What is the cause of a foreign body sensation, like a grain of sand, in the corneal region of the left eye after cataract surgery, which was not experienced during the first operation?

From the Guidelines

The patient should seek immediate medical attention from their ophthalmologist for this foreign body sensation in the left eye following cataract surgery. This feeling of a "grain of sand" in the corneal area that wasn't experienced after their first cataract operation could indicate several possible complications, such as corneal epithelial defects, a suture-related issue, dry eye exacerbated by surgery, or potentially an early sign of infection 1. According to the 2024 American Heart Association and American Red Cross guidelines for first aid, a person who has persistent foreign-body sensation in the eye should seek immediate medical attention 1.

While waiting for the appointment, the patient can use preservative-free artificial tears (such as Systane Ultra or Refresh Optive) every 2-3 hours for temporary relief. They should avoid rubbing the eye and maintain all prescribed post-operative medications including antibiotic drops (typically moxifloxacin or tobramycin 4 times daily) and anti-inflammatory drops (prednisolone acetate 1% or difluprednate 0.05% 4 times daily). This sensation often results from temporary corneal nerve disruption during surgery or from microscopic irregularities on the corneal surface that typically resolve within days to weeks with proper treatment. However, prompt evaluation is essential to rule out more serious complications that could affect surgical outcomes.

Some key points to consider in the diagnosis and management of this condition include:

• The patient's symptoms and medical history, including the recent cataract surgery
• The possibility of dry eye syndrome, which is a common cause of ocular irritation and can be exacerbated by surgery 1
• The importance of proper treatment and follow-up to prevent more serious complications and promote optimal recovery. The most recent and highest quality study on dry eye syndrome preferred practice pattern suggests that dry eye is a frequent cause of ocular irritation and can compromise results of corneal, cataract, keratorefractive, and other anterior segment surgery 1.

From the Research

Possible Causes of Foreign Body Sensation

• A retained foreign body, such as a metallic or polyethylene object, in the corneal region can cause a foreign body sensation, as reported in studies 2, 3, 4, 5.
• The foreign body may not be visible on standard slit lamp examination, and additional tests such as fluorescein staining or ultrasound biomicroscopy may be necessary to detect it 2, 3.
• In some cases, the foreign body may be embedded deep within the upper palpebral conjunctiva (UPC) or iris, making it difficult to detect without careful examination 2, 3.

Risk Factors for Retained Foreign Bodies

• History of trauma or injury to the eye, such as during cataract surgery, can increase the risk of a retained foreign body 3.
• Failure to use proper eye protection during activities that involve potential eye hazards, such as cutting iron material, can also increase the risk of a retained foreign body 4.
• Contact lens wear can cause ocular complications, including retained foreign bodies, and patients with a history of contact lens wear and red flag symptoms should be referred for an urgent ophthalmic review 6.

Importance of Thorough Examination

• A thorough history and complete physical examination, including slit lamp examination and additional tests as needed, are essential to detect retained foreign bodies and prevent potential sight-threatening ocular complications 6, 2, 3, 4, 5.