- Published on
Emergency and Acute Medicine: Ultraviolet Keratitis
Ultraviolet keratitis is a painful ocular condition caused by corneal epithelial damage following exposure to ultraviolet (UV) light. Also known as photokeratitis, snow blindness, UV conjunctivitis, or welder’s flash, it results from absorption of UV radiation—particularly at wavelengths around 290 nm—by the corneal epithelium. This exposure damages epithelial cells and penetrates to nociceptor nerve endings, leading to intense pain due to subepithelial nerve stimulation.
The condition is commonly associated with occupational exposures such as welding, electrical work, and mechanical tasks, as well as recreational exposures including skiing, snowboarding, water sports, and use of tanning beds. The severity of injury is directly related to the intensity and duration of UV exposure. Importantly, patients are often unaware of the exposure at the time of injury.
Symptoms typically develop with a delay of 6–12 hours after exposure. Patients usually present with bilateral eye pain, photophobia, tearing, and redness. A foreign-body sensation is commonly reported, but purulent discharge is absent. Additional findings may include eyelid edema, facial erythema, and blepharospasm. On examination, visual acuity may be mildly decreased. Conjunctival injection, chemosis, and excessive tearing are typical. Slit-lamp examination with fluorescein staining reveals multiple superficial punctate epithelial lesions across the cornea, which are characteristic of the condition.
Diagnosis is clinical and relies heavily on history and physical examination. A key diagnostic clue is a history of UV exposure several hours prior to symptom onset. Evaluation should include assessment of visual acuity, extraocular movements, and a detailed ocular exam with fluorescein staining. Lid eversion is important to rule out retained foreign bodies, and the anterior chamber should be assessed for signs of inflammation such as cells or flare. Laboratory tests and imaging are generally not required unless other injuries are suspected.
Management is primarily supportive, as ultraviolet keratitis is a self-limited condition. In the emergency setting, topical anesthetics may be used to facilitate examination but should not be prescribed for outpatient use due to the risk of delayed healing and corneal ulceration. Treatment includes oral analgesics such as ibuprofen or acetaminophen (with or without opioids for severe pain), topical antibiotic ointment (e.g., erythromycin) to prevent secondary infection, and short-acting cycloplegic agents to relieve ciliary spasm. Eye patching may provide comfort but does not accelerate healing.
Disposition is generally outpatient, as most cases resolve completely within 24–72 hours. Admission is rarely required but may be considered in cases of severe visual impairment, inability to care for oneself, or when both eyes are patched and functional vision is significantly impaired. Follow-up with an ophthalmologist within 24–48 hours is recommended to ensure proper healing and symptom resolution.
Key clinical pearls include recognizing the delayed onset of symptoms after UV exposure, which is critical for diagnosis, and understanding that the condition, while extremely painful, is typically benign and self-limited. Preventive measures are essential—individuals at risk should use appropriate UV-protective eyewear, as regular glasses or contact lenses do not provide adequate protection.
0 Comments
