Chalcosis or chalcosis bulbi refers to mild ocular inflammation due to an intraocular foreign body containing copper between about 70 to 85%. Chalcosis results in deposition of copper on lens capsule (sunflower cataract), Descemet’s membrane (Kayser- Fleischer ring), iris (green discolouration), sluggish pupillary response, vitreous degeneration and liquefaction, yellow retinal plaques and degeneration.
The intensity of inflammatory response due to copper containing foreign body depends upon the copper content. It may lead to
Foreign body containing less than 70% is relatively inert in the eye.
Chalcosis may be acute or chronic.
Intraocular copper rarely may be resorbed, but a longstanding Chalcosis may produce similar clinical features as are seen in Wilson’s disease (hepato-lenticular degeneration) with endogenous copper deposition. This includes characteristic Kayser-Fleischer ring and sunflower cataract (impregnation of copper within lens capsule in the pupillary area).
Intraocular foreign bodies containing copper are notorious for their destructive effect on the eye. The reason that they are non-magnetic generally makes them more difficult to remove as compared to iron or steel foreign bodies.
Grant W Morton, Schuman Joel S. Toxicology of the Eye Volume 1 and 2 – Effects on the Eyes and Visual System from Chemicals, Drugs, Metals and Minerals, Plants, Toxins and Venoms: also, Systemic Side Effects from Eye Medications Fourth Edition. Charles C Thomas- Publisher 1993. P 439- 454.
Symptoms vary according to the size, location and content of copper in intraocular foreign body.
There may be no reaction, if the copper content is less than 70%. The most intense reactions are associated with copper content more than 85%. Larger foreign bodies offer more surface area from which to liberate copper ion. A foreign body in mid- vitreous may not incite inflammation or it may be quietly encapsulated. Locations near vascularised retina and ciliary body are more prone to incite inflammation.
Acute Chalcosis presents rapidly with
Chronic Chalcosis may present with
Copper containing foreign bodies are the most common non-magnetic foreign bodies.
Copper diffuses within the eye in its ionised form. Foreign bodies containing more than 85% copper typically form diffuse deposits, whereas foreign bodies with lower copper content usually causes more localised response. Copper has affinity for intraocular basement membranes e.g. Descemet’s membrane and Lens capsule.
Causes of Chalcosis includes
Diagnosis is based on clinical features such as
There may be diminution of vision, visual field defects, abnormal electroretinogram, or ocular hypotension.
Histologically, no stain specific for copper exists. However, copper itself functions as a vital stain and shows as tiny opaque (black) dot in unstained sections.
Prophylaxis for endophthalmitis should be given.
Oral steroids suppress inflammatory response.
Initial local therapy
Initial therapy involves closure of an open Eyeball due to injury.
Foreign bodies with copper content of 85% or more may incite acute inflammatory response. It requires prompt removal of foreign body.
Vitrectomy with or without lensectomy and scleral buckle may be done.
Peribulbar dexamethasone suppresses both inflammation and encapsulation of intraocular copper.
Complications may be
Prevention involves use of protective eyewear designed to reduce ocular injuries.