An intraocular foreign body (IOFB) describes any object that penetrates the outer layers of the eye and becomes lodged inside. These injuries are a serious medical emergency, requiring immediate attention from an eye care professional. Ignoring an IOFB can lead to severe complications and permanent vision loss.
Understanding Intraocular Foreign Bodies
An intraocular foreign body is distinct from a foreign body on the surface of the eye, as it enters the globe, causing a penetrating or perforating injury. These objects can become embedded in various parts of the eye, including the anterior chamber, lens, or the posterior segment like the retina and choroid. The most frequent types of IOFBs are metallic, often originating from activities involving metal-on-metal impact.
Common scenarios leading to an IOFB include high-speed impacts from activities such as hammering, grinding, or chiseling. Explosions and firearm use can also cause these injuries, sometimes resulting in multiple, small foreign bodies. While manual laborers are at a higher risk due to their work environments, incidents can also occur during home DIY projects or other activities where eye protection is not worn. The severity of the injury depends on factors like the object’s size, shape, composition, and its velocity upon impact. Organic materials like wood or vegetable matter carry a particularly high risk of infection.
Recognizing Symptoms and Seeking Urgent Care
Symptoms of an intraocular foreign body can vary, but commonly include sudden pain, redness, and a feeling that something is in the eye. Blurred or decreased vision, sensitivity to light (photophobia), and excessive tearing are also frequently reported. Sometimes, a visible foreign body may be present, or fluid might leak from the eye, although a small leak might not be immediately noticeable. Symptoms can sometimes be mild or delayed, even with a serious injury.
If an intraocular foreign body is suspected, immediate emergency medical attention is necessary. Do not rub the affected eye or attempt to remove the object, as this can cause further damage or push the object deeper. Instead, gently cover the eye with a protective shield, such as a commercially prepared shield or the bottom of a paper cup, to prevent any unintentional pressure.
Diagnosis and Treatment Approaches
Ophthalmologists diagnose an intraocular foreign body through a combination of detailed patient history and comprehensive eye examinations. Initial examination techniques include a slit-lamp examination to inspect the front part of the eye and indirect ophthalmoscopy to view the back of the eye. These examinations help identify the entry wound, assess any visible foreign bodies, and evaluate the extent of ocular damage.
Imaging studies are important for precisely locating and characterizing the foreign body, especially if it is not visible during examination. Computed tomography (CT) scans are considered the primary imaging modality due to their high sensitivity in detecting metallic, glass, and stone foreign bodies. While X-rays can detect radiopaque objects, they may miss non-metallic foreign bodies. Magnetic resonance imaging (MRI) is generally avoided if a metallic object is suspected, as the magnetic field can cause the object to move and inflict further damage.
Treatment almost always involves surgical removal of the foreign body. The specific surgical technique depends on the object’s location, size, and composition. For foreign bodies in the anterior chamber, a limbal incision might be used, sometimes with viscoelastic solution to maintain the chamber. For objects in the posterior segment, a pars plana vitrectomy (PPV) is a common approach, where the foreign body is removed using specialized forceps or an intraocular magnet. The primary goals of treatment are safe removal of the object, reconstruction of the eye, and preservation or restoration of vision.
Potential Vision Risks and Prevention
Untreated or delayed treatment of an intraocular foreign body can lead to severe complications. One significant risk is endophthalmitis, a serious infection inside the eye, which can occur in 7% to 13% of cases. Other potential issues include retinal detachment, cataract formation, chronic inflammation (uveitis), and glaucoma. Depending on the foreign body’s material, long-term complications like siderosis (from iron fragments) or chalcosis (from copper) can also lead to optic nerve damage and vision loss. In some instances, severe damage can result in permanent vision loss or even the need for eye removal.
Preventing intraocular foreign bodies largely involves wearing appropriate eye protection in high-risk environments. Safety glasses, goggles, or face shields should be used during activities such as construction, grinding, hammering, or when operating power tools. This also extends to certain sports or handling chemicals where projectile risks exist. Since a significant number of these injuries occur at work or at home, consistent use of protective eyewear is a straightforward and effective measure to safeguard vision.