![]() Lens dislocation occurs in 90% of patients, and is thought to be due to decreased zonular integrity due to the enzymatic defect. It is associated with intellectual disability, osteoporosis, chest deformities, and increased risk of thrombotic episodes. ![]() Homocystinuria is an autosomal recessive metabolic disorder most often caused by a near absence of cystathionine b-synthetase. Homocystinuria – Homocystinuria is the second most common cause of heritable ectopia lentis. Lens dislocation in Marfan syndrome is usually bilateral and occurs most often in the superotemporal direction, though other directions are not uncommon. It is thought that the increased incidence of ectopia lentis with Marfan syndrome is due to altered fibrillin microfibrils leading to incompetent zonular fibers and structural abnormalities of the lens capsule. Marfan syndrome is an autosomal dominant disease resulting from various mutations to the fibrillin-1 gene located on chromosome 15. Marfan Syndrome – Marfan syndrome is the most common cause of heritable ectopia lentis, and ectopia lentis is the most frequent ocular manifestation of Marfan syndrome, occurring in approximately 75% of patients. Systemic diseases associated with ectopia lentis: Other ocular disorders associated with ectopia lentis The lens dislocation is usually bilateral and commonly not symmetrical. The irides often appear atrophic with marked transillumination of the periphery on slit lamp examination. The pupils are characteristically oval and ectopic, and often dilate poorly. Įctopia lentis et pupillae – ectopia lentis et pupillae is a rare congenital autosomal recessive (AR) disorder in which there is asymmetric eccentric pupils that are displaced in the opposite direction of a lens dislocation. In simple ectopia lentis, the lens dislocation is usually bilateral and occurs most often in the superotemporal direction. mutations to the FBN1 gene can also result in Marfan syndrome). Significant overlap exists between the genetics of simple ectopia lentis and the systemic diseases associated with ectopia lentis (e.g. ![]() These mutations often result in irregularity and degeneration of the zonular fibers, leading to lens dislocation. Mutations resulting in simple ectopia lentis include mutations to the ADAMTSL4 gene located on chromosome 1 (recessive inheritance pattern) and the FBN1 gene located on chromosome 15 (dominant inheritance pattern). ![]() Both are hereditary and can be inherited in an autosomal dominant or recessive pattern. Simple ectopia lentis – simple ectopia lentis can occur as a congenital disorder or as a spontaneous disorder later in life. Ocular diseases associated with ectopia lentis Though trauma is the most common cause of ectopia lentis, if the trauma is minor, one should consider other underlying diseases that could predispose the patient to lens dislocation. Traumatic ectopia lentis is most often the result of a direct blow to the eye, such as from a baseball or golf ball, but can also occur after blunt trauma to the head or orbit. It may be present at birth or occur at any age. The lens is being seen through dilated pupil in down gaze.Įctopia lentis can occur due to trauma, ocular disease, or systemic disease. Traumatic dislocation of crystalline lens into vitreous cavity. ![]()
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