Cataract surgery is one of the most common and successful surgical procedures performed globally, involving the removal of the eye’s cloudy natural lens and replacement with an artificial intraocular lens. While generally considered safe, any surgical intervention carries a risk of minor complications. A corneal abrasion, a scratch on the eye’s surface, is among the most frequent minor issues that can occur following the procedure. Understanding the specific causes of this temporary injury during surgery is important for patient reassurance and management.
What is a Corneal Abrasion?
A corneal abrasion is an injury confined to the corneal epithelium, the thin, highly-innervated layer of cells that forms the outermost protective surface of the cornea. Because this layer contains a dense network of nerve endings, damage results in immediate and often intense discomfort. Patients typically experience a feeling that something is lodged in the eye, known as a foreign body sensation.
Other common symptoms include acute pain, excessive tearing (lacrimation), and a heightened sensitivity to light (photophobia). These symptoms distinguish an abrasion from milder, expected post-operative discomfort. The abrasion causes a physical defect that temporarily disrupts the smooth surface, which can also lead to blurred or hazy vision until the cells repair themselves.
Identifying the Specific Causes During Cataract Surgery
Corneal abrasions during cataract surgery stem from several factors related to the instruments and environment of the operating room. The most common cause is mechanical trauma from the instruments used to keep the eye open and perform the procedure. The eyelid speculum, which holds the eyelids apart, can inadvertently scrape the delicate epithelial surface upon insertion or removal.
Surgical instruments themselves may cause trauma if they brush against the corneal surface during entry, manipulation, or withdrawal through the small incisions. For instance, movement of the instrument sleeve or the insertion of the intraocular lens can disrupt the epithelium. Manipulation of the main surgical incision can also lead to an extension of an existing epithelial break.
Another significant cause is desiccation, or excessive drying of the corneal surface during the operation. The cornea, normally bathed in tears, can dry out when exposed to the air under the intense illumination of the operating microscope. If the surgical team does not apply adequate lubrication, the epithelium can become compromised and break down, leading to an abrasion.
Chemical irritation and irrigation solutions can also contribute to epithelial damage. Accidental exposure to non-balanced salt solutions or excessive contact with the surgical prep solution, such as a povidone-iodine wash, can irritate and weaken the epithelium. While these solutions are necessary for a sterile field, improper handling can cause a temporary chemical injury to the surface cells.
Pre-existing patient factors also increase susceptibility to an abrasion, even with normal surgical handling. Conditions such as Epithelial Basement Membrane Dystrophy (EBMD) or chronic severe dry eye syndrome result in weaker adhesion between the corneal layers. This fragility means the epithelium is more easily sloughed off by the normal forces of blinking or instrument contact during the procedure.
Treatment and Recovery Timeline
The primary goals of treating a corneal abrasion are to prevent infection, manage pain, and promote rapid healing of the epithelial surface. Treatment protocols typically involve the application of topical antibiotic drops or ointment to safeguard against bacterial infection while the surface layer is compromised. Lubricating drops or gels are also used to keep the eye moist and comfortable.
For pain relief, the surgeon may prescribe oral non-steroidal anti-inflammatory drugs (NSAIDs) or special drops to relax the eye muscles and relieve light sensitivity. A common and effective treatment is the placement of a therapeutic bandage contact lens, which acts as a protective shield over the injury. This lens reduces the friction caused by blinking, allowing the new epithelial cells to migrate and heal without disruption.
Recovery from a corneal abrasion is swift because the epithelial cells regenerate quickly. Small abrasions often resolve entirely within 24 to 48 hours. Larger defects may take up to 72 hours for complete re-epithelialization. Patients are monitored closely, and the temporary nature of the injury means it rarely impacts the long-term success of the cataract surgery.