Pitfalls in the Use of Ocular Ultrasound for Evaluation of Acute Vision Loss

Background

Retinal detachment is a true medical emergency. It is a time-critical, vision-threatening disease often first evaluated in the Emergency Department (ED). Diagnosis can be extremely challenging and confused with other ocular pathology. Several entities can mimic retinal detachment, including posterior vitreous detachment and vitreous hemorrhage. Ocular ultrasound can assist the emergency physician in evaluating intraocular pathology, and it is especially useful in situations where fundoscopic examination is technically difficult or impossible. Accurate and rapid diagnosis of retinal detachment can lead to urgent consultation and increase the likelihood of timely vision-sparing treatment.

Objectives

This case demonstrates both the utility of ocular ultrasound in the accurate and timely diagnosis of retinal detachment and potential pitfalls in the evaluation of intraocular pathology in the ED.

Case Report

A 38-year-old woman presented with acute onset of bilateral visual loss that was concerning for retinal detachment. Rapid evaluation of the intraocular space was performed using bedside ocular ultrasound. Bedside ocular ultrasound correctly diagnosed retinal detachment in the right eye. Posterior vitreous detachment in the left eye was incorrectly diagnosed as retinal detachment.

Conclusion

This case illustrates the importance of bedside ocular ultrasound and highlights some of the pitfalls that can occur when evaluating for retinal detachment. Following is a discussion regarding methods to distinguish retinal detachment from vitreous hemorrhage and posterior vitreous detachment.     

Use of Ocular Ultrasound for the Evaluation of Retinal Detachment

Background: Retinal detachment is an ocular emergency posing diagnostic difficulty for the emergency practitioner. Direct fundoscopy and visual field testing are difficult to perform and do not completely rule out retinal detachment. Ophthalmologists use ocular ultrasound to enhance their clinical acumen in detecting retinal detachments (RD), and bedside ultrasound capability is readily available to many emergency practitioners (EP). Study Objective: Our study sought to assess whether ocular ultrasound would be a helpful adjunct for the diagnosis of RD for the practicing EP. Methods: This was a prospective observational study with a convenience sample of patients. As part of a general course on emergency ultrasonography, practitioners received a 30-min training session on ocular ultrasound before beginning the study. Trained practitioners submitted ultrasound scans with interpretation on patients with signs and symptoms consistent with retinal detachment. Results: Thirty-one of the 72 practitioners trained submitted ocular ultrasound reports on patients presenting to the Emergency Department with concerns for retinal detachments. EPs achieved a 97% sensitivity (95% confidence interval [CI] 82–100%) and 92% specificity (95% CI 82–97%) on 92 examinations (29 retinal detachments). Disc edema and vitreous hemorrhage accounted for false positives, and a subacute retinal detachment accounted for the only false negative. Conclusion: These data show that trained emergency practitioners can use ocular ultrasound as an adjunct to their clinical assessment for retinal detachment.     

A Narrative Review of Common Uses of Ophthalmic Ultrasound in Emergency Medicine

BackgroundThe timely evaluation of ocular conditions in the emergency department (ED) can be difficult due to a general lack of specialized equipment, trained personnel, and the time-sensitive nature of emergent ocular conditions. Recently, the use of ocular point-of-care ultrasound (POCUS) has been shown to be particularly useful in the ED. POCUS can be used to promptly diagnose various ocular pathologies, which include ocular trauma, vitreous hemorrhage, central retinal artery occlusion, and retinal detachment.ObjectivesThis narrative review seeks to inform the reader of current literature regarding the use of POCUS for the assessment of various ocular emergencies in the ED. The goal of this review is to provide the emergency physician with succinct and up-to-date information and instruction regarding the current uses of POCUS for patients presenting with particular ocular emergencies. Ocular pathologies that are common (ocular trauma) or for which ultrasound is particularly useful (such as retinal detachment) are discussed. Other ocular pathologies are also briefly discussed, such as central retinal artery occlusion, which is a promising new application for ultrasound evaluation.DiscussionThere have been many studies that provide evidence for the utility of POCUS in the evaluation of trauma and other ocular pathologies, including vitreous hemorrhage, retinal detachment, and central retinal artery occlusion.ConclusionsOcular POCUS is a useful modality in the evaluation of acute ocular complaints in the ED. Emergency physicians should be aware of these findings and feel confident in the utility of ocular POCUS in the ED.     

Asteroid Hyalosis Masquerading as Vitreous Hemorrhage on Point‐of‐Care Sonography

Point‐of‐care ocular sonography is frequently used in the emergency department to evaluate patients with vision disorders. We describe a case series of 3 patients who ultimately had a diagnosis of asteroid hyalosis, a lesser‐known condition that on point‐of‐care sonography may be mistaken for vitreous hemorrhage. Asteroid hyalosis is considered a benign degenerative condition. In contrast, vitreous hemorrhage may be an ocular emergency that warrants an urgent ophthalmologic consultation if there is an underlying retinal tear or detachment. Although similar in appearance on sonography, recognition of the subtle pathognomonic sonographic features along with their clinical presentations can differentiate these diseases, with vastly different management strategies and dispositions.     

A Unique Case of Valsalva Retinopathy: Preretinal Hemorrhage Identified on Bedside Ultrasound

BackgroundEmergency physicians frequently evaluate patients with vision changes. The differential for this chief symptom is broad. We present a unique cause of a fixed scotoma that started while the patient was running sprints.Case ReportThe patient described a bright central scotoma that later became a dark oblique line across her central vision. This painless defect moved predictably with eye movements. Ocular ultrasonography was performed and revealed a well-demarcated hyperechoic lesion in the posterior segment of the right eye. There was no similar lesion found in her left eye. In consultation with ophthalmology, the patient's history and examination were consistent with valsalva retinopathy. To our knowledge, this is only the second published case of valsalva retinopathy/premacular hemorrhage identified on ocular ultrasonography in emergency medicine literature. In this article, we further expand on management and provide correlating fundoscopic images.Why Should an Emergency Physician Be Aware of This?Emergency physicians frequently evaluate patients with visual changes. Valsalva retinopathy is a rare cause of a visual scotoma that can be diagnosed through history and ultrasound. It often resolves over weeks to months without intervention. However, it does require urgent ophthalmologic evaluation to rule out peripheral retinal tears, which may require laser retinopexy or surgical management.     

Point-of-care ultrasound for the evaluation of non-traumatic visual disturbances in the emergency department: The VIGMO protocol

ObjectivesTo establish a standardized approach for the rapid and accurate identification of non-traumatic, ophthalmologic pathology in patients with eye complaints in the emergency department.MethodsIn this detailed protocol we offer an easy, reproducible method for the use of ocular point-of-care ultrasound (POCUS) in helping practitioners identify and distinguish between common eye pathology encountered in the emergency setting: retinal detachment, vitreous detachment, vitreous hemorrhage, optic nerve pathology, and syneresis.ConclusionsThis protocol can help identify patients that may need urgent ophthalmology consultation those that can follow-up on an outpatient, and those that may need additional emergent testing.     

Ultrasonographic assessment of paediatric ocular emergencies: A tertiary eye hospital based observation

BACKGROUND: The purpose of this study is to assess the utility of ocular ultrasound B scan in the emergency at the first point of care for detecting posterior segment and orbital pathologies in cases of paediatric ocular emergencies.METHODS: A prospective observational study involving 122 paediatric patients presenting to eye emergency over a period of ninety days were assessed with ultrasonography for the posterior segment as well as orbital pathology whenever indicated. The ocular ultrasound was performed gently over closed eyelids.RESULTS: Posttraumatic globe injuries were the most common indication for posterior segment evaluation, which constituted 80 (65.57%) eyes. Among these 52 patients had an anechoic posterior segment and 28 patients had variable findings such as vitreous haemorrhage (8.19%), retinal detachment (6.55%), choroidal detachment (4.91%), posteriorly dislocated clear lens (0.81%) and retained intraocular foreign body (5.73%). Non-traumatic cases constituted around 42 (34.42%) eyes, which included corneal ulcer (7.37%), retinoblastoma (6.55%), endophthalmitis (4.91%), extra-ocular muscle cysticercosis (4.91%), orbital cellulitis (4.09%), periocular haemorrhage (2.45%), proptosis(1.63%), paediatric cataract (1.63%) and cryptophthalmos (0.81%). No adverse events of performing the ultrasound was noted.CONCLUSION: First point ultrasonography in paediatric ocular emergencies is a cheap, portable and an effective tool in the assertion of significant posterior segment and orbital diseases.     

Acute lower extremity pain in an adult patient secondary to bilateral popliteal cysts

Lower leg and calf pain is a common presenting complaint in the Emergency Department and may involve a variety of etiologies, including musculoskeletal and vascular pathology such as deep venous thrombosis. Baker's cysts are a periodic finding in patients suspected of having deep venous thrombosis. As more emergency physicians perform their own lower extremity ultrasound examinations, they encounter Baker's cysts as the cause of unilateral leg pain or swelling. Bilateral Baker's cysts are very rare and may present a diagnostic challenge in the Emergency Department if bedside ultrasound is not available. We present a case of bilateral Baker's cysts in a young dancer who presented complaining of bilateral lower extremity pain and upper calf swelling. The bilateral cysts were diagnosed on bedside ultrasound by the treating emergency physician and a disposition quickly made.     

Do Emergency Physicians Save Time When Locating a Live Intrauterine Pregnancy with Bedside Ultrasonography?

OBJECTIVE: To determine whether patients presenting to the emergency department (ED) with first-trimester pregnancy complications have a decreased length of stay (LOS) when a live intrauterine pregnancy (IUP) is diagnosed by emergency physicians (EPs). METHODS: This study was performed at an urban community ED with a residency program and an annual census of 65,000. A retrospective chart review from October 1995 to August 1998 identified 1,419 patients who received ultrasound examinations confirming live IUP in the first trimester with pain and/or bleeding. Two hundred seventy-seven of these patients received their ultrasound examinations from EPs; 1, 142 patients received a study from radiology and were not scanned by EPs. The LOSs for the two groups were compared and defined as the time from being placed into a room to discharge from the ED. Significance was determined using a two-tailed t-test. Median times with confidence intervals were calculated. RESULTS: When patients had a live IUP confirmed by an EP, the median LOS was 21% (59 min) less than those who received an ultrasound examination by radiology (p = 0.0001; 95% CI = 49 min to 1 hr 17 min). When evaluated by time of day, patients who presented after hours (6 PM to 6 AM) and were scanned by EPs spent 28% (1 hr 17 min) less time in the ED (p = 0.0001; 95% CI = 55 min to 1 hr 37 min). CONCLUSIONS: Emergency physicians identifying live IUP with bedside ultrasonography significantly decreased patients' LOSs in the ED. The decrease in LOS was most apparent for patients presenting during evening and nighttime hours.     

Bedside Emergency Department Ultrasonography in the Evaluation of Ocular Pathology

The number of potential uses of emergency department (ED) ultrasound is growing. This brief report describes its use in two ED patients who presented with acute ocular pathology. The diagnoses were quickly made with ED ultrasound, and subsequently confirmed with more traditional methods of ocular evaluation.     

A Survey of Bedside Ultrasound Use by Emergency Physicians in California

Objective. The purpose of this study was to investigate the current practice of emergency physician–performed bedside ultrasound examinations in California and to assess differences between academic and community practice. Methods. We queried all emergency departments (EDs) in California to determine whether bedside ultrasound was used by emergency physicians. Among EDs that were using bedside ultrasound, we administered a survey to assess use patterns, credentialing criteria, and quality assurance (QA) programs. Results. We contacted all eligible EDs (n = 293) by telephone and had a 100% response rate for our primary question: 101 EDs (34%) reported use of bedside ultrasound. Of these 101 EDs, 97 (96%) responded to the secondary survey, showing the following: (1) 48% of physicians at each site were credentialed to use ultrasound in at least 1 modality; (2) 70% of EDs used American College of Emergency Physicians (ACEP) criteria for credentialing guidelines; and (3) 33% had an ultrasound QA program. Comparing practice settings, 68% of academic departments used bedside ultrasound compared with 29% of community departments (difference, 39%; 95% confidence interval [CI], 23% to 54%; P < .0001). In academic departments, a mean of 60% of physicians were credentialed, compared with 41% in community EDs (difference, 19%; 95% CI, 2.5% to 35%; P = .036). Conclusions. Most California EDs do not use bedside ultrasound. Although most EDs using ultrasound report that they follow ACEP emergency ultrasound guidelines, most do not have a QA program as recommended by these guidelines. Compared with community EDs, academic EDs are more likely to use bedside ultrasound, have physicians credentialed in ultrasound use, and have QA programs.     

An Inexpensive and Easy Simulation Model of Ocular Ultrasound That Mimics Normal Anatomy as Well as Abnormal Ophthalmologic Conditions

We have constructed a simple and inexpensive simulation model for the educational instruction of health care providers to detect normal and abnormal ocular conditions in the bedside emergency setting. Such a training model serves to increase the comfort level in performing ocular ultrasound examinations and can increase the accuracy of examination interpretation. Ophthalmologic examinations can be difficult in the emergency setting, and ultrasound has become a useful tool in the diagnosis of emergent ocular conditions.     

Bedside Ultrasound Diagnosis of Acute Embolic Femoral Artery Occlusion

Background

Acute limb ischemia is both a limb-threatening and life-threatening disease process. Nontraumatic acute peripheral arterial occlusion is most commonly caused by a thrombosis or an embolism.

Objectives

There is limited evidence on the use of bedside ultrasound for the detection of acute limb ischemia, but duplex ultrasonography is standard in the diagnosis and operative planning in chronic limb ischemia. Emergency physicians may use bedside ultrasound in the evaluation of patients with symptoms and signs suggestive of this disease entity.

Case Report

A 64-year-old man with a past medical history of hypertension and an ischemic stroke presented to the Emergency Department with <2 h of severe upper left leg pain that radiated down to his foot. A bedside ultrasound of the left lower extremity was emergently performed. On B-mode ultrasound evaluation, echogenic material was visualized in the left common femoral artery, the artery was noncompressible, and there was an absence of Doppler flow signal. He was then directly taken to the operating room for an emergent limb-saving procedure.

Conclusion

A focused examination of the aorta, iliac vessels, and femoral artery bifurcation with bedside ultrasonography may help to localize peripheral arterial occlusions and can assist the emergency physician in seeking timely surgical consultation and management.     

Unique Method of Ocular Ultrasound Using Transparent Dressings

Background

Utilizing bedside ocular ultrasound to aid in diagnosing pathology such as retinal detachment, lens disruption, ocular foreign bodies, or increased intracranial pressure is becoming more pervasive in the Emergency Department. To eliminate an air interface, one must apply ultrasound gel between the patient's skin and the probe. In ocular ultrasound, this practice results in discomfort for the patient as gel seeps into their eyes. To limit patient discomfort, many physicians do not apply a sufficient amount of gel for the examination. This can result in decreased image quality and may cause the ultrasonographer to apply greater pressure to the eye to obtain a satisfactory image. This can be harmful to patients with a ruptured globe and may also be painful to the patient.

Discussion

Traditionally, the first step in ocular ultrasound is to place a generous amount of water-soluble ultrasound gel on the eyelid to eliminate the air interface. The authors promote a different and simple technique. A transparent dressing is placed over a closed eye. A generous amount of ultrasound gel is applied to the dressing. A linear ultrasound probe is then placed on the gel and a standard ultrasound scan is obtained. Transparent dressings, which are used as sterile coverings for i.v. sites, have been found to allow satisfactory ultrasound transmission. These products remove the air interface between the eyelid and the dressing. This allows ultrasound gel to be placed on the transparent dressing and not directly on the eyelid, potentially eliminating discomfort for the patient, and creating an easier cleanup. Because a generous amount of ultrasound gel is applied, the ultrasonographer is able to apply minimal pressure on the eye to complete the study, which may decrease harm to the patient's eye. When finished, the transparent dressing is removed. There is no cleanup or patient irritation.

Conclusion

This article demonstrates a unique method of ocular ultrasound. The technique can be easily incorporated into emergency bedside ocular ultrasound.     

Can emergency physicians accurately distinguish retinal detachment from posterior vitreous detachment with point-of-care ocular ultrasound?

Study objective

There is significant overlap between the symptoms of patients presenting with retinal detachment (RD) and posterior vitreous detachment (PVD). Urgency to obtain consultation and treatment are dependent on the ability to accurately distinguish these two conditions. The objective of this study was to determine the ability of emergency physicians to differentiate RDs from PVDs using point-of-care (POC) ocular ultrasound.

Examiner Position in Ocular Point-of-Care Ultrasound: A Proposed Technique

BackgroundOcular point-of-care ultrasound (POCUS) is a fast and safe non-invasive procedure used to evaluate the structural integrity and pathology of the eye. Ocular POCUS can be used for evaluation of posterior chamber and orbital pathology, including retinal detachment, vitreous detachment or hemorrhage, foreign body, lens dislocation, and increased intracranial pressure.DiscussionThe purpose of this brief communication is to describe a technique for conducting an ocular POCUS that may in some cases be easier and more comfortable by adjusting the position of the sonographer relative to the patient.ConclusionsTo our knowledge, this proposed technique has not been described in previous literature and may result in greater comfort for both sonographer and patient.     

Performance, training, quality assurance, and reimbursement of emergency physician-performed ultrasonography at academic medical centers.

OBJECTIVE: To determine the current state of bedside emergency physician-performed ultrasonography in terms of prevalence, training, quality assurance, and reimbursement at emergency medicine residency programs. METHODS: The link to a 10-question Web-based survey was e-mailed to ultrasound/residency directors at 122 emergency medicine residency programs in the United States. RESULTS: The overall response rate was 84%. Ninety-two percent of programs reported 24-hour emergency physician-performed ultrasonography availability. Fifty-one percent of programs reported that a credentialing/privileging plan was in place at their hospital, and 71% of programs had a quality assurance/image review procedure in place. Emergency medicine specialty-specific guidelines of 150 ultrasonographic examinations and 40 hours of didactic instruction were met by 39% and 22% of residencies, respectively, although only 13.7% of programs were completing the 300 examinations recommended by the American Institute of Ultrasound in Medicine. Sixteen programs (16%) reported that they were currently billing for emergency physician-performed ultrasonography; of those not billing, 10 (12%) planned to bill within 1 year, and 32 (37%) planned to bill at some point in the future. CONCLUSIONS: Performance and training in emergency physician-performed ultrasonography at academic medical centers continues to increase. The number of emergency medicine residency programs meeting specialty-specific guidelines has more than doubled in the last 4 years, but only a small number are meeting American Institute of Ultrasound in Medicine guidelines. Although only 16% of programs reported that they were currently billing for emergency physician-performed ultrasonography, most had plans to bill in the future.     

Lung ultrasound in the evaluation of patients with pleuritic pain in the emergency department

The evaluation of pleuritic pain in the emergency setting is a diagnostic challenge. Most patients are discharged from the Emergency Department (ED) with a diagnosis of chest wall pain not otherwise specified. It is important to rule out possible sources of acute pleuritic pain, like pulmonary embolism, pneumonia, lung cancer, and pneumothorax. Clinical examination, plain film radiography of the chest, and other routine investigations may be inadequate to make the correct diagnosis. In this setting, another bedside test to aid diagnosis would be useful. ED bedside lung ultrasound is a novel technique for the diagnosis of lung diseases. We report on 5 patients who presented to our ED complaining of pleuritic pain, few other symptoms, and negative routine investigations, in whom bedside lung ultrasound aided in making the diagnosis.