. Indocyanine green angiography in choroidalosteoma

摘要

A choroidal osteoma appears ophthalmoscopically as a yellow to orange choroidal mass which is irregular and slightly elevated and usually situated adjacent to the optic disc. Its diagnosis is essentially based on ophthalmoscopy, ultrasonography and computer tomodensitometry of the orbit, which shows a plaque-like lesion in the posterior pole with the density of normal bone. The osteoma is most commonly found in young women and is of unknown cause. The tumour is considered to be a choristoma, although it has not been fully established whether it is congenital. An osteoma consists of compact bone lying in the choroid. The intratrabecular spaces are filled with loose connective tissue containing blood vessels. Some vascular tufts may extend outside the tumour mass and lie external to Bruch's membrane. These tufts must be differentiated from choroidal new vessels, a possible sight threatening complication of choroidal osteomas.