What is Marfan syndrome and how it affects the eyes

Among the many causes and risk factors that can impair visual function, special attention deserves the Marfan syndrome.

What is Marfan syndrome?

Marfan syndrome (MFS- Marfan syndrome) is a autosomal dominant genetic disease affecting connective tissue.

Connective tissue has the function of interconnecting the tissues of the body by providing structural support and support to the organs.

Prevalence

Marfan syndrome affects both sexes with a prevalence of about 1:5000 people.

Genetic causes

Subjects suffering from MFS present a mutation in the gene coding for fibrillin-1 proteinwhich is an important connective tissue protein crucial for maintaining the integrity of elastic fibres.

Transmission

Transmission is autosomal, i.e. not sex-linked, and dominant, in the sense that there is no such thing as a healthy carrier, only a sick one.

The syndrome cannot, therefore, skip a generation but can be transmitted from the affected parent to their children with a 50% probability for each pregnancy.

Signs and symptoms

Defects in the gene, which codes for the fibrillin-1 protein, have the greatest effect on the cardiovascular, skeletal and muscular systems and, above all, on the visual apparatus.

Clinical manifestations

People with this syndrome are usually taller and thinner than average and present:

• slim body and long arms
• longer lower body (dolichomegaly)
• very long fingers with elongated thumb (arachnodactyly)
• scoliosis
• careened or excavated chest
• flat feet
• dislocated collarbones, hips and knees

These characteristics may not occur simultaneously in an individual.

The severity of the clinical manifestations of Marfan syndrome can vary greatly from person to person, even within the same family.

Some individuals present mild symptoms, while others may have severe complaints.

Disorders cardiovascular

Cardiovascular disorders are the most serious and usually involve mitral valve prolapse and dilatation of the ascending aorta (aneurysm). Progressive dilatation of the aorta, dissection and rupture are complications that are still the main cause of death or cause of emergency surgery.

Ocular alterations

Approximately 54% of individuals with Marfan syndrome have ocular changes, which among other things are decisive in the diagnosis of the syndrome.

In addition, some of the eye complications for Marfan syndrome sufferers are: premature cataract, retinal detachment e glaucoma

Diagnostic criteria based on ocular parameters

Individuals with Marfan syndrome may present with a highly variable clinical picture, so it is not always easy to immediately establish the presence of pathology.

In general, the diagnosis of the syndrome takes into account certain international criteria (the Ghent criteria) based on the most common and uncommon clinical signs.

Ectopia of the crystalline lens

One of the most significant diagnostic criteria, based on certain ocular characteristics, is the ectopia of the crystalline lens (ectopia lentis) in the presence of which the crystalline lens, the natural lens of the eye, is not located in place, but displaced to the periphery, leading to a marked reduction in visual acuity.

Other ocular alterations

Other ocular parameters that are used in the diagnosis of Marfan syndrome include:

• abnormal and flat cornea;
• increased axial length of the eyeball;
• hypoplastic iris or hypoplastic ciliary muscle;
• miosis, i.e. a pupillary reduction.

Management of the patient with Marfan syndrome

Precisely because of the complex clinical picture presented by a person suffering from this syndrome, theapproach to patient management is multidisciplinary and involves several medical specialities such as the cardiologist, the geneticist and the ophthalmologist.

At present, there is still no specific therapy for this disease. However, action can be taken to slow the progression of certain symptoms, and to prevent dangerous complications, both pharmacologically and by adopting an appropriate lifestyle.

Prevention and information therefore play a decisive role in the survival of the person with Marfan syndrome.

Marfan syndrome also induces an increased susceptibility to refractive defectsmyopia in particular, for which treatment with corrective lenses is strongly recommended.

In some cases, however, surgical removal of the crystalline lens is performed if it is completely damaged.

Famous personalities

Among the many illustrious people suffering from Marfan syndrome is Niccolò Paganini, the great musician who owed part of his virtuosity to his long, supple hands; in fact, with his long fingers, he was able to hit notes that for others were impossible

Musicians suffering from Marfan syndrome include Rachmaninov and his huge pianist hands.

Then there are the great heads of state: Abraham Lincoln, the great American president, and the French 'General' Charles De Gaulle.

• Harry Dietz. Marfan Syndrome. GeneReviews. 2017. https://www.ncbi.nlm.nih.gov/books/NBK1335/
• Loeys BL et al. Revised Ghent criteria for the diagnosis of Marfan syndrome (MFS) and related conditions. J Med Genet 2010; 47:476-485