Due to copyright issues, an electronic copy of the thesis must be ordered from the faculty. For the faculty to have time to process the order, the order must be received by the faculty at the latest 2 days before the public defence. Orders received later than 2 days before the defence will not be processed. After the public defence, please address any inquiries regarding the thesis to the candidate.
Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Professor Emeritus Einar Stefansson, University of Iceland
- Second opponent: Professor Eyvind Rødahl, University of Bergen
- Third member and chair of the evaluation committee: Professor II Mona Elisabeth Skjelland, University of Oslo
Chair of the Defence
Professor Emeritus Truls Erik Bjerklund Johansen, University of Oslo
Principal Supervisor
Professor II Liv Kari Drolsum, University of Oslo
Summary
This thesis describes a new optically based non-invasive method for measuring ocular surface microcirculation.
Oxygen transfers from inhaled air in the lungs to red blood cells, which travel through the vessel network, and is delivered by capillaries in the microcirculation to tissue cells. Clinical medicine lacks standardized examining equipment to measure oxygen delivery, yet it is known that microvascular dysfunction plays a central role in several disease states.
The Oxygen Delivery Index (ODIN) concept assesses three outcomes that influence the oxygen delivery to tissue cells. Computer assisted video microscopy and diffuse reflectance spectroscopy are used for data collection. Parameters quantified during analysis are functional capillary density, capillary blood flow velocity and microvascular oxygen saturation.
The research hypothesis was that limbal tissue requires more nutritional support than the bulbar conjunctiva since corneal epithelial cells continuously proliferate at the limbus. We expected to find differences in microvascular structure and function comparing the two regions. By applying the ODIN concept to the ocular surface of porcine models (paper I and II) and humans (paper III) the research group confirmed that there are differences in microvascular architecture at limbus and bulbar conjunctiva. Further, the method detected higher capillary density and oxygen extraction at limbus compared with bulbar conjunctiva in healthy humans.
The method has been developed and adjusted through refinement of components in the technical setup, data recording technique and analytic software. Further application studies can characterize the value of the ODIN concept for evaluating, screening, monitoring or treating ocular diseases (e.g. glaucoma), conditions of the central nervous system (e.g. brain death) or systemic circulatory failure (e.g. sepsis).
Additional information
Contact the research support staff.