Changes

==Introduction==

==Introduction==

This occurs in all species due to '''rupture of the zonular fibres'''. The fibres can be '''abnormally developed, degenerate, or they can rupture directly due to trauma'''.  

Lens luxation occurs in all species due to '''rupture of the zonular fibres'''. The fibres can be '''abnormally developed, degenerate, or they can rupture directly due to trauma'''.  

Lens luxation occurs much '''more frequently in dogs''' than in cats.  

Lens luxation occurs much '''more frequently in dogs''' than in cats.  

'''Primary lens luxation''' is seen more commonly in dogs. The luxation is due to weakened zonule fibres that rupture early in life (before 5 years of age). The condition is '''inherited in small terrier breeds''' such as: Dandie Dinmont, Fox, Jack Russell, Tibetan and Welsh. The Border Collie and Shar Pei are also affected. Studies have shown that the insertion of the zonule fibres into the lens capsule are abnormal. In such cases, minor trauma will rupture the weakened fibres and lead to lens luxation.  

'''Primary lens luxation''' is seen more commonly in dogs. The luxation is due to weakened zonule fibres that rupture early in life (before 5 years of age). The condition is '''inherited in small terrier breeds''' such as: Dandie Dinmont, Fox, Jack Russell, Tibetan and Welsh. The Border Collie and Shar Pei are also affected. Studies have shown that the insertion of the zonule fibres into the lens capsule are abnormal. In such cases, minor trauma will rupture the weakened fibres and lead to lens luxation.  

Cats do not show a genetic predisposition for luxation.  

Cats do not show a genetic predisposition for luxation.  

<u>Blunt trauma</u>: can lead to traumatic luxation and may lead to other ocular lesions.

<u>Blunt trauma</u>: can lead to traumatic luxation and may lead to other ocular lesions.

<u>Glaucoma</u>: when the globe enlarges in chronic glaucoma the zonules may break. Glaucoma is also caused by lens luxation and it may be difficult to decide which condition arose first if both are present in the eye.

<u>[[Glaucoma]]</u>: when the globe enlarges in chronic glaucoma the zonules may break. Glaucoma is also caused by lens luxation and it may be difficult to decide which condition arose first if both are present in the eye.

<u>Uveitis</u>: inflammatory mediators in the posterior chamber may weaken the zonules. This is the most common cause of luxation in cats and horses.

<u>[[Uveitis|Uveitis]]</u>: inflammatory mediators in the posterior chamber may weaken the zonules. This is the most common cause of luxation in cats and horses.

<u>Cataract</u>: if the lens swells due to cataract the zonules may break.

<u>Cataract</u>: if the lens swells due to cataract the zonules may break.

[[Category:To Do - Helen]]

[[Category:To Do - Review]]

[[Category:Neurological Diseases - Cat]]

[[Category:Neurological Diseases - Horse]]

[[Category:Expert Review]]