Rigid gas permeable contact lenses in hyperbaric environments

Area of Science:

• Ophthalmology
• Diving Medicine
• Biomaterials Science

Background:

• Hard gas permeable contact lenses are frequently worn by individuals in various environments.
• Hyperbaric environments involve increased ambient pressure, posing unique physiological challenges.

Purpose of the Study:

• To investigate the occurrence and potential origin of bubbles forming under hard gas permeable contact lenses during simulated decompression in a hyperbaric environment.

Main Methods:

• Twenty-four exposures using three different hard gas permeable contact lens materials were conducted in a hyperbaric chamber.
• Simulated dry air dive profiles included depths of 45.72m, 22.86m, and 11.43m with varying durations.
• Visual observation for bubble formation under the lenses was performed at different simulated depths.

Main Results:

• Bubbles were observed forming under all tested hard gas permeable contact lens materials.
• Bubble formation was detected at simulated depths as shallow as 1.98m, even after less stressful exposures.
• The timing and shallow depth of bubble appearance suggest they do not originate from nitrogen off-gassing from eye tissues.

Conclusions:

• The study indicates that bubble formation under hard gas permeable contact lenses is a common occurrence during hyperbaric decompression.
• Evidence suggests these bubbles originate from the tear layer rather than nitrogen diffusion from ocular tissues.
• Further research may be needed to understand the clinical implications of these bubbles for contact lens wearers in hyperbaric conditions.