Background
Intraocular foreign bodies (IOFBs) are rather variable in presentation, outcome, and prognosis. With increased awareness and advanced surgical techniques, the outcome and the prognosis for these potentially devastating injuries have substantially improved.
The most important limiting factor today is the damage occurring at the time of the initial injury. One effective method appears to be prophylactic chorioretinectomy (see Surgical Care), which reduces the risk of postinjury proliferative vitreoretinopathy (PVR).
Pathophysiology
The final resting place of and damage caused by an IOFB depend on several factors, including the size, the shape, and the momentum of the object at the time of impact, as well as the site of ocular penetration. [1, 2]
IOFBs transversing the lens are less likely to cause major retinal damage; conversely, a smaller wound size usually means deeper penetration.
In addition to the initial damage caused at the time of impact, the risk of endophthalmitis and subsequent scarring (eg, PVR) play an important role in the planning of the surgical intervention. [3]
Epidemiology
Frequency
United States
According to the United States Eye Injury Registry (USEIR), the surveillance arm of the American Society of Ocular Trauma (ASOT), the incidence among eyes with open-globe injury is 16% in the United States. The most common cause is hammering; the incidence over time shows a decrease at the workplace and an increase in the home. [4]
International
The frequency greatly varies (up to 41%) worldwide, depending upon the population surveyed.
Mortality/Morbidity
Most IOFBs cause internal damage, and most will come to rest in the posterior segment. Commonly injured structures include the cornea, the lens, and the retina.
Race
No racial predilection has been found so far.
Sex
According to the USEIR, 93% of patients with IOFBs are male.
Age
According to the USEIR, the average patient is aged 31 years.
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Metal intraocular foreign body located in the left temporal pars plana region seen on axial CT scan.
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Same metallic intraocular foreign body as in previous image, as seen on coronal CT scan view.