TY - JOUR
T1 - Focused tortuosity definitions based on expert clinical assessment of corneal subbasal nerves
AU - Lagali, Neil
AU - Poletti, Enea
AU - Patel, Dipika V.
AU - McGhee, Charles N.J.
AU - Hamrah, Pedram
AU - Kheirkhah, Ahmad
AU - Tavakoli, Mitra
AU - Petropoulos, Ioannis N.
AU - Malik, Rayaz A.
AU - Utheim, Tor Paaske
AU - Zhivov, Andrey
AU - Stachs, Oliver
AU - Falke, Karen
AU - Peschel, Sabine
AU - Guthoff, Rudolf
AU - Chao, Cecilia
AU - Golebiowski, Blanka
AU - Stapleton, Fiona
AU - Ruggeri, Alfredo
N1 - Publisher Copyright:
© 2015 The Association for Research in Vision and Ophthalmology, Inc.
PY - 2015
Y1 - 2015
N2 - PURPOSE. We examined agreement among experts in the assessment of corneal subbasal nerve tortuosity. METHODS. Images of corneal subbasal nerves were obtained from investigators at seven sites (Auckland, Boston, Linköping, Manchester, Oslo, Rostock, and Sydney) using laser-scanning in vivo confocal microscopy. A set of 30 images was assembled and ordered by increasing tortuosity by 10 expert graders from the seven sites. In a first experiment, graders assessed tortuosity without a specific definition and performed grading three times, with at least 1 week between sessions. In a second experiment, graders assessed the same image set using four focused tortuosity definitions. Intersession and intergrader repeatability for the experiments were determined using the Spearman rank correlation. RESULTS. Expert graders without a specific tortuosity definition had high intersession (Spearman correlation coefficient 0.80), but poor intergrader (0.62) repeatability. Specific definitions improved intergrader repeatability to 0.79. In particular, tortuosity defined by frequent small-amplitude directional changes (short range tortuosity) or by infrequent large- amplitude directional changes (long range tortuosity), indicated largely independent measures and resulted in improved repeatability across the graders. A further refinement, grading only the most tortuous nerve in a given image, improved the average correlation of a given grader’s ordering of images with the group average to 0.86 to 0.90. CONCLUSIONS. Definitions of tortuosity specifying short or long-range tortuosity and considering only the most tortuous nerve in an image improved the agreement in tortuosity grading among a group of expert observers. These definitions could improve accuracy and consistency in quantifying subbasal nerve tortuosity in clinical studies.
AB - PURPOSE. We examined agreement among experts in the assessment of corneal subbasal nerve tortuosity. METHODS. Images of corneal subbasal nerves were obtained from investigators at seven sites (Auckland, Boston, Linköping, Manchester, Oslo, Rostock, and Sydney) using laser-scanning in vivo confocal microscopy. A set of 30 images was assembled and ordered by increasing tortuosity by 10 expert graders from the seven sites. In a first experiment, graders assessed tortuosity without a specific definition and performed grading three times, with at least 1 week between sessions. In a second experiment, graders assessed the same image set using four focused tortuosity definitions. Intersession and intergrader repeatability for the experiments were determined using the Spearman rank correlation. RESULTS. Expert graders without a specific tortuosity definition had high intersession (Spearman correlation coefficient 0.80), but poor intergrader (0.62) repeatability. Specific definitions improved intergrader repeatability to 0.79. In particular, tortuosity defined by frequent small-amplitude directional changes (short range tortuosity) or by infrequent large- amplitude directional changes (long range tortuosity), indicated largely independent measures and resulted in improved repeatability across the graders. A further refinement, grading only the most tortuous nerve in a given image, improved the average correlation of a given grader’s ordering of images with the group average to 0.86 to 0.90. CONCLUSIONS. Definitions of tortuosity specifying short or long-range tortuosity and considering only the most tortuous nerve in an image improved the agreement in tortuosity grading among a group of expert observers. These definitions could improve accuracy and consistency in quantifying subbasal nerve tortuosity in clinical studies.
KW - Corneal nerves
KW - In vivo confocal microscopy
KW - Plexus
KW - Subbasal nerve
KW - Tortuosity
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U2 - 10.1167/iovs.15-17284
DO - 10.1167/iovs.15-17284
M3 - Article
C2 - 26241397
AN - SCOPUS:84939832467
SN - 0146-0404
VL - 56
SP - 5102
EP - 5109
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 9
ER -