Box 2

Conditions associated with intraocular calcification

Retinal and RPE lesions

Retinoblastoma

Astrocytic hamartoma

Chronic retinal detachment

RPE metaplasia

Cysticercosis

Choroidal lesions

Choroidal osteoma

Sclerochoroidal calcification

Choroidal granuloma

Others

Optic nerve head drusen

Scleral calcification (Cogan’s plaque)

Phthisis bulbi

low-to-medium internal reflectivity with regular internal structure (Fig. 16).

Age-related macular and extramacular degeneration

Exudative age-related macular and extramacular degeneration (ARMD/AREMD) with subretinal or sub-retinal pigment epithelium exudate or hemorrhage can resemble choroidal melanoma closely. Ultrasonographically, exudative ARMD/AREMD appears as a mass lesion with moderately high internal reflectivity. When the subretinal blood becomes organized, however, these lesions can display low internal reflectivity and choroidal

excavation, similar to that seen with a choroidal melanoma.

Scarring, fibrosis, and calcification can occur in chronic stages of exudative ARMD/AREMD, leading to the formation of disciform lesions. Nonhemorrhagic disciform lesions appear as two or three highly reflective spikes on A-scan. On B-scan, they are mildly to moderately elevated, dome-shaped, and heterogeneous (see the article by Sharma and colleagues, elsewhere in this issue). Hemorrhagic disciform lesions can be localized or diffuse. They usually exhibit a bumpy, lobulated surface with indistinct margins. On ultrasonography, they display irregular internal structure with areas of high and low internal reflectivity as a result of fibrovascular proliferation, exudation, and clotted or unclotted hemorrhage (Fig. 17). Calcification and vitreous hemorrhage can be associated with these lesions. Unlike choroidal melanoma, internal vascularity is not present in these lesions. Serial examination of hemorrhagic disciform lesions can help distinguish them from choroidal melanomas. Hemorrhagic disciform lesions tend to decrease in size, whereas choroidal melanomas remain stable or increase in size. Very rarely, spontaneous regression of choroidal melanoma can occur.30

Posterior scleritis

Nodular posterior scleritis appears as an elevated mass that can resemble an amelanotic choroidal melanoma closely. Ultrasonographic features of these lesions are described in the article by Ventura and colleagues, elsewhere in this issue.

INTRAOCULAR CALCIFICATION

Intraocular calcification can result from several tumors and degenerative processes (Box 2).