A corneal ulcer, also known as keratitis, is an open sore that develops on the clear, dome-shaped outer layer of the eye called the cornea. The cornea focuses light, and any disruption to its surface can significantly impact vision. This condition is considered an ophthalmologic emergency because it can rapidly progress, potentially leading to corneal scarring, permanent vision loss, or blindness if left untreated. Symptoms include severe pain, redness, blurred vision, and a notable sensitivity to light, requiring immediate attention from an eye care specialist.
Is a Corneal Ulcer Transmissible?
The corneal ulcer itself, the physical open wound on the eye’s surface, is generally not contagious from person to person. Simply being near someone with a corneal ulcer will not cause you to develop the condition, as the ulcer is the result of an infection or injury that has already breached the cornea’s protective barrier.
However, the organisms that often cause the ulcer, such as bacteria or viruses, can be transmissible. For example, the Herpes Simplex Virus (HSV) can be passed through direct contact and then cause an ulcer if it reaches the eye. Developing an ulcer requires that the organism gain entry through a compromised corneal surface.
A person needs a specific risk factor, such as a scratch, dry eye, or improper contact lens use, for the transmitted organism to take hold and create the ulcer. The risk of transmission is highest when direct contact is made with an infectious source, such as touching an active cold sore and then touching one’s eye. Most corneal ulcers are caused by an individual’s own bacteria or poor hygiene practices, not by direct transmission from another person.
Identifying the Origin of Corneal Ulcers
Corneal ulcers are broadly categorized into infectious and non-infectious causes, with infectious agents being the most common trigger. The development of an ulcer starts when the protective outer layer of the cornea, the epithelium, is damaged, creating an entry point for microbes. This initial break can be extremely small, such as a microscopic scratch from a contact lens.
The most frequent infectious origin is bacterial, often involving organisms like Pseudomonas, Staphylococcus, and Streptococcus species. These bacteria are frequently introduced through contaminated contact lenses, cases, or solutions. Viral causes are also significant, most notably the Herpes Simplex Virus, which can cause recurring attacks and is a leading cause of unilateral infectious corneal blindness in the developed world. The varicella-zoster virus, which causes shingles and chickenpox, is another viral agent that can lead to an ulcer.
Fungal keratitis can occur after an eye injury involving plant material or through the improper use of contact lenses and steroid eye drops. A severe cause is the parasitic infection known as Acanthamoeba keratitis, often linked to contact lens wearers who expose their lenses to tap water, hot tubs, or swimming pools. This free-living amoeba is commonly found in fresh water and soil and presents a serious risk when hygiene is poor.
Non-infectious ulcers arise from physical damage or underlying health conditions. Trauma to the eye, including cuts, burns, or corneal abrasions, can directly lead to an ulcer if the wound does not heal correctly. Severe dry eye syndrome can leave the corneal surface vulnerable and prone to breakdown. Eyelid disorders that prevent the eye from fully closing, a condition called lagophthalmos, result in prolonged exposure and drying of the cornea, which can lead to ulceration.
Essential Steps for Prevention
Prevention focuses on minimizing risk factors that create an entry point for infectious agents or cause physical damage to the cornea. Strict adherence to contact lens hygiene is the most effective preventative measure, as contact lens wear is the greatest risk factor for infectious corneal ulcers. Never sleeping in contact lenses is important, as overnight wear significantly increases the risk of a serious ulcer.
Contact lens users should follow these guidelines:
- Avoid exposing lenses to any form of water, including while showering, swimming, or using a hot tub, as water can harbor organisms like Acanthamoeba.
- Always clean, rub, and rinse lenses with fresh, sterile disinfecting solution.
- Never reuse or “top off” the solution in the lens case.
General eye safety is important. Use protective eyewear during activities like yard work, home repairs, or sports. Avoiding rubbing the eyes reduces the chance of causing a micro-abrasion. Managing chronic eye conditions, such as severe dry eye, through appropriate lubrication helps maintain the cornea’s integrity. Individuals with a history of recurrent viral infections, such as ocular herpes, should seek treatment at the first sign of an outbreak. Any sudden onset of eye pain, redness, or blurred vision must be addressed immediately by an eye care professional.