Bilateral choroidal effusions after taking acetazolamide for altitude sickness

Abstract

A fit and healthy 44-year-old woman took a single dose of oral acetazolamide (125 mg) in preparation for a hiking trip to Everest base camp. She awoke the next morning with profoundly blurred distance vision. She presented to eye casualty later that morning, approximately 18 hours postingestion: examination demonstrated myopia and bilateral choroidal effusions. Acetazolamide is used to minimise symptoms of altitude sickness. Rarely, its use can be linked with ophthalmic side effects, such as myopia. A handful of case reports also describe choroidal effusions secondary to its use as part of ophthalmic treatment (eg, postoperatively). This is the first reported case in which choroidal effusions have been demonstrated as a side effect of its prophylactic use against altitude sickness.

Acute Myopic Shift after a Single Dose of Acetazolamide: A Case Report and Review of the Literature

“…While remaining uncertain, pathophysiology is attributed to an idiosyncratic uveal reaction provoking an anterior displacement of the iris-lens diaphragm. The effect seems to be dose independent, starting from a single dose of 125 mg [22], and, as said, independent of prior drug exposure [1,10,16]. Also, the severity of the reaction does not appear to be correlated with the dose, though drug continuation does exacerbate the condition [12].…”

“…A uveal effusion was observed in about half of the patients. When acetazolamide was stopped, all cases recovered completely after a median of 5 days (2 – 14), with the aid of additional cycloplegia, anti-glaucomatous agents, and/or steroid treatment in about a quarter, a third, and more than half of the patients, respectively 1 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 .…”

“…Also, the severity of the reaction does not appear to be correlated with the dose, though drug continuation does exacerbate the condition 12 . In addition, the presence of the lens seems to be irrelevant, as cases have been reported after cataract surgery 12 , 21 , 23 as well as in phakic individuals 5 , 16 , 22 .…”