retina

Case Study: Multiple Traumas Complicate Genetic Disorder

Woman with Marfan syndrome lost to follow-up returns reporting reduced vision OD.

JEROME SHERMAN, O.D., New York, N Y.

A 38-year-old, six-foot tall black woman presented several months ago complaining of a gradual reduction in vision OD through a period of several months. She reported no precipitating factor. Her past medical history revealed Marfan syndrome.

Three decades of records revealed subluxated lenses O.U., myopic fundi, which we (three other eyecare practitioners and myself) diagnosed at age three O.U., the sequential diagnosis of dislocated lenses into the inferior vitreous O.U. and several retinal detachments O.U. The culprits: trauma via elbows and various objects — most recently an air hammer used on steel that caused the dispersion of small metal fragments.

In Marfan syndrome, mild trauma sometimes causes the subluxated lens to become dislocated. It also causes peripheral retinal weaknesses, such as lattice degeneration, to lead to retinal detachments.

Following trauma almost 20 years ago, B scan ocular ultrasound OS revealed a dislocated lens in the inferior vitreous (see figure 1) and a retinal detachment. Binocular indirect ophthalmoscopy revealed multiple circumferential bands of lattice degeneration. The patient underwent laser treatment for the bands of lattice degeneration after first undergoing a successful combined lensectomy, vitrectomy and scleral buckling procedure OS.

Figure 1: Notice the dislocated lens into the inferior vitreal cavity with underlying retinal detachment OS.

Following a different episode of trauma, the patient underwent a scleral buckle procedure OD, though the surgeon left her dislocated lens in place. He said he felt that it wasn't inflicting any damage and removing it would inflict unnecessary trauma to the eye.

Remarkably, despite these multiple traumas and surgical interventions, the patient retained a best-corrected visual acuity (BCVA) of about 20/40 O.U., until being lost to follow-up five years ago.

Exam findings

The patient's BCVA was 20/200 with +4.50 sphere (sph) OD and 20/40 with +3.00sph OS. These aphakic refractive errors suggested she had about 18.00D of myopia prior to her lens dislocations.

Tonometry revealed intraocular pressures (IOP) of 18 OD and 26 OS. Slit lamp exam showed the cornea OD to be quite edematous and folds in Descemet's membrane — the latter of which prevented any view of the fundus via all forms of ophthalmoscopy.

With no direct view of the fundus, we performed a B scan to check for another retinal detachment OD, a possible embedded metallic foreign body from the air hammer and to image the lens that hadn't undergone surgical removal.

As anticipated, gravity had caused the lens to now be located in the inferior vitreal cavity (see figure 2). Also, we imaged a retinal detachment (see figure 3) and an intraretinal macrocyst (arrow), which indicated that the retinal detachment was long-standing.

Figure 2: Lens found in the vitreal cavity OD

Figure 3: Retinal detachment with an intraretinal macrocyst (arrow)

Fortunately, B-scan was able to rule out an embedded metallic foreign body. (You can easily image metallic foreign bodies as small as .5 mm with B-scan ultrasound).

We were able to view the patient's left eye via ophthalmoscopy (see figure 4). The panoramic image (which is approximately 220°) revealed a 360° encircling element (arrows) associated with a superior scleral buckle. An enlarged image of her optic disc showed a .95V cup-to-disc ratio with a superior notch and a corresponding large zone of retinal nerve fiber layer dropout superiorly. In addition, we could see a massive amount of prominent laser burns to the three multiple circumferential zones of lattice degeneration in the inferior temporal quadrant. Further, we noticed two areas of fibro-glial tissue and an area of visible sclera.

Figure 4: Optos P200 C image of the LE shows encircling elements (1, 2, 7, 8, 9), fibro-glial tissue (3), atrophy (4), circumferential zones of lattice with laser burn (6) and 0.95V cup-to-disc ration with a superior notch (5).

Diagnosis

We diagnosed this patient as having corneal edema (with folds in the Decemets membrane) and a retinal detachment with an intraretinal macrocyst OD — both of which appear to have caused the patient's gradual loss in vision. Her left eye revealed serious glaucoma.

Discussion

Marfan syndrome is named for Antoine Bernard-Jean Marfan, a 19th century French pediatrician, who presented a case of a five-year-old girl who had disproportionately long limbs at a meeting of the Medical Society of Paris in 1896.¹

Soon thereafter, doctors used the term Marfan syndrome to describe arachnodactyly (long digits), cardiovascular abnormalities, such as dissection of the aorta, and ocular lens dislocation.¹

Today, doctors define Marfan syndrome as a spectrum disorder caused by an inherited autosomal genetic defect of the FBN1 gene on chromosome 15.¹ This gene codes for fibrillin, the connective tissue protein. The primary purpose of the connective tissue: to hold the body together and provide a framework for growth and development.² Individuals who have Marfan syndrome have defective connective tissue, causing musculoskeletal, cardiovascular, nervous system, pulmonary system, skin and ocular issues.^1,2

► Musculoskeletal. Marfan syndrome patients are typically slender, loose-jointed and very tall, or taller than those in their family who don't have Marfan syndrome.³ In addition, their fingers, arms, legs and toes may be disproportionately long in relation to the rest of their body.³ Also, people who have Marfan syndrome tend to have a long, narrow face, and the roof of their mouth may have an arch, causing the overcrowding of teeth.³

Other musculoskeletal issues: flat feet; scoliosis; pectus carinatum (a protrusion of the sternum or ribs), pectus excavatum; (a caved in or indented sternum and ribs); a protrusio acetabuli (the intrapelvic displacement of the medial wall of the socket that receives the femoral head to make the hip joint); a positive wrist sign (the thumb and index fingers overlap when encircling the contralateral wrist); and a positive thumb sign (the thumb extends beyond the hand's ulnar border when the patient holds the digit flexed in the arm.)^1,3

For physicians to use the musculoskeletal system as a means of diagnosis, the patient must have at least two major criteria or one major criterion in addition to two minor criteria. (For a list of major and minor criteria, visit www.emedicine.com/orthoped/TOPIC414.HTM.)

► Cardiovascular (heart and blood vessels). Most Marfan syndrome patients have disorders of the heart and blood vessels.³ Often, the valve between the left chambers of the heart is defective and may appear large and floppy, which causes an abnormal valve motion when the heart beats. Some people with this heart condition have a heart murmur due to the valve leaking. Large valve leaks may cause shortness of breath, fatigue and heart palpitations.³ In addition, as a result of the faulty connective tissue, the wall of the aorta (the artery that transports blood from the heart throughout the body) may become weak and stretch (aortic dilation), increasing the risk for an aortic rupture or tear. This can result in immediate death.³

Other cardiovascular issues: mitral valve prolapse — with or without regurgitation; calcification of the mitral valve annulus in patients younger than age 40; and dilation of the main pulmonary artery in the absence of valvular or peripheral pulmonic stenosis or any other obvious cause in patients younger than age 40.¹

For physicians to use the cardiovascular system as a means of diagnosis, the patient must have one of the major or minor criteria. For a list of the major and minor criteria, visit www.emedicine.com/orthoped/TOPIC414.HTM.)

► Nervous system. As Marfan syndrome patients age, the dura — a membrane comprised of connective tissue, which contains fluid that surrounds the brain and spinal cord — becomes weak and stretches, starting to weigh on the vertebrae in the lower spine and wear away the bone surrounding the spinal cord.³ This condition is called dural ectasia. The dural ectasia patient may experience minor discomfort, leg pain, numbness or weakness or radiated pain in the abdomen.³

► Pulmonary system. A total of 70% of Marfan syndrome patients have restrictive lung disease, primarily as the result of pectus abnormalities and/or scoliosis.³ Because fibrillin is expressed in the lung and associated with its elastin, researchers believe that the deficiency affects lung development and homeostasis.

In addition, people who have Marfan syndrome may experience spontaneous pneumothorax (lung collapse without trauma) and the early onset of empha-sema, without ever having smoked, due to the fibrillin-1 deficiency. Further, sleep-related breathing disorders, such as sleep apnea and snoring, are linked with Marfan syndrome, regardless of the individual's weight.

For physicians to use the pulmonary system as a means of diagnosing the condition, the patient must have either spontaneous pneumothorax or apical blebs.¹

► Skin. Stretch marks, regardless of weight change or pregnancy, may appear on those who have Marfan syndrome.³ These marks, which can occur at any age, pose no health risk and don't require treatment. They tend to show up at sites subject to stress, such as the lower back, hips and shoulders.³

Something else to keep in mind: Marfan syndrome patients are at an increased risk for developing an abdominal or inguinal (groin) hernia. These patients require medical treatment.

For physicians to use the skin as a means of diagnosis, the major criteria or one of the minor criteria must be present. For a list of the major and minor criteria, visit www.emedicine.com/orthoped/TOPIC414.HTM.

► Ocular. More than 50% of people who have Marfan syndrome experience lens dislocation in one or both eyes.³ The lens may be high or low and may shift to one side of the eye. This dislocation can be minimal or serious — the latter of which can cause a retinal detachment.

Other ocular manifestations: astigmatism, a hypoplastic iris or hypoplastic ciliary muscle — causing myopia — an abnormally flat cornea, an increased axial length of the globe (as measured by ultrasound), cataracts during middle age and glaucoma at an earlier age than the general population.^1,4

For physicians to use the eye as a means of diagnosis, the patient must have the major criterion or at least two minor criteria. For a list of the major and minor criteria, visit www.emedicine.com/orthoped/TOPIC414.HTM.

At least one in 5,000 Americans has Marfan syndrome. It women, men and children of all races and ethnic backgrounds, according to the National Marfan Syndrome Foundation.

Management

Unfortunately, due to the extent of damage to the patient's right eye — in particular the long-standing retinal detachment — we educated the patient that improved vision was unlikely. We did, however, recommend retinal detachment surgery, which the patient underwent within the last several weeks. The outcome of the surgery revealed no improvements in her vision, so we explained to the patient that she may want to consider undergoing a penetrating keratoplasty.

With regard to the glaucoma OS, we educated the patient that control of her IOP was crucial and placed her on maximum medical therapy for it. Also, we referred her for two selective laser trabeculoplasties. Unfortunately, she hasn't achieved the target IOP of 12 OS. Hence, surgical intervention — typically a trabeculectomy — will likely be the next recommendation.

When we asked the patient why she missed her scheduled and re-scheduled appointments for the last several years, she said she had become pre-occupied with her three-year-old son, who also has Marfan syndrome and multiple related problems, including subluxated lenses.

With successful surgery and some luck, we hope to prevent this young mother from blindness.

Because Marfan syndrome displays several ocular anomalies, you can play a significant role in detecting it. If you suspect the disease in an undiagnosed patient, immediately refer him to both a medical geneticist and a cardiologist for examination and diagnosis.⁴ The National Marfan Foundation can provide information at (800) 862-7326. OM

Special thanks to William He, a second-year optometry student at SUNY and Marc Sherman, a senior at the University of Michigan, for their invaluable assistance in crafting this case study.

1. emedicine from WebMD. Marfan Syndrome. Channell K. www.emedicine.com/orthoped/TOPIC414.HTM. Accessed July 11, 2008.

2. National Marfan Foundation. About Marfan Syndrome: What is Marfan Syndrome? www.marfan.org/nmf/GetContentRequestHandler.do?menu_item_id-2. Accessed July 11, 2008

3.National Marfan Foundation. About Marfan Syndrome: What are the Chracteristics of the Marfan Syndrome? www.marfan.org/nmf/GetContentRequestHandler.do?menu_item_id=4 Accessed July 11, 2008.

4. National Marfan Foundation. Ocular Concerns. Prepared by the Professional Advisory board of the National Marfan Foundation. www.marfan.org/nmf/GetSubContentRequestHandler.do?sub_menu_item_content_id=10&menu_item_id=42. Accessed July 14, 2008.

Dr. Sherman is president of the Optometric Retina Society (ORS) and professor at the State University of New York State College of Optometry. He's in private practice at the Eye Institute and Laser Center in New York. E-mail him at jsherman@sunyopt.edu.