Overview

A corneal ulcer is an open sore or erosion that develops on the cornea, the clear, dome-shaped surface covering the front of the eye. It is considered a serious eye condition that requires prompt medical attention to prevent vision loss or permanent scarring. Corneal ulcers are typically caused by infections but can also result from injury, contact lens misuse, or underlying health conditions. The condition can cause significant eye pain, redness, tearing, and vision disturbances. Early diagnosis and treatment are crucial to preserve eye health and prevent complications.

Causes

Corneal ulcers can develop due to various infectious and non-infectious causes:

• Bacterial Infections: Common in contact lens users, especially when lenses are worn overnight or handled improperly.
• Viral Infections: Herpes simplex virus (HSV) is a frequent cause of viral corneal ulcers, leading to recurrent episodes.
• Fungal Infections: Often result from eye injuries involving plant material or in individuals with compromised immunity.
• Parasitic Infections: Acanthamoeba, a parasite found in water and soil, can cause severe corneal ulcers, particularly in contact lens users.
• Trauma: Physical injury to the eye, such as scratches or foreign bodies, can lead to corneal ulceration.
• Dry Eye Syndrome: Severely dry eyes can cause corneal damage and ulceration if left untreated.
• Vitamin A Deficiency: Rare in developed countries but can cause corneal ulcers, particularly in malnourished individuals.
• Chemical Burns: Exposure to toxic chemicals can damage the cornea and lead to ulceration.

Symptoms

Symptoms of a corneal ulcer often develop rapidly and can include:

• Severe Eye Pain: Intense discomfort or sharp pain in the affected eye.
• Redness: Marked redness of the eye, especially around the cornea.
• Excessive Tearing: Increased tear production as the eye attempts to flush out the irritant.
• Blurry Vision: Decreased vision or blurry vision due to corneal clouding.
• Light Sensitivity: Photophobia or sensitivity to light is common.
• Discharge: Watery, yellow, or green discharge from the eye, especially in bacterial infections.
• Foreign Body Sensation: Feeling like something is stuck in the eye.
• Visible White Spot: In some cases, a visible white or grayish spot can be seen on the cornea.

Diagnosis

Diagnosing a corneal ulcer involves a thorough eye examination and specialized tests:

• Patient History: Inquiry about recent eye injuries, contact lens use, or previous eye infections.
• Slit-Lamp Examination: An ophthalmologist uses a special microscope to closely examine the cornea for ulcers.
• Fluorescein Staining: A dye is used to highlight the ulcer under a blue light, making it easier to detect.
• Corneal Scraping: A sample of cells from the ulcer may be taken for laboratory analysis to identify the specific infectious organism.
• Cultures: Bacterial, viral, or fungal cultures help guide targeted treatment based on the identified cause.

Treatment

Treatment of a corneal ulcer depends on the underlying cause and severity:

• Antibiotic Eye Drops: Broad-spectrum antibiotics are typically used initially for bacterial ulcers, later adjusted based on culture results.
• Antiviral Medications: Antiviral eye drops or oral medications are used for viral ulcers, especially those caused by herpes simplex.
• Antifungal Eye Drops: Essential for treating fungal ulcers, often requiring prolonged treatment.
• Antiparasitic Therapy: For Acanthamoeba infections, specialized medications and intensive treatment regimens are used.
• Cycloplegic Eye Drops: To relieve pain by relaxing eye muscles and preventing spasms.
• Avoidance of Contact Lenses: Discontinuing lens use during treatment is mandatory.
• Steroid Eye Drops: Sometimes used after the infection is controlled to reduce inflammation, but under strict medical supervision.
• Surgical Intervention: In severe cases, corneal transplant (keratoplasty) may be required if there is significant scarring or perforation.

Prognosis

The prognosis of a corneal ulcer varies depending on how quickly treatment is started and the severity of the condition:

• Good Prognosis with Early Treatment: Prompt diagnosis and treatment often lead to full recovery without vision loss.
• Risk of Scarring: Severe or delayed cases can result in permanent corneal scarring, leading to visual impairment.
• Possible Vision Loss: In untreated or aggressive infections, partial or complete vision loss can occur.
• Low Recurrence Risk: With proper treatment and good eye hygiene, the risk of recurrence is low, although individuals with underlying conditions may be at higher risk.
• Prevention Effective: Proper contact lens hygiene, eye protection from injury, and early treatment of eye infections significantly reduce the risk of corneal ulcers.

Overall, corneal ulcers are treatable with a good outcome when addressed early, but they should always be considered an ocular emergency due to the risk of vision loss.