Dark adaptation during systemic hypoxia induced by chronic respiratory insufficiency
Thylefors, Joakim LU
; Piitulainen, Eeva
LU
and Havelius, Ulf
LU
(2009)
In Investigative Ophthalmology & Visual Science
50(3).
p.12-1307
- Abstract
PURPOSE: To investigate dark adaptation during hypoxia in patients with chronic respiratory failure.
METHODS: At three visits, dark adaptation was recorded by computerized dark adaptometry in 13 patients with chronic respiratory insufficiency treated by long-term oxygen therapy. At visits 1 and 3, the patients were administered their usual oxygen supplement. At visit 2, no oxygen was given. At each visit, an analysis of arterial blood gases measured pH, partial pressure of O(2) (Pao(2)), partial pressure of CO(2) (Paco(2)), base excess (BE), standard bicarbonate (HCO(3)), and arterial oxygen saturation. Pulse oximetry (POX) was also recorded.
RESULTS: Significant differences were recorded between visits 1 and 2 and between... (More)
PURPOSE: To investigate dark adaptation during hypoxia in patients with chronic respiratory failure.
METHODS: At three visits, dark adaptation was recorded by computerized dark adaptometry in 13 patients with chronic respiratory insufficiency treated by long-term oxygen therapy. At visits 1 and 3, the patients were administered their usual oxygen supplement. At visit 2, no oxygen was given. At each visit, an analysis of arterial blood gases measured pH, partial pressure of O(2) (Pao(2)), partial pressure of CO(2) (Paco(2)), base excess (BE), standard bicarbonate (HCO(3)), and arterial oxygen saturation. Pulse oximetry (POX) was also recorded.
RESULTS: Significant differences were recorded between visits 1 and 2 and between visits 2 and 3 for Pao(2), arterial oxygen saturation, and POX; no differences were found for pH, Paco(2), BE, or HCO(3). No differences were seen between visits 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 persons at high altitudes, which is known to produce impaired dark adaptation. The result may partly reflect the influence of Paco(2) on the lumen of choroidal and retinal vessels. At high altitudes, with hypocapnic vasoconstriction the oxygen supply to the retina is further compromised, resulting in reduced dark adaptation. The authors hypothesize that respiratory insufficiency with hypercapnia 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)
- author
- Thylefors, Joakim
LU
; Piitulainen, Eeva
LU
and Havelius, Ulf
LU
- organization
- publishing date
- 2009
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Aged, Aged, 80 and over, Blood Gas Analysis, Chronic Disease, Dark Adaptation/physiology, Female, Humans, Hydrogen-Ion Concentration, Hypoxia/physiopathology, Male, Middle Aged, Oximetry, Oxygen/therapeutic use, Partial Pressure, Respiratory Insufficiency/physiopathology
- in
- Investigative Ophthalmology & Visual Science
- volume
- 50
- issue
- 3
- pages
- 6 pages
- publisher
- Association for Research in Vision and Ophthalmology Inc.
- external identifiers
-
- wos:000263665000043
- pmid:18936146
- scopus:62649105252
- pmid:18936146
- 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
- 2016-04-04 09:32:18
- date last changed
- 2022-02-28 08:24:31
@article{a678b1fb-c922-48db-b35e-1ba9464ca09b,
abstract = {{<p>PURPOSE: To investigate dark adaptation during hypoxia in patients with chronic respiratory failure.</p><p>METHODS: At three visits, dark adaptation was recorded by computerized dark adaptometry in 13 patients with chronic respiratory insufficiency treated by long-term oxygen therapy. At visits 1 and 3, the patients were administered their usual oxygen supplement. At visit 2, no oxygen was given. At each visit, an analysis of arterial blood gases measured pH, partial pressure of O(2) (Pao(2)), partial pressure of CO(2) (Paco(2)), base excess (BE), standard bicarbonate (HCO(3)), and arterial oxygen saturation. Pulse oximetry (POX) was also recorded.</p><p>RESULTS: Significant differences were recorded between visits 1 and 2 and between visits 2 and 3 for Pao(2), arterial oxygen saturation, and POX; no differences were found for pH, Paco(2), BE, or HCO(3). No differences were seen between visits 1 and 3 for any of the laboratory parameters. All patients had normal and unchanged dark adaptation at the three visits.</p><p>CONCLUSIONS: Hypoxia in chronic respiratory insufficiency was associated with normal dark adaptation, in contrast to hypoxia in healthy persons at high altitudes, which is known to produce impaired dark adaptation. The result may partly reflect the influence of Paco(2) on the lumen of choroidal and retinal vessels. At high altitudes, with hypocapnic vasoconstriction the oxygen supply to the retina is further compromised, resulting in reduced dark adaptation. The authors hypothesize that respiratory insufficiency with hypercapnia 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.</p>}},
author = {{Thylefors, Joakim and Piitulainen, Eeva and Havelius, Ulf}},
issn = {{1552-5783}},
keywords = {{Aged; Aged, 80 and over; Blood Gas Analysis; Chronic Disease; Dark Adaptation/physiology; Female; Humans; Hydrogen-Ion Concentration; Hypoxia/physiopathology; Male; Middle Aged; Oximetry; Oxygen/therapeutic use; Partial Pressure; Respiratory Insufficiency/physiopathology}},
language = {{eng}},
number = {{3}},
pages = {{12--1307}},
publisher = {{Association for Research in Vision and Ophthalmology Inc.}},
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}},
doi = {{10.1167/iovs.08-2104}},
volume = {{50}},
year = {{2009}},
}