This is a connective tissue disorder that presents dislocation of the lens of the eyes that result in vision problems. The lens is the structure of the eye that focuses light rays onto the retina and when dislocation of the lens occur, it can result in serious complication such as retinal detachment. There are four grades of ectopia lentis that are defined as minimal, mild, moderate and total dislocation. The ocular complications appear to be commonly serious and its associated abnormalities can consist of cataract formation, retinal detachment, amblyopia and glaucoma.
Causes
Normally, the lens is centered behind the pupil and kept in the position by radial fibers known as zonules that connect the lens to the ciliary body. There can be several causes of ectopia lentis which can be the result of disruption or dysfunction of zonular fibers. The degree of zonular disruption usually determines the degree of lens displacement. Other conditions that can develop this condition include syphilis disease that can cause zonular weakening. Some of the genetic diseases that are also associated with ectopia lentis include marfan syndrome, homocystinuria and isolated idiopathic ectopia lentis. Marfan syndrome is a genetic disease that causes weakening of the zonules, homocystinuria disease can present defective cystathionine beta synthase and individuals with isolated idiopathic ectopia lentis exhibit only this condition and don’t present any other abnormalities.
Symptoms
Individuals can continue for several years without developing any significant ocular problems. However, the most common symptom of this condition is the reduction in visual acuity. The symptoms of lens dislocation include fluctuation in vision, nearsightedness and blurred vision resulting from the irregularity of the cornea. The visual problems depend on the type and degree of displacement and other associated ocular defects.
Diagnosis
The diagnosis is based on the evaluation of the family history for visual disturbance, physical examination and various laboratory tests. The examination can consist of checking the visual acuity, a slit lamp exam, external ocular exam, retinoscopy and refraction. Dilated fundus examination may also be necessary along with the evaluation of intraocular pressure and the measurement of the corneal diameter. In the case of suspected hereditary condition, various tests may be necessary such as cardiac evaluation for marfan syndrome.
Treatment
The treatment may be based on where and how far the lens of the eyes has shifted along with other evident complications. With the progressive shifting of the lens, the ectopic lens is surgically removed by a process known as vitrectomy. In infants and children, generally, the intraocular lens is not inserted and may be done when the full growth of the individual is attained with a secondary surgery.
References
http://218.248.31.202/newsletterproject/issue/linkfiles/SL000224.pdf
http://www.retinareference.com/diseases/ff2c93ac2ead1616/documents/ff2c93ac2e/document.pdf
