IC-68: A Video Bouquet of Phaco
Complications Which Should Never
Have Occurred With Tips on Damage
Control and Prevention to Optimize
Postoperative Outcome
Arup Chakrabarti MS
Samar Basak FRCS
Brian Little FRCS
Khiun Tjia MD
A.R.Vasavada, FRCS
Ronald Yeoh FRCS
Suven Bhattacharjee MS
Video Handout (DVDs) of this Instruction Course will be distributed in the hall. Please collect
the video DVDs from the hall.
DESCRIPTION:
Video Bouquet of Phaco Complications That Should Not Have Occurred
This video course deals with genesis, management and prevention of unexpected
surgeon or technique related complications in phacoemulsification in uncomplicated
cataracts. Course demonstrates complications that may be encountered during all
steps of phaco (both uncomplicated and difficult cataracts) and offers a stepwise
strategy to prevent and manage them. Complications and remedial measures
demonstrated include wound burns, wound length anomalies, capsulorhexis
extension and retrieval, two stage rhexis, use of microrhexis forceps and scissors in
tricky cases, incomplete/difficult hydrodissection, hurdles in phaco-chop, misplaced
CTR, inappropriately used iris hook , how to convert to a safer non-phaco technique
in problem situations and many more.
Objective:
At the end of the course the attendee will learn how to avoid and successfully manage
certain intraoperative phaco complications which can not only mar the postoperative
outcome in uncomplicated as well as complicated cataracts but also can lead on to
sight-threatening sequelae (if not managed scientifically).
COURSE OUTLINE
Certain intra-operative complications are known to occur in phacoemulsification,
which are not necessarily related to what is known as phacoemulsification in difficult
situations. These complications may be more frequent in the hands of a novice
surgeon though not uncommon in the hands of an experienced surgeon. The
complications dealt with in this video course include the following.
Wound related: 1) Premature entry, 2) Wound Size anomalies (too large/small). 3)
Wound burns, 4) Tunnel wound suturing techniques.
Capsulorhexis Related: 1) Size related (too small/large rhexis), 2) Rhexis runaway, 3)
Rhexis retrieval, 4) Rhexis damage with paracentesis knife/iris hook, 5) two-stage
rhexis, 6) microrhexis assisted rhexis in difficult situations, 7) fibrotic anterior
capsule.
Hydrodissection: 1) Incomplete hydrodissection esp. in cases with capsulo-cortical
adhesions, 2) forceful nuclear rotation with zonular damage, 3) rhexis tear due to
uncontrolled hydrodissection, 4) nucleus prolapse into anterior chamber during
hydrodissection.
Pupil management: 1) Intraoperative miosis: How to avoid and How to manage, 2) Iris
chaffing, 3) iris hook induced trauma to anterior capsule, ciliary body and peripheral
iris.
Nucleus management: 1) Capsular bag damage during chopping of the nucleus, 2)
Incomplete chopping of the nucleus due to superficial embedding of the phacotip, 3
Strategies to deal with the nucleus chopped into fragments which are joined in the
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Video Bouquet of Phaco Complications That Should Not Have Occurred
centre, 4) strategies to deal with the nucleus in the presence of iris phaco and
descemets detachment, etc. 5) Intraoperative surge, 6) Nucleus chatter.
Cortex Removal: 1) Zonular dialysis during irrigation./aspiration, 2) Cortex removal
strategies in the presence of small pupil and posterior capsular rent,
Complications pertaining to the CTR: 1) Asymmetrically place CTR, 2) CTR in the
anterior chamber angle
Converting from a phaco to a non-phaco technique: This strategy is useful in the
event of intraoperative difficulties which may make it unsafe to continue with
phacoemulsification. Non-phaco techniques involve enlarging a preexisting scleral
tunnel or creating a new scleral tunnel and removing the nucleus manually, thereby
retaining he self sealing advantage of the phaco incision.
The complications will be demonstrated using video clippings. The management of
these complications also will be demonstrated. And finally tips will be offered to
minimize the incidence of these complications.
There will also be a panel discussion at the conclusion of each presentation.
Course No: IC 68
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Video Bouquet of Phaco Complications That Should Not Have Occurred
Day: Monday
Date: 19/09/2011
Time: 14:30 – 16:30 PM
Hall:
Speakers and Topics
(15 to 20 minutes per speaker including panel discussion)
1. Dr. Arup Chakrabarti
2. Dr. Samar Basak
:
Introduction
: 1.Wound Related Complications
2. PC Tear, Conversion to Posterior
Capsulorhexis,
3. Abandoned Phaco- Converting to Nonphaco
SICS
3. Dr .Brian C Little
: 1. Capsulorhexis Complications
2. CTR Complications
4. Dr. Ronald Yeoh
: 1. Indiscriminate Hydrodissection: Nucleus Drop
2. “Unusual” Complications
5. Dr. Khiun Tjia
Fragments
: 1.Intraop. Zonular Dialysis and Dense Nuclear
2. Posterior Capsular Tear in Quadrant Removal
3. Viscoshield Strategies
6. Dr. Arup Chakrabarti
Options
: 1. Early Intraop. Zonular Dialysis: Management
2. Iris Hook Problems
7. Dr. A Vasavada
Emulsification
: 1. Management in a Case of Split Capsulorhexis during
2. IOL Related Complications
8. Dr. Suven Bhattacharjee
: 1. Iris Trauma in Phaco
2. Intraoperative Surge
3. Phaco Chop- Difficulties & Complications
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Video Bouquet of Phaco Complications That Should Not Have Occurred
Video Bouquet of Phaco Complications That Should Not Have Occurred
With Tips on Damage Control and Prevention
Dr.Aup Chakrabarti
INTRODUCTION
Certain intraoperative complications are known to occur in phacoemulsification,
which are not necessarily related to what is known as “phacoemulsification in
difficult situations”. These complications may be more frequent in the hands of a
novice surgeon though not uncommon in the hands of an experienced surgeon. This
course deals with the following complications occuring during phaco emulsification.
I. WOUND RELATED
1. Premature Entry
2. Wound Size Anomalies
3. Wound Burns
4. Tunnel Suturing Techniques
II. CAPSULORHEXIS RELATED
1. Size Related
2. Rhexis Runaway
3. Rhexis Retrieval
4. Rhexis Damage with Paracentesis knife / Iris hook
5. Two Stage Rhexis
6. Microrhexis Forceps Assisted Rhexis in Difficult Situations
7. Fibrotic Anterior Capsule
III. HYDRODISSECTION RELATED
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Video Bouquet of Phaco Complications That Should Not Have Occurred
1. Incomplete Hydrodissection Especially In Cases with Capsulocortical
Adhesions.
2. Forceful Nuclear Rotation with Zonular Damage.
3. Rhexis Tear Due To Aggressive /Uncontrolled Hydrodissection.
4. Nuclear Prolapse into Anterior Chamber during Hydrodissection.
5. Posterior Capsular Blow Out
IV. PUPIL MANAGEMENT
1. Intraoperative Miosis
2. Iris Chafing
3. Iris Hook Introduced Trauma to Anterior Capsule, Ciliary Body and Peripheral
Iris.
V. NUCLEUS MANAGEMENT
1. Capsular Bag Damage During Chopping of The Nucleus
2. Incomplete Chopping Due to Superficial Embedding of the Phaco Tip.
3. Strategies To Deal With the Nucleus in Presence of Iris and Decemets
Detachments
4. Incomplete Chops
5. Intraoperative Surge.
VI. CORTEX REMOVAL
1. Zonular Dialysis During Irrigation / Aspiration
2. Cortex Removal Strategies in The Presence of Small Pupil and Posterior
Capsular Rent.
VII. CAPSULAR TENSION RING RELATED
1. Asymmetric Placement
2. CTR in The Anterior Chamber Angle
VIII. CONVERTING FROM A PHACO TO A NON PHACO TECHNIQUE
I. WOUND RELATED
An ideal incision would be one that would induce no astigmatism, allow easy access
to the anterior chamber and allow for a sutureless water tight closure at physiologic
anterior chamber pressures1.
1. Premature Entry.
This most commonly occurs while creating the tunnel dissection into the
cornea during construction of the sclerocorneal incision. The instrument may
become too deep entering the anterior chamber. This can also occur during
keratome entry if the keratome is directed parallel to the iris but too close to
the limbus, piercing the Descemets membrane too posteriorly. This can cause
iris prolapse, pigment loss,pigment dispersion and damage to blood – aqueous
barrier. Difficulty in insertion of phacotip can lead to subincisional
iridodialysis with or without haemorrhage, iris chafe and hyphaema. A small
peripheral iridotomy may be adequate to complete the procedure if the
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Video Bouquet of Phaco Complications That Should Not Have Occurred
premature entry is not too posterior. However, if the entry is too posterior, it
would be wiser to suture the wound and create an incision at another site.
2. Wound size anomalies.
If wound is too large, there will be excessive fluid egress with shallowing of
the anterior chamber. One or two sutures should be used to partially close the
wound and stabilize the anterior chamber. Another option would be to create
a fresh incision at a different site after closing the large incision.
If wound is too narrow, there will be difficulty in inserting the phacotip
causing excessive eye movement, wound burn and even Descemets
detachment. This can be overcome by enlarging the scleral tunnel and/or the
anterior chamber entry with a suitable keratome.
3. Wound Burns
This can occur due to
1) Incision being too narrow or long – In this case, the wound is to be
enlarged to the appropriate size.
2) Irrigating fluid deflection by dispersive viscoelastic in the anterior
chamber. This can be managed by providing irrigation for a few
seconds before applying phaco power at the beginning of the procedure
3) When a tight wound is exposed to high power prolonged phaco, small
wound burns can occur. This can be prevented by cooling the irrigation
fluid at 40 degrees F one day prior to surgery.
Wound burn can be recognized by unusual bubble formation along the length
of the phaco tip, whitening and distortion of the wound. Wound burns can
result in distortion of wound architecture leading to astigmatism. Multiple
tight sutures preferably horizontal mattress sutures or even a scleral patch
graft may be necessary in such cases.
4. Tunnel Suturing Techniques
The tunnel should be sutured with horizontal sutures. These do not attempt to
approximate the edges of the incision, but simply flatten the scleral tunnel
making the incision watertight. Elimination of the vertical vectors leads to a
more physiologic incision closure. The sutures are less likely to disturb the
alignment of the internal entry incision and therefore less likely to cause
astigmatism than radial sutures.
Radial sutures, on the other hand approximate the edges of the external
incision, pulling the scleral flap and cornea to a new unphysiological position
and separates and disturbs the internal entity site which is the true
astigmatism control site. Hence these sutures are to be avoided.
Clear corneal incisions which leak are closed with a single, interrupted radial
10-0 nylon suture which is removed after 2 weeks. In complicated cases,
where incision has to be enlarged, or in cases with an open posterior capsule
where vitrectomy is required, sutures are to be applied2.
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Video Bouquet of Phaco Complications That Should Not Have Occurred
II. CAPSULORHEXIS RELATED
1. Size Related
The optimum size of the capsulorhexis is debatable. It is determined by
a. The maturity of the cataract and expected phaco procedure - the rhexis
opening must allow adequate access to the cataract e.g. nuclear brown
hard cataract will require a bigger opening whereas in a white
cortically mature cataract a relatively smaller CCC will suffice
b. IOL optic size
Ideally, there should be a ¼ mm overlap of the anterior capsular rim
over the IOL edge. Thereby no portion of the CCC edge can fuse to the
posterior capsule so that the IOL edge forms a mechanical barrier to
lens epithelial cell migration behind the IOL. Also, concentric
placement balances the forces of the contracting capsular bag, hence
minimizing the tendency for postoperative IOL movement.
c. Anatomic abnormalities of the Zonules.
2. Rhexis Runaway
In this case, extreme care must be taken throughout the rest of the procedure.
Try to complete the procedure from the opposite direction. Undue pressure on
the posterior capsule is to be avoided. Hydrodissection is to be carefully
performed. The nucleus may prolapse into the anterior chamber and phaco
done there in between the layers of viscoelastic. Some advocate converting to
a canopener capsulotomy3.
3. Rhexis retrieval
The key to tackling rhexis retrieval is its timely recognition. The anterior
capsule can be grasped close to the leading peripheral edge of the discontinuity
in presence of viscoelastic and torn so that the tear edge is blunted off by
bringing it back toward the rhexis margin into which it is then blended.
4. Rhexis damage with paracentesis knife / iris hook
The rhexis may be accidentally torn during entry of the paracentesis knife or
iris hook after capsulorhexis. Therefore capsulorhexis should be done only
after paracentesis and iris hook insertion.
5. Two stage rhexis:
This method is used in white mature cataract, and in the presence of anterior
capsular tear. At first a small opening is made, later the capsulorhexis may be
enlarged to the desired size with rhexis forceps after making a snip with
Vannas scissors. In the first case this is followed by decompression of the
liquified cortex under pressure followed by the second stage, all under good
viscoelastic cover. This allows control and visualization during CCC and allows
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Video Bouquet of Phaco Complications That Should Not Have Occurred
for enlargement as needed for lens implantation. However tears or zonular
dehiscence may occur with the phaco tip during phaco.
6. Microrhexis Forceps Assisted Rhexis in Difficult Situations
In case of anterior capsular tear, inject viscoelastic above and below the tear to
support it. Then using capsulorhexis forceps the torn capsule is grasped at its
furthest extent and redirected centrally, converting it into rounded outgrowth
of the capsulorhexis. Alternatively, employing a Vannas scissors to create a
larger tear of the anterior capsule incorporating the original tear will prevent
further extension of the tear and further complications.
7. Fibrotic anterior capsule
These cases mostly require a completely individual CCC where an additional
application of Vannas scissors or comparable instrument is required.
III HYDRODISSECTION RELATED
1. Incomplete hydrodissection especially in cases with capsulocortical adhesions.
If hydrodissection is incomplete, some areas of cortex remain attached to the
capsular bag making nucleus rotation difficult. In cases with zonular weakness
such as in pseudoexfoliation this can lead to further compromise of the
zonules. This can be remedied by further hydrodissection in each quadrant
for 3600 combined with gentle bimanual rotation of the nucleus or gentle visco
dissection.
2. Forceful nuclear rotation with zonular damage.
3. Rhexis tear due to uncontrolled hydrodissection.
Small notches or tears in the rhexis can act as weak points. During
hydrodissection, the force of the fluid stream filling the bag and pushing the
nucleus superiorly results in the notch or tear splitting outward toward the
equator. 75 % of the time, the tear stops at the equator. In 25 % cases, it
extends through the equator into the posterior capsule. The nucleus will pop
up into the anterior chamber.
The procedure should be continued without creating undue force on the
ruptured capsule. Viscoelastic is introduced beneath the nucleus to sequestrate
the vitreous in cases of vitreous face exposure; Emulsification is accomplished
within layers of viscoelastic. If the wound is sclerocorneal , it can be enlarged
for extracapsular removal of the nucleus.
4. Nuclear prolapse into anterior chamber during hydrodissection. This is
described above.
5. Posterior Capsular Blow Out
During hydrodissection the nucleus may prolapse anteriorly blocking the
rhexis margin. Further injection of fluid will accumulate between the nucleus
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Video Bouquet of Phaco Complications That Should Not Have Occurred
and the posterior capsule resulting in increase in pressure and posterior
capsular blow out.
IV. PUPIL MANAGEMENT
1. Intraoperative miosis:
A
4
pupil smaller than 4 mm is defined as a small pupil by Howard Fine . The more
common causes of small pupil are pseudoexfoliation 5, anterior uveitis, previous
trauma with iris scarring or posterior synechiae, long -term miotic drops and old
age.
The main aim in managing the miotic pupil is to achieve an adequate pupillary
aperture to perform safe phacoemulsification.
Preoperative management
If possible, the use of miotic agents should be discontinued at least 2 weeks prior
to surgery. Dilating drops 1 % tropicamide with 2.5 % phenylephrine is used at 15
minutes interval, 3-4 times before surgery along with topical NSAIDs like
flurbiprofen 4 times from 1 week prior to surgery. A clinical note should be made
regarding dilation status so that you know what to expect at the theatre. A
retrobulbar block assists pharmacologic dilation.
Surgical Technique
A. A Kuglen hook is used to examine the iris for adhesion and mobility.
Peripupillary adhesions can be broken at this time. Additionally, both the
blunt viscoelastic cannula and gentle visco dissection can be used to sweep
under the iris to release posterior synechiae. Occasionally thin veneer like
membranes will remain on the anterior capsule which should be removed
with a Utrata or a Kelman McPherson forceps. If the pupil is large enough
after these steps, no further manipulations are necessary .The less the iris is
manipulated, the better.
B. Sretch Pupiloplasty: Two Kuglen hooks, one inserted through the incision and
the other through the paracentesis can be used to stretch the pupil employing
a slow, constant bimanual stretch under viscoelastic. A single stretch will
often be adequate. However a second stretch 900 away will create a significant
increase in pupil diameter 6,7
C. Iris hooks: Micro iris retractors- both metal (titanium) and flexible (nylon) are
available to dilate the pupil.
D. Multiple Sphincterotomies :
This technique was devised by Howard Fine in which eight equally
spaced mini- sphincterotomies are made.
E. Sector Iridectomies: either superiorly or inferiorly.
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Video Bouquet of Phaco Complications That Should Not Have Occurred
2. Iris Chafing
This is a known complication of phaco especially in the hands of beginners. This
results due to a direct trauma to the iris by phaco probe or other instruments.
Causes are
1. Small Pupil: There is little room for the phaco probe to work and the iris
tissue can get caught up within the phaco probe. The inferior iris is more
affected in these situations.
2. Shallow anterior chamber: especially at the time of entry of probe into the
anterior camber can result in direct trauma to the iris tissue. Both upper and
lower halves of iris can be affected.
3. Repeated iris prolapse: due to repeated efforts to reposit the tissue.
4. Use of high vacuum.
Prevention:-Pupillary dilation is the most important consideration. Adequate
anterior chamber depth should be maintained at the time of entry of phaco probe
into the anterior chamber. The level of the phaco tip should be downwards during
insertion and upwards and parallel to the iris plane while doing phaco. Phaco
should be performed in the central 5-6 mm. The rhexis margin should never be
crossed. Vacuum should be kept on the lower side. If a vacuum is high, the probe
should be kept away from the iris.
All mechanical pupil dilating techniques create a variably flaccid pupil. During
phaco, this flaccid tissue appears magnetically attracted to the phaco tip and if
aspirated and emulsified, severe iris damage results. To prevent this, low or zero
vacuum should be used during phaco techniques that require sculpting. In
addition, removal of segments with high vacuum should be performed above the
plane of the pupil and away from the pupillary margin.
Occasionally, iris strands may be produced after a high power encounter with the
phaco tip. To prevent further damage, isolate the iris strands with dispersive
viscoelastic and perform phaco away from that area. Often, cutting the persistent
strands with intraocular microscissors under viscoelastic cover is useful.
3. Iris hook introduced trauma to anterior capsule, ciliary body and peripheral iris:
Iris hook introduction after capsulorhexis can lead to anterior capsular tears by
catching the edge. The pupil should never be stretched after beginning
capsulorhexis as capsular tears can occur by catching the edge. Also, shallowing of
the anterior chamber during stretching maneuvers may lead to posterior positive
pressure tearing the capsule outward.
If the iris hooks are too anterior, the iris will be pulled anteriorly when the
silicone cinches are tightened, resulting in difficulty in passing the phaco tip over
the iris and iris chafing. If the paracentesis is too parallel to the iris, the iris edge
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Video Bouquet of Phaco Complications That Should Not Have Occurred
may curl up and cause difficulty. Damage to the iris sphincter can occur if the
pupil is enlarged to the maximum resulting in severe postoperative pupil
irregularity and dysfunction. The pupil is to be enlarged slowly by tightening the
silicone cinches
sequentially a little bit at a time to minimize iris tears. The
subincisional retractors are to be slightly released to decrease the contact of the
iris with the phacoemulsification needle thereby diminishing iris chafing.
V. NUCLEUS MANAGEMENT
1 Capsular bag damage during chopping of the nucleus:
Anterior Capsule: - Anterior capsule tear is most common in the early phases of
phaco when the surgeon passes the chopper under the anterior capsular edge of
the CCC. Creating a large CCC usually more than 5 mm can help to avoid this
complication. The site of chopper placement to create the initial chop is at the
hydrodelineation line which is more central than the hydrodissection line thereby
protecting the capsular bag from the chopper. Using the aspiration from the phaco
tip to pull the endonucleus towards the incision moves the cleavage line more
proximally away from the equator and capsular edge. The phaco tip can be
inclined and slid in direct contact with and over the nuclear material, so that it
can slip below the anterior capsular edge without tearing or otherwise engaging it.
A modified chopper with raised top section to push the edge of the CCC so that
the instrument slides below the capsular edge without difficulty is useful.
Zonular dialysis: Occurs when the anterior capsule rather than being torn is
engaged and pulled by the chopper. The ensuing dialysis is opposite the incision.
It can occur when the nucleus is pushed ahead of the chopper or during rotational
maneuvers in the presence of poor hydrodissection (900 away from the incision).
To avoid this complication, use appropriate machine setting of ultrasound power,
vacuum and flow. Watch the movement of the nucleus while driving the ultra
sound tip into it. When chasing nuclear fragments near the equator, vacuum and
flow are to be adjusted accordingly. A good hydrodissection is a necessity.
Posterior capsule rupture: In case of soft cataract, the ultrasonic tip can be passed
too deeply into the nucleus. When phaco energy is applied, the thicker epinucleus
followed by the thinner cortex and then the posterior capsule is aspirated. This is
most likely with tips that have enhanced occlusive properties such as the 0 degree
tip, and when beveled tips are used bevel down. While emulsifying the soft
nucleus it is best to hydrodissect the entire nucleus in the anterior chamber away
from the posterior capsule. Mostly aspiration force with little phaco power is to be
used.
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Video Bouquet of Phaco Complications That Should Not Have Occurred
In moderate nucleus, there is less chance of tear of the posterior capsule. In hard
nucleus (black, brown or amber), the risk of tear increases due to the increased
force required to drive the ultrasound tip into the hard nucleus as well as to hold
it well enough to create a chop.
2. Incomplete chopping due to superficial embedding of the phaco tip.
This occurs in hard cataracts. More force is required to drive the ultrasonic tip into
the hard nucleus. It is also difficult to hold it well enough to chop it. This can be
prevented by creating a crater that is one or two phaco tip diameter deep and use
of elevated vacuum power to improve the holding power. If chopping is
incomplete, the tip should be replaced more deeply and the chop repeated and
completed. Rotating the nucleus 1800 and replacing the phaco tip deeply to
complete the crack from the opposite side can be helpful.
When the nucleus is particularly leathery, cracking through the posterior aspect
of the nucleus is impossible. An alternative technique described by Gimbel and
Anderson Penno can be used .The capsulorhexis is enlarged to 6mm. The nucleus
is hydrodissected again and the pole opposite the incision is prolapsed into the
anterior chamber and flipped in a supracapsular method. The crack is then
completed and the sections emulsified.
3. Strategies to deal with the nucleus in presence of iris and Decemets detachments:
To minimize the oedema of the cornea, it is helpful to use 0 degree tip, which due
to a smaller surface area, occludes more easily. Use of high vacuum (22 to 400 mm
Hg) with moderate flow (18-20 cc/min), slow pulse or burst phaco for the entire
procedure will decrease the total power delivered to the anterior segment. A
dispersive viscoelastic will protect the endothelium. Dividing the nucleus into
smaller pieces; will help phaco to proceed more rapidly
4. Incomplete Chops
It is important to separate the instruments both vertically and horizontally.
Without the vertical components it is possible to make incomplete chops,
removing facets but leaving the posterior plate intact. The plate can be mobilized
by gentle viscodissection below it. This will elevate it to the plane of the iris away
from the posterior capsule where it can easily be chopped. Under no
circumstances, should bevel up or bevel down phaco with high vacuum be
attempted.
5. Intraoperative Surge.
Surge occurs when a nuclear fragment is held by high vacuum and is then
abruptly aspirated with a burst of ultrasound so that fluid from the anterior
chamber rushes to the phaco tip and leads to collapse of the anterior chamber.
The development of surge is a principal limiting factor in the selection of high
levels of vacuum or flow. When the phaco tip is occluded, flow is interrupted and
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Video Bouquet of Phaco Complications That Should Not Have Occurred
vacuum builds to its preset level. Additionally, the aspiration tubing may collapse
in the presence of high vacuum levels. Emulsification of the occluding fragment
then clears the occlusion. Flow instantaneously begins reaching the present level
immediately. In addition, if the aspiration line tubing is not reinforced to prevent
collapse the tubing, constricted during occlusion, then expands on occlusion break
resulting in vacuum production. These factors cause a rush of fluid from the
anterior segment into the phaco tip. The fluid in the anterior chamber may not be
replaced rapidly enough by infusion to prevent shallowing of the anterior
chamber. Therefore there is a subsequent rapid anterior movement
of the
posterior capsule and collapse of the cornea. This abrupt forceful movement of the
posterior capsule as well as stretching of the bag around nuclear fragments may be
a cause of capsular tears. In addition, the posterior capsule can be literally sucked
into the phaco tip, tearing it. The magnitude of the surge is contingent on the
presurge settings of flow and vacuum.
Surge can de divided into a preocclusive, occlusive and post occlusive phases.
Preocclusion modification: The vacuum preset or flow maximum preset should be
decreased. Decreased flow will result in slower generation of vacuum and less
absolute vacuum level during occlusion, the net effect being a decrease of post
occlusion surge.
Attention to wound size and construction, selection of a phaco tip with a soft
sleeve of adequate size to adequately seal and prevent excess fluid outflow will
augment anterior chamber stability. Finally, elevating the infusion bottle will
increase fluid inflow.
Occlusion Modification: The Alcon Legacy employs an Aspiration Bypass System
(ABS) which consists of high “vacuum tubing” and the “aspiration bypass tip”. The
tubing is reinforced to prevent collapse during periods of high vacuum. The tip
has 0.175 mm holes drilled in the shaft of the needle which provide a continuous
alternate fluid flow during occlusion. The higher the vacuum the greater the flow
through the bypass hole. Thus complete occlusion never occurs. This will cause
dampening of the surge on occlusion break.
The dual linear foot pedal of the B & L millennium is another device to control
surge in the occlusive phase. It can be programmed to separate both the flow and
vacuum from power so that flow or vacuum can be lowered before beginning the
phacoemulsification of an occluding fragment thus dramatically decreasing the
surge.
Post occlusion Modification: Some phaco machines have microprocessors that
instantaneously sense the resumption of flow after occlusion and immediately
slow the pump lowering vacuum, the engine for surge thereby decreasing the
phase.
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Video Bouquet of Phaco Complications That Should Not Have Occurred
Other methods devised to reduce surge include using 1) anterior chamber
maintainer to get more fluid into the eye. However another port has to be made
which is cumbersome if you are doing the case under topical anesthesia. 2) Air
pump- is connected to the infusion bottle (one of the two infusion bottles used).
When switched on, it pumps air into the infusion bottle, which goes to the top of
the bottle and because of the pressure, pumps the fluid down with greater force.
The amount of fluid coming out of the hand piece is much more than normal and
with more force to compensate for the surge. An air filter can be used to sterilize
the air used.
6. Nucleus Chatter
Chatter is defined as a fragment bouncing from the phaco tip due to aggressive
application of phaco energy. Low pulsed or burst power should be applied at a
level high enough to emulsify the fragments without driving it from the phaco tip.
VI .CORTEX REMOVAL
1. Zonular dialysis during irrigation / aspiration
Cortical removal can be a cause of zonular damage due to adhesion between the
cortex and the equatorial capsular bag especially in predisposed eyes e.g. in the
history of trauma, pseudoexfoliation, Marfans syndrome, homocystinuria and
Weill Marchesani Syndrome. A successful outcome is more likely when the
surgery is preceded by
a comprehensive preoperative examination. Cortical
viscodissection prior to aspiration will limit the stress on the remaining zonules
without requiring the counteraction of an unstable capsular bag8. Applying
traction to the cortex tangential to the bag is helpful. Performing irrigation and
aspiration after implantation of the IOL will allow the lens to stretch the bag and
acts as a barrier between the phacotip and posterior capsule. A capsular bag
tension ring is advantageous.
2. Cortex removal strategies in the presence of small pupil and posterior capsular
rent
Posterior Capsular Tear : Dispersive viscoelastic should be placed over the rent to
minimize the chance of further vitreous advancement and the need for further
vitrectomy. A reverse soft shell technique may be useful. The remaining cortex
should stripped toward the capsular tear. The 0.3 mm I /A tip should be embedded
into the cortex before the application of vacuum so as not to aspirate vitreous.
Lowering the infusion bottle will decrease inflow and resultant turbulence, which
might enlarge the capsular rent and/ or force more vitreous forward. The surgeon
should attempt to avoid working directly over the capsular tear and never strip
cortex directly away from the capsular tear, as this will immediately enlarge the
tear. Manual cortex removal may be utilized. If cortex is difficult to remove, and
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Video Bouquet of Phaco Complications That Should Not Have Occurred
not too voluminous it should be left behind. The vitrectomy tip can be
alternatively used in the vitrectomy or I/ A mode for complete cortical removal.
Small Pupil : Due to the iris flaccidity, following stretching a bimanual I/A may
be beneficial. Separating the irrigation and aspiration decreases anterior chamber
turbulence and the tendency for aspiration of iris into the 0.3 mm I / A tip.
Alternatively, using a standard coaxial I/A through the main incision and Kuglen
hook through the paracentesis, the hook can be used to push the iris away from
or hold it up over, the I/A tip so that the iris is not aspirated. Finally, pulling the
I/A orifice immediately adjacent to the cortex to be aspirated permits preferential
aspiration of cortex rather than iris.
Most phaco machines control flow and preset the vacuum in I/ A. Therefore once
the cortex has occluded the I/ A tip, the vacuum will build until the cortex is
aspirated with a post aspiration surge, which often aspirates the flaccid iris. Low
vacuum should be used, to grab the cortex. The vacuum can be gradually
increased until aspiration occurs, and then it can be decreased before aspiration of
the iris.
VII. CAPSULAR TENSION RING RELATED
1. Asymmetric placement
CTR may have one end of the loop in and one out of the capsular bag if the
surgeon is not careful.
2. CTR in the anterior chamber angle
VIII. CONVERTING FROM A PHACO TO A NON PHACO TECHNIQUE
Conversion may be required in cases of intraoperative miosis, complicated
capsulorhexis, problems in hydro procedures, nuclear emulsifications, posterior
capsule tears, zonular dialysis, and malfunctioning instrumentation9. These intra
operative difficulties may make it unsafe to continue with phacoemulsification.
The final anatomical and functional out come may be better in such cases with a
non phaco technique.
If the capsulorhexis in intact, relaxing incision should be given in the rhexis. The
preexisting scleral tunnel should be enlarged with a 5.25 mm keratome. If the
incision was clear corneal, another new scleral tunnel can be created. Nuclear
expression should be done gently after injecting viscoelastic under the nuclear
fragments and coaxing them into the anterior chamber. Alternatively, the
fragments may be removed using a wire vectis and a lens spatula. Sinskey hook or
spatula can be swept across the anterior chamber to check for vitreous in the
anterior chamber. A good automated vitrectomy is required when vitreous is in
the anterior chamber. If the anterior hyaloid face is broken, dry aspiration of the
16
Video Bouquet of Phaco Complications That Should Not Have Occurred
cortical matter should be done. A 6 mm PCIOL may be implanted in the ciliary
sulcus or in the bag; or an anterior chamber IOL or scleral fixated IOL may be
used according to the situation. If the wound is unstable, it should be sutured.
CONCLUSION
Thus the proper management of the complications occurring
phacoemulsification can provide optimal functional and visual outcome.
1.
2.
3.
4.
5.
6.
7.
8.
9.
during
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