Post on 23-Dec-2014
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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 CME
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)
Techniques (ICCE)
Smith’s method
Arruga’s method
Erysiphakes
Cryo surgery
Chemical dissolution of zonular fibers
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
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
Arruga’s Forceps
Erysiphakes technique
Suction cup-like devices were used to remove the lens with traction
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
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
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
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
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
Indications of ICCE
Operating microscopes not available
Unstable / luxated cataracts
Week zonular support
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:
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%)
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)
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)
Patient preparation
Pharmacologic pupillary dilation with topical
mydriatic and cycloplegic agents to facilitate
lens removal (iris retractors intraoperatively)
Anaesthesia
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)
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)
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)
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)
ECCE (cont’d)
Methods
1. Nucleus expression (manual)
2. Phacoemulsification (Ultrasonic
fragmentation)
Patient preparation(cont’d)
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)
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)
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)
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)
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
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
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
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
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
Lens nucleus
Removed by a variety of techniques,
each
with its own set of instruments:
Lens expressor
Lens loop
Spoon, Vectis
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
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)
Procedure ECCE
Capsulotomy
Christmas tree
Can-opener
Capsulorrhexis
(cont’d)
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)
Procedure ECCE
Capsulotomy (cont’d)
Can-Opener
Cystotome used to make a series of
connected punctures or small tears in circle
(cont’d)
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)
Procedure ECCE Capsulorrhexis (cont’d)
This technique provides:
Structural integrity for the lens
capsule
Maintain implant stability
Centeration
(cont’d)
Nuclear expression
Manual
1. Whole (Lens loop, spoon, vectis,
irrigation)
2. Fragmentation with forceps/nuclear
splitter)
Ultrasonic fragmentation
Lens cortex aspiration
1. Syringe connected to cannula
2. Pump system controlled by foot
switch
Posterior capsular polishing
Abrasive tipped irrigation cannula /
low vacuum clean using low
aspiration remove epithelial and
cortical particles from the capsular
surface
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
Wound suturing
10/0 Nylon
Proper suture tension postoperative Astigmatism
Loose sutures – Against-the-rule Astigmatism
Tight sutures – With-the rule Astigmatism
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
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
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
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
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
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
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)
Phacoemulsification (cont’d)
Instrumentation
Ultrasound
Irrigation system
Aspiration system
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
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
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
Phacoemulsification(cont’d)
Aspiration (cont’d) Diaphragm Pump
Flexible diaphragm overlying a fluid chamber with one-way valves at the inlet and outlet
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
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