Luke Nicholson1, Clara Vazquez-Alfageme1, Jayashree Ramu1, Ioanna Triantafyllopoulou1, Namritha V Patrao1, Mahdi Muwas1, Farrah Islam1, Philip G Hykin1, Sobha Sivaprasad2. 1. National Institute for Health Research Moorfields Biomedical Research Centre and University College London Institute of Ophthalmology, London, United Kingdom. 2. National Institute for Health Research Moorfields Biomedical Research Centre and University College London Institute of Ophthalmology, London, United Kingdom; King's College Hospital National Health Service Foundation Trust, London, United Kingdom. Electronic address: senswathi@aol.com.
Abstract
PURPOSE: To validate the use of concentric rings as a method to measure topographic area of retinal nonperfusion in ultra-widefield angiography with the ischemic index method, which is the most frequently used method to measure nonperfusion in ultra-widefield angiography. DESIGN: Validation study and reliability analysis. METHODS: setting: Single-center study performed at National Institute for Health Research Moorfields Biomedical Research Centre, London, United Kingdom. STUDY POPULATION: Twenty-eight ultra-widefield angiogram images of eyes with central retinal vein occlusion. OBSERVATION PROCEDURE: The concentric rings method consists of 6 macula-centered concentric rings divided into 12 segments each. Each image was graded by 5 graders using both the concentric rings and the ischemic index methods. MAIN OUTCOME MEASURES: Agreement between the 2 methods was calculated using the intraclass correlation coefficient. Intertest agreement, intergrader agreement, test-retest reliability, and the time taken to grade using these 2 methods were compared. RESULTS: The intertest agreement between concentric rings method and ischemic index method was 0.965. The intergrader agreement was 0.910 for the concentric rings method and 0.898 with the ischemic index method. The test-retest reliability was 0.975 for the rings and 0.979 for the ischemic index. Average grading time per image was 187 s and 297 s for the concentric rings method and ischemic index method, respectively, P < .001. CONCLUSION: The concentric rings method has an "almost-perfect" intergrader agreement and intertest agreement with the ischemic index method, with a shorter grading time.
PURPOSE: To validate the use of concentric rings as a method to measure topographic area of retinal nonperfusion in ultra-widefield angiography with the ischemic index method, which is the most frequently used method to measure nonperfusion in ultra-widefield angiography. DESIGN: Validation study and reliability analysis. METHODS: setting: Single-center study performed at National Institute for Health Research Moorfields Biomedical Research Centre, London, United Kingdom. STUDY POPULATION: Twenty-eight ultra-widefield angiogram images of eyes with central retinal vein occlusion. OBSERVATION PROCEDURE: The concentric rings method consists of 6 macula-centered concentric rings divided into 12 segments each. Each image was graded by 5 graders using both the concentric rings and the ischemic index methods. MAIN OUTCOME MEASURES: Agreement between the 2 methods was calculated using the intraclass correlation coefficient. Intertest agreement, intergrader agreement, test-retest reliability, and the time taken to grade using these 2 methods were compared. RESULTS: The intertest agreement between concentric rings method and ischemic index method was 0.965. The intergrader agreement was 0.910 for the concentric rings method and 0.898 with the ischemic index method. The test-retest reliability was 0.975 for the rings and 0.979 for the ischemic index. Average grading time per image was 187 s and 297 s for the concentric rings method and ischemic index method, respectively, P < .001. CONCLUSION: The concentric rings method has an "almost-perfect" intergrader agreement and intertest agreement with the ischemic index method, with a shorter grading time.
Authors: R Filek; P Hooper; T Sheidow; J Gonder; D K Varma; L Heckler; W Hodge; S Chakrabarti; C M L Hutnik Journal: Eye (Lond) Date: 2017-04-28 Impact factor: 3.775
Authors: Philip Hykin; A Toby Prevost; Sobha Sivaprasad; Joana C Vasconcelos; Caroline Murphy; Joanna Kelly; Jayashree Ramu; Abualbishr Alshreef; Laura Flight; Rebekah Pennington; Barry Hounsome; Ellen Lever; Andrew Metry; Edith Poku; Yit Yang; Simon P Harding; Andrew Lotery; Usha Chakravarthy; John Brazier Journal: Health Technol Assess Date: 2021-06 Impact factor: 4.014
Authors: Luke Nicholson; Jayashree Ramu; Errol W Chan; James W Bainbridge; Philip G Hykin; Stephen J Talks; Sobha Sivaprasad Journal: JAMA Ophthalmol Date: 2019-06-01 Impact factor: 7.389
Authors: Luke Nicholson; Roxanne Crosby-Nwaobi; Joana C Vasconcelos; A Toby Prevost; Jayashree Ramu; Amy Riddell; James W Bainbridge; Philip G Hykin; Sobha Sivaprasad Journal: Invest Ophthalmol Vis Sci Date: 2018-08-01 Impact factor: 4.799