Digital subtraction indocyanine green angiography of occult choroidal neovascularization.

OBJECTIVE This study aimed to use a new technique for ocular imaging, digital subtraction indocyanine green angiography (DS-ICGA), to evaluate patients with occult choroidal neovascularization (CNV). DESIGN The design was a cross-sectional study of patients with occult CNV. PARTICIPANTS A total of 31 eyes of 31 patients were studied. INTERVENTION Digital subtraction of sequentially acquired indocyanine green angiographic frames was used to image the progression of the dye front in eyes with occult CNV. A method of pseudocolor imaging of the choroid was developed that allows differentiation and identification of underlying choroidal arteries and veins. RESULTS The DS-ICGA of occult CNV showed consistent findings. Occult CNV was imaged with greater detail and in a shorter period of time than with conventional indocyanine green angiography. The fundus landmarks were retained with DS-ICGA much better than with conventional indocyanine green angiography. CONCLUSIONS The DS-ICGA uses time to dissect the choroidal circulation. With DS-ICGA, occult CNV could be imaged more quickly and in greater detail than with conventional imaging techniques. The DS-ICGA may improve the authors ability to image, and subsequently treat, occult CNV.