Incidence and Causes of Overdiagnosis of Optic Neuritis

Abstract

IMPORTANCE Diagnostic error is an important source of medical error. Overdiagnosis of optic neuritis may prompt unnecessary and costly diagnostic tests, procedures, and treatments. OBJECTIVE To assess the incidence of and characterize factors contributing to overdiagnosis of acute optic neuritis. DESIGN, SETTING, AND PARTICIPANTS In this retrospective clinic-based cross-sectional study of new patient encounters, 122 patients referred for acute optic neuritis at a university-based Midwestern neuro-ophthalmology clinic between January 2014 and October 2016 were studied. Data were analyzed from September 2016 to July 2017. INTERVENTIONS Definite diagnosis was determined by neuro-ophthalmologists. For patients with alterative diagnoses, the Diagnosis Error Evaluation and Research taxonomy tool was applied to categorize the type of diagnostic error. MAIN OUTCOMES AND MEASURES The primary outcome was the primary type of diagnostic error in patients erroneously diagnosed as having optic neuritis. Secondary outcomes included final diagnosis and interventions undergone prior to referral. RESULTS A total of 122 patients were referred with acute optic neuritis during the study period; 88 (72.1%) were female, and the mean (SD) age was 42.6 (14.0) years. Of these, 49 patients (40.2%; 95% CI, 31.4-49.4) were confirmed to have optic neuritis, and 73 (59.8%; 95% CI, 50.6-68.6) had an alternative diagnosis. The most common alternative diagnoses were headache and eye pain, functional visual loss, and other optic neuropathies, particularly nonarteritic anterior ischemic optic neuropathy. The most common diagnostic error was eliciting or interpreting critical elements of history, which occurred in 24 of 73 patients (33%) with alternative diagnoses. Other common errors included errors weighing or considering alternative diagnoses (23 patients [32%]), errors weighing or interpreting physical examination findings (15 patients [21%]), and misinterpreting diagnostic test results (11 patients [15%]). In patients with alterative diagnoses, 12 (16%) had normal magnetic resonance imaging findings preceding the referral, 12 (16%) had received a lumbar puncture, and 8 (11%) had received unnecessary treatment with intravenous steroids. CONCLUSIONS AND RELEVANCE These data suggest that nearly 60% (95% CI, 50.6-68.6) of patients referred for optic neuritis have an alternative diagnosis, with the most common errors being overreliance on a single item of history and failure to consider alternative diagnoses. Understanding pitfalls leading to overdiagnosis of optic neuritis may improve clinicians' diagnostic process.

Incidence and Mimickers of Acute Idiopathic Optic Neuritis: Analysis of 291 Consecutive Patients from Southern Finland

“…It is becoming increasingly clear that early treatment is more effective than delayed treatment in MS. 32 The practice of performing the MRI upfront, before any medical treatment, is also supported by our finding of six intracranial compressive lesions (2%) as mimickers of ON. In another recent study from the USA, 4% of suspected ON cases had optic sheath meningioma 33 illustrating that intracranial compressive lesions are not uncommon mimickers of ON. There are also reports of optic nerve lymphoma and optic nerve sheath melanoma cases as serious compressive lesions mimicking ON.…”

Population-based Incidence of Pediatric and Adult Optic Neuritis and the Risk of Multiple Sclerosis

“…The authors acknowledged the possibility of misdiagnosis reported by recent studies showing that misdiagnosis of optic neuritis may be as high as 60% and misdiagnosis of MS as high as 67%. 40,41 Thus, we used specific diagnostic codes for intractable diseases and excluded as many as possible mimic conditions to increase diagnostic accuracy. We only included a diagnosis of MS or NMO based on additional diagnostic codes for registration of rare intractable diseases, which could have resulted in underestimation of conversion rates to MS or NMO.…”

Visual Loss in Neuro-Ophthalmology

“…The annual incidence of acute optic neuritis is estimated in population-based studies to be between 1 and 5 per 100,000 people in the general population [23]. The majority of patients with acute optic neuritis are aged between 18 and 46 years, with a mean age of 30-35 years.…”