; intercept: 0.27, 95% CI: -0.2 to 0.56). On ICGA, CNV composition was capillary in 28%, mature in 14.3%, and mixed (capillary and major neovascular complex) in 57.7% of eyes. Similarly, OCTA revealed capillary, mature, and mixed CNV in 28.9%, 15.9%, and 55.5% of eyes, respectively. Conclusions: OCTA provides the clinician the ability to perform precise structural and vascular assessment of CNV noninvasively. Our study is, to our knowledge, the largest OCTA analysis to date of CNV secondary to neovascular AMD analyzed simultaneously by ICGA and OCTA.