To determine and validate the diagnostic ability of a linear discriminant function (LDF) based on retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) thickness obtained using high-definition optical coherence tomography (Cirrus HD-OCT) for discriminating between healthy controls and early glaucoma subjects.
We prospectively selected 214 healthy controls and 152 glaucoma subjects (teaching set) and another independent sample of 86 healthy controls and 71 glaucoma subjects (validating set). Two scans, including 1 macular and 1 peripapillary RNFL scan, were obtained. After calculating the LDF in the teaching set using the binary logistic regression analysis, receiver operating characteristic curves were plotted and compared between the OCT-provided parameters and LDF in the validating set.
The proposed LDF was 16.529−(0.132×superior RNFL)−(0.064×inferior RNFL)+(0.039×12 o’clock RNFL)+(0.038×1 o’clock RNFL)+(0.084×superior GCIPL)−(0.144×minimum GCIPL). The highest area under the receiver operating characteristic (AUROC) curve was obtained for LDF in both sets (AUROC=0.95 and 0.96). In the validating set, the LDF showed significantly higher AUROC than the best RNFL (inferior RNFL=0.91) and GCIPL parameter (minimum GCIPL=0.88). The LDF yielded a sensitivity of 93.0% at a fixed specificity of 85.0%.
The LDF showed better diagnostic ability for differentiating between healthy and early glaucoma subjects than individual OCT parameters. A classification algorithm based on the LDF can be used in the OCT analysis for glaucoma diagnosis.
*Department of Ophthalmology, Seoul National University College of Medicine
‡Department of Ophthalmology, Seoul National University Hospital, Seoul
†Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea
Supported by a grant of the Korea Health technology R&D Project, Ministry of Health & Welfare, Republic of Korea (Grant Number: A121615).
Disclosure: The authors declare no conflict of interest.
Reprints: Jin Wook Jeoung, MD, PhD, Department of Ophthalmology, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, Korea (e-mail: email@example.com).
Received January 27, 2014
Accepted November 27, 2014