Diving After Eye Surgery and Glaucoma
By Dr. Sawatzky
Over the past several years, I have been asked about a number of eye problems and diving but the answers are too short to justify an entire column. Therefore, in this column I will discuss diving after non-corneal eye surgery and glaucoma. Several previous columns have been written on the eye and diving, including: "Eye Surgery 2000" (September 1999), "Contacts and Diving" (Aug. 1998), "Corneal Eye Surgery" (May 1997), and "The Eye and Diving I and II" (December 1994 and February 1995).
In general, there are three things that must be evaluated before a diver with an eye problem can safely return to diving. First, "Is there an increased risk of infection of the eye?" All water (in which we dive) contains bacteria and other organisms that can cause infections of the eye (chlorinated tap and shower water is usually sterile). If the infection gets into the inside of the eyeball, vision may be permanently damaged or destroyed. Therefore, any diver who has an eye in which the surface of the eye (cornea, sclera, or conjunctiva) has been cut, should not dive until it has healed. Cuts of the tissues around the eye are less serious but the diver should still avoid known dirty/contaminated water and watch for any signs of infection.
The second type of problem is gas inside the eye. If an eye, which contains gas, is exposed to changes in pressure, the gas inside the eye will attempt to expand and contract in accordance with Boyle's Law. The resultant stress on the tissues of the eye may cause significant damage. But why would an eye contain gas? In many types of eye surgery, gas is intentionally injected into the eyeball by the surgeon as part of the procedure. The diver must wait at least until the gas has been absorbed (usually several weeks) before they return to diving. The same restriction has been used historically for flying. Unfortunately, for patients who must travel long distances to have the surgery performed, this restriction can impose significant hardship (long dangerous drives in the winter on icy roads for the surgery and for follow-up). We are currently conducting research at DCIEM (in cooperation with the University of Toronto) to see if it is possible to relax this restriction in any way. Early results suggest that a gas bubble smaller than 10% of the volume of the eye is okay for commercial flights (maximum cabin altitude 8,000 feet above sea level). In diving however, the pressure and volume changes are much greater and any gas in the eye is probably dangerous (the pressure change going from sea level to 8,000 feet altitude is the same as changing depth in water by five feet).
An associated problem is hollow eye implants. If a person has had this done, they should never dive. The pressure changes could cause the implant to implode
For the complete article "Diving after Eye Surgery and Glaucoma" pick up a copy of the March Issue of DIVER Magazine.