An Investigation of Ultramarathon-Associated Visual Impairment

Abstract

Ultramarathon-associated visual impairment typically presents as a painless clouding of vision that is self-limited but tends to recur in certain runners. Risk appears higher among those with a history of refractive surgery, which is relevant for ultramarathon runners who are considering, or who have a history of, refractive surgery.

Ultramarathon-Induced Bilateral Corneal Edema: A Case Report and a Review of the Literature

“…Elevation of blood lactate could cause increased lactate in the aqueous humor, which would in turn decrease the lactate gradient between endothelial cells and aqueous humor, thus impairing the facilitated transport of lactate to the anterior chamber. We agree with Hoeg et al [ 1 ] that this accumulation of lactate caused by increased production and decreased excretion is one of the underlying mechanisms of the acute corneal edema induced by ultramarathon running (Fig. 3 ).…”

“…Many runners take 24–36 h to finish these races. As Hoeg et al mentioned in their investigation, environmental stimuli increase the metabolic rate of the cornea [ 1 ]. During the race, the corneal epithelium must endure wind, temperature changes and enhanced ultraviolet (UV) light exposure, and cope with decreased oxygen tension at higher elevations.…”

“…In a survey-based investigation, 173 ultramarathon runners described their visual impairment as painless blurred vision that resolved spontaneously 24–48 h after they stopped running. Corneal edema was confirmed via slit lamp examination in eight of the runners [ 1 ]. This phenomenon was also reported in a cyclist in a 161-km mountain bike race [ 2 ].…”

Corneal Opacity in a Participant of a 161-km Mountain Bike Race at High Altitude

“…[8][9][10] Refractive eye surgery may be adversely affected by high altitude, wind, and excessive exposure to sunlight and UV radiation. 3,8,14 UV light intensity is enhanced at altitude, and the likelihood of trauma to corneal tissue is enhanced by airborne flying debris along dirt roads where high altitude endurance events are held. Impurities in the air caused by flying dust particles and strong winds can traumatize already sensitive tissues.…”

“…2 According to one study, most of these athletes report painless blurry vision and cloudiness. 3 The underlying etiology is still unknown, but it may be related to corneal edema. We are presenting a case of a 161-km mountain biker with corneal edema.…”