Dental, Mask, and Eye Barotrauma
Barotrauma is tissue injury caused by a pressure-related change in body compartment gas volume. It can affect the spaces around teeth, behind a face mask, or underneath hard contact lenses.
(See also Overview of Diving Injuries.)
Dental barotrauma can occur during descent or ascent, when pressure in the air spaces at the roots of infected teeth or adjacent to fillings changes rapidly and causes pain or tooth damage. The affected tooth may be tender when percussed with a tongue blade.
Mask barotrauma occurs when the pressure in the space behind the face mask is not equalized during descent. The resulting relative vacuum can lead to local pain, conjunctival hemorrhage, and ecchymosis of the skin enclosed by the mask. Retro-orbital hemorrhage is possible but rare.
If retro-orbital hemorrhage is suspected, complete eye examination (including visual acuity, extraocular movements, and intraocular pressure measurement) and head CT are done. Mask barotrauma may be avoided when pressures are equalized within the face mask by exhaling from the nose into the mask.
Eye barotrauma occurs when small air bubbles are trapped behind hard contact lenses. The air bubbles can damage the eye and cause soreness, decreased visual acuity, and halos around lights. A screening ophthalmic examination should be done to rule out other causes. Pressure behind goggles cannot be equalized, so they should not be used for diving.