Corneal ulcer is an inflammation of the cornea secondary to infection. It will cause red eyes, pain, excessive tearing, blurred vision and light sensitivity. Corneal ulcer can be caused by bacteria, viruses, fungi and parasites. If left untreated or if infection is severe, corneal ulcer can lead to permanent damage of vision.

Bacterial keratitis

Bacterial infections are the most common cause of corneal ulcer. Most of the time Pseudomonas Aeruginosa, Staphylococcus species and Streptococcus species are responsible for this type of infection. Bacterial keratitis can develop quickly. There is a high risk of getting infection from long hours of wearing contact lenses or not taking care of them correctly. Thus, proper care of contact lenses will reduce the risk of developing a corneal infection.

Fungal keratitis

Improper use of contact lenses or steroid eye drops can lead to fungal infection. A corneal injury that results in plant material like being hit by a tree branch also will cause fungal keratitis which is mostly due to Fusarium or Aspergillus species. Candida species will typically cause keratitis in the eye with preexisting ocular surface disease or eyes that have recently been treated with topical steroid. Fungal keratitis is devastating, hard to treat and remains a common cause of blindness in tropical countries.

Herpes simplex keratitis

Herpes keratitis is a viral infection caused by herpes simplex virus. It may cause recurring attacks and be very contagious when contact with someone who has the virus. After primary infection, the virus lies in a dormant state, living in the nerve cell of the eye. It can be triggered by stress, trauma, fever or certain medications.
Acanthamoeba keratitis

Lastly, parasitic infection caused by Acanthamoeba is a rare, vision threatening corneal ulcer. Acanthamoeba is a microscopic, single-cell living organism and can be found in freshwater and soil. People who wear contact lenses develop higher risk of getting Acanthamoeba keratitis when they clean lenses with tap water, swimming while wearing contacts or contact with contaminated water. Early diagnosis and treatment of Acanthamoeba keratitis is essential to prevent loss of vision.

An ophthalmologist will be able to assess your eye and diagnose the type of corneal ulcer/infectious keratitis you have. All these conditions may cause severe pain and impaired vision. Therefore, corneal ulcer/infectious keratitis may need serious medical attention and should be treated immediately to prevent the conditions from worsening.