Algorithm Variability in Quantification of Epithelial Defect Size in Microbial Keratitis Images.
Algorithm Variability in Quantification of Epithelial Defect Size in Microbial Keratitis Images.
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DOI:
10.1097/ico.0000000000002258
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发表时间:
2020-05
期刊:
影响因子:
2.8
通讯作者:
Woodward MA
中科院分区:
文献类型:
--
作者:
Kriegel MF;Huang J;Ashfaq HA;Niziol LM;Preethi M;Tan H;Tuohy MM;Patel TP;Prajna V;Woodward MA
To investigate sources of measurement variability when quantifying morphology of microbial keratitis (MK) from slit lamp photography (SLP) images using a semi-automated, image-analysis algorithm. Prospectively enrolled patients with MK underwent SLP to obtain images of their epithelial defects (ED). Eyes were stained with fluorescein and imaged multiple times under blue light, at low and high magnifications. A masked research assistant chose the 3 best images and annotated each 3 times to provide seed regions corresponding to ED and healthy cornea. The algorithm returned ED area for each seeded image. Eyes without EDs and algorithm failures were excluded. Variance components were estimated with a random effects model and intraclass correlation coefficients (ICC) estimated intra-grader reliability. A total of 42 eyes from 42 MK participants were photographed. After excluding poor quality images, eyes with no EDs, and algorithm failures, 34 patients with 92 images and 274 seeds were analyzed. No significant differences in average ED area were found between seedings or high versus low SLP magnifications (all p>0.5, paired t-tests). Minimal measurement variability was due to image (0.9%), magnification (0.2%), or seed (0.1%). Most variability was attributable to differences in ED sizes between patients (85.2%). 13.7% of variability was unexplained. Multiple iterations of the algorithm on the same image showed good consistency (ICC=0.98, 95% confidence interval, 0.97-0.99). Image-analysis algorithms showed good reliably for measuring ED area from SLP images. Most measurement variability was due to between-patient differences, not imaging settings or application of the algorithm by the user.