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    The major ocular abnormality in Marfan syndrome is ectopia lentis (lens subluxation or dislocation.  While relatively little is known about the exact mechanism of this ocular pathology in Marfan syndrome, a number of theories have been suggested.  Wheatley et. al (1995) found that while fibrillin is localized to the superficial capsule and ciliary epithelial surface at the attachment of the zonules in normal eyes, Marfan patients lack such localization and exhibit abnormal ciliary processes with absent or severely disorganized zonules. This pathology was found to be positively correlated with lens subluxation.  Clinically, ectopia lentis is bilateral in 60-87% of Marfan patients and is stable from childhood.  Symptoms include fluctuating blurred vision, monocular diplopia, and pain.  On exam, patients demonstrate refractive instability with myopia and astigmatism, iridodonesis, phacodinesis, and a recessed angle. The most common direction of dislocation on exam is superotemporal.   In addition, there may be secondary complications from lens movement such as phacolytic uveitis from posterior subluxation of the lens to the vitreous.  

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Marfan Eyes/Ocular 

     Retinal tears and detachments are also quite common in patients with Marfan syndrome.  The Marfan eye has many risk factors for tears and detachments including high myopia, excess lattice degeneration, vitreous liquefaction, choroidal and scleral thinning, and vitreous traction from ectopia lentis.  Each of these changes is thought to be related to fibrillin alterations.  Retinal detachment occurs in 5-26.5% of patients with Marfan syndrome and is bilateral in 30-42% of these cases.  Rigorous screening and close follow-up of symptoms is important to prevent retinal detachment in these cases.

Other ocular manifestations of Marfan syndrome include flattened cornea (causing astigmatism), keratoconus, increased globe length (causing myopia), iris coloboma, cataracts, glaucoma, strabismus, amblyopia, and vascular malformations.  Central to each of these findings is the ubiquitous abnormality of fibrillin in the ocular connective tissue of the Marfan patient. 

With regard to ectopia lentis, a number of treatment options exist.  Mild subluxation allows for near normal vision with the patient seeing through the phakic portion of the pupil.  The other extreme would be severe subluxation in a child which requires urgent surgical correction to avoid irreversible amblyopia.  The principle surgical method employed in Marfan syndrome is lens extraction with either IOL placement or contact lens correction.  Surgery is indicated when the lens position causes irregular astigmatism and glare, when the lens is posteriorly dislocated into the vitreous, when the lens is dislocated anteriorly and causes secondary glaucoma, or in the setting of cataract formation.  Because of the altered anatomy and weakening of the connective tissues in Marfan syndrome, all of the usual complications of lens extraction are amplified.  As the capsule is unstable from loss of zonules, the intraocular lens (IOL) must either be placed in the anterior chamber, or be secured to the iris or sclera with permanent prolene sutures. 

One important complication of IOL fixation to the sclera in young patients is that the 10-0 prolene sutures may break three to ten years following surgery.  This has led many surgeons to use larger suture such as 8-O gortex or 9-O prolene in the hopes that the suture will last longer.   In cases of complete posterior lens dislocation, a pars plana vitreolensectomy can be performed.  Another surgical option is to secure the capsule to the sclera using sutured cionni modified capsular tension rings (CTR from Morcher) or Ahmed capsular tension segments (CTS from Morcher).  These surgical interventions, while complicated, have great success in restoring vision in these patients.

Features of the Eyes

 Some features of the eye related to Marfan syndrome that can cause vision problems include:

Dislocated lenses About 6 in 10 people with Marfan syndrome have dislocated lenses in one or both eyes. This means the lens, located at the front of the eye, has slipped out of place because the connective tissue that holds the lens in place (called zonules) is weak. When this happens, the lens can slip in any direction—up, down, to the side, or back. It can slip a little or completely out of place, and anywhere in between. With the lens out of place, the eye can’t focus properly and vision is blurry. About 6 in 10 people with Marfan syndrome have dislocated lenses in one or both eyes.

Symptoms of lens dislocation depend on severity and may include mild to severe nearsightedness, blurred vision, and fluctuating vision. Lens dislocation can only be confirmed by an ophthalmologist using a slit-lamp eye examination after fully dilating the pupil. For most people, dislocated lenses occur before age 20, although lenses can dislocate at any age. Babies and children can have dislocated lenses. Dislocated lenses are rare in the general population, so people with dislocated lenses should be tested for Marfan syndrome if there is not another known cause.

Retinal Detachment Retinal detachment is a separation of the light-sensitive membrane in the back of the eye (the retina) from its supporting layers. Symptoms that may indicate a retinal detachment include:

• Flashing lights

• New floaters

• A gray curtain moving across your field of vision These symptoms do not always mean a retinal detachment is present, but you should see your eye doctor immediately if any of these signs occur.

Head trauma can cause retinal detachment in anyone, and those who are highly myopic (nearsighted) are always at risk for retinal detachment. For people with Marfan syndrome, however, retinal detachment can happen spontaneously.

See your doctor immediately if you see flashing lights, new floaters or a gray curtain moving across your field of vision.

Severe Myopia Myopia is nearsightedness. Objects in the distance are blurred and only objects close to the eye are in focus.

Astigmatism Astigmatism is blurred vision caused by an irregular curve of either the lens or the cornea.The cornea is the layer of tissue covering of the very front of the eye.

Amblyopia Amblyopia is when the vision in one of the eyes is reduced because the eye and the brain are not working together properly. The eye looks normal, but it is not being used normally because the brain is favoring the other eye. This condition is also sometimes called “lazy eye. “

Strabismus Strabismus is when the two eyes do not focus on the same object simultaneously. One eye may drift in or out compared to the other eye. The eyes may alternate fixating on an object or one eye may fixate more. It occurs in people with Marfan syndrome at a higher rate than in the general population.

In the general population, the deviating eye more commonly turns inward, toward the nose. In people with Marfan syndrome, the deviating eye usually turns outward. The eyes may also deviate vertically. Strabismus can cause loss of depth perception, double vision, and amblyopia. However, amblyopia is often present first and leads to strabismus, but once amblyopia is successfully treated, the strabismus may correct itself. 

Wider Scope

EPIDEMIOLOGY

• Incidence: 1/5000 - 1/2000.  60-87% with ectopia lentis.
• Gender:  Males and females equally represented.
• Genetics:  Autosomal dominant.  80% from FBN1 mutations on chromosome 15.
• Other mutations include TGFBR1 and TGFBR2.

SIGNS (Ocular)

• Ectopia lentis (most commonly superotemporal dislocation)
• Retinal detachment
• Myopia
• Hypoplastic iris with miosis
• Amblyopia
• Strabismus
• Keratoconus
• Enophthalmos

SYMPTOMS

• Ocular complaints.
• Ocular:  blurred vision, monocular diplopia, pain, flashes and floaters.

TREATMENT of ocular complications

• Lens extraction for ectopia lentis with
  Contact lens or IOL (anterior chamber, sutured to sclera/iris)
• Retinal laser for detachments or tears
• Regular screen for myopia, amblyopia, strabismus, keratoconus, and glaucoma.

 

Ocular Features 

What are the ocular features of Marfan syndrome?Most people with Marfan syndrome suffer from near-sightedness (axial and lenticular myopia) and visual distortion (astigmatism). Other signs and symptoms include ectopia lentis, corneal thinning, flattened corneal curvature, cataracts, glaucoma, strabismus, and retinal detachment.

What is ectopia lentis?Ectopia lentis is a shift in the location of the lens inside the eye. The lens moves from its centered location in the eye so that the person is not looking through the center of their lens.  This dislocation is caused by weakness in the connective tissue that holds the lens in place (zonules). Ectopia lentis occurs in roughly sixty-percent of individuals with Marfan syndrome and is one of the major criteria for the clinical diagnosis of this condition 

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Richard G.