Risk factors for development of HAR:
(1) ascent to a high altitude above 3,658 meters (12,000 feet)
(2) rapid ascent to altitude with lack of acclimatization (Mullner-Eidenbock et al report that well-acclimatised persons are at higher risk)
(3) hypoxemia
(4) heavy exertion
(5) repeated Valsalva maneuvers
(6) use of nonsteroidal anti-inflammatory drugs
(7) higher baseline intra-ocular pressures
(8) hemoconcentration
(9) history of acute mountain sickness
(10) increases in blood pressure
Things that can be done to improve the retinopathy:
(1) descent to a lower altitude
(2) breathing supplemental oxygen
(3) reduced exertion
(4) hemodilution if hemoconcentrated
