Ultraviolet keratitis among mountaineers and outdoor recreationalists.

OBJECTIVE Ultraviolet (UV) keratitis is a self-limited, inflammatory condition resulting in pain and temporary visual disturbance following acute UV radiation exposure. It may afflict mountaineers and other outdoor recreationalists because snow, water, and sand reflect a high percentage of UV radiation reaching the earth's surface. We examined the cases of UV keratitis that have occurred on National Outdoor Leadership School (NOLS) courses in order to better understand its epidemiology and to help prevent this affliction on wilderness expeditions. METHODS We retrospectively reviewed all cases of UV keratitis that occurred on NOLS courses from 1984-2009. Subject demographics and contributing factors were recorded and descriptive information reported. RESULTS Fifteen cases of UV keratitis occurred during the study period with an overall incidence of 0.06% in those exposed. All cases occurred in mountainous or snowy terrain except one case which occurred while boating on a river. Thirteen of the 15 (87%) cases occurred in participants who were not wearing sunglasses. Two cases (13%) occurred in participants who were wearing sunglasses without side shields. Ten cases (71%) occurred in sunny conditions, and 4 cases (29%) occurred in cloudy or low visibility conditions. In all cases, symptoms resolved within 36 hours after cessation of UV exposure. CONCLUSION Appropriate eye protection, including adequate lenses with appropriate side shields, should be worn in mountain or water environments in order to prevent UV keratitis. This data supports the conventional conception of UV keratitis as a relatively mild and self-limited condition, if treated appropriately.