Case Study of the Week: Photokeratitis

Why do we wear sunglasses anyway?  Is the sole purpose of Ray-Bans to exude the laid back hipster lifestyle that's currently trending?  Or, is the function of those sleek Nike sports shades to intimidate opponents on the race course?  For some, yes, but for most of us sunglasses not only serve to as a fashion statement but also to protect our vision.  What happens when we forget the importance of UV protective eyewear?

Case Presentation

A 25 year-old male patient presents to your clinic with a complaint of red, painful eyes and blurred vision.  He works in construction and yesterday spent 12 hours working on a roof in the bright sunlight.  About 6 hours after he finished working and went indoors his symptoms developed.  He was not wearing sunglasses or protective eyewear.  He denies the possibility of an ocular foreign body as well as discharge from his eyes.  The patient states he feels like he has "sand in his eyes".  His vital signs are within normal limits.  He has no prior medical history.

On exam you note the patient is rocking back and forth in pain.  His eyes are closed and pain increases when he attempts to open them.  He appears to be very sensitive to light.  His conjunctiva are injected bilaterally and mild eyelid edema is present.  Exam with fluorescein stain reveals small, superficial irregularities over the cornea and no foreign body.  Based on this patient's history, symptoms and physical exam you diagnose him with Photokeratitis

Management and Outcome

Care of Photokeratitis is largely supportive and focused on pain relief.  On initial arrival to the clinic or emergency department, topical anesthetic drops such as proparacaine may be used to relieve pain.  While these agents provide significant pain relief, they can lead to delayed healing and corneal ulcer formation and therefore should not be sent home with or prescribed to the patient.  

Lubricant ointments may also help reduce pain without negative side effects.  Patients may use an agent such as Lacrilube for comfort.  Treatment with antibiotic ointments is controversial.  While this may prevent superinfection, no evidence supports this practice. 

Cycloplegic drops that dilate the pupil may relieve photophobia in patients with Photokeratitis however dilation of the eye may last up to days and can be uncomfortable for the patient.  Use of these agents is controversial.  

NSAIDs and oral narcotic medications are the treatment of choice for pain relief in patients with Photokeratitis.  Patients should be prescribed an NSAID pain reliever as well as a narcotic agent for breakthrough pain if neeeded.  Pain with Photokeratitis ranges from mild irritation to severe pain and analgesic agents should be administered appropriately.  

The prognosis for patients diagnosed with Photokeratitis is excellent and most symptoms resolve within 24 to 76 hours.  Rarely, superinfection or vision loss may occur.  Patients with persistent symptoms should be referred to an ophthalmologist for further evaluation. 

Discussion

Photokeratitis, also known as UV Keratitis and Snow Blindness, is caused by ultraviolet irradiation of the eyes.  Symptoms are typically latent and do not manifest for 6 to 12 hours after injury.  Photokeratitis is most commonly seen among individuals with occupational or recreational exposure to ultraviolet light such as welders and skiers.  Photokeratitis is usually a self-limited condition and resolves on its own.  While the condition typically resolves without long-term sequelae, Photokeratitis is extremely painful and medical providers should offer adequate pain relief. 

Photokeratitis is preventable.  Wearing protective eyewear or sunglasses that block UV-A and UV-B radiation will prevent UV related injury to the eye.  Educate your patients with occupational or recreational exposure to UV light about the importance of proper eyewear to prevent ocular UV damage. 

 

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