What is the indication of using Indocyanine green angiography indication in eye?
High-Yield Explanation
ANSWER: (A) Occult choroidal neovascularizationREF: Vaughan & Asbury's General Ophthalmology 17th ed chapter 2, Kanski 5th Ed Ch 14, Khurana 4th EdPg275INDOCYANINE GREEN ANGIOGRAPHYThe principal use for fluorescein angiography in age-related macular degeneration is in locating subretinal choroidal neovascularization for possible laser photocoagulation. The angiogram may showr a well-demarcated neovascular membrane. Frequently, however, the area of choroidal neovascularization is poorly defined ("occult") because of surrounding or overlying blood, exudate, or serous fluid.Indocyanine green angiography is a separate technique that is superior for imaging the choroidal circulation. Fluorescein diffuses out of the choriocapillaris, creating a diffuse background fluorescence. As opposed to fluorescein, indocyanine green is a larger molecule that binds completely to plasma proteins, causing it to remain in the choroidal vessels. Thus, larger choroidal vessels can be imaged. Unique photochemical properties allow the dye to be transmitted better through melanin (eg, in the retinal pigment epithelium), blood, exudate, and serous fluid. This technique therefore serves as an important adjunct to fluorescein angiography for imaging occult choroidal neovascularization and other choroidal vascular abnormalities. Following dye injection, angiography is performed using special digital video cameras. The digital images can be further enhanced and analyzed by computer.