What are the other Names for this Condition? (Also known as/Synonyms)

• HAR (High Altitude Retinopathy)

What is High Altitude Retinopathy? (Definition/Background Information)

• High Altitude Retinopathy (HAR) is an eye condition in which the retina develops certain abnormal changes due high altitudes, typically 12,000 feet and above (from mean sea level). Due to lower air pressure at higher altitudes, the oxygen levels in the body decrease, thereby affecting the retina
• Though the condition may not be apparent immediately; while descending, the individual can experience retinal hemorrhage (loss of blood to the retina) and papilledema (a condition where increased pressure around the brain leads to swelling of the optic nerve)
• High Altitude Retinopathy is one of the four high altitude illnesses, including acute mountain sickness, high altitude cerebral edema, and high altitude pulmonary edema

Incidence:

• Individuals of all age groups and gender may be affected
• There is no racial or ethnic preference noted worldwide

Risk factors:

• Ascending to high altitudes (heights); spending longer durations at higher altitudes
• Lower oxygen saturation
• Higher volumes of red blood cells in the body (hematocrit)
• Higher baseline intraocular pressure (pressure within the eye)

The above factors are typically noted in younger individuals who are physically fit.

Signs and symptoms:

• The signs and symptoms of High Altitude Retinopathy are typically not noted (asymptomatic condition)
• In rare cases, an individual may experience eye floaters, blurring of vision, and loss of vision

Diagnosis:

• The diagnosis of High Altitude Retinopathy is done clinically
• A dilated fundus exam (after placing eye drops to dilate the eye) can display the features of the condition

Treatment:

• If High Altitude Retinopathy takes effect while one is still at the high altitude, immediate treatment measures may include descending to lower altitudes and administration of oxygen
• Presently, there are no proven treatments for the condition, but any complications and side effects may be effectively treated

Prevention:

• The primary prevention method is to avoid ascending to high altitudes, especially those who are at a high risk for High Altitude Retinopathy
• Secondary methods to prevent the condition include slowly ascending to higher elevations in order to gradually adapt to the change in altitude, maintaining blood oxygen levels, avoiding strenuous activities, and descending to lower altitudes when possible

Prognosis: The prognosis of High Altitude Retinopathy varies depending on each individual case; the outcomes may vary significantly from one to another.