Comparison of Diagnostic Accuracy Depending on Optic Disc Size in Early and Advanced Glaucoma Using Scanning Laser Tomography and Spectral Domain OCT

Abstract

Purpose: : To investigate the influence of optic disc size and degree of glaucomatous damage on glaucoma detection by Scanning Laser Tomography and Spectral Domain OCT.

Methods: : One hundred fifty nine subjects - 86 healthy controls, 23 patients with preperimetric open angle glaucoma and 50 patients with perimetric open angle glaucoma were included in the study. All patients were members of the Erlangen Glaucoma Registry and received a detailed standardized glaucoma examination including Scanning Laser Tomography (HRT 3, Heidelberg Engineering, Germany) and determination of retinal nerve fibre layer (RNFL) thickness by spectral domain OCT (Spectralis HRA+OCT^®, Heidelberg Engineering, Germany). Results were compared using the area under the ROC curve between diagnostic groups and quartiles according to optic disc size as measured by Scanning Laser Tomography after correction for corneal curvature.

Results: : The area under the ROC curve was 0.94 for mean RNFL thickness by spectral domain OCT compared to 0.84 for Moorfields regression analysis and 0.88 for the Glaucoma Probability Score using Scanning Laser Tomography for patients with preperimetric open angle glaucoma and 0.99 for mean RNFL thickness by spectral domain OCT compared to 0.92 for Moorfields regression analysis and 0.96 for the Glaucoma Probability Score using Scanning Laser Tomography for patients with perimetric open angle glaucoma. The area under the ROC curve in subgroups of quartiles according to optic disc size ranged from 0.84 to 0.92 for Moorfields regression analysis, 0.89 to 0.99 for Glaucoma Probability Score and 0.97 to 0.99 for mean RNFL thickness by spectral domain OCT.

Keywords: imaging/image analysis: clinical • nerve fiber layer • optic disc