Repeatability of Measuring Corneal Nerve Migration Rate in Individuals With and Without Diabetes.
OBJECTIVE
To assess the repeatability of measuring the corneal nerve migration rate in individuals with and without neuropathy.


METHODS
Wide-field montages of the subbasal corneal nerve plexus were generated at baseline and after 3 weeks for 14 participants. Montages were manually examined side by side to identify a referent landmark in the inferior whorl region (origin) and throughout each montage. A software program was developed to measure nerve migration of all identified points relative to the origin. Repeatability was determined by measurement of nerve migration for within observer (one researcher on 2 occasions, 5 days apart) and between observers (2 observers) within 4 different zones based on the distance from the origin and in the vertical section of the wide-field montage. The impact of images being montaged with fully automated software on repeatability was also investigated.


RESULTS
The mean difference between observations 1 and 2 for observer 1 was 0.02 ± 1.3 μm/wk (P = 0.94), with an intraclass correlation coefficient (ICC) of 0.99 [95% confidence interval (CI) = 0.99-1.00], and the mean difference between observer 1 and 2 was 0.3 ± 1.2 μm/wk (P = 0.41), with an ICC of 0.99 (95% CI = 0.99-1.00). The mean difference between observations 1 (images montaged by semiautomated software) and 2 (images montaged by fully automated software) was 1.2 ± 4.9 μm/wk (P = 0.41), with an ICC of 0.96 (95% CI = 0.87-1.00).


CONCLUSIONS
Measuring corneal nerve migration rate is highly repeatable for within and between observers and when using different methods of image montaging.
*Institute of Health and Biomedical Innovation, Queensland University of Technology, Queensland, Australia; †Department of Information Engineering, University of Padova, Padova, Italy; ‡Department of Diabetes and Endocrinology, Princess Alexandra Hospital, Brisbane, Australia; §School of Medicine, University of Queensland, Brisbane, Australia; ¶Center for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, Manchester, United Kingdom; and ‖Weill Cornell Medicine-Qatar, Doha, Qatar.
Khaled
K
Al Rashah
Nicola
N
Pritchard
Cirous
C
Dehghani
Alfredo
A
Ruggeri
Pedro
P
Guimaraes
Christopher
C
Poole
Anthony
A
Russell
Rayaz
R
Malik
Nathan
N
Efron
Katie
K
Edwards
D000328:Adult; D000368:Aged; D003315:Cornea / Q000294:innervation*; D003929:Diabetic Neuropathies / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D014276:Trigeminal Nerve / Q000473:pathology*; D020433:Trigeminal Nerve Diseases / Q000175:diagnosis* / Q000503:physiopathology