cataract surgery

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Intra capsular cataract extraction (ICCE) ICCE ICCE evolved into a very successful operation Preferred surgical technique before the refinement of modern ECCE surgery However there remained 5% rate of potentially blinding complications including: Infection Hemorrhage RD

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Page 1: Cataract surgery

Intra capsular cataract extraction (ICCE)

ICCE ICCE evolved into a very successful operation

Preferred surgical technique before the

refinement of modern ECCE surgery

However there remained 5% rate of

potentially blinding complications including: Infection Hemorrhage RD CME

Page 2: Cataract surgery

ECCE has replaced ICCE, almost entirely in

most parts of the world:

1. Better operating microscopes

2. More sophisticated surgical aspiration

systems

3. More sophisticated IOL implants

Intra capsular cataract extraction (ICCE)

Page 3: Cataract surgery

Techniques (ICCE)

Smith’s method

Arruga’s method

Erysiphakes

Cryo surgery

Chemical dissolution of zonular fibers

Page 4: Cataract surgery

Smith’s technique

Smith used external pressure with muscle hook

to mechanically break the inferior zonules

Expelled the lens through the limbal incision

The lens would “Tumble”, I.e. the inferior pole

would exit the eye before the superior pole

Page 5: Cataract surgery

Arruga’s method

Toothless forceps (Arruga’s) used to

grasp the lens capsule and then

gently pulled from the eye using side-

to-side motion that broke the zonules

Page 6: Cataract surgery

Arruga’s Forceps

Page 7: Cataract surgery

Erysiphakes technique

Suction cup-like devices were used to remove the lens with traction

Page 8: Cataract surgery

Cryo surgery

Cryprobe: Hollow metal-tipped probe, cooled by

liquid nitrogen, that is touched to the lens surface

As the temperature of the probe tip falls below

freezing, an ice ball forms and the lens adheres to

it

This instrument forms an ice ball, fusing the lens

capsule, cortex, and nucleus

Lessening the risk of capsular rupture as the

cataract is removed

Page 9: Cataract surgery

Chemical dissolution of zonular fibers

The enzyme is irrigated into posterior chamber to

dissolve the zonular fibers in order to facilitate

ICCE surgery

Enzyme alpha-chymotrypsin enhances the safety

of ICCE by increasing the ease of lens removal

Page 10: Cataract surgery

Extra capsular cataract extraction (ECCE)

Shift from ICCE to modern ECCE

To decrease the rate of potentially blinding: Complications

To facilitate the placement of PC IOLs

By leaving the PC intact, the surgeon could

decrease the risk of: Vitreous loss and Complications like RD, CME, and Bullous Keratopathy

Page 11: Cataract surgery

Extra capsular cataract extraction (ECCE)

Key to the development of modern

ECCE technique were the growing use

of:

Operating microscopes for increased

magnification &

Improved methods of cortical removal

Page 12: Cataract surgery

Extra capsular cataract extraction (ECCE)

Charles Kelman in 1967 developed phacoemulsification

This new type of ECCE: Ultrasonically emulsified the lens nucleus,

Allowing the operation to be performed through a small incision

This method has continued to grow in popularity as:

Techniques &

Instrumentation

Page 13: Cataract surgery

Indications of ICCE

Operating microscopes not available

Unstable / luxated cataracts

Week zonular support

Page 14: Cataract surgery

Advantages of ICCE

CryoprobesCapsular

forcepsErysiphakes

Allow this procedureTo be performedUnder most

conditions

• Entire lens removed with no capsule left behind to:

• Opacify or

• Require additional surgery

• Less sophisticated instrumentation required

• Non automated extraction devices:

Page 15: Cataract surgery

Disadvantages of ICCE

Delayed healing

Iris incarceration

Delayed visual rehabilitation

Vitreous incarceration

• Large ICCE incision 12 – 14 mm (160 - 180)

• Postoperative wound leaks with inadvertent filteration

• Endothelial cell loss > following ICCE than ECCE

• Corneal / endothelial cell trauma from lifting / folding

of the cornea (lens delivery / cryprobe)

• Cystoid macular edema (transient 50%, persistent 2%

- 4%)

Page 16: Cataract surgery

Vitreous complications:In young patients PC is firmly adherent to anteriorhyaloid; attempted ICCE will usually result in vitreous loss

Intact vitreous face may opacify and vision Adherence to corneal endothelium (corneal edema) Adherence to iris (pupillary block glaucoma) Broken vitreous face may incarcerate in the wound

with vitreous traction causing: RD CME

Vitreous in AC causing open angle glaucoma

Disadvantages of ICCE (cont’d)

Page 17: Cataract surgery

IOL implantation problematic since posterior

capsular support missing

IOL choices include:

ACL /Sutured PC IOL (Iris fixation IOLs no longer

available)

These significant disadvantages and risks led to

loss of popularity of ICCE

Disadvantages of ICCE(cont’d)

Page 18: Cataract surgery

Patient preparation

Pharmacologic pupillary dilation with topical

mydriatic and cycloplegic agents to facilitate

lens removal (iris retractors intraoperatively)

Anaesthesia

Page 19: Cataract surgery

Patient preparation

Orbital massage / osmotic agents (manitol,

glycerine, isosorbide) before surgery

1. Intermittent digital pressure on closed eye lids

or

2. Occulopressive device (honann baloon, mercury

bag, sponge ball, strap)

3. Massage helps to:

Distribute the anaesthetic agent within orbit

Orbital volume

Pressure on the globe

IOP

(cont’d)

Page 20: Cataract surgery

Patient preparationOrbital massage (cont’d)

4. Minimizes vitreous prolapse during cataract extraction and facilitates an angle supported IOL

5. Osmotic agents are used less frequently: Volume load in patients with heart and

kidney failure

Nausea (Occasional)

Urinary urgency during surgery

(cont’d)

Page 21: Cataract surgery

Procedure

Postoperative course

VA should be consistent with:1. Refractive state of the eye

2. Clarity of the cornea

3. Clarity of the media

4. Visual potential of the retina and optic nerve

Patient preparation(cont’d)

Page 22: Cataract surgery

ECCE

ECCE involves removal of the nucleus

and cortex through an opening in the

anterior capsule (anterior

capsulotomy), leaving the posterior

capsule in place.

Patient preparation(cont’d)

Page 23: Cataract surgery

ECCE (cont’d)

Methods

1. Nucleus expression (manual)

2. Phacoemulsification (Ultrasonic

fragmentation)

Patient preparation(cont’d)

Page 24: Cataract surgery

ECCE (cont’d)

Methods

Preferred method of routine cataract

surgery

Selection of technique for nucleus

removal depends upon: Instrumentation available

Surgeon’s level of experience with each

technique

Patient preparation(cont’d)

Page 25: Cataract surgery

Advantages of ECCE surgery

Smaller incision

Less traumatic to corneal endothelium

Eliminates complications (short and long

term) associated with vitreous adherent

to: Incision wound

Iris

Cornea

(cont’d)

Page 26: Cataract surgery

Advantages of ECCE surgery

Intact posterior capsule allows better

anatomical position for IOL fixation

Intact posterior capsule incidence of:

CME

RD

Corneal edema

(cont’d)

Page 27: Cataract surgery

Advantages of ECCE surgery

Intact posterior capsule ability of bacteria,

introduced into eye, to gain access to vitreous

cavity and cause endophthalmitis

2ndry IOL implantation Filtration surgery Corneal Transplantation Wound rapair

Technically easier and safer when intact PC is present

(cont’d)

Page 28: Cataract surgery

Contraindications (ECCE)

Zonular weakness

ECCE requires zonular integrity for selective

removal of nucleus and cortical material

Therefore when zonular support appears

insufficient to allow safe removal of the

cataract through ECCE surgery, ICCE or Pars

Plana Lensectomy should be considered

Page 29: Cataract surgery

Instrumentation (ECCE)

A wide range of instruments is

available for each step of ECCE:

Opening the anterior capsule

Dissecting and removing the nucleus

Removing the lens cortex

Polishing PC

Page 30: Cataract surgery

Cystotome

Used for anterior capsulotomy (opening in the

anterior of the lens)

Fashioned from 25 gauge needles by bending

at its hub and beveled tip

Prefabricated cystotomes also commercially

available

The needle tip is used to puncture and tear the

anterior capsule

Page 31: Cataract surgery

Irrigation and aspiration system coaxial, double-lumen blunt cannulas

One lumen irrigates BSS into the AC

Second lumen aspirates lens material out of the

AC

Irrigation is gravity fed from a solution bottle

Fluid flow is regulated with adjustment of bottle

height

The flow may be constant, or the surgeon can

employ a foot control connected to a pinch valve

Page 32: Cataract surgery

Irrigation and aspiration system coaxial, double-lumen blunt cannulas (cont’d)

Aspiration:

Syringe connected to the cannula

Elaborate pump system controlled by

a foot switch

Page 33: Cataract surgery

Lens nucleus

Removed by a variety of techniques,

each

with its own set of instruments:

Lens expressor

Lens loop

Spoon, Vectis

Page 34: Cataract surgery

Procedure ECCE

Pupillary dilation

Critical to the success of ECCE esp.

phacoemulsification

Cycloplegic / mydriatic drops

NSAID (topical/oral) these agents help to

maintain dialation during surgery

Page 35: Cataract surgery

Procedure ECCE

Incision Incision: Mid limbal, chord length 8 – 12

mm, which is smaller than for ICCE The initial incision consists of a limbal

groove Some surgeons prefer more posterior

incision with anterior dissection creating a flap of tunnel

A stab incision is made into AC AC depth stabilized by viscoelastic

agents, air bubble, or continuous fluid irrigation

Cystotome is inserted for anterior capsulotomy

(cont’d)

Page 36: Cataract surgery

Procedure ECCE

Capsulotomy

Christmas tree

Can-opener

Capsulorrhexis

(cont’d)

Page 37: Cataract surgery

Procedure ECCE

Capsulotomy (cont’d)

Christmas tree With cystotome anterior capsule punctured

inferiorly and

The flap of the capsule drawn toward the

wound and cut with scissors

(cont’d)

Page 38: Cataract surgery

Procedure ECCE

Capsulotomy (cont’d)

Can-Opener

Cystotome used to make a series of

connected punctures or small tears in circle

(cont’d)

Page 39: Cataract surgery

Procedure ECCE Capsulorrhexis

Continuous tear anterior capsulotomy popular in phacoemulsification, can be performed with either:

Csytotome or Capsulorrhexis forceps

First a small tear is created, The edge this tear is then grasped with

cytotome tip/forceps, and A smooth tear is created, removing a

circular portion of anterior capsule

(cont’d)

Page 40: Cataract surgery
Page 41: Cataract surgery

Procedure ECCE Capsulorrhexis (cont’d)

This technique provides:

Structural integrity for the lens

capsule

Maintain implant stability

Centeration

(cont’d)

Page 42: Cataract surgery

Nuclear expression

Manual

1. Whole (Lens loop, spoon, vectis,

irrigation)

2. Fragmentation with forceps/nuclear

splitter)

Ultrasonic fragmentation

Page 43: Cataract surgery

Lens cortex aspiration

1. Syringe connected to cannula

2. Pump system controlled by foot

switch

Page 44: Cataract surgery

Posterior capsular polishing

Abrasive tipped irrigation cannula /

low vacuum clean using low

aspiration remove epithelial and

cortical particles from the capsular

surface

Page 45: Cataract surgery

IOL implantation

AC filled with viscoelastic / BBS / air Viscoelastic most reliable AC maintainer It also protects corneal endothelial IOL inserted in the ciliary sulcus / capsular bag Sulcus fixation:

Requires greater IOL diameter (>12.5 mm) Large diameter optic (6 mm) More forgiving in case of postoperative

decentration

Bag fixation: IOL diameter <12.5 mm Optic diameter 5.00 mm

Page 46: Cataract surgery

Wound suturing

10/0 Nylon

Proper suture tension postoperative Astigmatism

Loose sutures – Against-the-rule Astigmatism

Tight sutures – With-the rule Astigmatism

Page 47: Cataract surgery

Postoperative course ECCE

As with ICCE, VA on the first postoperative day should be consistent with:

Refractive state of the eye

Clarity of the cornea

Clarity of the media

Visual potential of the retina and optic nerve

Page 48: Cataract surgery

Postoperative course ECCE

Lid: Mild eye lid edema and erythema may occur

Conjunctiva: May be injected and boggy

Cornea: Should be clear and free of striate /

edema

AC: Should be of normal depth and mild cellular

reaction typical

Page 49: Cataract surgery

Postoperative course ECCE (cont’d)

Posterior capsule: Should be clear and intact

Implant: Should be well positioned and stable

Red reflex: Should be strong and clear

IOP: Elevations may be associated with

retained

viscoelastic

Page 50: Cataract surgery

Postoperative course ECCE

Antibiotics and Corticosteroids:

Topical antibiotic and corticosteroids are used

for first few weeks

Vision:

Steady improvement in vision and comfort, as

inflammation subsides

Page 51: Cataract surgery

Postoperative course ECCE (Cont’d)

Refraction:

Refraction stable by 6th – 8th weeks,

Glasses may then be prescribed

Astigmatism:

If significant astigmatism along the axis of

incision, selective sutures removed by 6th

week, according to keratometry corneal

topography

Page 52: Cataract surgery

Phacoemulsification Phacoemulsification is an ECCE technique

that differs from “standard ECCE with

nuclear expression” by the:1. Size of incision required2. Method of nucleus removal

This technique uses ultrasonically driven

needle (phaco tip) to fragment the nucleus

and aspirate the lens substance through a

needle port

Page 53: Cataract surgery

Phacoemulsification (cont’d)

Advantages Lower incidence of wound related

complications

Faster healing

Rapid visual rehabilitation

AC depth controlled during surgery and

providing safeguards against positive

vitreous pressure and choroidal

haemorrhage (closed system)

Page 54: Cataract surgery

Phacoemulsification (cont’d)

Instrumentation

Ultrasound

Irrigation system

Aspiration system

Page 55: Cataract surgery

Phacoemulsification (cont’d)

Ultrasound

The phacoemulsification hand piece

contains a piezoelectic crystal that

vibrates at frequency of 24000 – 56000

Hz

The vibration is transmitted to the head

which is attached to the phaco tip

Page 56: Cataract surgery

Phacoemulsification(cont’d)

Aspiration

The aspiration system of

phacoemulsification machine varies

according to the pump design:

1. Peristaltic Pump

2. Diaphragm Pump

3. Venture Pump

Page 57: Cataract surgery

Phacoemulsification(cont’d)

Aspiration (cont’d) Peristaltic Pump

Consists of set of rollers that move along a flexible tubing, forcing fluid through the tubing and creating a relative vacuum at the aspiration port of phacoemulsification needle

Page 58: Cataract surgery

Phacoemulsification(cont’d)

Aspiration (cont’d) Diaphragm Pump

Flexible diaphragm overlying a fluid chamber with one-way valves at the inlet and outlet

Page 59: Cataract surgery

Phacoemulsification(cont’d)

Aspiration (cont’d) Venturi Pump

Creates a vacuum based on the venturi

principle:- That a flow of gas across a port

creates a vacuum proportional to the rate of the

gas

Page 60: Cataract surgery

Phacoemulsification

Irrigation Fluid dynamics of

phacoemulsification requires constant irrigation through the irrigation sleeve around the ultrasound tip

Constant irrigation: Maintains AC depth Cools the phacoemulsification

probe Prevents heat buildup and

adjacent tissue damage

Page 61: Cataract surgery