Travel time to cataract surgical services in Kenya, Malawi and Rwanda: demonstrating a standardised indicator of physical access to cataract surgery

Mccormick, Ian; Nesemann, John M.; Zhao, Jinfeng; Mdala, Shaffi; Kitema, Gatera Fiston; Mwangi, Nyawira; Gichangi, Michael; Tang, Kevin; Burton, Matthew J.; Ramke, Jacqueline