Frequency and Causes of Segmentation Errors in Spectral Domain Optical Coherence Tomography Imaging in Glaucoma

ABSTRACT

PURPOSE: To determine the frequency and potential causes of segmentation errors in spectral domain optical coherence tomography (SD-OCT) imaging of retinal nerve fiber layer (RNFL) scans. METHODS: Segmentation errors for the RNFL thickness analysis were recorded during a retrospective chart review of 214 eye scans from 132 consecutive patients with glaucoma or glaucoma suspect who underwent a complete eye exam using Spectralis™ OCT scanning from August 2014 to November 2014. Segmentation errors were classified as inner, outer, inner and outer segmentation errors, and degraded images. The risk factors including age, sex, intraocular pressure, spherical equivalents, severity of glaucoma, and associated ocular disorders were evaluated using logistic regression analysis. RESULTS: A total of 71 eye scans included segmentation errors. Risk factors of inner segmentation error (8.9%) were age, epiretinal membrane, and degenerative myopia. Risk factors of outer segmentation error (29.9%) were age, peripapillary atrophy, posterior vitreous detachment, and severity of glaucoma. Risk factors of inner and outer segmentation errors (6.1%) were age and degenerative myopia. The single risk factor of degraded image (2.3%) was degenerative myopia. CONCLUSIONS: Segmentation errors for SD-OCT RNFL scans in glaucoma patients are common. Clinicians should carefully review the scans for segmentation errors when using SD-OCT images in glaucoma diagnosis or during patient follow-up.