POCUS Education for the Week

Josh Greenstein, MD FACEP

A 59-year-old male presented to the ED with right eye pain and blurry vision for one hour after being struck in the eye. On examination, visual acuity was count fingers at four feet, and intraocular pressure was 60 mmHg. The eye was mildly injected, pupils were round, and reactive to light, and there was no afferent pupillary defect. Seidel test was negative. A bedside ultrasound was obtained (see attached), and the following CT was also obtained afterwards.

What is the Diagnosis?

Posterior lens dislocation (PLD)

Can you explain what I am looking at?

CT - Axial maxillofacial CT demonstrating a posteriorly dislocated lens (arrowhead) at the posterior aspect of the right globe (arrow).

Video - A transverse ocular ultrasound demonstrates a posterior dislocated lens (arrow).

How do you get a PLD?

It is typically caused by trauma and when the lens shifts from its normal position due to disruption of zonular fibers. In posterior dislocations, the lens is seen floating in the vitreous or resting on the retina. Non-traumatic causes include hereditary connective tissue disorders.

What are some atraumatic risks factors for a posterior lens dislocation?

Risk factors include male sex, high myopia, prior pars plana vitrectomy, and pre-existing lens subluxation.

What are the symptoms?

Blurred vision, monocular diplopia, floaters, or fluctuating visual acuity.

What is the differential diagnosis?

The differential includes retinal detachment, globe rupture, posterior vitreous detachment, hyphema, corneal laceration, conjunctival hemorrhage, retrobulbar hemorrhage, and iatrogenic complications.

When concerned for a PLD do I need a CT scan?

Initial evaluation involves a detailed eye examination and ocular ultrasound. CT is indicated in trauma cases, especially if globe rupture is suspected or ocular compression must be avoided.

When I am done with the ultrasound machine what do I do?

Providers should clean the probe and return it to critical care, room 6 or in front of the peds desk.

What is the treatment?

Management involves stabilization, evaluation for associated injuries, and emergent ophthalmology consultation. Mydriatics and lens repositioning may be considered in select cases, but definitive treatment typically involves surgical removal and implantation of an artificial lens.