In the deep winter, with snow falling around the
country, it seems like the last thing on an outdoor
enthusiast's mind would be the sun. However as we
approach the late winter months, it is vital to remind
your patients about the dangers of sunburn and
particularly snowblindness. Here are a few
common
misconceptions:
Though you can experience sunburn and keratitis
in the winter, the risk is less than the summer.
False - Snowblindness, a form of keratitis
which involves
UV damage to the cornea, is actually much more
dangerous in winter conditions, particularly at high
altitudes. UV radiation increases by a factor of 4%-6%
with every 1000 ft of elevation. While dry sand or water
reflect no more than 30% of UVB light, snow can
reflect up to 85%, making snowblindness a very real
danger during winter months.
Usually UV damage occurs after long exposures
on sunny days.
False - The Everest Base Camp Clinic
team learned the
hard way that snowblindness can occur quickly even
on overcast days. In overcast conditions, all it took
was as little as an hour without goggles while filming
on a summit descent to give the experienced team a
bad bout of snowblindness to deal with. It should also
be noted that a cornea burn may not be noticed for 6 to
12 hours after exposure.
Topical steroid is the fastest and most effective
treatment.
False - Though topical steroid helps to
resolve
snowblindness more quickly, if the case is a
misdiagnosed eye infection, the steroid could worsen
the situation. Treatment consists of patching the eye
with a few drops of antibiotic ointment. After 24 hours,
if the eye has developed any pus or infectious material
it should be left unpatched but the patient should
continue antibiotic and sunglass use. Steroid should
only be used when diagnosis can be made certain by
an ophthalmologist.
Any sunglasses or goggles are sufficient for
preventing snowblindness.
False Though most protection is better
than none,
special protection is vital especially on glaciers and at
high altitudes. The Everest Base Camp Clinic
provides the following guidelines on proper
sunglasses:99-100% UV absorption-
Polycarbonate or CR-39 lens (lighter, more
comfortable than glass)
- 5-10% visible light transmittance
- Large lenses that fit close to the face
- Wraparound or side shielded to prevent incidental
light exposure
Remember to be mindful of the sun's effects in the
outdoors even in the winter months, and warn your
patients to have a more safe and enjoyable excursion
this month!
