The Case:
The patient is a 61-year-old male with non-insulin dependent diabetes, hypertension, coronary artery disease status post CABG in 2019 who presented with blurry vision of the left eye after being hit on the face with a blunt object by his roommate approximately ten days prior to presentation. The patient reports that over the past year his roommate had been abusing him physically. Ten days prior to presentation, the patient was hit in the face with an unknown blunt object, causing him to lose consciousness for an unknown period. He awoke with left eye swelling and blurry vision in the left eye which he has had since. He denies headache, dizziness, eye pain, tearing or discharge, foreign body sensation, or double vision.
On exam the patient’s left periorbital area was ecchymotic with mild conjunctival injection. The left pupil was approximately 3 mm, sluggishly reactive to light with intact accommodation. Extraocular muscles were intact without pain with range of motion. Visual acuity was OD 20/40, OS 20/200 without correction. Fluorescein exam was completed without any uptake. Intraocular pressures were unremarkable.
On point-of-care ocular ultrasound of the affected eye using the linear probe a round, mobile structure was noted in the posterior chamber with an absence of the lens in its typical position, consistent with posterior lens dislocation.
As the patient was also having facial pain and reported multiple episodes of blunt facial trauma over the past months, CT facial bones was completed which demonstrated chronic fracture deformities of the left inferior orbital wall, a communited chronic nasal bone fracture, and confirmed posterior lens dislocation.
In this case, ophthalmology was consulted for lens dislocation. Their exam confirmed posterior lens dislocation with no evidence of entrapment. The patient was scheduled for lensectomy and lens implantation. OMFS was consulted for multiple facial fractures for which patient was set up to follow up in clinic. Surgery was completed approximately one month after presentation with improvement in vision to 20/80 at last documented ophthalmology follow up appointment.
Discussion:
Lens dislocation, or ectopia lentis, refers to subluxation or dislocation of the lens of the eye from its typical location. Lens dislocation is most commonly due to trauma but can also occur spontaneously, for example in Marfan syndrome and homocystinuria (2) or in cases or prior ocular surgery such as cataract surgery (4). The lens can either be subluxed, which on ultrasound is seen as unilateral detachment of the lens in the vitreous while the contralateral aspect remains attached to the iris. Complete dislocation is visualized on ultrasound as a dependent round or oval structure in the vitreous with mobility with eye movements (2).
What is the utility of point-of-care ultrasound in identifying lens dislocation?
In a prospective cohort study of patients with suspected traumatic eye injuries, compared to CT imaging, point of care ocular ultrasound had a specificity for identifying lens dislocation of 99.4% and a sensitivity of 96.8% (2). A major advantage of point-of-care ocular ultrasound is its use in quickly evaluating for lens dislocations in situations where advanced imaging may delay diagnosis.
Lens dislocations can also be associated with traumatic cataracts and vitreous hemorrhage, which can also be visualized on ultrasound.
Point-of-care ocular ultrasound should not be performed if there is suspicion for globe rupture.
What are the complications of lens dislocation?
Anterior lens dislocations often need more emergent surgical intervention because they can cause acute angle-closure glaucoma. Posterior dislocations can often be managed in an urgent outpatient basis (1). Other complications of untreated lens dislocation include uveitis, glaucoma, cataracts, and permanent vision loss.
What is the management of lens dislocation?
When a lens dislocation is identified in the emergency department, ophthalmology should be consulted emergently.
In cases where vision is minimally impacted and there is minimal damage to surrounding structures, observation may be an acceptable choice in management (4). Otherwise, surgical intervention is warranted. Surgical management includes lens exchange or lens fixation.
Most patients who undergo surgical treatment have favorable results, with approximately 85% of patients achieving 20/40 or better visual acuity (4).
Authored by Jordyn Cohen, MD
Resources:
1: Glickman, Andrew, et al. “Bedside Ocular Ultrasound Diagnosis of a Traumatic Lens Dislocation.” Cureus, Cureus, 24 Apr. 2021, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8075821/.
2: Bell, Daniel J. “Ectopia Lentis: Radiology Reference Article.” Radiopaedia Blog RSS, Radiopaedia.org, 8 Feb. 2021, https://radiopaedia.org/articles/ectopia-lentis?lang=us.
3: Diagnosis of Traumatic Eye Injuries with Point-of-Care Ocular ... https://www.annemergmed.com/article/S0196-0644(19)30103-9/fulltext.
4: “Dislocated Intraocular Lens.” EyeWiki, 4 Oct. 2021, https://eyewiki.aao.org/Dislocated_Intraocular_Lens#:~:text=IOL%20dislocation%20may%20cause%20several,and%20elevation%20in%20intraocular%20pressure.