Automated Retroillumination Photography Analysis for Objective Assessment of Fuchs Corneal Dystrophy.
OBJECTIVE
Retroillumination photography analysis is an objective tool for the assessment of the number and distribution of guttae in eyes affected with Fuchs corneal dystrophy (FCD). Current protocols include manual processing of images; here, we assess validity and interrater reliability of automated analysis across various levels of FCD severity.


METHODS
Retroillumination photographs of 97 FCD-affected corneas were acquired, and total counts of guttae were previously summated manually. For each cornea, a single image was loaded into ImageJ software. We reduced color variability and subtracted background noise. Reflection of light from each gutta was identified as a local area of maximum intensity and counted automatically. Noise tolerance level was titrated for each cornea by examining a small region of each image with automated overlay to ensure appropriate coverage of individual guttae. We tested interrater reliability of automated counts of guttae across a spectrum of clinical and educational experience.


RESULTS
A set of 97 retroillumination photographs was analyzed. Clinical severity as measured by a modified Krachmer scale ranged from a severity level of 1 to 5 in the set of analyzed corneas. Automated counts by an ophthalmologist correlated strongly with Krachmer grading (R = 0.79) and manual counts (R = 0.88). Intraclass correlation coefficients demonstrated strong correlation at 0.924 (95% CI, 0.870-0.958) among cases analyzed by 3 students, and 0.869 (95% CI, 0.797-0.918) among cases for which images were analyzed by an ophthalmologist and 2 students.


CONCLUSIONS
Automated retroillumination photography analysis allows for grading of FCD severity with high resolution across a spectrum of disease severity.
*Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD; †George Washington University School of Medicine & Health Sciences, Washington, DC; ‡Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; §Department of Medicine, University of California Irvine, Irvine, CA; and ¶University of Maryland, College Park, MD.
Allen O
AO
Eghrari
Aisha A
AA
Mumtaz
Brian
B
Garrett
Mahsa
M
Rezaei
Mina S
MS
Akhavan
S Amer
SA
Riazuddin
John D
JD
Gottsch
D000328:Adult; D016022:Case-Control Studies; D003941:Diagnostic Techniques, Ophthalmological; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D005642:Fuchs' Endothelial Dystrophy / Q000000981:diagnostic imaging*; D006801:Humans; D008029:Lighting / Q000379:methods*; D008297:Male; D010781:Photography / Q000379:methods*; D015203:Reproducibility of Results