Ocular Siderosis Facts

Nyctalopia

Concentrically constricted visual field

Decreased vision

Signs

Rust-colored corneal stromal staining

Iris heterochromia

Pupillary mydriasis and poor reactivity

Brown deposits on the anterior lens

Cataract

Vitreous opacities

Peripheral retinal pigmentation (early)

Diffuse retinal pigmentation (late)

Narrowed retinal vessels

Optic disc discoloration and atrophy

Secondary open-angle glaucoma from iron accumulation in the trabecular meshwork

        ERG Changes:

                Electroretinogram (ERG) changes in siderosis include an increased a-wave and normal b-wave during the very early phase of toxicity, with a diminishing b-wave amplitude later. Eventually, the ERG may become extinguished.

Serial ERGs can be helpful for following eyes with small retained foreign bodies. If the b-wave amplitude decreases, removal of the foreign body generally is recommended