RT Journal Article SR Electronic T1 Inverted Ångström sign on iOCT: cannulated Schlemm’s canal during gonioscopy-assisted transluminal trabeculotomy JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP e250219 DO 10.1136/bcr-2022-250219 VO 15 IS 7 A1 Karthikeyan Mahalingam A1 Viney Gupta A1 Shikha Gupta YR 2022 UL http://casereports.bmj.com/content/15/7/e250219.abstract