Pitfalls & Challenges
Ocular POCUS in children should be considered primarily a “rule-in” tool, where abnormal findings can support the diagnosis and expedite ophthalmology consultation, but a normal scan should not be used to exclude disease when the history or examination raises concern.
As with all pediatric POCUS, child cooperation remains a challenge. An uncooperative child can lead to motion artefact, incomplete views, or missed findings. Short, focused sweeps combined with distraction or parental assistance can improve image acquisition, while definitive diagnosis should always involve ophthalmology when cooperation or image quality is limited. Artefacts also present a challenge. Reverberation artefact within the vitreous may mimic hemorrhage or other pathology. Optimizing gain and depth, performing sweeps in multiple planes, and comparing both eyes can reduce the risk of misinterpretation.
Even with optimal technique, certain conditions, such as anterior segment pathology may limit visualization of the posterior segment, reducing diagnostic confidence and making comparisons with the unaffected eye especially important [5]. If there is uncertainty due to limited visualization, an ophthalmology referral should always be organized.
Differentiating vitreous hemorrhage/detachment from retinal detachment is another common difficulty, as both appear as echogenic material within the posterior chamber. A key distinction is that retinal detachments remain tethered to the optic nerve head, while vitreous hemorrhage is more mobile and free-floating with eye movement. Vitreous detachment also will remain horizontal when the patient moves their eye side to side.
In suspected globe rupture, POCUS is contraindicated because even minimal probe pressure can worsen the injury. If rupture is a leading concern, POCUS should be avoided; however, in cases where scanning was performed for another indication and a rupture is incidentally suspected, the study should be stopped immediately and urgent ophthalmology consultation obtained.
Safety is another important consideration. Ocular tissues are particularly sensitive to ultrasound acoustic output, so the MI/TI should always be kept as low as possible. Ideally, an “ocular” preset should be used. If the machine does not offer one, the user must manually minimize output settings (MI ≤ 0.23, TI ≤ 1.0). Users should also refrain from applying color or pulsed wave doppler to avoid increasing the power output.