OVERVIEW

What is ultraviolet keratitis?

Ultraviolet (UV) keratitis, also known as actinic keratitis, photokeratitis, arc eye, or snow blindness, is an acute ocular syndrome characterized by eye pain, redness, and photophobia after exposure to intense ultraviolet radiation (from sunlight or artificial sources).

Patients may initially experience no obvious discomfort, with symptoms appearing after a latent period. The condition is self-limiting, and symptoms typically resolve over time.

Is ultraviolet keratitis common?

UV keratitis often occurs in settings with UV disinfection lamps, such as hospitals, usually due to accidental exposure. It has a relatively low incidence, and large-scale epidemiological data remain limited.

SYMPTOMS

What are the common symptoms and manifestations of ultraviolet keratitis?

• Patients may experience eye pain, tearing, photophobia, blurred vision, a gritty sensation in the eyes, dizziness, headache, and other discomforts 6–8 hours after exposure to ultraviolet light (e.g., while skiing on snow or swimming at the beach), making it difficult to open their eyes or, in rare cases, causing temporary vision loss.
• Some patients may also exhibit signs of sunburn, such as facial erythema and edema.

The severity of these symptoms correlates with the duration of UV exposure—the longer the exposure, the worse the symptoms.

CAUSES

How does ultraviolet keratitis develop?

Ultraviolet (UV) rays damage the eyes because they cannot pass through them and are entirely absorbed, leading to pathological changes in ocular tissues.

Different parts of the eye absorb UV rays to varying degrees, with the cornea absorbing the most. Due to the layered filtering by ocular structures, UV rays rarely reach the retina (unless extremely intense) and are mostly absorbed by the cornea, lens, and aqueous humor.

Additionally, UV absorption by the eye increases with age, making older individuals more susceptible to ultraviolet keratitis.

What eye damage can UV rays cause?

Modern medical research confirms that excessive UV exposure can lead to dry eyes, eye fatigue, conjunctivitis, keratitis, uveitis, and may trigger lens degeneration causing cataracts. Severe cases can even result in retinitis.

In which environments is ultraviolet keratitis most likely to occur?

• Natural UV exposure, such as prolonged outdoor activities at beaches or sunbathing in summer;
• Electronic screens (computers, TVs, displays), fluorescent lamps;
• Sunlamps;
• High-voltage circuit short circuits;
• Laboratory or germicidal UV lamps;
• Disinfection lamps in hospitals, kindergartens, or cafeterias;
• Arc welding.

DIAGNOSIS

How is ultraviolet keratitis diagnosed?

A detailed medical history should be obtained to confirm excessive ultraviolet exposure. Combined with symptoms of keratitis (such as photophobia, tearing, eye pain, often bilateral), diagnosis can generally be effectively made.

What tests are needed to diagnose ultraviolet keratitis?

Diagnosing ultraviolet keratitis requires a visual acuity test and fluorescein eye drop examination:

• Visual acuity test: Shining a flashlight into the eyes reveals tearing, as well as widespread conjunctival hyperemia and edema. The absence of discharge or unaffected palpebral conjunctiva helps distinguish photokeratitis from conjunctivitis.
• Fluorescein eye drop examination: Applying fluorescein eye drops shows punctuate staining of the corneal surface in the palpebral fissure, aiding in the diagnosis of keratitis.

What diseases should ultraviolet keratitis be differentiated from?

Ultraviolet keratitis should be distinguished from other types of keratitis, such as bacterial keratitis, fungal keratitis, and viral keratitis. Differentiation is usually possible based on the history of ultraviolet exposure and slit-lamp microscopic examination.

TREATMENT

What department should I visit for ultraviolet keratitis?

Generally, you should go to the ophthalmology department.

Can ultraviolet keratitis be cured?

Ultraviolet keratitis is self-limiting. Even without treatment, it will heal over time and will not adversely affect vision.

How is ultraviolet keratitis treated?

This condition is self-limiting, and symptoms usually gradually improve within 2–3 days. The goal of treatment is to speed up recovery and improve comfort. Treatment includes general care and medication:

• General treatment: Rest with eyes closed and apply a wet towel compress.
• Medication:
  • Use eye drops or gels that promote epithelial growth to accelerate corneal healing.
  • Preventive antibiotic eye drops may be prescribed by a doctor to prevent infection (do not self-medicate), such as erythromycin, bacitracin, or polymyxin-bacitracin.
  • For severe pain, oral pain relievers (e.g., mild opioids like oxycodone) can temporarily alleviate discomfort.

What are the adverse effects of frequent UV exposure for patients with ultraviolet keratitis?

Long-term corneal exposure to UV light may lead to pterygium or a rare corneal degeneration (climatic droplet keratopathy), though the incidence is low.

DIET & LIFESTYLE

What should patients with ultraviolet keratitis pay attention to in daily life?

• Do not wear contact lenses during the onset period, avoid eye strain, and reduce the use of TVs, computers, etc. It is best to avoid them altogether.
• Do not rub your eyes during the healing process to ensure eye cleanliness.
• Avoid strenuous exercise during the illness.
• Maintain a normal and healthy diet.

PREVENTION

Can ultraviolet keratitis be prevented? How to prevent ultraviolet keratitis?

Ultraviolet keratitis is caused by excessive exposure to ultraviolet (UV) rays. Therefore, reducing UV exposure can minimize the occurrence of this condition and serve as an effective preventive measure. Common methods to prevent UV-related eye damage include:

• Nearsighted individuals should wear glasses with UV protection.
• Wear sunglasses or hats when going outdoors to reduce direct sunlight exposure.
• When skiing in snowy mountains, use professional snow goggles.
• Occupational workers performing welding tasks should wear protective goggles and helmets.