Correcting magnification error in foveal avascular zone area measurements of optical coherence tomography angiography images with estimated axial length  

作　　者：Deepaysh D.C.S.Dutt Seyhan Yazar Jason Charng David A.Mackey Fred K.Chen Danuta M.Sampson 

机构地区：[1]Centre for Ophthalmology and Visual Science(Incorporating Lions Eye Institute),The University of Western Australia,Perth,WA,Australia [2]Garvan Institute of Medical Research,Sydney,Australia [3]Ophthalmology,Department of Surgery,University of Melbourne,East Melbourne,VIC,Australia [4]Centre for Eye Research Australia,Royal Victorian Eye and Ear Hospital,East Melbourne,VIC,Australia [5]Surrey Biophotonics,Centre for Vision,Speech and Signal Processing and School of Biosciences and Medicine,The University of Surrey,Guildford,UK [6]Institute of Ophthalmology,University College London,London,UK [7]Lions Eye Institute,2 Verdun Street,Nedlands,WA 6009,Australia

出　　处：《Eye and Vision》2024年第5期18-27,共10页眼视光学杂志（英文）

摘　　要：Background:To generate and validate a method to estimate axial length estimated(AL_(est))from spherical equivalent(SE)and corneal curvature[keratometry(K)],and to determine if this AL_(est)can replace actual axial length(AL_(act))for correcting transverse magnification error in optical coherence tomography angiography(OCTA)images using the Littmann-Bennett formula.Methods:Data from 1301 participants of the Raine Study Gen2-20 year follow-up were divided into two datasets to generate(n=650)and validate(n=651)a relationship between AL,SE,and K.The developed formula was then applied to a separate dataset of 46 participants with AL,SE,and K measurements and OCTA images to estimate and compare the performance of AL_(est)against AL_(act)in correcting transverse magnification error in OCTA images when measuring the foveal avascular zone area(FAZA).Results:The formula for AL_(est)yielded the equation:AL_(est)=2.102K−0.4125SE+7.268,R^(2)=0.794.There was good agreement between AL_(est)and AL_(act)for both study cohorts.The mean difference[standard deviation(SD)]between FAZA corrected with AL_(est)and AL_(act)was 0.002(0.015)mm^(2)with the 95%limits of agreement(LoA)of−0.027 to 0.031 mm^(2).In comparison,mean difference(SD)between FAZA uncorrected and corrected with AL_(act)was−0.005(0.030)mm^(2),with 95%LoA of−0.064 to 0.054 mm^(2).Conclusions:AL_(act)is more accurate than AL_(est)and hence should be used preferentially in magnification error correction in the clinical setting.FAZA corrected with AL_(est)is comparable to FAZA corrected with AL_(act),while FAZA measurements using images corrected with AL_(est)have a greater accuracy than measurements on uncorrected images.Hence,in the absence of AL_(act),clinicians should use AL_(est)to correct for magnification error as this provides for more accurate measurements of fundus parameters than uncorrected images.

关 键 词：OCTA KERATOMETRY Spherical equivalent Axial length Littmann-Bennett formula 

分 类 号：R77[医药卫生—眼科]