Blinded By The Light

aka Ophthalmology Befuddler 018

A 22 year-old male had a session on the sunbed in the morning, went for a surf around lunchtime, and helped his mate with some welding in the afternoon. Fortunately there were no mountains nearby.

It’s late evening now and he has presented to the emergency department with intense bilateral eye pain and is refusing to open his tightly clenched eyelids.

Questions

Q1. What is the likely diagnosis?

Answer and interpretation

Ultraviolet keratitis/ keratopathy

Other names for this condition are solar keratitis, photokeratitis, welder’s flash, arc eye, bake eyes, and snow blindness.

Q2. Who are at risk of this condition?

Answer and interpretation

Anyone exposed to excess UV radiation:

welders
sunbed users
people in high altitude environments
(UV levels increase by about 4% for every 1000 feet/ 305 m)
people exposed to sunlight reflection from:
water (sea foam reflects about 25% of UV, sandy beaches about 15%) or
snow (fresh snow reflects about 80% of UV)

Q3. What are the features to look for on history?

Answer and interpretation

History:

Patient at risk? (see Q2) — symptoms typically emerge 6 to 12 hours following the at-risk activity.
Symptoms — intense pain, red eyes, blepharospasm and tearing; usually bilateral.
Use of eye protection? Previous episodes?

Q4. What are the features to look for on examination?

Answer and interpretation

Examination:

Apply topical anesthesia ASAP — you’re unlikely to see anything if the patient refuses to open their eyes!

Visual acuity — usually near normal
Pupils — relatively miotic, sluggish reaction to light

Slit lamp

Conjunctival injection
Cornea — widespread superficial punctate epithelial defects that stain with fluorescein and are often bilateral. Mild or minimal corneal edema.
Anterior chamber — mild AC reaction

Rule out a foreign body, chemical injury and exposure keratopathy (do the eyelids close correctly?)

Q5. What is the management?

Answer and interpretation

oral analgesia (may need opioids) and topical cycloplegia (e.g. 1% cyclopentolate) for comfort for up to about 3 days
topical antibiotics are often given
some authorities advise a pressure patch to the most affected eye for 24 hours
patients should return if there is not significant improvement after 24 hours

Educate the patient about the risk of UV, the use of equipment and protective gear

The topical anesthesia was so effective, the patient asks if he can take some home.

Q6. Will you give him a topical anesthetic to take home?

Answer and interpretation

Repeated use of topical anesthesia may lead to:

a delay in corneal healing
chronic corneal ulceration
inhibition of the corneal blink reflex

Q7. Why do thermal injuries tend to affect the eyelid more than the globe?

Answer and interpretation

The eye itself is protected by reflex blinking and Bell’s phenomenon (when the eye closes, the front of the globe rolls upwards)

Q8. How are thermal burns to the eye and lids managed?

Answer and interpretation

It depends on severity of injury and the structures involved.

Eyelid burns

superficial burns — irrigation and topical antibacterial ointment
partial thickness or worse — get an ophthalmology review.

Eye burns

superficial thermal eye burns — most can be managed like a corneal abrasion if there is only epithelial involvement.
more severe injuries (e.g. hot metal injuries) — these can result in globe perforation, and should be treated along the lines of a globe rupture