Accuracy and Feasibility of Three-Dimensional Ultrasound Testing in Eye Clinic and Emergency Department Patients with Vision Complaints

BACKGROUND

Ocular emergencies comprise 2-3% of emergency department (ED) visits, with retinal detachment requiring emergency surgery. Two-dimensional ultrasound is a rapid bedside tool but is highly operator dependent.

OBJECTIVE

We determined three-dimensional ultrasound (3DUS) feasibility, acceptability, and usability in eye pathology detection using the ophthalmologist examination as reference standard.

METHODS

We performed a prospective, blinded cohort study of a 3DUS-enabling device in 30 eye clinic and ED patients with visual symptoms and calculated 3DUS performance characteristics. Two expert readers interpreted the 3DUS images for pathology. All participants completed surveys.

RESULTS

3DUS sensitivity was 0.81, specificity 0.73, positive predictive value 0.54, negative predictive value 0.91, and likelihood ratio (LR)+/LR- 3.03 and 0.26, respectively. Novice and expert sonographers had "substantial" agreement in correct diagnosis of abnormal vs. normal (κ = 0.68, 95% confidence interval 0.48-0.88). Most patients indicated that 3DUS is fast, comfortable, helps them understand their problem, and improves provider interaction/care, and all sonographers agreed; 4/5 sonographers felt confident performing ultrasound. Expert readers correctly identified an abnormal eye in 83/120 scans (76%) and correct diagnosis in 72/120 scans (65%), with no statistical difference between novice (79%; 69%) and expert (72%; 61%) sonographers (p = 0.39, p = 0.55), suggesting reduced operator dependence. Reader diagnosis confidence and image quality varied widely. Image acquisition times were fast for novice (mean 225 ± 83 s) and expert (201 ± 51) sonographers, with fast expert reader interpretation times (225 ± 136).

CONCLUSIONS

A 3DUS-enabling device demonstrates a sensitivity of 0.81 and specificity of 0.73 for disease detection, fast image acquisition, and may reduce operator dependence for detecting emergent retinal pathologies. Further technological development is needed to improve diagnostic accuracy in identifying and characterizing retinal pathology.

Benefits to utilising ultrasound in examining the eye

Ocular ultrasound (US) is not one of ACEMs 'big 5' in terms of US capability that is expected of a trainee or FACEM. Most texts have a small chapter dedicated to ocular US but it is usually at the back or a subsection of a chapter where it is rarely seen or appreciated. However, it is a straightforward scan to perform with many benefits which will be discussed in this article. The eye offers an excellent medium for US beam penetration, making good quality images of the retina easy and quick to acquire. This has the added benefit of being able to share images with an ophthalmologist remotely, improving time to definitive treatment. It can also be used in patients who cannot cooperate with sitting at a slitlamp, for example moribund or trauma patients. The authors propose that ocular US teaching should be incorporated into the ACEM syllabus, being a vital adjunct to a comprehensive eye examination.

Usefulness of point-of-care ultrasound for the evaluation of non-traumatic eye emergencies

The role of clinical ultrasound or Point-of-Care Ultrasound (POCUS) in patients with urgent pathology has expanded exponentially in recent years. With clinical ultrasound, physicians can make a quick assessment and decide how to act in time critical situations. Ocular ultrasound is one of the most recently developed applications. In patients with severe non-traumatic ocular pathology it has numerous clinically relevant uses: retinal detachment, occlusion of the central retinal artery or optic nerve pathologies, among others. The technique is widely available, easy to perform, and can provide information even when fundoscopy is impossible. In this review, we describe the bases of clinical ocular ultrasound, focusing on the management of the main non-traumatic urgent ophthalmological pathologies that the physician may face in their clinical practice.