Footnotes

• Funding None of the authors has any financial disclosures related to this manuscript. This research was funded by That Man May See and the South Asia Research Fund. The Department of Ophthalmology at UCSF is supported by a core grant from the National Eye Institute, EY02162. Dr Acharya is supported by a National Eye Institute K23EY017897 grant and a Research to Prevent Blindness Career Development Award. Dr Lietman is supported by a National Eye Institute grant U10-EY015114 and a Research to Prevent Blindness award. The sponsors did not have a role in the design and conduct of the study; collection, management, analysis and interpretation of the data; and preparation, review or approval of the manuscript.

• Competing interests None.

• Ethics approval This study was conducted with the approval of the University of California, San Francisco; Aravind Eye Hospital, Madurai, India; Dartmouth-Hitchcock Medical Center, Hanover, NH.

• Provenance and peer review Not commissioned; not externally peer reviewed.