12. Eye Disorders
Patients with perforating eye lesions will not be accepted on a commercial flight until the lesion is sufficiently closed, and there is no trapped intraocular air.
Photo: Eye dept.,
The retina and the optic disc are sensitive to a lack of oxygen. Oxygen availability is a function of oxygen saturation and blood supply. The eye’s hemodynamic conditions are complicated, among other things, because the pressure of the eye offers resistance to oxygen supply. Therefore, it is possible to ensure a better supply of oxygen to the eye’s intraocular structures by reducing eye pressure and increasing the blood’s oxygen saturation, on condition that the patient is otherwise aerodynamically normal.
Normally, there is no air within the eye, but air can persist after certain eye operations and penetrating or violent blunt trauma. During ascent in an airliner, this air will expand and as a primary consequence lead to a pressure increase as with acute glaucoma. The blood supply to the retina and especially the optic disc are thereby reduced, with possible irreversible damage as a consequence.
Where there are perforating lesions to the eye, the pressure variations associated with normal flight increase the risk of intraocular structures being pressed out through the lesion.
Normally, eye patients in a quiescent state are not generally affected. The patient may usually travel without an escort on condition that the unaffected eye is normal.
In cases of retinal detachment, the retina, to a greater or lesser extent, is loosened from the inner side of the eye. This loosening takes place between the sensory portion and the pigmental epithelium. The loosened neuroretina has no sight function, but is kept alive by the continuing retinal blood supply.
It has long been known that in certain cases of retinal detachment, the retina can resettle if the patient is placed horizontally. It is similarly known that, in certain cases, the extent of the retinal detachment can recede or remain stationary when the patient is placed horizontally.
At present, retinal detachment is generally treated surgically. The postoperative outcome is first and foremost dependent upon whether the macula was loosened or was in position before the operation.
Therefore, patients with retinal detachment may be transported in a seated position if the macula is already loosened, but should be transported in the recumbent position if the macula is still in place. If there is any doubt as to whether the macula is in place or not, the patient should be transported in the recumbent position.
As the eye’s blood supply is not significantly compromised, and as the pressure within the eye is low in cases of retinal detachment, no further precautions will normally be required.
Retinal detachment is a sub-acute disorder that should receive surgical treatment within a couple of days if the macula is in place and within one week if the macula has been loosened.
For transportation after an operation for retinal detachment, see section on eye operations.
Glaucoma is a collective term that incorporates a broad series of eye conditions where blood supply to the optic disk is compromised, often because of increased intraocular pressure, leading to a progressive loss of optic nerve fibres with a corresponding loss of visual field.
In cases of acute glaucoma, the pressure can quickly climb to over 50 mm Hg, with consequential pro-nounced pain and a disrupted general condition. These patients should not be transported by commercial flight.
Patients with glaucoma may fly when intraocular pressure has normalised.
If pressure normalisation therapy is not available at the place of treatment, and if the patient must be transported by commercial flight for treatment at a specialist unit, he or she must have oxygen in order to optimise oxygen supply to the optic disc.
Acute vascular occlusion
This is understood as a state where the retinal blood supply is suddenly compromised because of the closure of one of the vessels leading to or from the retina.
Central or branch vein occlusion is not an unusual condition, which often appears together with glaucoma. As occlusion can occur in connection with an intraocular pressure peak, any pressure increase, even within a healthy eye, should be normalised before transportation by commercial flight.
There is generally no treatment for central or branch arterial occlusion.
During the air transportation of patients suffering acute vascular occlusion, a supply of oxygen should be available for the patient to maximise oxygen supply to the retina.
Blunt ocular injuries may be complicated by increased pressure. Therefore, before flying one should ensure that pressure is normal in order to avoid further damage from hypoxia.
Patients with a penetrating ocular trauma should not fly until the lesion is closed, and it is ensured that there is no trapped intraocular air.
If the injury to the eye requires an acute surgical intervention, and this cannot be carried out at the location where trauma occurred, every effort should be made to ensure recumbent transportation in an aircraft that can maintain cabin pressure at sea level. Preferably, the patient should be sedated and have analgesics administered.
Patients who have undergone eye surgery can usually be transported by commercial flight on condition that postoperative eye pressure is normal and that there remains no expandable gas or air after surgery.
In certain types of retina surgery, expanding gas or air is used and can persist in the eye after the operation.
In other types of intraocular surgery (e.g. for cataracts), air may have been used. This will usually be re-absorbed within the first 24 hours after operation.
Before these patients fly by commercial flight, one must ensure that any intraocular air or gas used during the operation has been reabsorbed.
001. Aeromedical Problems
013. Airline Requirements
016. Cardiac Disorders
012. Eye Disorders
013. Mental Disorders
016. Infectious Diseases
017. Orthopaedic Injuries
123. Jet Lag
124. The STEP System
27. The History of Air Transportation of Patients
28. Conversion Tables
Latest update: 06 - 03 - 2015