This document provides information on cataract surgery and intraocular lens implantation in dogs. It discusses the structure of the normal eye, different types and classifications of cataracts. It describes various surgical techniques for cataract removal including discission and aspiration, extracapsular extraction, and phacoemulsification. It also covers patient selection, pre-operative care, anesthesia, intraocular lenses, and post-operative care and complications. The goal of cataract surgery is to remove the opaque lens and restore vision through implantation of an intraocular lens.

1. Prepared by:
Dr Irawati P. Sarode
Assistant Professor
College of Veterinary & Animal Sciences, Parbhani
MAFSU, Nagpur
Department of Veterinary Surgery & Radiology
CATARACT SURGERY IN CANINES
WITH SPECIAL REFERENCE TO
INTRAOCULAR LENS IMPLANTATION

2. STRUCTURE OF NORMAL EYE

3. CATARACT
✓ The term cataract comprises a common group of
ocular disorders manifested as loss of transparency
of lens or its capsule
✓ Cataract refers to group of lens disorders of varying
age of onset, speed and extent of progression
appearance & etiology

4. CATARACT CLASSIFICATION
✓ Stage of development (maturity)
o Incipient
o Immature
o Mature
o Hypermature
o Morgagnian
✓ Age of development
o Congenital
o Developmental
o Juvenile
o Senile
o Acquired
✓ Position within the lens
o Anterior capsular
o Anterior sub capsular
o Cortical
o Equatorial
o Nuclear
o Posterior sub capsular
o Posterior capsular
✓ Etiology or pathogenesis
o Primary: Inherited
o Secondary: Traumatic
Intraocular disease
Nutritional
Radiation
Diabetic
Toxic
✓Consistency
o Fluid
o Soft
o Hard

5. DEGREE OF MATURATION
1.Incipient cataract 2.Immature cataract.
3.Mature cataract 4.Hypermature cataract

6. LOCATION WITHIN LENS
Sub capsular Lamellar cataract Anterior polar Partial cataract
Nuclear cataract Cortical cataract Total cataractPosterior cataract

7. ETIOLOGY
Traumatic cataract Nutritional cataract Toxic cataract
Diabetic cataract Cataract due to PRA

8. TREATMENT
✓ MEDICAL THERAPY
• Improvement of vision in early stages of cataract, or in
advanced stages of resorption with use of mydriatics
• Diabetic cataracts: Aldose reductase inhibitors
(systemic & topical)
• Antioxidants : Selenium- vitamin E
Orgotein (super oxide dismutase)
Zinc ascorbate
Carnosine
• Other alternative remedies: Grape seed extract

9. SURGICAL TREATMENT
Potential cataract patients should be referred as early as
possible
• Cataract surgery is only means of treatment
• Cataract surgery is an elective procedure
• Age of the patient not a contraindication
• Types of cataract unsuitable for surgery.
e.g., cataracts secondary to other inherited eye diseases –
generalized progressive retinal atrophy (GPRA),
post-traumatic cataracts
cataract secondary to, or associated with, uveitis

10. SURGICAL CORRECTION
✓ Discission and aspiration
✓ Intracapsular extraction
✓ Extracapsular extraction
✓ Phacoemulsification :
1. One – handed
a. V shaped Phacoemulsification
b. Nuclear flip technique
2. Two - handed / bimanual
a. Nuclear segmentation
b. Divide and conquer
c. Chip and flip
d. Croissant
e. Phaco chop
f. Stop & chop
g. Split and lift

11. PATIENT SELECTION
✓ Complete medical history
✓ General physical examination
✓ Temperament
✓ Complete ophthalmic history
✓ Complete ophthalmic examination
• Schirmer tear test
• Slit lamp examination/ biomicroscopy
• Fluroscin staining test
• Ophthalmoscopy
• Tonometry
• Gonioscopy
• Fundoscopy
• Electroretinography
• Retinal ultrasound :
o B-mode ultrasonography (10 MHz)
o High resolution ultrasound (20 MHz)
o Ultrasound biomicroscopy (50-100 MHz)

12. PREOPERATIVE COMPLICATIONS
✓ KCS
✓ Corneal disease
✓ Eyelid deformity
✓ Retinal degeneration
✓ Retinal detachment
✓ Lens induced uveitis
✓ Posterior synechiae
✓ Lens subluxation
✓ Vitrous presentation
into anterior chamber
✓ Lens capsule rupture
✓ Diabetes mellitus

13. PREOPERATIVE THERAPY
✓ Broad spectrum topical ophthalmic antibiotics every 6 hrs
for 24-48 hrs prior to surgery
✓ Topical corticosteroids for 48-72 hrs prior to surgery or up
to 4 weeks ( if LIU is present)
✓ Topical non steroidal anti inflammatory agents every 30
minutes beginning 1-3 hrs prior to surgery
✓ Mydriasis with 1% Atropine 1-2 hrs prior to surgery
✓ Bolus of IV antibiotics at induction of anesthesia
✓ Systemic non steroidal anti inflammatory agents
✓ Systemic corticosteroids

14. ANESTHESIA
✓ General anesthesia with systemic neuromuscular
blocking agents ( Nasiesse and Davidson 1991)
• Induction of GA using routine procedures, &
maintenance with isoflurane / methoxyflurane
inhalation
• Atracurium or Pancurium
• Induction of general anesthesia with Propofol (5 mg/kg)
,atropine 0.03 mg/kg SC & Xylazine 1 mg/kg, IM as
premedicant, in combination with peribulbar nerve
block using 2% Lignocaine HCL

15. INCISION SIZE

16. Site Advantages Disadvantages
Limbal Easy to convert to ECCE
Instruments don't distort
cornea
Induces astigmatism
Always requires suture
Iris prolapse more common
Conjunctival manipulation & cautery
Eye is red after surgery
Scleral Rarely induces astigmatism
Seals nicely
Hard to convert to ECCE
Technically difficult
Iris prolapse more common
Conjunctival manipulation & cautery
Instruments distort cornea
Eye is red after surgery
Corneal Rare astigmatism
No cautery or conjunctival
manipulation
Eye is white after surgery
Hard to convert to ECCE
Technically difficult
Instruments distort cornea
Increased risk of endophthalmitis

17. DISCISSION AND ASPIRATION
• Opening cornea and anterior lens capsule
• Irrigation and aspiration to remove the contents
from within the capsule
• Restricted to young animals with liquid
cataracts / animals with very small eyes (usually
exotic pets)

18. EXTRACAPSULAR CATARACT EXTRACTION
(ECCE)

19. INTRACAPSULAR CATARACT EXTRACTION
• Removal of entire lens without opening or tearing lens
capsule
• Method restricted to removal of luxated lens, following
tearing of zonules
• Minimal postoperative inflammation
• Anterior movement of vitreous body
• Combination of technique with prophylactic vitrectomy
• Implantation of synthetic IOL fixed by sutures in ciliary
sulcus
o Barrier against vitreous movement
o To improve post operative vision

20. PHACOEMULSIFICATION
• Requires smaller incision in either sclera or clear cornea (5.5 -
3.2 mm or less) on the side of the cornea
• Insertion of small probe into the eye
• Ultrasonic waves soften and break up cloudy center of the lens
• Removal by suction
Phacoemulsification hand piece

21. VISCOELASTIC DEVICES
1. Maintain
space:
e.g. AC during rhexis
bag during IOL insertion
Cohesive best
2. Create
space:
e.g. Creating sulcus
shift lens material
Cohesive best
3. Sealing off:
e.g. Sealing capsular tear
keeping iris away
Dispersive best
4. Coating:
e.g. Protect corneal endothelium
Lubricate cornea
Dispersive best

22. ARSHINOFF SHELL TECHNIQUE
✓ Phase I during CCC
1. Place dispersive OVD
2. Place cohesive OVD just over
lens
3. Dispersive pushed up to coat
endothelium
4. As soon as phaco starts cohesive
is aspirated & dispersive coating
remains
✓ Phase II during IOL
insertion
1. Place cohesive OVD in the bag
2. Place dispersive OVD just inside
wound to seal prior to IOL
placement
3. When IOL is inserted, dispersive
helps to keep cohesive in place;
bag formed

23. CAPSULORHEXIS
✓ Basic techniques
• Continuous curvilinear
capsulorhexis (CCC)
a. Cystitome
b. Combo
c. Forceps
• Can opener

24. HYDRODISSECTION
• Free rotation of lens within capsular bag facilitating its
fragmentation
• Performed immediately after capsulectomy with irrigation
solution injected through 25- 27- gauge cannula attached to 3
ml syringe
• Requires multiple injections in different quadrant of lens

25. PHACOEMULSIFICATION
GOAL
✓ To remove lens with minimum
ultrasound to reduce damage to
cornea
TREND
✓ To use increasing vacuum &
decreasing ultrasound power to
remove nucleus
Phacoemulsification Unit
BASIC TECHNIQUE
✓Sculpting
✓Nuclear segmentation
✓Nuclear removal

26. PHACO LOCATION
a) Endocapsular
b) Supracapsular
c) Anterior chamber shell
d) ½ bag ½ anterior chamber

27. PHACO LOCATION ADVANTAGES DISADVANTAGES
Endocapsular No flip required
Energy away from
cornea
Tear anterior capsule
with chopper or phaco tip
Supracasular Less risk of heating
anterior capsule
Energy closer to cornea
Nuclear flip close to
cornea
AC Shell Little stress on bag Energy closer to cornea
Slow
½ AC ½ Bag Less risk of heating
anterior capsule
Energy closer to cornea

28. SCULPTING
• Performed by engaging superior cortex &
nucleus with ventral edge of needle always
with bevel up, & pushing needle across lens
from 12- to 6-o’clock position
•Phacoemulsification power controlled
linearly to make efficient sculpting
•Young dogs : 40% power & in older dogs :85
-90%
•Power increased while reaching central lens
then gradually decreased while proceeding 6-
o; clock position

29. NUCLEAR FRAGMENTATION
✓ Single most important step in 2- handed phacoemulsification
✓ Quick isolation & mobilization segment of nucleus
✓ Nuclear bowl rapidly collapsed inward & fragmented
✓ Phaco needle & nucleus rotator positioned against opposite
sides of groove

30. ASPIRATION
• Aspiration of loose lens cortical material by
positioning I/A canula as far peripherally in
capsular bag as possible
• Stripping of cortical material from equator &
towards capsulectomy
• Positioning canula tip upward to aspirate difficult
to remove fragments

31. DIVIDE AND CONQUER METHOD
• Rotation of lens to 90% after being fractured
• Creation of 4 isolated fragments
• , Displacement of isolated lens fragments toward
pupil, where they ca be easily fragmented

32. INTRAOPERATIVE COMPLICATIONS
✓ Anterior capsular fibrosis
✓ Intraoperative miosis
✓ Expanding vitreous
syndrome
✓ Iris prolapse
✓ Intraoperative hemorrhage
✓ Vitreous presentation
✓ Cavitation bubbles
✓ Phaco machine failure
✓ Lens capsule
a. anterior radial tears
b. posterior capsule tears
c. polishing opacities
d. zonular tears or dehiscence
✓ Displaced or dislocated
lens fragments

33. INTRAOCULAR LENSES

34. MATERIALS OF INTRAOCULAR LENSES
A. Thermoplastics
B. Synthetic elastomers
C. Acrylate polymers
1. Hydrogel & hybrid hydrogel lenses
2. Soft acrylic IOLs
3. Collamer IOLs

35. TYPES OF INTRAOCULAR
LENSES
1.Traditional
2.Monofocal
Multifocal
3.Accomodating
4. Aspheric
5. Blue light filtering
6.Toric
7. Light adjustable
8. Piggyback

36. ✓ Two main types of IOLs used in veterinary medicine
• Non foldable ,Hard –PMMA
• Foldable – silicon & acrylic polymers
✓ Latest type of soft lenses designed for dogs made of
hydrophilic acrylate
✓ Lenses implanted within capsular bag
✓ Anterior chamber & iris supported lenses not used
(high extend of complications)
✓ Optic power - 41 D
✓ Size differ from 14 -18 mm ( haptic size)
7 mm (optic size)

37. PARAMETERS OF CANINE
INTRAOCULAR LENSES
Style Posterior chamber
Design One-piece, biconvex
optic
Sterilization Ethylene oxide
Optic Polymethymethacrylate
Optic size 7 mm
Haptic length 14-18 mm
Haptic configuration Modified “C” loop
Haptic forward angulation 2-15º
• Dialing holes on the optic
• Suture holes on the haptics
• Lenses vaulted at 10º -12º
CONVENTIONAL IOL

38. ✓Injectable by 2.8 mm incision
✓25% hydrophilic acrylic
✓360º square edges
✓10º haptic angulation
✓Power 41 D

39. Folded IOL
✓ Folded & placed in special forceps
✓ Incision size grows bit with increased power of IOL-
3.5mm
✓ Moustache style fold: wider incision but haptics flow
into bag
✓ Axial style fold: smaller incision but haptic needs
guidance

42. SUTURE FIXATION OF IOL
1. Suture is passed beneath
iris to exit sclera 2 mm
posterior to limbus
2. IOL haptic pulled into
ciliary sulcus as tension
is placed on suture
1.Ab interno method

43. 2. Ab externo method
1. Suture 1st preplaced
by threading suture
needle through ciliary
sulcus & into lumen
of a hypodermic
needle
2. Lens anchoring suture
pulled into the posterior
chamber

44. ✓ After lens has been
extracted, lens anchoring
suture pulled through
incision, cut & tied to
each haptic of IOL
✓ After IOL has been
positioned, incision is
closed & IOL anchoring
sutures tied to external
sclera

45. WOUND CLOSURE
✓ Use of 8-0 to 10-0 monofilament absorbable
suture material with simple interrupted or
simple continuous suture pattern
✓ Use of suture pattern & degree of tightness
to provide watertight seal without creating
astigmatism

46. POSTOPERATIVE COMPLICATIONS
IMMEDIATE VERSEUS LONG TERM
✓ IMMEDIATE
✓ Corneal ulceration
✓ Wound dehiscence within 3
days post surgery
✓ Surgery induced corneal
astigmatism
✓ Corneal edema
✓ Ocular hypertension (post
operative pressure spike)
✓ Uveitis
✓ Fibrin in the AC
✓ Hyphema / vitreal hemorrhage
✓ Acute endophthalmitis
✓ Toxic anterior segment
syndrome (TASS)
✓ LONG
✓ Posterior capsular opacities
(PCO)
✓ IOL decentration
✓ IOL luxation out of the bag
✓ Glaucoma
✓ Retinal detachment
✓ Corneal edema
✓ Endophthalmitis
✓ Corneal stromal abscess

47. POST OPERATIVE CARE
✓ Careful handling of patient
✓ Freedom from excitement,
Keep dog calm and quiet
✓ Keep the Elizabethan collar
on at all times for 1 to 3
weeks after surgery, to keep
him from hurting himself
✓ Avoid rubbing, pressing,
massaging, heat, dust, dirt
and bright sun for 1 month

48. ✓ Broad spectrum systemic
antibiotic for 5-7 days
✓ Instillation of mydriatic eye
drops 2-3 times daily
✓ Instillation of antibiotic eye
drops 3- 4 times daily
✓ Instillation of anti-
inflammatory eye drops 4
times a day

49. ✓ Use a harness instead of a collar when on walks
to reduce pressure on his head (and eye) from
pulling
✓ Cancel all grooming and vaccination
appointments for about 6 weeks
✓ Avoid swimming ,splashing of water on eyes for
1 month
✓ Avoid strenuous physical activity for 1 month
✓ Daily check up for first two weeks
✓ Schedule and keep all follow-up appointments

50. Thank you…