[Expansion of intraocular gas due to reduced atmospheric pressure. Case report and review of the literature]

Abstract

Since the advent of vitrectomy and the increased use of intraocular gases, there had been concern voiced about the safety of air travel for patients with intraocular gas. Anecdotal reports and experimental models verify the danger of acute glaucoma and central retinal artery occlusion following depressurization and expansion of intraocular gas. However, the amount of gas, that can be compensated for, is a matter of controversy.

Case report i: A 58-year old man underwent vitrectomy with intraocular air tamponade as a primary procedure for retinal detachment. The patient went home by airplane with a residual gas volume of less than 30% of the volume of the eye. Before takeoff at 530 m (1739 ft) above sea level, the intraocular pressure was 12 mmHg. During the ascent, severe ocular pain and loss of vision occurred.

Case report ii: A 38-year old woman underwent vitrectomy for primary repair of retinal detachment. The eye was injected with a 15% mixture of perfluoroethan (C2F6). When traveling home to Italy by car, the eye contained a residual gas volume of 50% of the volume of the globe. Intraocular pressure was 17 mmHg. During the ascent to the "Brennerpass", 1375 m (4511 ft) above sea level, the eye became severely painful and vision was lost for approximately three minutes. Descending to a lower altitude relieved the symptoms.

Conclusion: The expansion of intraocular gases depends on the atmospheric pressure and the mechanisms for compensation. Small volumes of intraocular gas or moderate traveling altitudes can cause a symptomatic rise in intraocular pressure.