(O-A1) Point-of-care Ocular Ultrasound vs. Ophthalmoscopy for the Evaluation of Acute Visual Complaints in the Emergency Department

Objectives: The objective of this study was to compare the test characteristics of EP-performed ophthalmoscopy with ocular POCUS using formal ophthalmologist evaluation as the gold standard.

Background: According to the 2017 National Hospital Ambulatory Medical Care Survey, visual complaints account for over 1% of all emergency department visits nationwide. Prior to the introduction of point-of-care ultrasound (POCUS), emergency medicine physician (EP) performed non-dilated ophthalmoscopic exam was considered standard of care. However, limited training and experience significantly limits the accuracy of this physical examination.

Methods: This was a single center, prospective, observational study of a convenience sample of adult patients who presented to an urban, university hospital with >105,000 visits annually. Patients, who presented with acute visual complaints, were eligible to be enrolled between January 2017 - May 2019. The treating physician, a PGY1-3 Emergency Medicine resident performed a visual inspection of the eye and the non-dilated fundoscopic examination. A separate PGY1-3 Emergency Medicine resident, blinded to the indication, performed the ocular POCUS using the Logiq e linear transducer (4-10 MHz) and a separate visual examination of the eye without the use of an ophthalmoscope. Each resident had performed >25 previous ocular ultrasounds per the American College of Emergency Physicians and Accreditation Council for Graduate Medical Education (ACGME) guidelines for emergency medicine POCUS training. Using a power analysis of 80%, our sample size calculation of 40 patients was based on previous data demonstrating a 50% difference in sensitivities between ocular POCUS and EP-performed ophthalmoscopy for diagnosing acute ocular pathology with an average prevalence of 30% in patients presenting with acute visual complaints. Data are presented as proportions with 95% confidence intervals (CIs). Statistical analysis included Fisher Exact and chi square tests.

Results: 226 patients were enrolled. 104 of whom had a formal consultation and evaluation by a board-certified ophthalmologist within 24 hours of the patient’s emergency department visit. 87 patients were diagnosed with ocular pathology yielding a prevalence of 83.65% (95% CI 32.12-45.18). The following are the test characteristics for EP-performed ophthalmoscopy: sensitivity 16.49% (95% CI 9.73-25.4), specificity 100% (95% CI 59.04-100), and accuracy 67.85% (95% CI 75.12-90.18). The following are the test characteristics for ocular POCUS: sensitivity 87.21% (95% CI 78.27-93.44), specificity 100% (95% CI 81.47-100), and accuracy 95.08% (95% CI 88.98-98.35).

Conclusions: Point-of-care ocular ultrasound was more sensitive and specific than EP-performed ophthalmoscopic examination for the diagnosis of acute ocular pathology in the emergency department.

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Funding (Optional): none