Altitude Retinopathy: Causes, Symptoms & Treatment

High altitude retinopathy is a hemorrhage of the retina and corresponds to a response to decreasing partial pressure of oxygen in the breathing air. The condition is considered a mountain climber’s disease and may be the sign of altitude sickness. Immediate descent to lower altitudes is required for therapy.

What is altitude retinopathy?

Retinopathy is a retinal disease associated with vascular changes in the retina that can result in permanent retinal damage and visual field loss. The causes of retinopathy can vary from swelling to diabetes. The so-called high altitude retinopathy is a subtype of the disease group of retinopathies, which is causally related to natural changes in the breathing air at high altitudes. This form of retinopathy was first described in 1969, and Singh and colleagues are considered to be the first describers. Since the first reports, numerous cases of high-altitude retinopathy have been documented, primarily affecting mountaineers and other alpine athletes. The presence of marked retinopathy may be the symptom of altitude sickness, which can result in life-threatening cerebral edema.

Causes

At high altitudes above sea level, the partial pressure of oxygen in the air we breathe decreases. The vessels of the retina respond to the decreasing partial pressure of oxygen. The blood-retinal barrier breaks down: high-altitude retinopathy sets in. Causative factors are mainly the ascent speed, the own constitution, the severity of the physical strain and the altitude reached at the end. From altitudes of 5000 meters above sea level, altitude retinopathies are common phenomena. From 7000 meters they affect almost everyone. Gender does not play a role. Since the hemorrhages usually occur mainly in the areas of the peripheral visual field, mountaineers often do not perceive them subjectively. Nevertheless, altitude retinopathy may correlate with vascular changes in the brain and thus be the sign of altitude sickness. However, the correlation between the pulmonary as well as cerebral edema of altitude sickness and severe altitude retinopathy is not yet considered conclusively established.

Symptoms, complaints, and signs

Patients with altitude retinopathy show changes in the retina. These changes manifest as hemorrhages that are often exclusive to the peripheral visual field. Once the hemorrhages are located in the central visual field, the patient subjectively perceives the changes as visual loss. The vascular changes may be accompanied by edema in the optic disc or optic nerve. Particularly when the optic nerve is involved, the visual impairment increases because the visual information can no longer pass to the brain undisturbed. When the macular area is involved in height retinopathy, patients notice the changes immediately and with great intensity. A decrease in visual acuity to near zero is a conceivable symptom of this phenomenon. If retinopathy is present in the setting of altitude sickness, it is accompanied by cerebral vascular changes and may be associated with severe headache, vomiting, dizziness, loss of appetite, shortness of breath, and tinnitus or general weakness. As a sign of altitude sickness, altitude retinopathy can cause cerebral or pulmonary edema to develop during its course, which can be fatal if left untreated.

Diagnosis and course of the disease

The suspected diagnosis of high-altitude retinopathy is usually made immediately after onset not by the physician but by persons accompanying the affected person. The decisive factor is visible changes in the retina, which the patient describes as reducing visual acuity. Only after descent is the presence of retinopathy confirmed by physicians or emergency physicians. In most cases, the diagnosis is confirmed by ophthalmologic examinations and eventually leads to testing for altitude sickness. For patients with high-altitude retinopathy, the prognosis depends largely on whether the appearance is the sign of high-altitude disease. High altitude disease has a much less favorable prognosis than isolated retinopathy. The timing of diagnosis also affects prognosis.

Complications

In most cases, altitude retinopathy does not result in special or serious complications. The patient can counteract the disease relatively easily, thereby limiting the symptoms slightly.As a rule, bleeding occurs on the retina of the eye. This hemorrhage causes visual complaints in the patient. These can also lead to blurred vision or double vision and also worsen the general condition of the affected person. Headaches, nausea and vomiting are not uncommon. The drop in blood pressure can also cause dizziness, which in the worst case can lead to a loss of consciousness. In this case, the affected person can injure himself in a fall. In some cases, shortness of breath also occurs, leading to panic attacks or sweating. In general, the patient’s ability to cope with stress decreases. The treatment of altitude retinopathy is a descent to a lower altitude. This usually does not cause any particular complications. In acute cases, medication can also be used. Furthermore, the patient must rest and take it easy. Whether further ascent is possible generally cannot be predicted.

When should one go to the doctor?

If retinal changes are noticed, a physician should be consulted immediately. High altitude retinopathy requires prompt evaluation and treatment because serious complications can develop if the disease progresses. For this reason, a doctor should be consulted as soon as the first abnormalities are noticed. People who suddenly notice a reduction in vision should consult an ophthalmologist. A visit to the doctor is indicated at the latest when accompanying symptoms such as headache, shortness of breath and nausea and vomiting occur. A general feeling of weakness also requires medical clarification. If retinopathy occurs in conjunction with altitude sickness, hospitalization must be sought immediately. If left untreated, the condition can cause life-threatening cerebral or pulmonary edema. Externally, altitude retinopathy is most recognizable by visible hemorrhages in the retina. The eye may also be swollen or watery. People who are at an altitude of more than 5000 meters above sea level are particularly susceptible to the development of altitude retinopathy. Mountaineers, hikers and co. should descend immediately with mentioned warning signs and seek medical attention.

Treatment and therapy

The first steps in the treatment of altitude retinopathy are taken by the patient himself. Further ascent to even higher altitudes is absolutely contraindicated. The affected person should strive to descend as soon as possible. If he is unable to do so because he is also suffering from symptoms of altitude sickness, contacting the mountain rescue service or downward transport of the patient by his companions is indicated. For mild to moderate symptoms of altitude sickness, the recommendation is to take at least one day off. Headache can be treated with a nonsteroidal anti-inflammatory such as ibuprofen. Antiemetic can be given for nausea. Acetazolamide helps with acclimatization. These measures are primarily for the purpose of stabilizing the patient and allowing them to descend. If symptoms are severe, descent should be immediate. If possible, patients are given oxygen and dexamethasone to prevent the development of cerebral edema. Whether or not altitude retinopathy was the sign of altitude sickness, the patient should be examined by a physician once they reach the bottom. Normally, isolated retinopathy regresses once the individual has left the causative altitude.

Prevention

High-altitude retinopathy may be prevented by the same prophylactic measures as altitude sickness. A slow ascent should be aimed for. The body adapts to altitude changes only to a certain extent in a few days. This adaptation corresponds to the production of red blood cells and is considered acclimatization. For mountain tours above 4500 meters, the climber should spend at least a week at altitudes of 2000 meters in advance and make day trips to higher areas. When climbing, a break every 500 meters of altitude can prevent altitude sickness.

Aftercare

Aftercare for altitude retinopathy primarily refers to precautions. To protect themselves from discomfort at higher altitudes, sufferers can carry an altimeter and train their conscious self-observation. In this way, problems with the retina can be detected in time.Mountaineers who suffer from this condition usually already know from experience at what altitude it becomes difficult for them. It is then advisable to return to the previous position or altitude so that the symptoms subside. Rapid changes in altitude or short-term mountain tours are not recommended. Intensive preparation and a gradual ascent are better, so that the body gets used to the current altitude. If the complaints occur more frequently, those affected should consult a doctor. The first sign is the reduction of vision, then other problems such as headaches and dizziness may occur. However, if the companions have all the necessary information about altitude sickness, it is still possible to participate in mountain tours; provided that the sufferers give themselves enough time. Following the symptoms and the descent, patients should first rest. This reduces the risk of loss of consciousness, which can lead to accidents and injuries. During such a recovery break, the feeling of panic also disappears.

This is what you can do yourself

In case of altitude retinopathy, it is recommended to carry an altimeter with you at all times. Modern automobiles have altitude measurement built into their on-board function. In addition, the use of an additional mobile device to attach to clothing is advisable. Affected persons can often estimate the altitudes at which their health problems occur based on existing experience. These should only be approached slowly and with several breaks. At the first signs of altitude retinopathy, it is advisable to change the existing position and return to a lower altitude. If the symptoms increase, a visit to the doctor is necessary in order not to take further risks. Sudden changes in altitude should be avoided. A mountain hike scheduled at short notice should generally be avoided. If good preparation and planning for an ascent takes place, many affected persons can also visit places at higher altitudes despite the illness. Several days or weeks should be allowed for this, so that the organism can slowly get used to the existing altitude. During this time, a gradual change in altitude is possible and tolerable for the body. To avoid health risks, the planning should be discussed with a doctor in advance. Accompanying persons should be informed of the condition, and good self-reflection is necessary during the altitude change.