A corneal ulcer is an open sore that develops on the cornea, the transparent, dome-shaped surface covering the front of the eye. This layer focuses light and protects inner eye structures. When this protective surface is compromised, an ulcer forms, representing a serious medical condition that demands immediate professional attention. A delay in treatment can lead to rapid worsening and potentially permanent vision impairment.
How to Visually Identify an Eye Ulcer
The most distinguishing visual sign of a corneal ulcer is an abnormal mark or patch on the typically clear corneal surface. This visible lesion generally appears as an opaque, white, or grayish-white spot, contrasting sharply with the underlying colored iris. The size can vary widely, from a tiny pinpoint to a larger lesion, sometimes only detectable with specialized magnification tools.
The texture of the ulcerated area may appear dull, rough, or slightly crater-like, representing a loss of tissue from the cornea’s outer layer. Surrounding the lesion, the conjunctiva (the white part of the eye) usually becomes noticeably inflamed. This inflammation presents as intense redness or a bloodshot appearance.
In severe infections, a collection of pus may be visible at the bottom of the anterior chamber (the space between the cornea and the iris). This accumulation, referred to as hypopyon, indicates a deep and advanced inflammatory response. Any change in the clarity of the cornea, which should be transparent, paired with intense redness is a strong indication of this condition.
Associated Pain and Discomfort
While visual signs aid identification, the sensory experience often compels a person to seek immediate help. A hallmark symptom is intense eye pain, ranging from a persistent, deep ache to a sharp, burning sensation. This discomfort is caused by the exposure of numerous nerve endings within the damaged corneal tissue.
Patients frequently report a pronounced foreign body sensation—the feeling that grit, sand, or an eyelash is stuck in the eye. This persistent irritation triggers excessive tearing, known as epiphora, as the eye attempts to flush out the irritant. The eye may also produce a noticeable discharge, which can be watery or thick and pus-like depending on the underlying infection.
Photophobia, an extreme sensitivity to light, is another common symptom that makes bright environments painful. Inflammation can also cause vision to become blurred or hazy, as the ulcer distorts the cornea’s smooth, light-refracting surface. These sensory symptoms signal a severe disruption to the eye’s normal function.
Common Causes of Corneal Ulceration
Most corneal ulcers develop from an infection that takes hold after the cornea’s protective outer layer has been damaged. Bacterial infections are the most frequent cause, often linked to improper care or overuse of contact lenses, particularly when worn while sleeping. Bacteria can colonize the lens or its case, and any minor scratch provides an entry point for the organisms.
Viral infections are another category, with the Herpes Simplex Virus (HSV), responsible for cold sores, being a common culprit. This virus can cause recurrent ulceration, as it may remain dormant and reactivate due to stress or a weakened immune response. Fungal keratitis, while less common, occurs after an eye injury involving plant material or in contact lens wearers using non-sterile solutions.
The cornea can also become vulnerable following trauma, such as a scratch or abrasion from a fingernail, dust, or foreign objects. Severe dry eye syndrome can predispose the cornea to damage, as insufficient lubrication compromises the protective tear film. Any condition that prevents the eyelid from closing fully, such as Bell’s palsy, can lead to drying and subsequent breakdown of the corneal surface.
When Emergency Care is Required
A corneal ulcer must be treated as an ophthalmic emergency due to the potential for permanent vision loss. If an opaque spot on the cornea is noticed, or if severe eye pain, blurred vision, or thick discharge develops, immediate care from an eye specialist or emergency room is required. Delaying treatment, even by a few hours, allows the infection to penetrate deeper layers of the cornea, leading to scarring and irreversible damage.
Prompt diagnosis allows for the initiation of targeted, high-dose antibiotic, antiviral, or antifungal eye drops, often administered hourly to combat the infection. While waiting for professional care, immediately remove contact lenses and avoid rubbing the affected eye. Over-the-counter eye drops should not be used unless instructed by a medical professional, as some formulations can inadvertently worsen the condition.