New Floaters After Minor Eye Trauma: Ocular POCUS When Fundoscopy Is Limited
This article also appears in the Southern Medical Association News at this link.
Case Presentation
A 46-year-old man presents to the emergency department after being struck in the right eye by his toddler’s elbow the previous evening. He reports blurred vision and new floaters in the right eye. He denies eye pain, flashes of light, or a curtain descending over his vision.
He has no history of diabetes, hypertension, or prior eye disease, and takes no anticoagulant or antiplatelet medication. The left eye is unaffected.
On examination, visual acuity in the right eye is 20/30. Pupils are equal and reactive with no afferent pupillary defect. Intraocular pressure is normal and there is no hyphema. Fundoscopic examination is limited by poor posterior visualization.
A point-of-care ocular ultrasound of the right eye is performed.
What do you see, and what’s the diagnosis?
Clip 1: Ocular ultrasound of the right eye demonstrating echogenic debris within the vitreous chamber that swirls freely with eye movement, consistent with vitreous hemorrhage. The retina remains apposed to the posterior globe, with no thick membrane tethered at the optic disc.
POCUS Findings
The ultrasound demonstrates vitreous hemorrhage without sonographic evidence of retinal detachment, characterized by:
Mobile, low-amplitude echogenic material within the vitreous chamber
Debris that swirls and resettles with eye movement rather than moving as a single sheet
No attachment to the optic disc
No thick, bright, V-shaped membrane
Findings that become apparent only after the gain is increased, and are easy to miss at standard settings
What a Normal Ocular POCUS Should Show
Uniformly anechoic vitreous chamber, even at increased gain
Smooth, unbroken posterior globe contour
Anechoic lens with no internal echoes or membranes
Hypoechoic optic nerve sheath extending posteriorly from the disc
Clip 2: Normal ocular ultrasound demonstrating an anechoic posterior chamber.
Distinguishing Vitreous Hemorrhage from Retinal Detachment
Vitreous hemorrhage
Low-amplitude, particulate echoes that swirl with eye movement
Free-floating, with no fixed attachment point
Often requires increased gain to visualize
Common causes: proliferative diabetic retinopathy, trauma, retinal tear, retinal vein occlusion, posterior vitreous detachment
Retinal detachment
Bright, thick, continuous membrane
Undulates with eye movement but stays tethered, classically at the optic disc, producing a V shape when the detachment is extensive
Visible at standard gain
Common causes: retinal tear, trauma, posterior vitreous detachment, high myopia
Common Pitfalls
Gain set too low. Mild vitreous hemorrhage is frequently invisible at the gain used for a standard exam. Increase the gain until the vitreous just begins to fill with noise, then reassess.
Gain set too high. Excessive gain generates artifactual echoes that mimic hemorrhage. Compare with the unaffected eye at identical settings before calling a subtle finding abnormal.
Static imaging. Both hemorrhage and detachment are defined largely by how they move. Have the patient look left, right, up, and down while you watch. Debris that swirls and resettles behaves differently from a membrane that snaps back to its attachment.
Scanning in a single plane. Confirm findings in both transverse and longitudinal planes before acting on them.
Asteroid hyalosis. Brightly reflective, discrete particles suspended throughout the vitreous that also move with eye movement. The echoes are brighter and more punctate than hemorrhage, and vision is typically unaffected.
Suspected open globe injury. Ocular POCUS is contraindicated when globe rupture is suspected, because compression risks extrusion of intraocular contents. Assess mechanism and external findings before placing a probe on the eye.
Evidence
In the largest multicenter prospective study of emergency physician-performed ocular POCUS, covering 225 patients across four emergency departments, sensitivity and specificity were 81.9% and 82.3% for vitreous hemorrhage, and 96.9% and 88.1% for retinal detachment. [1] A systematic review and meta-analysis of 11 studies and 844 patients reported 94.2% sensitivity and 96.3% specificity for retinal detachment. [2]
The practical reading of these numbers: ocular POCUS answers "is the retina detached" well, and answers "is there blood in the vitreous" moderately well.
The more consequential limitation is what ultrasound cannot resolve. In a series of 106 eyes with dense vitreous hemorrhage evaluated with A- and B-scan ultrasound, all retinal detachments were correctly identified, but retinal tears were diagnosed and localized accurately in only 4 of 9 eyes. That same series had an 18.9% false-positive rate for retinal detachment. [3] Retinal tears are small, usually peripheral, and poorly resolved through blood.
This matters because vitreous hemorrhage and retinal tear share the same mechanisms, and an untreated tear can progress to detachment. [4] A retina that looks attached on POCUS does not exclude a peripheral tear.
Where POCUS Changes Management
In vitreous hemorrhage, ocular POCUS is most useful for triage rather than for definitive diagnosis.
Escalate to emergent ophthalmology evaluation when:
POCUS shows a detached retina, particularly when central vision is still preserved, since macula-on detachment is the most time-sensitive scenario
The study is equivocal or technically limited
Visual acuity is significantly reduced, or an afferent pupillary defect is present
The patient is on anticoagulant or antiplatelet therapy
The hemorrhage is dense enough to obscure the retina
The mechanism does not explain the finding, since spontaneous hemorrhage carries a higher likelihood of an underlying tear or proliferative retinopathy
Open globe injury is suspected, in which case the eye should not be scanned at all
Outpatient ophthalmology follow-up is reasonable when:
The mechanism is clear and minor
Visual acuity is at or near baseline
The patient is not anticoagulated
There is no sonographic evidence of retinal detachment
A dilated retinal examination can be reliably arranged, and the patient understands return precautions
In every case the definitive step is a dilated retinal examination. POCUS informs how quickly that needs to happen. It does not replace it.
Bedside Technique
Place a Tegaderm over the closed eyelid, then apply a generous layer of gel on top of the Tegaderm. This improves patient comfort and cleanup.
Use a high-frequency linear transducer with an ocular preset when available, which limits acoustic output to the eye.
Rest your hand on the bridge of the nose or the zygoma so that no pressure is transmitted to the globe.
Start at standard gain, then increase it deliberately to look for subtle vitreous echoes.
Sweep through the entire globe in two planes, with dynamic eye movement in each.
Scan the unaffected eye at identical settings for comparison.
For a quick bedside reference download the Hello Sono Ocular POCUS Reference Card.
Case Resolution
POCUS demonstrated mobile echogenic debris consistent with vitreous hemorrhage, with no sonographic evidence of retinal detachment. Given the clear traumatic mechanism, near-baseline visual acuity, absence of anticoagulation, and no findings of detachment, the patient did not require emergent operative or ophthalmologic intervention.
He was referred for outpatient ophthalmology evaluation with a dilated retinal examination, and given strict return precautions for worsening vision, a curtain or shadow in the visual field, new flashes, increasing floaters, or eye pain. He was counseled to sleep with the head of the bed elevated and to avoid strenuous activity and Valsalva until examined.
Impact of POCUS
In this case, a brief bedside examination:
Established a specific finding when fundoscopy was non-diagnostic
Provided immediate evidence against retinal detachment, the vision-threatening diagnosis on the differential
Converted an undifferentiated presentation into a defined referral with defined return precautions
Gave the receiving ophthalmologist concrete information ahead of the visit
What POCUS did not do was exclude a retinal tear. Recognizing that boundary is the difference between using ocular ultrasound well and over-trusting it.
Conclusion
Ocular POCUS is fast, well tolerated, and readily learned, and it answers the question that matters most at the bedside: is there sonographic evidence of retinal detachment. In a patient with new floaters and a fundoscopic examination limited by media opacity, it converts uncertainty into a defensible disposition.
Its value depends on knowing its limits. Vitreous hemorrhage on ultrasound is a finding, not a final diagnosis, and the underlying cause still has to be established by dilated examination. Used with that framing, ocular POCUS improves triage accuracy and speeds appropriate referral without displacing the ophthalmologist.
For practices considering implementing or expanding POCUS programs, tools such as POCUS ROI Calculators and a POCUS Billing Readiness Checklist can help estimate financial impact and ensure appropriate workflow and documentation processes are in place.
References:
Lahham S, Shniter I, Thompson M, Le D, Chadha T, Mailhot T, Kang TL, Chiem A, Tseeng S, Fox JC. Point-of-care ultrasonography in the diagnosis of retinal detachment, vitreous hemorrhage, and vitreous detachment in the emergency department. JAMA Netw Open. 2019;2(4):e192162. doi:10.1001/jamanetworkopen.2019.2162
Gottlieb M, Holladay D, Peksa GD. Point-of-care ocular ultrasound for the diagnosis of retinal detachment: a systematic review and meta-analysis. Acad Emerg Med. 2019;26(8):931-939. doi:10.1111/acem.13682
Rabinowitz R, Yagev R, Shoham A, Lifshitz T. Comparison between clinical and ultrasound findings in patients with vitreous hemorrhage. Eye (Lond). 2004;18(3):253-256. doi:10.1038/sj.eye.6700632
Shaikh N, Srishti R, Khanum A, et al. Vitreous hemorrhage: causes, diagnosis, and management. Indian J Ophthalmol. 2023;71(1):28-38. doi:10.4103/ijo.IJO_928_22
Schott ML, Pierog JE, Williams SR. Pitfalls in the use of ocular ultrasound for evaluation of acute vision loss. J Emerg Med. 2013;44(6):1136-1139. doi:10.1016/j.jemermed.2012.11.079