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Ophthalmology – Ectopia Lentis
Ectopia lentis refers to displacement of the crystalline lens from its normal position due to weakness or disruption of the zonular fibers. The condition may present as subluxation (partial displacement) or luxation (complete dislocation). It can occur as an isolated ocular finding or as part of systemic connective tissue or metabolic disorders, and may also result from trauma.
The condition is strongly associated with systemic diseases such as Marfan syndrome (where 60–75% of patients develop ectopia lentis) and homocystinuria (seen in 80–85% of cases). Other associations include Ehlers–Danlos syndrome, Weill–Marchesani syndrome, hyperlysinemia, sulfite oxidase deficiency, and congenital ocular anomalies. Trauma is also an important cause, particularly in unilateral cases. Genetically, ectopia lentis may be inherited in autosomal dominant or recessive patterns, often involving mutations in genes such as FBN1 (fibrillin) or ADAMTSL4, both critical for zonular integrity.
The underlying pathophysiology involves weakening, stretching, or rupture of the zonular fibers that suspend the lens. In connective tissue disorders like Marfan syndrome, abnormal fibrillin leads to fragile zonules, whereas in metabolic disorders like homocystinuria, defective cysteine metabolism weakens zonular structure. This results in progressive lens instability and displacement.
Patients may present with blurred vision, monocular diplopia, or fluctuating refractive error, depending on the degree of lens displacement. A history of trauma or systemic disease, or a family history, may be present. On examination, slit-lamp findings reveal decentered lens position, abnormal zonules (stretched, broken, or absent), and sometimes irregular lens edges. Additional findings may include corectopia (displaced pupil), elevated intraocular pressure, or signs of associated systemic disease.
Diagnostic evaluation includes a thorough ocular exam and systemic assessment. In patients without trauma or known diagnosis, serum or urine homocysteine levels should be checked due to the serious systemic risks of homocystinuria, including thromboembolism. Imaging such as echocardiography may be required when conditions like Marfan syndrome are suspected. Genetic testing may help confirm the diagnosis in selected cases.
Management depends on severity and underlying cause. Initial treatment focuses on optical correction with glasses or contact lenses and treatment of amblyopia, especially in children. In cases where the lens dislocates into the anterior chamber, urgent management is required to prevent pupillary block glaucoma, including medications such as mannitol, steroids, and mydriatics, along with positioning the patient supine.
Surgical treatment is indicated when vision cannot be corrected optically or when complications arise. This typically involves lensectomy with anterior vitrectomy, followed by visual rehabilitation using contact lenses or aphakic spectacles. In some cases, intraocular lens implantation may be considered, though this is often limited in children due to poor zonular support.
Regular follow-up is essential to monitor for progressive lens displacement, amblyopia, glaucoma, and retinal detachment, particularly in conditions like Marfan syndrome. Prognosis is generally good with early diagnosis and appropriate management, with many patients achieving visual acuity of 20/40 or better, provided complications are addressed promptly.
Ectopia lentis refers to displacement of the crystalline lens from its normal position due to weakness or disruption of the zonular fibers. The condition may present as subluxation (partial displacement) or luxation (complete dislocation). It can occur as an isolated ocular finding or as part of systemic connective tissue or metabolic disorders, and may also result from trauma.
The condition is strongly associated with systemic diseases such as Marfan syndrome (where 60–75% of patients develop ectopia lentis) and homocystinuria (seen in 80–85% of cases). Other associations include Ehlers–Danlos syndrome, Weill–Marchesani syndrome, hyperlysinemia, sulfite oxidase deficiency, and congenital ocular anomalies. Trauma is also an important cause, particularly in unilateral cases. Genetically, ectopia lentis may be inherited in autosomal dominant or recessive patterns, often involving mutations in genes such as FBN1 (fibrillin) or ADAMTSL4, both critical for zonular integrity.
The underlying pathophysiology involves weakening, stretching, or rupture of the zonular fibers that suspend the lens. In connective tissue disorders like Marfan syndrome, abnormal fibrillin leads to fragile zonules, whereas in metabolic disorders like homocystinuria, defective cysteine metabolism weakens zonular structure. This results in progressive lens instability and displacement.
Patients may present with blurred vision, monocular diplopia, or fluctuating refractive error, depending on the degree of lens displacement. A history of trauma or systemic disease, or a family history, may be present. On examination, slit-lamp findings reveal decentered lens position, abnormal zonules (stretched, broken, or absent), and sometimes irregular lens edges. Additional findings may include corectopia (displaced pupil), elevated intraocular pressure, or signs of associated systemic disease.
Diagnostic evaluation includes a thorough ocular exam and systemic assessment. In patients without trauma or known diagnosis, serum or urine homocysteine levels should be checked due to the serious systemic risks of homocystinuria, including thromboembolism. Imaging such as echocardiography may be required when conditions like Marfan syndrome are suspected. Genetic testing may help confirm the diagnosis in selected cases.
Management depends on severity and underlying cause. Initial treatment focuses on optical correction with glasses or contact lenses and treatment of amblyopia, especially in children. In cases where the lens dislocates into the anterior chamber, urgent management is required to prevent pupillary block glaucoma, including medications such as mannitol, steroids, and mydriatics, along with positioning the patient supine.
Surgical treatment is indicated when vision cannot be corrected optically or when complications arise. This typically involves lensectomy with anterior vitrectomy, followed by visual rehabilitation using contact lenses or aphakic spectacles. In some cases, intraocular lens implantation may be considered, though this is often limited in children due to poor zonular support.
Regular follow-up is essential to monitor for progressive lens displacement, amblyopia, glaucoma, and retinal detachment, particularly in conditions like Marfan syndrome. Prognosis is generally good with early diagnosis and appropriate management, with many patients achieving visual acuity of 20/40 or better, provided complications are addressed promptly.
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