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DARK ADAPTATION DURING SYSTEMIC HYPOXIA INDUCED BY CHRONIC RESPIRATORY INSUFFICIENCY.

Thylefors, Joakim; Piitulainen, Eeva LU and Havelius, Ulf LU (2009) In Investigative Ophthalmology & Visual Science 50. p.1307-1312
Abstract
PURPOSE: To investigate dark adaptation during hypoxia in chronic respiratory failure patients. METHODS: At three visits, dark adaptation was recorded by computerized dark adaptometry in thirteen patients with chronic respiratory insufficiency treated by long term oxygen therapy (LTOT). At visits 1 and 3, the patients were on their usual oxygen supplement. At visit 2, no oxygen was given. Each visit, an analysis of arterial blood gases measured pH, partial pressure of O2 (PaO2), partial pressure of CO2 (PaCO2), base excess (BE), standard bicarbonate (HCO3), and arterial oxygen saturation. Pulse oximetry (POX) was also recorded. RESULTS: Significant differences were recorded between visit 1 and 2 and between visit 2 and 3 for PaO2, arterial... (More)
PURPOSE: To investigate dark adaptation during hypoxia in chronic respiratory failure patients. METHODS: At three visits, dark adaptation was recorded by computerized dark adaptometry in thirteen patients with chronic respiratory insufficiency treated by long term oxygen therapy (LTOT). At visits 1 and 3, the patients were on their usual oxygen supplement. At visit 2, no oxygen was given. Each visit, an analysis of arterial blood gases measured pH, partial pressure of O2 (PaO2), partial pressure of CO2 (PaCO2), base excess (BE), standard bicarbonate (HCO3), and arterial oxygen saturation. Pulse oximetry (POX) was also recorded. RESULTS: Significant differences were recorded between visit 1 and 2 and between visit 2 and 3 for PaO2, arterial oxygen saturation, and POX; no differences were found for pH, PaCO2, BE, or HCO3. No differences were seen between visit 1 and 3 for any of the laboratory parameters. All patients had normal and unchanged dark adaptation at the three visits. CONCLUSIONS: Hypoxia in chronic respiratory insufficiency was associated with normal dark adaptation, in contrast to hypoxia in healthy individuals at high altitudes, which is known to produce impaired dark adaptation. Our result may partly reflect the influence of PaCO2 on the lumen of both choroidal and retinal vessels. At high altitudes, with hypocapnic vasoconstriction the oxygen supply to the retina is further compromised, resulting in reduced dark adaptation. We hypothesize that respiratory insufficiency with hyper- or normocapnia will have larger choroidal and retinal vessel lumens, added to by further dilation of retinal vessels during hypoxia. The tentative net effect would be preserved dark adaptation. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Investigative Ophthalmology & Visual Science
volume
50
pages
1307 - 1312
publisher
The Association for Research in Vision and Ophthalmology, Inc.
external identifiers
  • WOS:000263665000043
  • PMID:18936146
  • Scopus:62649105252
ISSN
1552-5783
DOI
10.1167/iovs.08-2104
language
English
LU publication?
yes
id
a678b1fb-c922-48db-b35e-1ba9464ca09b (old id 1262088)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/18936146?dopt=Abstract
date added to LUP
2008-11-04 11:21:50
date last changed
2016-10-13 04:32:24
@misc{a678b1fb-c922-48db-b35e-1ba9464ca09b,
  abstract     = {PURPOSE: To investigate dark adaptation during hypoxia in chronic respiratory failure patients. METHODS: At three visits, dark adaptation was recorded by computerized dark adaptometry in thirteen patients with chronic respiratory insufficiency treated by long term oxygen therapy (LTOT). At visits 1 and 3, the patients were on their usual oxygen supplement. At visit 2, no oxygen was given. Each visit, an analysis of arterial blood gases measured pH, partial pressure of O2 (PaO2), partial pressure of CO2 (PaCO2), base excess (BE), standard bicarbonate (HCO3), and arterial oxygen saturation. Pulse oximetry (POX) was also recorded. RESULTS: Significant differences were recorded between visit 1 and 2 and between visit 2 and 3 for PaO2, arterial oxygen saturation, and POX; no differences were found for pH, PaCO2, BE, or HCO3. No differences were seen between visit 1 and 3 for any of the laboratory parameters. All patients had normal and unchanged dark adaptation at the three visits. CONCLUSIONS: Hypoxia in chronic respiratory insufficiency was associated with normal dark adaptation, in contrast to hypoxia in healthy individuals at high altitudes, which is known to produce impaired dark adaptation. Our result may partly reflect the influence of PaCO2 on the lumen of both choroidal and retinal vessels. At high altitudes, with hypocapnic vasoconstriction the oxygen supply to the retina is further compromised, resulting in reduced dark adaptation. We hypothesize that respiratory insufficiency with hyper- or normocapnia will have larger choroidal and retinal vessel lumens, added to by further dilation of retinal vessels during hypoxia. The tentative net effect would be preserved dark adaptation.},
  author       = {Thylefors, Joakim and Piitulainen, Eeva and Havelius, Ulf},
  issn         = {1552-5783},
  language     = {eng},
  pages        = {1307--1312},
  publisher    = {ARRAY(0x965a008)},
  series       = {Investigative Ophthalmology & Visual Science},
  title        = {DARK ADAPTATION DURING SYSTEMIC HYPOXIA INDUCED BY CHRONIC RESPIRATORY INSUFFICIENCY.},
  url          = {http://dx.doi.org/10.1167/iovs.08-2104},
  volume       = {50},
  year         = {2009},
}