Kahraman-Koytak P, et al. - Researchers retrospectively studied 35 cases with unilateral optic nerve sheath meningiomas (ONSM) in the tertiary neuro-ophthalmology practice at Emory University School of Medicine between January 2002 and March 2017 to assess factors contributing to the initial misdiagnosis of ONSM by using the Diagnosis Error Evaluation and Research taxonomy tool. They observed optic neuritis as the most common initial misdiagnosis. The most common sources of diagnostic errors were biased preestablished diagnoses, inaccurate funduscopic examinations, a failure to order the correct test (MRI brain/orbits with contrast), and a failure to correctly interpret MRI results. They noted that easier access to neuro-ophthalmologists, improved diagnostic strategies, and education regarding neuroimaging could help to prevent the diagnostic failures.