A white cornea is a visible change in the normally clear, dome-shaped front surface of the eye, appearing cloudy or opaque. The cornea’s transparency is essential for focusing light onto the retina, allowing for clear vision. When this clarity is compromised, it affects sight. Any whitening of the cornea warrants prompt medical evaluation.
Common Causes of Cornea Whitening
Several conditions can lead to cornea whitening. A common cause is a corneal ulcer, an open sore often resulting from infections. These can be bacterial (e.g., Staphylococcus aureus), viral (e.g., herpes simplex virus), fungal, or parasitic (e.g., Acanthamoeba). Eye injuries, severe dry eye, or prolonged contact lens wear can create an entry point for these microorganisms, leading to an ulcer.
Cornea whitening can also stem from keratitis, which is inflammation of the cornea. Keratitis can be infectious or non-infectious, resulting from injuries, extended contact lens use, or severe dry eyes. For instance, diffuse lamellar keratitis is a non-infectious complication of refractive surgery. Herpes simplex keratitis, a viral form, is a leading cause of corneal blindness.
Corneal scarring from previous infections, injuries, or diseases can also cause white spots. These scars block or distort light, leading to decreased or hazy vision. Chemical burns, severe dry eye, and certain inflammatory conditions can also result in corneal scarring. The extent of vision impairment depends on the scar’s location; central scars cause more significant vision loss.
Genetic conditions known as corneal dystrophies are another cause. These rare, inherited disorders involve abnormal deposits in the cornea, leading to clouding. Over 20 types exist, affecting various corneal layers. For example, macular corneal dystrophy results in dense grayish-white deposits that can cloud the stroma, the thickest layer of the cornea. Granular dystrophy involves small, white, crumb-like spots forming in the superficial central corneal stroma.
Arcus senilis presents as a white, gray, or bluish arc or ring around the edge of the cornea. Common with aging, it is caused by fatty deposits, primarily cholesterol. While often benign and not affecting vision in older adults, arcus senilis in younger individuals (arcus juvenilis) may indicate high cholesterol or other health concerns, such as carotid vascular disease if present in only one eye.
Recognizing Accompanying Symptoms
A white cornea rarely appears in isolation; it is often accompanied by other symptoms that provide clues about the underlying cause. Pain is common, ranging from mild discomfort to severe aching, often described as a foreign body sensation. This can also lead to excessive tearing and blinking.
Redness or a bloodshot appearance is another frequent symptom, caused by dilated blood vessels. Blurred or decreased vision indicates compromised light-focusing ability, manifesting as out-of-focus objects or haziness. Sensitivity to light, known as photophobia, causes discomfort or pain in bright light, leading individuals to squint or avoid well-lit environments.
Excessive tearing or discharge, sometimes appearing as yellow-green pus, can signal an infection. Eyelid swelling may also occur, indicating inflammation or infection. Any sudden onset of these symptoms, especially severe pain, rapid vision loss, or unusual discharge, warrants immediate medical attention. Delay in seeking care can lead to permanent eye damage or blindness.
Diagnosis and Management of a White Cornea
Diagnosing the cause of a white cornea involves a thorough examination by an eye care professional. This typically includes a detailed medical history and a specialized slit-lamp examination, which allows the doctor to view the cornea and other eye structures in magnified detail. This examination helps identify the location, size, and characteristics of the corneal opacity. To pinpoint infectious causes, a corneal scraping may be performed, where a sample of cells is collected for culture to identify bacteria, fungi, or viruses. Imaging tests, such as corneal topography, can also map the curvature and irregularities of the corneal surface.
Management varies significantly depending on the cause. For bacterial infections, antibiotic eye drops are prescribed. Viral infections may require antiviral eye drops, while fungal infections necessitate antifungal medications. Steroidal eye drops may also decrease inflammation, though their use with infections requires careful supervision.
In cases of severe scarring or corneal dystrophies that significantly impair vision, surgical interventions like a corneal transplant (keratoplasty) may be recommended. This procedure replaces damaged cornea with healthy donor tissue. Different types of corneal transplants exist.
For benign conditions like arcus senilis, which typically do not affect vision, observation is usually the only management required. However, a doctor may recommend further tests for underlying health conditions if it appears in younger individuals.