Fact-sheet: Intraocular lens dislocation
Updated on 02/02/2026 at 2:43 PM
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Definition
Lens subluxation or dislocation corresponds to partial or complete displacement of the lens due to injury of the zonular fibers of Zinn:
- anteriorly = anterior lens dislocation
- posteriorly = subluxation (partial rupture of the zonular fibers of Zinn), or posterior lens dislocation
It may be:
- Post-traumatic (most common etiology)
- Secondary to an ocular abnormality: aniridia, intraocular tumor, post-infectious (including syphilis)
- Congenital and isolated: ectopia lentis
- Congenital and part of a malformation syndrome: Marfan syndrome, Homocystinuria, Weill-Marchesani syndrome, Ehlers-Danlos syndrome
Clinical features
- Decreased visual acuity
- Ocular pain
- Ocular redness
- Change in the appearance of the eye
Ultrasound
First-line examination
Subluxation: the lens remains fixed on one side while the other side is displaced into the vitreous (posterior subluxation)
Dislocation: the lens is no longer fixed and moves into the vitreous in cases of posterior dislocation
Search for vitreous hemorrhage and/or other associated ocular lesions.
CT
The lens is spontaneously dense.
Its displacement is easily assessed on CT.
Useful in post-traumatic work-up to look for associated lesions.
MRI
Abnormal position of the lens, appearing as a T2-hypointense lentiform structure on orbital or brain MRI:
- dependent within the globe in cases of posterior dislocation
- displaced but still attached on one side in cases of subluxation