Ectopia Lentis

Anatomi lensa• a biconvex, avascular, colorless, and almost completely transparent structure, • about 4 mm thick and 9 mm in diameter• suspended behind the iris by the zonule (suspensory ligament )• connects it with the ciliary body• Anterior to the lens is the aqueous; posterior to it, the vitreous

• A subcapsular epithelium is present anteriorly• lens nucleus is harder than the cortex• With age, subepithelial lamellar fibers continuously produced, so that the lens gradually becomes

larger and less elastic throughout life.• The lens consists of about 65% water, about 35% protein• Potassium is more concentrated in the lens than in most tissues. Ascorbic acid and glutathione are

present in both oxidized and reduced forms.

Background

• Ectopia lentis is defined as displacement or malposition of the crystalline lens of the eye• considered dislocated or luxated when • it lies completely outside the lens patellar fossa• in the anterior chamber• free-floating in the vitreous• directly on the retina.

• In the absence of trauma, ectopia lentis should evoke suspicion for concomitant hereditary systemic disease or associated ocular disorders.[4, 5]

Pathophysiology• Disruption or dysfunction of the zonular fibers• degree of zonular impairment determines the degree of lens

displacement.

Epidemiology• The most common cause of ectopia lentis is trauma,

• Mortality/Morbidity• visual disturbance• underlying etiologic abnormality.

• Sex• more prone to ocular trauma than females• Male and female frequency varies with the etiology of the lens displacement.

• Age• Ectopia lentis can occur at any age.[6] It may be present at birth, or it may

manifest late in life.

History• Common presenting symptoms (visual disturbance) include the following:

• Red painful eye (secondary to trauma)• Decreased distance visual acuity (secondary to astigmatism or myopia)• Poor near vision (loss of accommodative power)• Monocular diplopia

• Determine if there is a history of ocular trauma.• Possible systemic disease associations

• Cardiovascular disease (eg, Marfan syndrome)• Skeletal problems - Marfan syndrome, Weil-Marchesani syndrome, or homocystinuria• Pertinent family history (autosomal recessive conditions) homocystinuria,

hyperlysinemia, ectopia lentis et pupillae, [7] or sulfite oxidase deficiency

Ocular examination• Vision

• visually debilitating aries with the degree of malpositioning of the lens.

• Amblyopia common cause of decreased vision in congenital ectopia lentis and preventable and treatable.

• External ocular examination• orbital anatomy eg. hereditary

malformations (marfan syndrome enophthalmos with facial myopathic appearance)

• Measure corneal diameter (Marfan syndrome megalocornea)

• Strabismus is not uncommon (secondary to amblyopia).

• Retinoscopy and refraction• myopia with astigmatism• Keratometry may degree of corneal astigmatism.

• Slit lamp examination• evaluasi lens position• identify phacodonesis or cataract.• Measure intraocular pressure

• pupillary block• phacoanaphylaxis or phacolytic• posttraumatic angle recession• poorly developed angle structures• lens in the anterior chamber

• Dilated fundus examination• Retinal detachment is one of the

most serious consequences of a dislocated lens.

Causes• Traumatic dislocation (the most

common cause)• Hereditary ectopia lentis without

systemic manifestations• autosomal dominant inheritance

with the genetic defect located on chromosome 15 dysfunctional zonular apparatus

• characterized by asymmetric eccentric pupils

• Usually is bilateral and typically autosomal recessive

• Systemic conditions commonly associated with ectopia lentis• Marfan syndrome is the most frequent cause• 75% of patients with Marfan syndrome and

usually is bilateral, symmetrical, and supertemporal

• Homocystinuria is the second most common cause of hereditary ectopia lentis• inborn error of metabolism near absence of

cystathionine b-synthetase (converts homocysteine to cystathionine)

• usually is bilateral, symmetrical, and inferonasal• Weil-Marchesani is a rare syndrome

characterized by skeletal malformations (eg, short stature

• A high level of homocysteine in the blood (hyperhomocysteinemia) makes a person more prone to endothelial cell injury, which leads to inflammation in the blood vessels, which in turn may lead to atherogenesis, which can result in ischemic injury.[3]

Laboratory Studies

• a hereditary ondition is suspected • cardiac evaluation for Marfan syndrome, • check serum and urine levels of homocysteine or methionine for

homocystinuria)

Komplikasi• most common ocular complications of ectopia lentis include • Amblyopia• Uveitis • Glaucoma• retinal detachment

surgery • Indications for lensectomy include the following:• Lens in the anterior chamber• Lens-induced uveitis• Lens-induced glaucoma• Lenticular opacity with poor visual function• Anisometropia or refractive error not amenable to optical correction (eg, in a

child to prevent amblyopia)• Impending dislocation of the lens

Marfan Syndrome

Marfan Syndrome• connective tissue disorder• manifestations involving primarily the ocular, skeletal, and

cardiovascular systems,• caused by the deficiency of a structural extracellular matrix protein,

fibrillin-1,