Corneal ulcer

Corneal Ulcer

A corneal ulcer, also known as ulcerative keratitis, is an inflammatory or infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. It is a common condition in humans and is particularly prevalent in contact lens wearers. Corneal ulcers are a serious problem and can lead to severe vision loss or even blindness if left untreated.

Causes

Corneal ulcers are most commonly caused by an infection with bacteria, viruses, fungi, or parasites. The following are the primary causes:

• Bacterial infection, especially in people who wear contact lenses, is the most common cause. Bacteria such as Pseudomonas aeruginosa, Staphylococcus aureus, and others can invade the cornea, particularly if contact lenses are worn overnight or not properly disinfected.
• Viral infections caused by the herpes simplex virus (HSV) or the Varicella zoster virus can lead to corneal ulcers.
• Fungal infections can occur after a corneal injury involving plant material, or in immunocompromised patients, involving fungi such as Fusarium or Aspergillus species.
• Parasitic infections like Acanthamoeba keratitis are rare but can occur in contact lens users, particularly those who use homemade or inappropriate cleaning solutions.

Symptoms

Symptoms of a corneal ulcer include:

• Severe pain and redness in the affected eye
• Blurred vision or vision loss
• Sensitivity to light (photophobia)
• A feeling of having something in the eye
• Watery eye or discharge

Diagnosis

Diagnosis of a corneal ulcer involves a thorough examination by an eye care professional. Tools and techniques used in diagnosis include:

• Slit lamp examination: A microscope with a bright light used to examine the eye in detail.
• Fluorescein staining: A dye is used to highlight areas of damage on the cornea.
• In some cases, samples of the ulcer may be taken to identify the causative agent through cultures or PCR testing.

Treatment

Treatment of corneal ulcers depends on the underlying cause:

• Antibiotic eye drops are used for bacterial infections.
• Antiviral medication is used for herpes simplex virus infections.
• Antifungal eye drops or oral medications are used for fungal infections.
• Pain management may include the use of pain relievers and patching or bandaging the eye.

In severe cases, surgical intervention such as corneal transplantation may be necessary.

Prevention

Preventive measures include:

• Practicing good contact lens hygiene, including proper cleaning, disinfecting, and not wearing lenses longer than recommended.
• Avoiding contact with contaminated water, especially when wearing contact lenses.
• Seeking prompt treatment for any eye injuries or infections.

Complications

If not treated promptly, corneal ulcers can lead to serious complications, including:

• Scarring of the cornea, leading to permanent vision loss
• Perforation of the cornea
• Spread of infection, leading to endophthalmitis, a severe, vision-threatening infection inside the eye
• Chronic or recurrent ulcers