Cataract

cataract surgery and affection in pets

1. CataractCataract
Opacity of lens is known as cataractOpacity of lens is known as cataract
Cataracts are the most common cause of Cataracts are the most common cause of
treatable blindness in dogs treatable blindness in dogs

2. 
severe cataracts severe cataracts
cause blindnesscause blindness

By disrupting the By disrupting the
ability of the lens to ability of the lens to
focus light rays focus light rays
onto the retina onto the retina

toy poodle, toy poodle,
miniature and miniature and
standard poodle, standard poodle,
English cockerEnglish cocker

3. 
Spaniel, Boston Spaniel, Boston
terrier, golden terrier, golden
retriever, rottweiler, retriever, rottweiler,
Labrador retriever,Labrador retriever,

Miniature Miniature
schnauzer, bichon schnauzer, bichon
frise, and chow frise, and chow
chow chow

4. 
prevalence of cataracts increases with ageprevalence of cataracts increases with age
in dogsin dogs

Diabetes mellitus is the second most common cause Diabetes mellitus is the second most common cause
ofof
cataracts in the dog cataracts in the dog

less common causes include other metabolicless common causes include other metabolic
diseases, toxins, drugs, congenital abnormalities, diseases, toxins, drugs, congenital abnormalities,
dietary deficiencies,dietary deficiencies,

trauma, radiation therapy, and aging trauma, radiation therapy, and aging

5. Tapetum Tapetum
Eyeshine
occurs in a
wide variety of
colors
including blue,
green, yellow,
pink and red.

6. 
Incipient cataracts Incipient cataracts
involves <10% to 15% involves <10% to 15%
of the lensof the lens

7. 
Immature cataracts vary widely in Immature cataracts vary widely in
appearance and may affect only a small appearance and may affect only a small
portion of the lens to almost the entire lensportion of the lens to almost the entire lens

8. 
By definition,By definition,

a tapetal reflection is apparent with a tapetal reflection is apparent with
immature cataracts, althoughimmature cataracts, although

vision may be diminished if the cataract is vision may be diminished if the cataract is
well developed. well developed.

9. A mature cataract
affects the entire lens
A mature cataract
appears as a solid
white opacity of the
lens, and affected dogs
are severely impaired
visually

11. 
Hypermature cataracts Hypermature cataracts
have undergone have undergone
liquefaction andliquefaction and
resorptionresorption
Hypermature cataracts Hypermature cataracts
often have a crystalline often have a crystalline
appearancewith appearancewith
wrinkling of the lens wrinkling of the lens
capsule capsule

12. A tapetal reflection may
or may not be present.
Vision with hypermature
cataracts is variable
depending upon the
degree of liquefaction.

13. 
Congenital/ aquired Congenital/ aquired

Complete/ partialComplete/ partial

Stationary / progressiveStationary / progressive

Senile/toxicSenile/toxic

Juvenile cataract – prognosis is goodJuvenile cataract – prognosis is good

14. 
Capsular/ cortical/ Capsular/ cortical/
lamellar(bet. Lens lamellar(bet. Lens
nucleus and nucleus and
cortex)/nuclear/diffcortex)/nuclear/diff
use(entire lens use(entire lens
substance)substance)

15. 
The most common treatment for The most common treatment for
cataracts is surgical removal by cataracts is surgical removal by
phacoemulsification.(Phaco- lens phacoemulsification.(Phaco- lens
and emulsification- liquifying/ and emulsification- liquifying/
breaking)breaking)

16. 
Tests indicatedTests indicated

prior to surgery include a complete prior to surgery include a complete
ophthalmic examination,ophthalmic examination,

complete blood count, biochemical complete blood count, biochemical
panel, urinalysis, electroretinography panel, urinalysis, electroretinography
(ERG), and ocular ultrasonography.(ERG), and ocular ultrasonography.

17. Treatment Treatment

Discission/ Discission/
needling : ant . needling : ant .
Capsule is incised Capsule is incised
in cruciate fashion, in cruciate fashion,
using a cataract using a cataract
needle – needle –
aqu.humour in aqu.humour in
contact with lens contact with lens
substance- substance-
facilitate resorption facilitate resorption
– repeated many – repeated many
timestimes

18. 
Removal of lens : Removal of lens :
intracapsular (with intracapsular (with
capsule)- difficult in capsule)- difficult in
animals – sus.lig is animals – sus.lig is
tough tough

Extra capsular Extra capsular
(without capsule)- (without capsule)-
successfulsuccessful

19. ProcedureProcedure

Extracapsular: fix the eye ballExtracapsular: fix the eye ball

Canthotomy may be done to increase the Canthotomy may be done to increase the
exposureexposure

Incise the cornea at limbus- graefe’s knife/ Incise the cornea at limbus- graefe’s knife/
scissorsscissors

Incise the anterior capsule of lens Incise the anterior capsule of lens

Catract scoop is used to remove the lens Catract scoop is used to remove the lens
substancesubstance

Suture the corneal woundSuture the corneal wound

In man dissolution of the opaque lens by In man dissolution of the opaque lens by
using 0.02% trypsine has been reported.using 0.02% trypsine has been reported.