About the Authors

Wanjiku Mathenge

Affiliations Rift Valley Provincial Hospital, Nakuru, Kenya , London School of Hygiene and Tropical Medicine, London, United Kingdom

John Nkurikiye

Affiliation King Faisal Hospital, Kigali, Rwanda

Hans Limburg

Affiliation London School of Hygiene and Tropical Medicine, London, United Kingdom

Hannah Kuper

To whom correspondence should be addressed. E-mail: hannah.kuper@lshtm.ac.uk

Affiliation London School of Hygiene and Tropical Medicine, London, United Kingdom

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

WM, HL, and HK designed the study and contributed to writing the paper. WM and HL analysed the data. WM and JN enrolled patients. WM designed the study except the RAAB methodology, was the principal investigator and collected data in the field, did all the preliminary analyses as per RAAB guidelines, and enrolled patients in conjunction with JN. JN initiated the survey in Rwanda and was one of the ophthalmologists who conducted it. HL trained the survey teams in the survey protocol and procedures. With their inputs, HL calculated the sample size and selected the clusters. He also participated in the examination of the first cluster as part of the training. The software used for the survey was developed by HL, who also analysed the survey data, reviewed the draft manuscript, and calculated all the confidence intervals.