ConditionEyes & vision
Ectopia Lentis (Dislocated Lens)
Ectopia lentis is a displacement of the eye's natural lens from its normal position behind the pupil. The lens is held by tiny fibers called zonules. When they are weak or broken, the lens tilts or shifts partly (subluxation) or falls out of place completely (luxation). The most common causes are eye injury and inherited connective tissue disorders, especially Marfan syndrome. It causes blurred vision, high or changing astigmatism and sometimes double vision in one eye, and may need glasses, contact lenses or surgery.
Also called: Dislocated lens, lens subluxation, lens luxation, displaced lens
At a glance
- What it is
- The lens is displaced from its normal position because its supporting fibers are weak or torn.
- Partial vs complete
- Subluxation (still partly in place) or luxation (fully dislocated, forward or backward).
- Main causes
- Trauma, Marfan syndrome, homocystinuria, Weill-Marchesani syndrome, pseudoexfoliation.
- Symptoms
- Blurred or fluctuating vision, astigmatism, double vision in one eye.
- Treatment
- Glasses or contacts, lens removal surgery with an artificial lens.
When to get help
Call 911 or go to the ER
- Sudden severe eye pain, redness, blurred vision, headache and vomiting (possible lens blocking fluid drainage and acute glaucoma)
- Lens visible in the front of the eye after an injury, or sudden vision loss
See a doctor within a day or two
- A curtain or shadow over vision, or many new floaters and flashes (possible retinal detachment)
- A significant blow to the eye followed by blurred vision
Book a routine appointment
- Frequent glasses changes, high astigmatism or double vision in one eye in a child or young adult
- A child with tall stature, long limbs and nearsightedness (possible Marfan syndrome)
- A trembling or shimmering iris when the eye moves
How the lens is held in place
The lens sits behind the iris, suspended by hundreds of fine zonular fibers attached to the ciliary body. These fibers are made largely of fibrillin, a connective tissue protein. If the zonules are stretched, weak or broken on one side, the lens shifts in the opposite direction.
Causes of ectopia lentis
Trauma
Blunt injury to the eye, such as from a ball, fist or fall, is the most common cause overall. It is usually one-sided and may come with other eye injuries.
Inherited and systemic conditions
| Condition | Typical direction of lens shift | Other features |
|---|---|---|
| Marfan syndrome | Upward and outward | Tall stature, long limbs, aortic enlargement, nearsightedness |
| Homocystinuria | Downward and inward | Intellectual disability, blood clots, tall thin build |
| Weill-Marchesani syndrome | Small, round lens, often forward | Short stature, stiff joints, short fingers |
| Isolated familial ectopia lentis | Variable | Eye findings without systemic features |
| Sulfite oxidase deficiency | Variable | Severe seizures in infancy |
| Ehlers-Danlos syndrome (rarely) | Variable | Joint hypermobility, skin changes |
Ectopia lentis is present in about 60% of people with Marfan syndrome and is one of the major diagnostic features.
Acquired eye conditions
- pseudoexfoliation syndrome, which weakens zonules with age
- high nearsightedness
- advanced or mature cataract
- previous eye surgery
- syphilis affecting the eye (rare)
Symptoms
- blurred vision that glasses only partly correct
- frequently changing glasses prescription, or high astigmatism
- double vision in one eye (monocular diplopia), when the lens edge crosses the pupil
- glare
- sudden change in vision if the lens moves further
- in children, amblyopia (lazy eye) if vision is not corrected early
Signs a doctor may see include a trembling iris (iridodonesis) or trembling lens (phacodonesis) with eye movement, and the edge of the lens visible within the pupil after dilation.
Complications
- glaucoma: a lens moving forward can block fluid drainage and cause a sudden rise in eye pressure
- retinal detachment, particularly in Marfan syndrome
- cataract
- inflammation if the lens dislocates into the back of the eye
- amblyopia in children
Diagnosis
- Visual acuity and refraction
- Slit-lamp examination after dilating the pupil
- Eye pressure measurement
- Retinal examination for tears and detachment
- Ultrasound biomicroscopy to view the zonules and lens position
- Systemic evaluation when no injury explains it: echocardiogram for aortic enlargement, plasma homocysteine level, and genetic testing (such as FBN1 for Marfan syndrome)
Treatment
Optical correction
Many people, especially with mild subluxation, do well with glasses or contact lenses. Sometimes the best vision comes from correcting through the part of the pupil without the lens (aphakic correction). In children, glasses and patching treat or prevent amblyopia.
Surgery
Surgery is recommended when vision cannot be corrected adequately, when the lens causes glaucoma or inflammation, or when it is dislocated into the front of the eye. Options include:
- removing the lens and placing an artificial lens supported by a capsular tension ring or segment, or fixed to the iris or sclera
- removing the lens without implanting one, then using contact lenses or glasses
Surgery is more complex than routine cataract surgery because of the weak zonules, and should be done by an experienced surgeon.
Treating the underlying condition
People with Marfan syndrome need cardiology follow-up for the aorta. Homocystinuria is treated with vitamin B6, diet and other measures to reduce clot risk, and needs special care around anesthesia.
Outlook
With early correction or surgery, most people achieve good vision. Children need close monitoring to prevent amblyopia. Lifelong eye exams are recommended because of the risk of glaucoma and retinal detachment.
Frequently asked questions
What is ectopia lentis?
Ectopia lentis is a displacement of the eye's lens from its normal central position, caused by weak or broken zonular fibers that hold it. It can be partial (subluxation) or complete (luxation) and causes blurred or double vision.
What causes a dislocated lens?
The most common causes are blunt eye injury and inherited connective tissue disorders, especially Marfan syndrome. Homocystinuria, Weill-Marchesani syndrome, pseudoexfoliation syndrome and previous eye surgery are other causes.
Is ectopia lentis a sign of Marfan syndrome?
It can be. About 60% of people with Marfan syndrome have ectopia lentis, typically with the lens shifted upward. Anyone with a dislocated lens and no history of injury should be evaluated for Marfan syndrome, including a heart scan, and for homocystinuria.
Can a dislocated lens be fixed?
Yes. Mild cases are often managed with glasses or contact lenses. If vision cannot be corrected or complications develop, the lens can be removed surgically and replaced with a specially supported artificial lens, or vision corrected with contact lenses afterward.
Is a dislocated lens an emergency?
Usually not, but it can be. If a lens shifts forward and blocks fluid drainage, eye pressure can rise suddenly, causing severe pain, redness, headache and vomiting. This needs emergency treatment. Sudden vision loss or symptoms of retinal detachment also need urgent care.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Ophthalmology (EyeWiki): Ectopia lentis
- American Academy of Ophthalmology: Marfan syndrome and the eye
- The Marfan Foundation: Eye problems in Marfan syndrome
- MedlinePlus Genetics: Homocystinuria
- National Organization for Rare Disorders (NORD): Weill-Marchesani syndrome