What is NOT Normal?

Several pathologic findings can disrupt normal patterns in the eye as seen on ultrasound. The following conditions represent important pediatric ocular pathologies that can be identified with ultrasound and should be recognized as abnormal.

Abnormalities of the lens

Abnormalities of the lens are observed either by changes in its position within the eye (dislocation) or by alterations in its contour or echogenicity (cataracts).

Lens Dislocation

Lens dislocation is the displacement of the lens from its normal position. It can be acquired (often traumatic) or congenital (ectopia lentis).

· Sonographic appearance: The normally circular, echogenic lens is displaced from its central location behind the iris, floating or tilted in the posterior chamber or vitreous. “Floating lens sign” refers to when the lens is seen moving freely with eye movements.

Figure 8. Lens dislocation evidenced by the displacement of the lens in the vitreous at the posterior aspect of the globe. Video courtesy of Dr. Jade Seguin, used with permission.

Contour & Echogenicity

Any variation from the normal smooth, anechoic lens can indicate an abnormality of the lens.

· Sonographic appearance: If the lens appears heterogeneous, thickened, irregular in contour, or hyperechoic, this suggests a structural or developmental abnormality, such as congenital or acquired cataracts.

 

Figure 9. Abnormal lens evidenced by its irregular contour with a thickened, hyperechoic appearance.  Findings were ultimately consistent with cataracts. Video courtesy of Dr. Jade Seguin, used with permission.

 

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Abnormalities of the Vitreous

Vitreous Hemorrhage

Vitreous Hemorrhage refers to bleeding into the vitreous chamber of the eye. In children, it can be caused by various intraocular diseases, however, is most commonly caused by trauma [20].

· Sonographic appearance: The appearance will vary depending on the amount of blood. It may appear as echogenic debris within the vitreous chamber, or a hyperechoic focus/membrane deep in the vitreous.

 

 

Figure 10. Vitreous hemorrhage as seen by the echogenic debris within the vitreous. Video courtesy of Dr. Jade Seguin, used with permission.

 

 

Vitreous Detachment

Vitreous detachment is usually benign and does not lead to vision loss. It refers to the separation of the posterior vitreous body from the retina. It is uncommon in children and usually occurs secondary to trauma.

Sonographic appearance:

· A Hyperechoic membrane will be seen floating in the vitreous. The membrane will NOT be tethered to the optic disc, but rather it will be free floating in the posterior chamber.

·  Vitreous hemorrhages remain horizontal when the patient moves their eye side to side.

·  Most often seen in the middle section of the posterior eye

 

Figure 11. Vitreous detachment. Note how there is no connection to the optic nerve and the horizontal appearance of the detachment membrane. Video courtesy of Dr. Eric Roseman, Kings County Emergency Medicine, via POCUS Atlas . Used under CC BY-NC 4.0 license.

 

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Abnormalities of the Retina

Any disruption of the normally thin, echogenic, and anchored retinal layer can indicate a pathology.

Retinal Detachment

Retinal detachments can lead to permanent vision loss if not treated in a timely manner. Retinal detachment occurs when the sensory layer of the retina separates from the underlying layer. In children, trauma is the most common cause, although other congenital or acquired conditions can also lead to detachment [20].

Sonographic appearance:

· A thin, hyperechoic membrane will be seen floating in the vitreous. The membrane will be tethered posteriorly at the optic nerve head. This gives a “V-shaped” appearance.

· A detached retina will move with eye motion but remain anchored posteriorly at the ON head.

** This anchoring will distinguish retinal detachment from a vitreous hemorrhage and detachment**

· Small detachments will be tethered closed to the posterior aspect of the eye and will move less with eye movements [21].

Figure 12. Retinal Detachment, with a “V-shaped” appearance due to anchoring to the ON head. Image courtesy of Dr. Michael Kidon, Denver Health Emergency Medicine, via POCUS Atlas . Used under CC BY-NC 4.0 license.

 

Masses and structural changes

Any thickening or focal lesion arising from or within the retina should be considered abnormal. This may represent tumors (e.g. retinoblastoma), bleeding (retinal hemorrhages), vascular anomalies (e.g. Coat’s disease), or developmental structural changes.

· Sonographic appearance: Thickening or echogenic structures within or extending from the retinal layer, distinct from the thin, normally smooth retina. Echogenicity may be variable, and calcifications may be present (e.g. retinoblastoma).

 

Figure 13. Posterolateral mass protruding from the retina in a child with Coats disease. Image courtesy of Dr. Jade Seguin, used with permission.

 

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Intraocular Foreign Bodies (IOFB)

Foreign materials (metal, glass, wood, etc.) can become lodged in the globe of the eye and can often be visualized with ultrasound.

Key Considerations: IOFB may be associated with vitreous hemorrhage, retinal detachment and/or globe rupture. If an IOFB is visualized, stop scanning immediately and notify ophthalmology. This helps prevent further displacement of the foreign body and protects against worsening injury if the globe is ruptured, since any pressure could precipitate complications or extrusion of intraocular contents.

· Sonographic appearance: Foreign material will appear as a hyperechoic object with posterior acoustic shadowing, reverberation or comet tail artifact [20]. IOFB can be located in the anterior chamber, lens, vitreous, retina, or other regions of the globe, depending on the mechanism and trajectory of injury.

 

Figure 14. Hyperechoic structure seen anteriorly, adjacent to the globe. Note that with dynamic eye movements the foreign body does not move suggesting this is outside of the globe. Video courtesy of Dr. Robert Jones, MetroHealth Medical Center / Case Western Reserve University, via POCUS Atlas . Used under CC BY-NC 4.0 license.

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Periorbital Abnormalities

Abnormalities of the periorbital tissues can be identified by changes in tissue echogenicity, swelling, or the presence of fluid collections. Assess for hypoechoic or anechoic areas, asymmetry between orbits, restricted extraocular eye movement, and disruption of normal soft tissue planes. Examples include:

· Soft tissue edema/cellulitis: Diffuse hypoechoic thickening of the periorbital soft tissues. Often poorly defined and may involve the eyelids and surrounding orbital tissues

· Abscess: Well-defined, localized hypoechoic or anechoic collection with irregular borders; may show internal echoes and sometimes posterior enhancement.

· Glioma: A mass arising from the optic nerve or adjacent to the orbit, which may cause displacement of ocular tissue

· Orbital Fractures: PoCUS can he used to assess for fractures of the infraorbital rim and lateral orbital wall [22-25]. Fractures will be seen as a discontinuity or displacement of the echogenic bone cortex [25].

 

Figure 15. Hypoechoic collection in the medial retro-orbital fat of the right orbit. Subsequent CT confirmed a right medial orbital abscess. Image courtesy of Dr. Jade Seguin, used with permission.

 

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Optic Disk Variants and Findings

Both anatomical variants and optic disc pathologies may occasionally be observed during ocular ultrasound. While these are discussed in greater detail in the KidSONO Optic Nerve Module, it is useful to recognize how they may appear in relation to the posterior globe and retinal plane:

· Optic Disc Drusen (figure 16): Drusen are acellular deposits that calcify over time. They are typically buried in early childhood, becoming superficial around age 12 [27]. In early childhood, the buried deposits push the optic nerve head anteriorly into the vitreous, appearing as focal elevations of the optic disk from the posterior globe. Late in childhood they can appear as echogenic foci (due to calcified deposits) with posterior shadowing located at the optic disk. They are typically bilateral.

· Tilted Optic Discs (figure 17): Represent an anatomical variant in which the optic disc is oriented obliquely. This results in an apparent elevation or irregular contour of the posterior globe that can mimic pathology, buts its simply due to the disc’s oblique angle.

 

Figure 16. Optic disk drusen. Image courtesy of Dr. Jade Seguin, used with permission

Figure 17. Video demonstrating a tilted optic disc, which can pathology at the posterior globe/retinal plane. Video courtesy of Dr. Jade Seguin, used with permission

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Pupillary Response 

PoCUS can be used as an adjunct to assess pupillary response through closed eyelids using standardized light stimulation. It can be particularly valuable in pediatric trauma and critically ill children where direct assessment may be limited. Ultrasound assessment has shown excellent agreement with clinical examination for pupillary light reflex, including direct and consensual responses (ICC 0.93–0.96; agreement 87.36%) [28].

The transducer is placed transversely on the lower eyelid at approximately a 45-degree angle from the globe, using a torchlight for pupillary light reflex examination [28].

Sonographic findings suggestive of abnormal pupillary response include:

· Absent or reduced pupillary constriction

· Delayed or asymmetric response,

· Absent consensual response

 

Figure 18. Ocular PoCUS assessment of pupillary response through closed eyelids. B-mode images demonstrate pupillary diameter measurement at baseline (left) and following light stimulation (right). Image courtesy of Dr. Jade Seguin, used with permission

 

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Globe Rupture

In suspected globe rupture, POCUS is contraindicated because even minimal probe pressure can worsen the injury. In children with obvious trauma to the eye presenting with a misshapen globe, peaked pupil, Seidel sign, or extrusion of intraocular contents, POCUS should NOT be performed.

In the case that globe rupture was not the clinical suspicion, and PoCUS was performed, it will appear as:

· Loss of normal spherical shape of the globe

· Flattening of the anterior chamber

· Buckling of the sclera

· Vitreous hemorrhage

 

Figure 19. POCUS of the right orbit following blunt ocular demonstrating complete loss of normal globe architecture, consistent with globe rupture. Video courtesy of Dr. Earl Cummings, MUSC Emergency and Pediatric Emergency Medicine, via POCUS Atlas . Used under CC BY-NC 4.0 license.

What is Normal?

The normal pediatric eye appears symmetric and well-structured, with clear chambers, a centered lens, and an intact retina on ultrasound. Because a generous amount of gel is used in ocular ultrasound to minimize pressure on the eye, a thin layer of gel will be visible on the image. The eye will have the same appearance in both sagittal and transverse planes, reflecting its round, symmetric shape.

• Eyelid: Thin, echogenic superficial layer.
• Anterior Chamber: Anechoic, uniform depth, no internal echoes.
• Iris: Thin echogenic line anterior to the lens.
• Posterior Chamber: Anechoic space immediately posterior to the iris.
• Lens: Bright, round, echogenic posterior border with an anechoic center. Symmetric and centered behind the iris.
• Vitreous: Uniformly anechoic, without internal echoes.
• Retina: Thin echogenic line along the posterior globe; flat and attached.
• Optic Nerve: Hypoechoic tubular structure extending posteriorly from the globe.

 

Figure 5. Normal ocular ultrasound of the right eye, labeled.

 

Figure 6. Normal eye on PoCUS.

 

 

Ocular Movements (figure 7):

Eye movements are seen as smooth, coordinated shifts of the globe. The lens and iris move together, and the retina remains attached and stable. Uniform motion in all directions indicates normal extraocular muscle function.

 

Figure 7. Normal ocular movements seen on ultrasound

 

 

What am I Looking at?

The eye is made up of several key structures, each with its own role in vision. A basic understanding of ocular anatomy is essential for orienting the probe and interpreting ocular PoCUS findings. Figure 4 illustrates the key anatomical structures of the eye as visualized with ultrasound.

 

Figure 4: Anatomical diagram of the eye in relation to ocular ultrasound

 

** Details on optic nerve POCUS for ICP/papilledema is covered in a separate KidSONO Module

Technique

Position:  Supine or head elevated at 30 degrees, on the bed or in a caregiver’s lap

1. Gather your equipment and select the ocular/ophthalmic preset*

2. Have the child close their eye and apply the Tegaderm adhesive (if available).

· If no Tegaderm adhesive is available, it is essential the child keeps their eye closed throughout the exam and to use sterile gel

· Ensure to press firmly at the inner canthus to avoid having air bubble under the Tegaderm

3. Apply a copious amount of sterile gel over the affected eye so the probe floats on the surface, minimizing pressure on the globe.

4. Place the probe in the transverse position over the affected eye (probe marker pointing towards the patients right) (figure 2).

5. Fan the probe superiorly and inferiorly until the anatomy of the eye is clearly visualized

6. Fully scan through the eye from superior to inferior, assessing the anatomy throughout. Document findings

7. Assess extraocular movements – ask the child to move their eyes left and right

8. Rotate the probe 90 degrees clockwise (probe marker facing cranially) to assess in the sagittal plane (figure 3).

9. Fan the probe medially and laterally until the anatomy of the eye is clearly visualized

10. Fully scan through the eye from medial to lateral, assessing the anatomy throughout. Document findings

11. If uncertain of findings, assess the non-affected eye to compare

 

 

Figure 2. Transverse probe position during ocular PoCUS with Tegaderm and copious gel

 

Figure 3. Sagittal probe position during ocular PoCUS with Tegaderm and copious gel

Indications 

• Ocular trauma
• Acute eye pain 
• Intraocular foreign body 
• Vision loss 
• Infection
• Change of vision
• Difficult and/or inconclusive fundoscopic exam
• Leukocoria 

Contraindications 

• Suspected globe rupture 

 

Equipment 

• US machine 
• High frequency linear probe 
• Tegaderm transparent adhesive 
• Sterile Gel

Preset

• Ocular/ophthalmic preset

* The eye is more vulnerable to the bioeffects of ultrasound than most other body tissues. For this reason, it is essential to maintain very low mechanical index (MI) and thermal index (TI) during ocular scanning to minimize the theoretical risk of tissue damage [3]. If your POCUS system does not provide a dedicated ocular/ophthalmic preset, the MI should be set at 0.23 or lower and the TI of 1.0 or lower [17-19]. Doppler modes (color and pulsed wave) increase acoustic output, and such, their use is not recommended in pediatric ocular POCUS.  

The MI/TI can be found on the imaging screen on most PoCUS machines. (Figure 1)  

 

Figure 1. Acceptable MI and TI as seen on ophthalmic preset of a Sonosite PoCUS unit. 

 

Ocular complaints are a common reason for presentation to the pediatric emergency department (ED). According to a five-year retrospective study in Ontario, children accounted for approximately 19% of the 774,057 eye-related ED visits, underscoring the substantial pediatric burden of ocular emergencies [1]. While many cases are benign, some may reflect serious ocular trauma or underlying systemic or neurological disease, making timely recognition and referral essential for preserving vision and preventing complications [2]. 

Ocular complaints, particularly in children, represent a diagnostic challenge to many non-ophthalmology specialists. Traditional diagnostic methods, such as direct fundoscopic examination performed by non-experts, can be challenging given the limited collaboration of the younger pediatric patients.  Other modalities such as computed tomography (CT), or magnetic resonance imaging (MRI), can be time-consuming, expose children to radiation, require transportation and sedation, and may not always be readily available. Furthermore, ophthalmology consultation may not be readily available for evaluation of children presenting to the ED. 

In recent years, point-of-care ultrasound (PoCUS) has emerged as a valuable tool for evaluating ocular complaints in the pediatric ED. It allows for rapid, bedside imaging performed by emergency physicians, providing real-time diagnostic information without the typical challenges associated with fundoscopic exam [3]. As PoCUS becomes increasingly integrated into pediatric emergency care, there is a growing body of evidence supporting its clinical utility in detecting ocular abnormalities [3-6]. Given the frequency of ocular complaints in children and the need for a more user-friendly diagnostic tool, PoCUS offers a compelling adjunct to fundoscopy and other imaging (CT/MRI) in appropriate clinical contexts. 

 

This module focuses on the normal and abnormal anatomy of the pediatric eye, providing learners with the foundational skills to identify common anterior and posterior segment findings using PoCUS. Assessment of the optic nerve for raised intracranial pressure or papilledema is beyond the scope of this module and is addressed in detail in a separate KidSONO module. 

 

Why Ultrasound?

Traditionally, bedside emergency evaluation of ocular pathology has relied on physical examination and direct fundoscopy. Direct fundoscopy is the primary examination for visualizing posterior segment pathology, including retinal detachment, vitreous detachment, vitreous hemorrhage, and intraocular masses, with MRI occasionally used for deeper structural or space-occupying lesions. However, fundoscopy presents significant challenges, particularly in children and when performed by non-ophthalmologists. It can be technically difficult to carry out, and many non-ophthalmology physicians report a lack of confidence in performing and accurately interpreting the exam [7-10]. Children’s cooperation can be particularly limited due to young age, developmental stage, anxiety, or fear, all of which may compromise the reliability of fundoscopic findings [3]. Moreover, the technique is known to have high false-negative rates when performed by non-ophthalmologists, emphasizing its dependency on examiner expertise [9]. Assessment of anterior segment pathology such as intraocular foreign bodies, corneal injuries, or lens abnormalities, typically relies on slit-lamp examination or CT imaging. Slit lamp assessment is a challenging skill at the bedside due to equipment limitations, lack of consistent training and routine use, and patient compliance. CT carries the disadvantage of ionizing radiation exposure, which is particularly concerning in pediatric populations.  

 

PoCUS offers a valuable alternative or precursor to these conventional methods, allowing real-time visualization of both anterior and posterior ocular structures at the bedside. Its versatility, portability, cost-effectiveness, and safety have contributed to its growing role as a frontline imaging modality in pediatric care. When performed by trained emergency physicians, PoCUS has demonstrated high sensitivity and specificity for a range of ocular pathologies. In a systematic review and meta-analysis in adult populations, PoCUS achieved high sensitivity and specificity across multiple ocular conditions (Table 1) [11]. 

Table 1. Diagnostic accuracy of PoCUS [11].

 

Ocular PoCUS, like other PoCUS applications, is a skill that can be readily acquired through focused training combining didactic instruction and hands-on practice [12, 13]. It has been demonstrated that PEM physicians are able to rapidly achieve competency in ocular scanning, even for more advanced applications such as optic nerve assessment (covered in a separate KidSONO module), highlighting the overall ease and accessibility of ocular PoCUS training [14]. 

 

Given these advantages, the use of PoCUS for ocular complaints is endorsed by several professional societies  [15, 16]. While ocular PoCUS is not intended to replace fundoscopy or advanced imaging such as CT or MRI, it functions as an effective adjunctive tool to support rapid bedside diagnosis and facilitate timely ophthalmology consultation when abnormalities are detected. In practice, ocular PoCUS should be applied as a “rule-in” test, helping confirm suspected pathology and prioritize urgent referral, rather than a “rule-out” test in cases where the clinical history or presentation raises concern for serious ocular disease. 

 

Author: Julia Stiz, MSc., RDMS

Secondary Author: Melanie Williman, MD, FRCPC

Reviewer(s): Jade Seguin, M.D., FRCPC ; Jackie Harrison, M.D., FRCPC

 

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