The Prevalence of Optical Coherence Tomography Artifacts in High Myopia and its Influence on Glaucoma Diagnosis.

ABSTRACT

PRCIS Optical coherence tomography (OCT) artifacts occur much more frequently in highly myopic eyes compared with non-highly myopic eyes. A longer axial length is predictive of having OCT artifacts. PURPOSE: To investigate the types and prevalence of artifacts on OCT scans in patients with and without high myopia. MATERIALS AND METHODS: Patients were divided into 4 groups based on whether they had glaucoma and/or high myopia. All peripapillary retinal nerve fiber layer (RNFL) scan images were individually inspected for the presence of artifacts. RESULTS: Two hundred twenty-six patients were enrolled. The prevalence of OCT artifacts was 18.6% in non-high myopes and 51.9% in high myopes ( P <0.001). Outer RNFL border misidentification was the most common type of artifact for non-high myopes, whereas retinal pathology-related artifact was the most common in high myopes. Univariable regression analysis showed that a longer axial length [odds ratio (OR) 1.815, P <0.001], a higher pattern standard deviation (OR 1.194, P <0.001), and thinner RNFL (OR 0.947, P <0.001) were predictive factors for the presence of OCT artifacts. The diagnostic capability of global RNFL thickness before and after manual correction of segmentation errors did not differ for both non-high myopes [area under the receiver operating curve 0.915-0.913 ( P =0.955)] and high myopes [area under the receiver operating curve 0.906-0.917 ( P =0.806)]. CONCLUSION: The prevalence of OCT artifacts was the highest in patients with both high myopia and glaucoma. The most common type of OCT artifact is different for non-high myopes and high myopes. Physicians need to be aware of a higher likelihood of OCT artifacts, particularly in those with a longer axial length, worse visual field, and thinner RNFL thickness.