[abstract] Ocular tear film bubble formation following air, heliox and nitrox dives

Rubicon Research Repository/Manakin Repository

[abstract] Ocular tear film bubble formation following air, heliox and nitrox dives

Show full item record


Title: [abstract] Ocular tear film bubble formation following air, heliox and nitrox dives
Author: Rogelj; Mekjavic, IB; Mekjavic, PJ
Abstract: Introduction Post-decompression ocular tear film bubbles have been suggested to reflect decompression severity. The present study investigated: 1) ocular tear film bubble formation following similar dives conducted with air, Heliox (20percentO2/80percentHe) and Nitrox (36percentO/64percentN2) breathing mixtures, 2) the utility of a hand held slit lamp microscope for field studies, 3) the repeatability of the method between two investigators, and 4) the persistence of ocular tear film bubbles following similar dives with air, heliox and nitrox breathing mixtures. METHODS: A total of 12 subjects (6 male and 6 female) participated in three simulated dives in a hyperbaric chamber to 30 msw for 15 minutes, followed by a no-stop decompression to surface. During one dive, the subjects inspired air, while on the remaining two dives they inspired either a Heliox or Nitrox gas mixture. The order in which the subjects conducted the dives was randomized and the dives were separated by a week. Subjects refrained from any other diving activity during their participation in the study. Prior to, and immediately after the dive, subjects' ocular tear film was examined with a Haag Streit Slit lamp microscope and a Heine handheld slit lamp microscope. Ocular eye exams were conducted by two investigators. Following each dive, subjects' ocular tear film was examined at the same time of day and on a daily basis for 3 successive days. Results: Preliminary results of seven subjects demonstrate no significant difference between the results obtained by the two investigators. Primarily due to the low power of the monocular handheld microscope, compared to the higher magnification offered by the binocular clinical slit lamp microscope, both investigators reported lower bubble scores with the former. There was a significant increase in post-dive bubbles following the air dive, whereas there were no significant differences between pre- and post-dive bubble scores for the Heliox and Nitrox dives. Tear film bubbles scores were significantly elevated on the day following the air dive. Conclusions: The method of counting ocular tear film bubbles with a slit lamp microscope is sufficiently sensitive to discern bubbles following a short air dive. That heliox and nitrox breathing mixtures should yield less tear film bubbles following a similar dive profile with air, was confirmed by the tear film bubbles scores. Elimination of nitrogen, reflected in the elevated tear film bubble scores, persisted for 24 hours following the air dive. The present study provides further support for tear film bubble counts as an objective index of decompression severity.
Description: Undersea and Hyperbaric Medical Society, Inc. (http://www.uhms.org )
URI: http://archive.rubicon-foundation.org/1411
Date: 2004

Files in this item

Files Size Format View
abstract.txt 259bytes Text file View/Open

This item appears in the following Collection(s)

  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

Show full item record

Browse

My Account