Visual Loss Following Intraocular Gas Injection: Small Correction

by Dr. med. Marie-Therese Silvanus, Patrick Moldzio, Prof. Dr. med. Norbert Bornfeld, Prof. Dr. med. Jürgen Peters in volume 6/2008

I wish to point out a small error, in order to ensure that those who are not familiar with the subject are not at risk of misinterpretation. The cabin pressure in passenger airplanes does not depend on the type of aircraft but can be controlled over a wide range. So-called "sea level flights," flights with a cabin pressure that equals that at sea level, are undertaken only in exceptional circumstances because the maneuver requires enormous amounts of fuel and puts the material under strain.

A jumbo jet is like a child's balloon, which is inflated owing to internal pressure and expands by about 20 cm when it has reached its cruising height. The rules of the International Civil Aviation Organization say that cabin pressure is not allowed to drop below the equivalent height of 2300 meters. As the authors report, most flights take place at 1800 meters equivalent pressure – a compromise between technology, economic considerations, and the medical requirements of passengers with moderate illness who may be on board.

The example of the jumbo jet (1700 meters) and the DC9 (2400 meters) may lead to misinterpretation: "Fly jumbo as it is safer." This is not the case. As recently published data have shown, it is mainly the modern aircraft types that travel at low pressures, presumably for reasons of profitability, but specialists in travel and aviation medicine follow this trend rather critically.

In any case, what is correct and extremely important is the authors' conclusion: In any clinical situation where pressure may play a part – for example after dives, pressure chamber treatments – in patients with the listed eye problems, the golden rule is: Be careful with heights, whether in an aircraft or on the ground (car, mountain lift, or by foot).
DOI: 10.3238/arztebl.2008.0482a


PD Dr. med. habil. Thomas Küpper
Institut für Arbeits- und Sozialmedizin
Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen
Pauwelstr. 30
52074 Aachen, Germany

References

1. Bundrett G: Sickness at high altitude: a literature review. J R Soc Health 2002; 122: 14–20.