One can turn around on the interstate and get to a lower elevation, but it’s not so easy on a plane, particularly over the ocean. Even a small bubble may expand enough for a dangerous IOP elevation, particularly in an eye with impaired outflow. No flying until the bubble is gone, without exception. But that’s not practical.Įlective travel can be delayed until the bubble is completely gone, but what about those who can’t delay travel?įor airplane travel, the answer is easy. Then again, for complete safety, one should neither fly nor drive in the mountains. The patient can stay with his family while on vacation and return home with them, rather than staying in Denver while the family is off skiing and then having to drive home to avoid air travel.įor a patient with a gas bubble in his or her eye, how soon can she fly or travel through the mountains? This is a more challenging question.įor complete safety, one should not change altitude with any gas in the eye. For someone who has just begun a family ski vacation in Colorado and who presents with a retinal detachment, oil is a good option. Patients are free to fly with silicone in situ, but this involves the tradeoff of requiring a second surgery in the future to remove the oil. It’s much easier to get a flight from Denver to Chicago than from Bangkok to New York.Īnother option is to use silicone oil instead of gas or air. Obviously, this depends on surgical urgency, the logistics of returning home, and where home is. What should we recommend for patients who need an air or gas bubble and also need to travel into areas of high altitude or by air?įor patients visiting Colorado, or anywhere else for that matter, there is always the option of returning home for their surgery rather than having it where they are visiting, avoiding the issue altogether. Let’s leave the science behind and get down to practicalities. 4 At this rate, a gas bubble in an eye taking off from sea level would be 30% to 40% larger within minutes. 3 That is about a 5 mm Hg increase per 1,000 feet.Īfter takeoff, commercial airplanes achieve cabin pressure at cruising altitude equivalent to the pressure at 6,000 to 8,000 feet elevation within 10 to 15 minutes. Researchers in Mexico City, using a rabbit model of intraocular gas and mountain travel, estimated an increase of 1.5 to 2.0 mm Hg in pressure in human eyes for every 100 m of altitude increase. But in other eyes, particularly the eyes we operate on, this may not be the case. With good outflow, an eye can tolerate these changes in altitude without a problem. From Denver, the Mile-High City at 5,280 feet, there is a 6,000-foot elevation change that can happen in less than an hour driving west on I-70, with a resulting 25% to 30% increase in bubble size in a patient with intraocular gas.Ī number of other states also have mountain passes over 5,000 feet. The highest US interstate highway pass is the Eisenhower Tunnel along I-70 in Colorado, at 11,158 feet. The highest paved road in the United States is the one leading to the top of Mount Evans in Colorado, at 14,130 feet. Only mountain climbers need concern themselves with elevations of 18,000 feet or more. A gas or air bubble at sea level will expand by 1.25 times at 5,000 feet, 1.5 times at 10,000 feet, and 2 times at 18,000 feet. Without delving too deeply into the weeds of physics and chemistry, here are a few simple numbers. Higher altitude means lower atmospheric pressure and a bigger gas bubble. As the pressure on a gas bubble decreases, its volume increases. Remember Boyle’s law? In simple terms, pressure and volume are inversely proportional in relation to gas. In this article, I share thoughts, tips, and tricks on this topic with the retina community at large because these issues are not unique to Colorado.įor those who have forgotten their high school and college chemistry, allow me to refresh your memories. How do we address these altitude issues? The mountain issue may not be relevant to retina surgeons in much of the country, but air travel is ubiquitous and an issue for patients everywhere who are leaving for somewhere on a jet plane. Know your local geography so that you can warn patients of potential trouble spots.Silicone oil is an option for patients who cannot avoid air travel before a gas bubble would have time to dissipate.It is important to consider patient travel plans and situations before inserting a gas bubble after vitrectomy.
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