Diplopia is believed to be a common eye-related symptom. However, to date, there are no available population-based estimates, which are necessary to understand the impact of this disabling symptom on the health care system and to identify steps to optimize patient care.Objective
To describe diplopia presentations in US ambulatory and emergency department (ED) settings.Design, Setting, and Participants
Ambulatory and ED visits in the United States by patients with diplopia were analyzed in this prespecified secondary analysis of National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey data collected for a 10-year period (2003-2012). Data were analyzed for the present study from October 6, 2016 to August 18, 2017.Main Outcomes and Measures
Numbers of ambulatory and ED diplopia presentations were estimated using weighted sample data. Weighted proportions of patient and clinician (ie, ophthalmologists, general practitioners, and specialty physicians) characteristics, diagnoses, and imaging use were calculated.Results
In total, 804 647 (95% CI, 662 075-947 218) ambulatory and 49 790 (95% CI, 38 318-61 262) diplopia-related ED visits occurred annually; 12.3% of ambulatory visits were primarily for acute- or subacute-onset diplopia. Mean (SD) patient age was 62.1 (20.3) years for ambulatory vs 48.1 (22.3) years for diplopia-related ED visits. Most visits primarily for diplopia were by patients 50 years or older (ambulatory, 79.1% [95% CI, 72.9%-84.2%]; ED, 51.8% [95% CI, 41.0%-62.4%]) who were white (ambulatory, 81.7% [95% CI, 74.8%-87.0%]; ED, 86.1% [95% CI, 77.8%-91.6%]) women (ambulatory, 51.1% [95% CI, 44.1-58.1]; ED, 52.8% [95% CI, 41.6%-63.7%]). Most diplopia-related ambulatory visits were conducted by ophthalmologists (70.4% [95% CI, 62.2%-77.5%]) even when symptoms were acute or subacute (89.0% [95% CI, 81.0%-93.9%]). The most common diagnosis in both settings was diplopia (International Classification of Diseases, Ninth Revision, Clinical Modification code 368.2). None of the 10 most frequent diagnoses was life threatening in the ambulatory setting, but approximately 16% of diplopia-related ED visits resulted in a stroke or transient ischemic attack diagnosis. Computed tomography or magnetic resonance imaging was ordered in 6.2% (95% CI, 2.8%-12.9%) of ambulatory and 59.7% (95% CI, 38.6%-77.7%) of ED visits, primarily for diplopia.Conclusions and Relevance
Approximately 850 000 diplopia visits occur in the United States annually; 95% were outpatient visits, and diagnoses were rarely serious in the ambulatory setting but potentially life threatening in 16% of diplopia-related ED visits. Given the low probability of a serious neurologic diagnosis in the ambulatory setting and higher probability in an ED, future cohort studies are needed to define the association of various diagnostic practice patterns, such as imaging, with patient outcomes.