Wilderness Medicine of Utah Newsletter

SNOWBLINDNESS

While hiking across a glacier one afternoon, you come across a 20-yr-old girl who is suffering from an increasing headache. She attributes the headache to dehydration, but also has painful and tearing eyes which she says is from old contacts. She has sufficient eye protection and says she only took them off for a "couple of minutes" while her group took pictures.

Is it possible that such a short exposure could cause snowblindness?
What is "sufficient eye protection"?
What do you recommend for this patient?
You have a topical steroid suitable for application on the eye. Should you give it?

ANSWERS:
1. Yes. First off, know that at high altitudes at high levels of exertion, time is perceived much differently. This girl may have passed more than an hour without her sunglasses, and that is more than enough. UV burning can occur on the cornea in less than hour.
2. Lenses advertised for mountaineering purposes should meet the appropriate requirements. To check, make sure your sunglasses are rated to block 99% of UVB and 95% of UVA radiation. Side-protectors are also a must on high altitude excursions on snow. Snow reflects 85% of UV radiation as opposed to dry sand which reflects only 17%. UV exposure also increases 4-6% for every 1000 feet of elevation gain.
3. It is best to patch the eye closed. In the case that both eyes are causing trouble, the worse of the two should be patched so that the patient can continue. Apply opthalmic antibiotic and check for infections after a few hours. The cornea should regenerate after 24-48 hours.
4. Topical steroid can speed regeneration and decrease irritation. If the snowblindness is a misdiagnosis of an infection however, topical steroid can worsen the infection. In this case, even though the diagnosis seems to be obvious, the patient may be right and the headache and eye pain may be unassociated. Unless the diagnosis is absolutely certain, steroids are best left to an opthalmologist.

Protect your eyes in the backcountry! No side shields, inadequate sunglasses, or a few minutes without them can prove a huge problem for you or your patients on any excursion on the glacier, ice climbing in a local canyon, or even within a popular ski resort.