cataract techniques

7/23/2019 Cataract Techniques

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Introduction and

Pre-op assessment



Introduction

Four surgical techniques to remove acataract:• Intracapsular (ICCE)• Extra-capsular (ECCE)

• Sutureless ECCE

•Phacoemulsification (phaco)



Intracapsular

ens removed in one piece! includingthe lens capsule

Simple technique! cheap! and no ris" ofposterior capsule opacification

#igh ris" of late complications! and

unsuita$le for %ounger patients



ICCE



Extracapsular

&nterior capsule opened! nucleusremoved in one piece! posterior capsule

and 'onules left in place Safe technique! smaller incision and

less inflammation! suita$le for allpatients

Posterior capsule opacit% common!needs microscope



ECCE Phaco



Phaco

&nterior capsule opened! nucleusfragmented ith ultra-sound and

removed! posterior capsule and 'onulesleft in place

*mm incision! minimal inflammation and

rapid recover% Complex and expensive equipment



+h% is cataract surgical

technique important,

Surgical technique ill dictate three

important aspects of cataractmanagement:

utput

utcome utla%



utput

& complex technique ma% ta"e longer!leading to feer cases per hour

Some surgeons ma% not $e trained insome techniques. Feer surgeonsmeans feer cases

Surgical complications increase thelength of the operation



utcome

Poor technique leads to $ad outcomes

Some operations are associated ith

$etter results• Feer $ad outcomes

• /ore good outcomes



utla%

Some techniques are more expensivethan others

Expensive surger% ill reach feerpeople



Pha"ic e%e



&pha"ic e%e



Correction of apha"ia

&pha"ic glasses• Safe simple• 0rea"a$le! and poor vision

I• Can $e safe inexpensive• Permanent! almost normal vision

Contact lens• ittle experience in 1hird +orld• , h%giene! , cost• Possi$l% appropriate for infantile cataract



/adurai I stud%

ECCE PC-I vs. ICCE 234 Corrected 5& 6738 or $etter at one %ear

• ICCE 234 94.;• ECCE PC-I 96.*;

Complications

• Feer in ECCE PC-I <ualit% of life

• Su$stantiall% $etter in ECCE PC-Igroup

&ravind E%e #ospital! S. India



I options

&C• /odern flexi$le open loop designs are safe

in older people• Can $e used after ICCE! or ECCE• /a% not $e so safe in &fricans

PC• Folda$le or rigid• =se in almost all e%es• nl% after ECCE



Conclusions

1here is no >one-si'e-fits-all? solution

Choice of technique ill depend on availa$le

facilities! surgeon@s preferences! and patientrequirements

Surgeons ill $e comforta$le ith one or totechniques! and should stic" ith them.

Surgeons in training should learn more thanone technique



Pre-op assessment



Indications for surger%

5& is sufficientl% poor that surger% isli"el% to improve it

Patient has s%mptoms of poor vision!hich ill $e relieved $% cataractsurger%

Patient experiences limitations innormal activities $ecause of poor vision

Complications of cataract A uveitis! glaucoma



&ims of pre-op assessment

Confirm diagnosis

Betermine prognosis

Plan surger%



Confirm diagnosis

Ensure visual loss is due to cataract Chec":

• 5&• Pupil reaction• ed reflex•

IP emem$er: Dlaucoma is also a

common cause of gradual loss of visionin older people



Betermine prognosis

Identif% co-mor$idit%• Bia$etes

• Dlaucoma• &/B

• Previous trauma

•

Corneal opacit%• &m$l%opia



Betermine prognosis

Identif% ris" factors for complications• Corneal opacit%

• Shallo &C• Small pupil

• Stuc" pupil

•

Pseudo-exfoliation• =nco-operative patient



Plan surger%

Choose the appropriate operation!$ased on:

• E%e examination• Surgeon s"ills

• &vaila$le equipment

Prepare patient accordingl%



0iometr%

Betermining correct poer of I forindividual patient.

eratometer measures poer of cornea &-scan 7 aser interferometer measures

length of e%e

Calculate correct poer of I to focuslight on retina! using regression formula



S formula

/ost idel% used formula (nosuperseded $% S-1)

I & A (8.Gx&) A (4.9x) & &-constant! $ased on position of

I in e%e•

&33H.*! &88.! *.G PC-I usuall% $eteen 33H and 339 in

$ag

22.75



Sources of error

Inaccuratemeasurement of

axial length• ff axis leads to

>shorter? e%e

• Indentation leads to

>shorter? e%e +rong &-constant

+rong I



Is $iometr% necessar%,

Jo C1 in 1hird +orld to demonstrateimproved unaided post-op 5&

Eritrea• 88 B I

• K3 B error in H;

• K8 B error in *;



esults of $iometr%

4

34

84

*4

I4

K3H 3H 39 84 83 88 8* 8I L8I

I poer

; e

% e s

ahan

Ei"u%u



Is $iometr% necessar%,

Jo C1 in 1hird +orld to demonstrateimproved unaided post-op 5&

I 83-8* B used in• H*; of e%es in ahan (G44 e%es)

• G9; of e%es at i"u%u (3!H44 e%es)

=nless folda$le I is used! 3-8Bastigmatism is li"el%

equires large stoc" of I@s



+hat poer to aim for

Emmetropia• Jo depth of field! so near o$Mects $lurred• #%permetropic error means all o$Mects

$lurred /%opia

• o m%opia (-4.G to A3) allos adequatedistance vision good intermediate vision

• #%permetropic error leads to emmetropia• /%opic error leads to A3 to A8! hich is

accepta$le



&naesthesia

etro$ul$ar • Dlo$e perforation! $rainstem anaesthesia

Peri$ul$ar • Dlo$e perforation

• Facial a"inesia

Su$-tenon@s• Safe! fast! effective! painless

• equires special cannula



Post-op complications

Posterior capsule

Posterior segment



Posterior capsule

Posterior capsule opacification (PC)occurs after ECCE

Influenced $%:• Patient

• Surger%

• I• , Brugs



PC incidence

/adurai I stud%• 3*.G; at %ears•

&ssumes 6738 or orse vision i"u%u E%e =nit

• .8; at to %ears• &ssumes 673H or orse vision

Incidence ma% $e loer in 1hird +orldas more mature cataracts



Patient

&ge• Nounger patients more li"el% to develop

PC• =niversal in congenital cataract

1%pe of cataract•

/ature cataracts ma% $e at less ris" thanimmature cataracts



Surger%

Clean capsule• #%drodissection

• Complete removal of all lens matter Capsulorrhexis smaller than optic

• Prevent apposition of &nt Post capsules

I placed in $ag



PC I position

4

4.8

4.I

4.6

4.H

3

4 84 I4 64 H4 344 384 3I4

+ee"s post-op

P r o $ a $ i l i t % o f i n t a c t c a

p s u l e

In $ag

not in $ag

Bata from traumatic cataract in children



I

Square edges

Posterior convex optic

Posterior angulated haptics ,&cr%lic material



PC patholog%

Proliferative• ens epithelial cells proliferating on

capsule• Elchnig@s pearls A visuall% disa$ling

Fi$rotic•

Fi$rous metaplasia of lens cells• /a% $e present prior to surger%

• Slol% progressive



PC diagnosis

educed 5& folloing initial good result

Elschnig@s pearls visi$le against red

reflex! esp. ith dilated pupil educed red reflex

0lurred vie of fundus detail



PC treatment

N&D laser capsulotom%• Inverted = opening

• &void central part of I Pars plana approach

• =se vitrector in children

•0ent 8GD needle sufficient in adults

• Cruciate incision



etinal detachment

=p to *4; of B follo cataract surger%

&pprox G times greater ris" of B in

pseudopha"ic e%es is" greatest for ICCE! least for ECCE

is" increased $% PC rupture and

vitreous loss Pro$a$l% due to alterations in vitreous



B after cataract surger%

4;

84;

I4;

64;

H4;

344;

&pha"ic7Pseudopha"ic Pha"ic

&s cataract surger% increases! li"el% that B

incidence ill also increase



5itreous traction



C%stoid macular oedema

ess li"el% ith ECCE

/ore li"el% if vitreous loss! chronic

uveitis Prevention

• &void complications

• 1reat uveitis ith steroids and JS&IB• Start treatment pre-op in high ris" patients



Bia$etic retinopath%

/aculopath%• /acular oedema ill $e orsened $%

cataract surger% Proliferative retinopath%

• +ill $e orsened $% cataract surger%• Increased ris" of ru$eosis

1reat retinopath% first! or laser intra-operativel%



Endophthalmitis

/eticulous heat sterilisation

Sterilise conMunctival sac• Povidone iodine 8.G; ith & and hen

draping

&void vitreous loss

Jo proven $enefit from proph%laxis Earl% treatment ith intraocular anti$iotic



Sutureless ECCE



ECCE pro$lems

&stigmatism• ver 8B of astigmatism in most patients

post ECCE• &stigmatism depends on:

• +ound length• +ound position•

Sutures Posterior capsule opacit%

• educe $% secure >in-the-$ag? I fixationith capsulorhexis



Sutureless ECCE preparation

Jot as eas% as standard ECCE

&ttend training course first

Start ith small nuclei• Nounger patients

• Immature cataracts



Incision

Cauterise generousl%• 1r% to prevent h%phaema

=se "nife to enter &C enlarge ound• Scissors ound is not self sealing• oo" for corneal >dimple? hen entering &C

Internal ound must $e larger thanexternal ound



+ound si'e

+ound must $e large enough to delivernucleus insert rigid I

/inimum si'e 6-mm• >Scleral funnel? A 34mm internal opening

#ard nucleus approx 6-9mm

#%drodissection can reduce si'e ofnucleus



+ound position



Scleral funnel incision



Capsulotom% #%drodissection

Capsulorrhexis or linear capsulotom%• &void can-opener

#%drodissection crucial• /a"es nucleus smaller

• /o$ilises nucleus

•

Bislocates nucleus into &C• oosens lens cortex and epinucleus



#%drodissection



#%drodelamination



emoving the nucleus

Jucleus cannot $e expressed $% lim$alpressure•

+ound too small• #igh ris" of 'onular dehiscence

Pull nucleus out of e%e•

#oo"! or sandich #%droexpression

• Saline or visco-elastic



Jucleus deliver%



Sutures

Scleral tunnel can $e self-sealing• Jo suture required

#oever! ound gape ma% lead toflattening of cornea! and >against therule? astigmatism



&dvantages

Some of $enefits of phaco ithout

cost

Fast

• Jo sutures

Earl% visual reha$ilitation



Bisadvantages

/ore difficult than normal ECCE

>&gainst the rule? shift

Cannot o$tain full $enefits of phaco

ithout folda$le lens

Jo clinical trial data %et



utcomes

G44 cases at ahan! Jepal

Six ee" follo-up on 9;

non ocular co-mor$idit% excluded 0iometr% used on all patients

esources used• /edian surgical time approx G minutes

• Cost of consuma$les approx O6.G4



Complications

#%phaema• 9.; had some h%phaema

•4.H; required &C ashout

Capsule rupture 7 vitreous loss• ne e%e (4.8;)

Corneal oedema• 1o e%es (4.;)



=ncorrected 5&

*H**4 H

33*3*3 G

* 8

4;

84;

4;

64;

H4;

344;

ne da% 6 )ee"s ne %ear

K6764

678 - 6764

676 - 673H

Significant reduction in proportion achieving

673H or $etter $eteen discharge and 6 ee"s (p4.4*)



0est corrected 5&

I8II8I 33H

:G36 G

4;

84;

I4;

64;

H4;

344;

ne da% 6 )ee"s ne %ear

K6764

678I - 6764

676 - 673H



&stigmatic change

Induced astigmatism calculated $%#ollada% method

/ean induced c%linder as A3.B 34*o

&gainst the rule shift in 63;! ith therule in 3;

Jo significant change $eteen 6 ee"sand one %ear • Slight against the rule shift



Future developments

Control astigmatism• 1emporal incision to reduce against the

rule shift Prevent h%phaema

Betermine longer term outcome!

particularl% PC and astigmatism andomised trial vs. phaco



Conclusions

Excellent visual results are possi$le

#%phaema is the most frequent

complication 8G; have an against the rule astigmatic

shift of at least 3.GB



Phaco



#istor%

Phacoemulsification invented $%Charles elman

Beveloped in 394@s! $ut supersededas required 6mm incision for PC-I

Folda$le I led to huge increase in

phaco in 3994@s



Phaco principle

Phaco pro$e• Irrigates•

&spirates• Emulsifies A vi$rates at ver% high frequenc%

0rea" up nucleus into small pieces Insert folda$le I peration completed through *.8mm

incision



Capsulorhexis



Conversion

Safe phaco depends on an intactcapsulorhexis

If the rhexis tears or extends to theequator! convert to an ECCE

&n uncomplicated ECCE is ala%s

$etter than a complicated phaco



Bivide Conquer



Conversion

If it is not possi$le to remove all thenuclear fragments safel%:•

Equipment failure• Small pupil

Convert to an ECCE•

5isco-express nuclear segments &n uncomplicated ECCE is ala%s

$etter than a complicated phaco



utcomes

679 vision at * ee"s

• =naided• Phaco **;

• ECCE 33;

• Corrected• Phaco H;

• ECCE 6H;

679 vision at 6 months

• =naided• Phaco *H;

• ECCE 83;

• Corrected• Phaco 98;

• ECCE H6;



Complications

Capsule rupture 7 5itreous loss• Phaco *;•

ECCE ; Capsule opacit% ithin one %ear

• Phaco 84;• ECCE 89;

Suture removal• Phaco *;• ECCE *;



&stigmatism

4

4.G

3

3.G

8

8.G

*

*.G

Pre-op +ee" * +ee" 6 /onth * /onth 6 /onth 38

Phaco ECCE



Costs

In =! phaco slightl% cheaper! oing toloer out-patient costs

0=1• Cost of phaco machine not included

• Cost of rigid I Q*H

•

Cost of phaco consuma$les Q*9! I QG4• Phaco quic"er than ECCE

+hat can %ou $u% for the price



+hat can %ou $u% for the priceof a phaco,

/ercedes-0en'saloon

uxur%round-the-orld cruise

ne %ear atxford =niversit%



Phaco advantages

Dives $est possi$le outcomes• /ost li"el% to have good unaided vision

•

/ost li"el% to have good $est correctedvision

educed ris" of PC opacit%

apid visual reha$ilitation /inimal follo-up requirement



Phaco disadvantages

Equipment dependent• Cost

•

/aintenance• &vaila$ilit%

/ore difficult in mature cataracts

Folda$le lenses not %et manufactured indeveloping countries



1he Future

Phaco ill $ecome more common• Jo idel% used in private practice in India•

Folda$le Is ill $e manufactured indeveloping countries

Cost of equipment ill limit it to highvolume units

/aMorit% of cataract operations in &frica India ill $e ECCE



Conclusion

/aMor determinants of outcome are:• Co-mor$idit%

•

&voidance of complications• Dood management of

complications

Selection

SafetySurgery

Choice of operation has little significance• /ore important to do the operation ell

cataract techniques

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