A scleral tear is a severe form of eye trauma, classified medically as an open globe injury, requiring immediate medical attention. This injury involves a full-thickness breach in the sclera, the dense, white, protective outer layer of the eyeball. The sclera functions as the supporting wall of the eye, maintaining its spherical shape and shielding delicate internal structures like the retina and lens. Because this structural barrier is compromised, a scleral tear carries a significant risk of permanent vision loss if not addressed rapidly.
The Role of the Sclera and Nature of the Injury
The sclera is a tough, fibrous layer composed primarily of irregularly arranged collagen bundles, extending from the cornea to the optic nerve sheath. This tissue provides an anchor point for the six extraocular muscles that control eye movement. Forming approximately 80% of the eyeball’s surface area, the sclera acts as the primary defense against mechanical stress.
A scleral tear constitutes a breach in this protective wall, occurring either as a laceration or a rupture. A laceration is a cut caused by a sharp object or high-velocity foreign body, creating a wound at the point of impact. In contrast, a rupture typically results from blunt force trauma, where sudden, intense internal pressure causes the eyeball to fail at its weakest points.
Rupture sites are predictably located where the sclera is naturally thinnest or less protected. Common failure points include the tissue adjacent to the limbus (the junction with the cornea) or near the insertion points of the rectus muscles. When the globe ruptures, it often leads to the extrusion, or prolapse, of the eye’s internal contents, such as the dark uveal tissue or the vitreous gel.
Mechanisms of Trauma and Recognizing Symptoms
Scleral tears most often result from high-energy blunt or penetrating trauma that overwhelms the structural integrity of the eye wall. Blunt force injuries, such as being struck by a baseball, a fist, or an airbag, are a frequent cause of globe rupture. These forces rapidly compress the eyeball, causing a rise in intraocular pressure that forces the sclera to tear at its weakest points.
Penetrating injuries, which cause a laceration, typically involve sharp objects or high-speed projectiles encountered in industrial or domestic settings. Common workplace accidents, such as metal striking metal or using power tools without protective eyewear, can generate fragments capable of piercing the sclera. Any injury that pierces the eyelid or surrounding bone should be treated with suspicion for an underlying scleral injury.
Recognizing the symptoms of a scleral tear is necessary for ensuring immediate emergency care. Patients often report severe eye pain and a sudden decrease in visual acuity, ranging from blurry vision to complete vision loss. A visible sign is often a large, deep subconjunctival hemorrhage (severe bleeding under the clear membrane covering the white of the eye) that may obscure the underlying scleral defect.
Other visible indicators of a tear include a misshapen or distorted pupil, which may appear peaked or teardrop-shaped due to the iris prolapsing into the wound. The presence of dark tissue (the internal uvea) protruding through the white of the eye is a definitive sign of an open globe injury. Any suspicion of a scleral tear requires immediate transport to an emergency department without applying pressure to the eye.
Surgical Repair and Immediate Care
A suspected scleral tear is an ophthalmologic emergency; the immediate goal is to protect the remaining visual potential and prepare the patient for surgery. The patient must be stabilized, and activities that could increase intraocular pressure, such as bending, lifting, or straining, must be strictly avoided. Pre-operative assessment typically includes a computed tomography (CT) scan of the orbit to determine the full extent of the injury, especially if a foreign body or a posterior tear is suspected.
The definitive treatment for a scleral tear is primary surgical repair, ideally performed within 24 hours of the injury to minimize infection risk and preserve the internal ocular environment. The main objectives are to restore the anatomical integrity of the eyeball and close the wound. This involves meticulous exploration of the wound site under an operating microscope to ensure the entire laceration is visualized, often requiring specialized surgical techniques to look behind the eye muscles.
The surgeon cleans the wound edges and removes any prolapsed or non-viable internal tissue, such as vitreous humor or uvea, to prevent complications like infection or traction on the retina. The scleral defect is then closed using fine, non-absorbable sutures (e.g., 9-0 or 10-0 nylon) placed to achieve a watertight seal and restore the globe’s normal curvature. Following closure, broad-spectrum antibiotics are often administered, sometimes directly into the eye, to combat the risk of bacterial infection.
Recovery Timeline and Visual Outcomes
The post-operative recovery period begins immediately, focusing on infection prevention and globe protection. Patients are typically given topical antibiotic and anti-inflammatory drops, which must be strictly followed for several weeks. Initial healing of the scleral wound takes place over the first few weeks, but full structural recovery and scar maturation can take several months.
Activity restrictions are an important part of the healing process to prevent strain on the newly repaired tissue. Patients are instructed to avoid heavy lifting, strenuous exercise, and any actions that involve lowering the head below the waist for a designated period. Wearing a protective eye shield, especially during sleep, is often required to safeguard the eye from accidental bumps or pressure.
The final visual outcome after scleral tear repair is highly variable and depends on several factors established at the time of injury and surgery. A major determinant of prognosis is the initial visual acuity upon presentation, with better acuity correlating with a more favorable outcome. The location of the injury is also significant, as tears involving the posterior pole or those extending near the ciliary body carry a poorer prognosis due to the increased risk of retinal damage.
Patients may require secondary surgeries, such as a vitrectomy, to address complications like retinal detachment, which are common after severe trauma. While the anatomical integrity of the globe can often be successfully restored, the functional recovery of vision is a protracted process. Visual acuity can continue to improve over six months to a year post-surgery, emphasizing the need for long-term follow-up care.