cataract surgery and affection in pets

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

2.  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

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

4.  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

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

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

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

8.  By definition,
 a tapetal reflection is apparent with
immature cataracts, although
 vision may be diminished if the cataract is
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
have undergone
liquefaction and
resorption
Hypermature cataracts
often have a crystalline
appearancewith
wrinkling of the lens
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
 Complete/ partial
 Stationary / progressive
 Senile/toxic
 Juvenile cataract – prognosis is good

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

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

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

17.  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

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

19. 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.