New online system may help ODs spot Marfan syndrome

September 10, 2012

Results of a recent survey underscore the potentially important role that optometrists could play in the diagnosis of Marfan syndrome, according to the National Marfan Foundation (NMF).

Marfan syndrome (also called Marfan’s syndrome) is a potentially fatal, genetic, connective tissue disorder. Most of the readily visible signs of Marfan syndrome are associated with the skeletal system.

Many individuals with the condition grow to above-average height. Some have long, slender limbs (dolichostenomelia) with long fingers and toes (arachnodactyly).

However, life-threatening aortic tears and ruptures are the most serious aspect of the disease, the foundation emphasized.

Marfan syndrome can also produce skeletal anomalies such as abnormal curvature of the spine (scoliosis), as well as pain in the joints, bones and muscles in some patients.

Eye conditions, including myopia, amblyopia, strabismus, glaucoma and retinal detachments are often early signs of Marfan syndrome.

One-third of Marfan patients in a recent NMF survey said a dislocated lens in the eye was the first sign to raise suspicion that they might have the life-threatening health condition.

However, only about 20 percent of respondents indicated an ophthalmologist (15 percent) or optometrist (4 percent) was the first person to suspect they might have Marfan syndrome.

Because early diagnosis and treatment are critical to preventing the life-threatening aortic tears and ruptures associated with Marfan syndrome, the NMF is urging optometrists to become more aware of Marfan symptoms and know when to refer patients to a specialist for the specific tests that are required for a diagnosis.

“Early diagnosis is critical so that patients can take medications to lower their heart rate and blood pressure, make lifestyle adaptations (no competitive or contact sports), and have their aorta monitored so they can have surgery before a potentially fatal tear or rupture,” said Irene Maumenee, M.D., a member of the NMF Professional Advisory Board and director of ophthalmic genetics at the University of Illinois Eye and Ear Infirmary.

Because Marfan syndrome can seriously affect the eyes and vision, patients with the disease are likely to seek an eye examination, the NMF emphasized.

Myopia – particularly severe myopia – and astigmatism are common among Marfan patients. A dislocating lens will round off and induce myopia. Myopia can also be the result of increased length of the eye. Once the lens is totally dislocated, it will drop into the vitreous and its absence in the visual axis will induce hyperopia.

Subluxation of the crystalline lens in one or both eyes is progressive and may occur in as many as 80 percent of Marfan patients.

With Marfan syndrome, early dislocation occurs commonly in a superotemporal direction, whereas in the similar condition, homocystinuria, the dislocation is often towards inferonasal.

Early onset glaucoma is also common among Marfan patients.

In some Marfan patients, a detachment of the retina may occur prior to lens dislocation or glaucoma.

In patients with a family history of Marfan syndrome or classic symptoms of the disease, such eye problems “should raise a red flag,” Dr. Maumenee said.

Potential Marfan patients should be referred immediately to a patient’s primary medical doctor or to a cardiologist for additional testing, including a recently developed genetic test for the condition, Dr. Maumenee said.

To help optometrists and other health care practitioners identify Marfan patients, the NMF has developed a mobile website, MarfanDX.org, that features the Ghent Nosology for Marfan Syndrome.

The new nosology, published in 2010 by an international panel of experts in the diagnosis and management of Marfan syndrome, offers seven simple formulas for diagnosing Marfan syndrome.

These formulas, along with an Interactive Systemic Score Calculator used to consider the lesser characteristics of Marfan syndrome throughout the body, such as facial features, manifestations in the arms and wrists, and severe myopia, and a Z-score calculator, are available to practitioners on www.MarfanDX.org.

The mobile website offers practitioners an interactive online scorecard, complete with illustrations and details on each on manifestation.

The online system will compute the patient’s Marfan Systemic Score and even provide a means to e-mail the results to a specialist.

“This site guides the practitioner through the diagnostic sequences needed to accurately identify the patient with Marfan’s. Optometrists can utilize this tool to re-familiarize themselves with Marfan’s syndrome and reaffirm their readiness to diagnose and provide care for patients with the condition as part of an integrated health care team,” said AOA Health Promotions Committee Chair Robert P. Bittel Jr., O.D.

Both the Ghent Nosology for Marfan Syndrome and Marfan Systemic Score system can now be accessed on the foundation’s new Marfan Diagnosis website (www.MarfanDX.org).

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