Cataract Opacity of lens is known as cataractCataracts are the most common cause of treatable blindness in dogs
severe cataracts cause blindness By disrupting the ability of the lens to focus light rays onto the retina toy poodle, miniature and standard poodle, English cocker
Spaniel, Boston terrier, golden retriever, rottweiler, Labrador retriever, Miniature schnauzer, bichon frise, and chow chow
prevalence of cataracts increases with age in dogs Diabetes mellitus is the second most common cause of cataracts in the dog less common causes include other metabolic diseases, toxins, drugs, congenital abnormalities, dietary deficiencies, trauma, radiation therapy, and aging
Tapetum Eyeshine occurs in a wide variety of colors including blue, green, yellow, pink and red.
Incipient cataracts involves <10% to 15% of the lens
Immature cataracts vary widely in appearance and may affect only a small portion of the lens to almost the entire lens
By definition, a tapetal reflection is apparent with immature cataracts, although vision may be diminished if the cataract is well developed.
A mature cataractaffects the entire lensA mature cataractappears as a solidwhite opacity of thelens, and affected dogsare severely impairedvisually
Hypermature cataracts have undergone liquefaction and resorptionHypermature cataracts often have a crystalline appearancewith wrinkling of the lens capsule
A tapetal reflection mayor may not be present.Vision with hypermaturecataracts is variabledepending upon thedegree of liquefaction.
Congenital/ aquired Complete/ partial Stationary / progressive Senile/toxic Juvenile cataract – prognosis is good
Themost common treatment for cataracts is surgical removal by phacoemulsification.(Phaco- lens and emulsification- liquifying/ breaking)
Tests indicated prior to surgery include a complete ophthalmic examination, complete blood count, biochemical panel, urinalysis, electroretinography (ERG), and ocular ultrasonography.
Discission/ Treatment needling : ant . Capsule is incised in cruciate fashion, using a cataract needle – aqu.humour in contact with lens substance- facilitate resorption – repeated many times
Removal of lens : intracapsular (with capsule)- difficult in animals – sus.lig is tough Extra capsular (without capsule)- successful
Procedure Extracapsular: fix the eye ball Canthotomy may be done to increase the exposure Incise the cornea at limbus- graefe’s knife/ scissors Incise the anterior capsule of lens Catract scoop is used to remove the lens substance Suture the corneal wound In man dissolution of the opaque lens by using 0.02% trypsine has been reported.