title: High-altitude retinopathy and altitude illness.
abstract: OBJECTIVE
  To determine the relationship between high-altitude retinopathy (HAR) and other altitude-related illnesses and establish a classification system for HAR.
  
  
  METHODS
  Observational case series.
  
  
  METHODS
  All 40 climbers among 3 Himalayan expeditions who ascended to altitudes between 16,000 and 29,028 feet above sea level (summit of Mt. Everest) were examined for signs of HAR and altitude illness (AI).
  
  
  METHODS
  All subjects had dilated fundus examinations before the ascent, intermittent fundus, and medical examinations during the climb and a dilated fundus and medical examination within 2 days after attaining their highest altitude.
  
  
  METHODS
  Careful fundus drawings or fundus photography or both were obtained for all participants. All subjects gave a subjective assessment of their symptoms of acute mountain sickness (AMS) and were assessed clinically for signs of high-altitude cerebral edema (HACE).
  
  
  RESULTS
  Nineteen of 21 climbers who ascended above 25,000 feet developed HAR. Fourteen of 19 climbers who attained altitudes between 16,000 and 25,000 feet were found to have retinopathy. A grading system for HAR describing the severity of the retinopathy was developed. Correlation of the retinopathy with other AI showed that AMS was endemic and that a statistically significant correlation exists between HAR and HACE (P = 0.0240).
  
  
  CONCLUSIONS
  Recognizing advancing grades of HAR may allow physicians to recommend initiating empiric treatment with oxygen, steroids, diuretics and immediate descent to prevent HAR progression, macular involvement, or potentially fatal HACE. High-altitude retinopathy is both a significant component of and a predictor of progressive AI.
authors.affiliation: Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston 02114, USA.
authors.forename: M
authors.initials: M
authors.lastname: Wiedman
authors.forename: G C
authors.initials: GC
authors.lastname: Tabin
mesh_terms: D000208:Acute Disease; D000531:Altitude; D000532:Altitude Sickness / Q000150:complications*; D005654:Fundus Oculi; D006801:Humans; D000860:Hypoxia / Q000150:complications*; D009051:Mountaineering; D012166:Retinal Hemorrhage / Q000145:classification / Q000209:etiology* / Q000473:pathology; D012171:Retinal Vessels / Q000473:pathology*