Curtis Marino, MD
Published Feb. 26, 2022
Probetrotters | Medical Education
Objective and Study Design
This was a prospective diagnostic study comparing the accuracy of ocular point-of-care ultrasonography (POCUS) in the emergency
department with the final diagnosis from an attending ophthalmologist.
Methods
The inclusion criteria of the study allowed eligibility of any patient presenting to four different emergency departments with symptoms concerning for Retinal Detachment (RD), Vitreous Hemorrhage (VH), and Vitreous Detachment (VD) with expectant emergent consultation with ophthalmologist. However, certain exclusion criteria did apply, for example, if a patient presented with trauma or globe rupture. Ocular POCUS was preformed prior to ophthalmologist examination.
POCUS was performed using a linear probe and with two components: static and kinetic exam. During the static exam, the eye is held still while ultrasound probe fanned through the globe, and during the kinetic exam, the probe is held still while the patient moves their eye laterally in both directions.
Findings of a hyperechoic membrane bound to the optic disc, but not the choroid was suggestive of RD (image A). A detached, thin, mobile membrane located between the vitreous and retina was consistent with VD (image B). A heterogenous echogenic fluid collection in the posterior chamber that rotates during the kinetic exam indicated VH (image C).
The diagnostic findings of the ocular POCUS were then compared to that of the ophthalmologist.
What are some possible flaws in the methods used?
- Sonographers ranged from physician assistants to emergency medicine residents to attendings. Depending on the degree ultrasound competence or trainee oversight could have resulted in a diagnostic predictability that is not applicable to clinicians that are more experienced with ultrasound.
- There could be variable diagnostic accuracy among consulted ophthalmologists in the study.
- Two different models of ultrasound machines were used among four different emergency departments; there could be variable quality among the ultrasound machines.
Results
There were 252 patients initially offered enrollment, of which, 13 declined and 14 were excluded, so the final analysis included 225 patients. RD had a sensitivity of 96.9% and specificity of 88.1%, VH had a sensitivity of 81.9% and specificity of 82.3%, and VD with a sensitivity of 42.5% and specificity of 96%. Overall, using ultrasound demonstrated a negative predictive value over 90% for each pathology.
| Retinal Detachment | Vitreous Hemorrhage | Vitreous Detachment |
Sensitivity | 96.9% | 81.9% | 42.5% |
Specificity | 88.1% | 82.3% | 96.0% |
Positive Predictive Value | 64.5% | 46.0% | 61.3% |
Negative Predictive Value | 99.0% | 94.3% | 91.8% |
Discussion
Multiple studies have demonstrated the usefulness of ultrasound in the diagnosis of vitreous detachment, vitreous hemorrhage, and retinal detachment. Although the sensitivity and specificity were quite variable among the studies, this study provides strong evidence for the diagnostic capabilities of retinal detachment using POCUS in the emergency department.
In the study, retinal detachment had the highest sensitivity compared with VH and VD. Among those, RD is the only true ophthalmologic emergency, therefore emergency medicine clinician’s ability to recognize findings more consistent with RD compared to VH and VD may influence the urgency for which patients should be evaluated by ophthalmology.
Take Home Points
Ocular POCUS is a useful diagnostic modality for Retinal Detachment, Vitreous Detachment and Vitreous Hemorrhage.
Ultrasound is the most sensitive in detecting retinal detachment, which is an ophthalmologic emergency.
Does this study influence your practice?
Not necessarily, prior studies have demonstrated that the sensitivity for retinal detachment exceeds 90% by emergency clinicians using ocular ultrasound [2, 3, 4]. The sensitivity for retinal detachment in this study is consistent with previous findings. The most useful take-away point however, is the high negative predictive value (>90%) for each RD, VD, and VH. A negative POCUS in the setting of visual symptoms may lead me to broaden my differential to consider alternative etiologies. However, I would consult ophthalmology if POCUS showed any finding suggestive of RD, VD, or VH with the same degree of urgency, regardless of which condition the findings were most consistent with.
[1] Lahham, Shadi, et al. “Point-of-Care Ultrasonography in the Diagnosis of Retinal Detachment, Vitreous Hemorrhage, and Vitreous Detachment in the Emergency Department.” JAMA Network Open, vol. 2, no. 4, 2019, https://doi.org/10.1001/jamanetworkopen.2019.2162.
[2] Yoonessi, Roxana, et al. “Bedside Ocular Ultrasound for the Detection of Retinal Detachment in the Emergency Department.” Academic Emergency Medicine, vol. 17, no. 9, 2010, pp. 913–917., https://doi.org/10.1111/j.1553-2712.2010.00809.x.
[3] Shinar, Zachary, et al. “Use of Ocular Ultrasound for the Evaluation of Retinal Detachment.” The Journal of Emergency Medicine, vol. 40, no. 1, 2011, pp. 53–57., https://doi.org/10.1016/j.jemermed.2009.06.001.
[4] Jacobsen, Bradley, et al. “Retrospective Review of Ocular Point-of-Care Ultrasound for Detection of Retinal Detachment.” Western Journal of Emergency Medicine, vol. 17, no. 2, 2016, pp. 196–200., https://doi.org/10.5811/westjem.2015.12.28711.