Document Detail


PRERETINAL PARTIAL PRESSURE OF OXYGEN GRADIENTS BEFORE AND AFTER EXPERIMENTAL PARS PLANA VITRECTOMY.
MedLine Citation:
PMID:  22972446     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
PURPOSE:: To evaluate preretinal partial pressure of oxygen (PO2) gradients before and after experimental pars plana vitrectomy. METHODS:: Arteriolar, venous, and intervascular preretinal PO2 gradients were recorded in 7 minipigs during slow withdrawal of oxygen-sensitive microelectrodes (10-μm tip diameter) from the vitreoretinal interface to 2 mm into the vitreous cavity. Recordings were repeated after pars plana vitrectomy and balanced salt solution (BSS) intraocular perfusion. RESULTS:: Arteriolar, venous, and intervascular preretinal PO2 at the vitreoretinal interface were 62.3 ± 13.8, 22.5 ± 3.3, and 17.0 ± 7.5 mmHg, respectively, before vitrectomy; 97.7 ± 19.9, 40.0 ± 21.9, and 56.3 ± 28.4 mmHg, respectively, immediately after vitrectomy; and 59.0 ± 27.4, 25.2 ± 3.0, and 21.5 ± 4.5 mmHg, respectively, 2½ hours after interruption of BSS perfusion. PO2 2 mm from the vitreoretinal interface was 28.4 ± 3.6 mmHg before vitrectomy; 151.8 ± 4.5 mmHg immediately after vitrectomy; and 34.8 ± 4.1 mmHg 2½ hours after interruption of BSS perfusion. PO2 gradients were still present after vitrectomy, with the same patterns as before vitrectomy. CONCLUSION:: Preretinal PO2 gradients are not eliminated after pars plana vitrectomy. During BSS perfusion, vitreous cavity PO2 is very high. Interruption of BSS perfusion evokes progressive equilibration of vitreous cavity PO2 with concomitant progressive return of preretinal PO2 gradients to their previtrectomy patterns. This indicates that preretinal diffusion of oxygen is not altered after vitrectomy. The beneficial effect of vitrectomy in ischemic retinal diseases or macular edema may be related to other mechanisms, such as increased oxygen convection currents or removal of growth factors and cytokines secreted in the vitreous.
Authors:
Ioannis K Petropoulos; Jean-Antoine C Pournaras; Alexandros N Stangos; Constantin J Pournaras
Related Documents :
15157776 - Subzero nonfreezing cryopresevation of rat hearts using antifreeze protein i and antifr...
2598816 - The specification of heart mesoderm occurs during gastrulation in xenopus laevis.
18422506 - Vertebral heart scale in the beagle dog.
22186986 - Safety of negative-pressure wound therapy over ocular structures.
10599656 - Methods for evaluation of retinal microvascular abnormalities associated with hypertens...
17948036 - Variation of blood pressure during topical phacoemulsification.
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-9-11
Journal Detail:
Title:  Retina (Philadelphia, Pa.)     Volume:  -     ISSN:  1539-2864     ISO Abbreviation:  Retina (Philadelphia, Pa.)     Publication Date:  2012 Sep 
Date Detail:
Created Date:  2012-9-13     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8309919     Medline TA:  Retina     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
*Laboratory of Retinal Neurobiology and Vascular Physiology, Department of Ophthalmology, University of Geneva, Geneva, Switzerland †Jules Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland ‡Department of Ophthalmology, King's College Hospital, London, United Kingdom.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Computational intelligence-based diagnosis tool for the detection of prediabetes and type 2 diabetes...
Next Document:  REDUCTION OF VITREOUS CONTAMINATION RATE AFTER 25-GAUGE VITRECTOMY BY SURFACE IRRIGATION WITH 0.25% ...