Air Pressure Build Up In The Tear Duct?

if you were to pinch your nostrils and blow really hard to clear your ears (frenzel maneuver) ,could the air pressure build up in the tear duct or at the back of the eye and have an negative effect on iris color causing a discolouration (basically a change in eye color)?

[Timothy D McGarity, M.D.]

Okay, now I know what the Frenzel is. The other user just asked this question. I don't understand why you would need to do this in scuba diving to clear your eyes, but I would understand doing this to clear your frontal, paranasal, ethmoid and maxillary sinuses. The eye and eye socket are not pneumonized and therefore don't undergoe the same changes which pneumonized air cavities do under several atmospheres of pressure (lungs, middle ear, air sinuses) under normal circumstances. There are anomalous or pathologic situations where there can be a "air" connection between the oral/nasal cavity/tear ducts and eye socket...in this case the Frenzel maneuver would cause the eye socket to be pneumonized (pressurized with air) and potentially cause orbital emphysema. This won't affect the intraocular structures such as the iris or lens or ciliary body. If this is occuring I'd definitely get it checked out and possibly avoid scuba diving.
Best wishes,
Timothy D. McGarity, M.D.
www.tmcgaritymd.com