About the Authors

Olof Birna Olafsdottir

Affiliations Department of Ophthalmology, University of Iceland, Reykjavik, Iceland, Department of Ophthalmology, Landspitali—The National University Hospital of Iceland, Reykjavik, Iceland

Thorunn Scheving Eliasdottir

Affiliations Department of Ophthalmology, University of Iceland, Reykjavik, Iceland, Department of Ophthalmology, Landspitali—The National University Hospital of Iceland, Reykjavik, Iceland

Jona Valgerdur Kristjansdottir

Affiliations Department of Ophthalmology, University of Iceland, Reykjavik, Iceland, Department of Ophthalmology, Landspitali—The National University Hospital of Iceland, Reykjavik, Iceland

Sveinn Hakon Hardarson

Affiliations Department of Ophthalmology, University of Iceland, Reykjavik, Iceland, Department of Ophthalmology, Landspitali—The National University Hospital of Iceland, Reykjavik, Iceland

Einar Stefánsson

einarste@landspitali.is

Affiliations Department of Ophthalmology, University of Iceland, Reykjavik, Iceland, Department of Ophthalmology, Landspitali—The National University Hospital of Iceland, Reykjavik, Iceland

Competing Interests

ES and SHH are involved in the development of the instrument (oximeter) used in the study and have financial interest in the company Oxymap ehf., which designed the instrument. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: OBO TSE JVK SHH ES. Performed the experiments: OBO TSE JVK. Analyzed the data: OBO SHH ES. Contributed reagents/materials/analysis tools: OBO ES. Wrote the paper: OBO TSE JVK SHH ES.