phaco is the perfect way to do cataract surgery

1. CATARACT
REVISITED
INDOREDRISHTI.WORDPRESS.COM

2. DR DINESH MITTAL DR SONALEE MITTAL
DRISHTI EYE HOSP VIJAYNAGAR INDORE

8. 1 Cataract surgery has evolved into a
refractive procedure with the goal of
eliminating or significantly reducing the
need for spectacle dependence.
•2. One must consider not only the
astigmatism induced by the cataract
incision itself, but also the correction of
preexisting astigmatism.
•3. Incision length, depth, and distance
from visual axis all affect astigmatism.

9. •4. LRIs are commonly used to correct
preexisting astigmatism, and
•published nomograms are helpful in
tailoring a surgical approach.
•5. Toric IOLs and excimer laser ablation
are alternative approaches to correcting
astigmatism in the patient for refractive
cataract surgery.
•No single approach is best suited for all
patients.

10. INTRAOCULAR LENS CALCULATIONS
•Choosing the appropriate IOL power is a
major determinant of patient
satisfaction with cataract surgery.
•accurate measurements ,
•selecting calculations ),
• and assessing the patient’s needs to
determine postoperative refractive
target

12. BIOMETRY
•At minimum, 2 measurements reqd
to calculate implant power:
&
( )
•Precise measurements critical
•error of 0.3 mm in axial length will
result in a 1-D error in IOL power.

13. Axial Length
•Axial length has been obtained utilizing
.
•This measurement is determined by
;
• an ultrasound pulse is applied and the transit
time through the eye is measured. Using
estimated velocities of ultrasound waves
through various media (ie, cornea, aqueous,
lens, and vitreous) the distance travelled
through the eye is calculated.

14. • The instrument should have an screen
to differentiate a good measurement from a poor
one. or spikes should be
observed when the probe is aligned properly
• These include the following: a tall peak for the
cornea, tall peaks for the anterior and posterior
lens capsule, tall peak for the retina, mod-erate
peak for the sclera, and moderate-to-low peaks for
orbital fat. If these spikes are not well seen, then
the probe may be misaligned.
A SCAN ULTRASOUND

15. •The must
be performed carefully, as com-
pressing the cornea will result in a
shorter-than-expected measurement
and should
be taken and averaged.
•If several are taken and differ by a
significant amount, they should be
readings
can be obtained.

16. •It is also prudent to
for comparison
•the machine should be
, checking measurements
against an eye of known axial length.

18. Immersion technique
The immersion technique may more accurately
represent the true axial length because there is
.
In this technique, the patient lies in the supine
position and a scleral shell is placed on the eye
and filled with Goniosol. The ultrasound probe is
placed in this solution and the beam is aligned
with the macula by having the patient look at the
probe tip fixation light.
Although the immersion method may be strongly
advocated by some users, applanation A-scan is
the more commonly used method

19. IMMERSION
TECHNIQUE
SHOWING
PROBE IN
OSSOINIG
SHELL

20. Optical biometry: IOLMaster
• In the last decade, the technique of
optical coherence biometry was in-
troduced by Haigis, which utilizes light
rather than ultrasound to measure the
length of the eye. The first device
introduced was the IOLMaster (Zeiss),
based on the principle of partial
coherence interferometry using a 780-
nm multimode laser diode.

22. •Measurements taken without contact
to eye, thus eliminating variability due
to an examiner technique.
•The distance measured lies between
the anterior surface of tear film &
retinal pigmented pigment epithelium
, which may
be more physiologically accurate

23. patient asked to focus on a small red
fixation light, & examiner maneuvers
focusing spot within the measurement
reticule, sampling areas until the best
peak pattern is obtained.
5 to 20 measurements obtained until the
readings differ by less than 0.1 mm.
Maximal axial length measured 40 mm.
IOLMASTER USE

24. IOL MASTER DISADVANTAGE
The primary disadvantage of this
optical device is that
, such as a corneal scar,
dense posterior subcapsular plaque,
darkly brunescent cataract, or vitreous
hemorrhage, will reduce the signal-to-
noise ratio (SNR) to the point that
.

25. A-scans should be
under the following conditions
• 1. Axial length is less than 22 mm or
greater than 25 mm in either eye.
• 2. The difference between the 2 eyes is
greater than 0.3 mm.
• 3. The measurements do not correlate
with the patient’s refraction (ie,
hyperopes should have shorter eyes,
and myopes should have longer eyes).

26. IOL CALCULATION BEST
IN UNOPERATED EYES

27. IOL CALCULATION BEST POST
KERATOREFRACTIVE SURGERY

28. ASCRS SITE FOR IOL POWER
CALCULATION

29. SPECULAR MICROSCOPY

30. SCLERAL TUNNEL VS CLEAR CORNEAL
• 1. The 2 most common types of
wounds for phaco are the scleral
tunnel and clear corneal incisions.
•2. Advantages of the
include conjunctival
coverage and a greater vertical
distance from the corneal
endothelium to the phaco probe

32. • 3. Advantages of the include an
undisturbed conjunctiva and the potential avoidance of a
retrobulbar block.
• 4. Choice of wound location is influenced by astigmatic
considerations, preexisting ocular disease states, and
ergonomic comfort of the surgeon.
• 5. Incision characteristics such as width, shape, and
tunnel length may all be modified, affecting astigmatic
outcome, endothelial cell loss, and self-sealing properties
of the wound.
SCLERAL TUNNEL VS CLEAR CORNEAL

34. INITIATION
OF GROOVE
OR
EXTERNAL
INCISION

35. INITIATION
OF TUNNEL
WITH
CRESCENT
BLADE

36. DISSECTI
ON OF
SCLERAL
TUNNEL
INTO
CLEAR
CORNEA

37. DIMPLING OF
CORNEA BY
DEPRESSING
THE POINT
OF
KERATOME

38. STRAIGHT
LINE
INCISION IN
DECEMET’S
MEMBRANE .5
MM
ANTERIOR TO
VASCULAR
ARCADE

39. ENLARGEMENT
OF 3.5 MM
INCISION TO 4
MM WITH
BLUNT TIPPED
KERATOME

40. CAPSULORRHEXIS
•1. it confines the IOL to the capsular
bag as the capsule fibroses and
contracts around the lens.
•2. Start the capsulorrhexis by making
the initial puncture with a bent 30-
gauge needle and flopping the tear
toward the incision so that it can be
grasped using capsulorrhexis forceps

41. A central puncture
with a cystotome
followed by a arched
curve creates a slit .
The capsular flap is
lifted and pulled in a
circular fashion by
cystotome or
capsular forceps

42. A central puncture with
a cystotome followed
by a arched curve
creates a slit . The
capsular flap is lifted
and pulled in a circular
fashion by cystotome or
capsular forceps

47. • 3. Always pull tangentially when tearing
the capsulorrhexis to maintain optimum
control.
• 4. If you start to lose control, inject more
viscoelastic material and begin tearing
tangentially again. If the capsulorrhexis
extends beneath the pupil margin,
repuncture the capsule and tear it in the
reverse direction
• 5. It takes practice to become good at
creating a uniformly consistent
capsulorrhexis

48. •1. Keep the cannula tip beneath the anterior
capsule while injecting fluid.
•2. Apply slow, constant pressure on the
syringe so that the fluid wave will propagate.
•3. Watch for a complete fluid wave to ensure
adequate hydrodissection.
•4. Watch for the “golden ring” sign as
confirmation of hydrodelineation.
•5. Confirm rotation of the lens before
proceeding to phacoemulsification.
HYDRODISSECTION AND HYDRODELINEATION

54. •1. Flow (aspiration rate) and vacuum
are controlled independently in a
peristaltic pump system.
•2. Aspiration flow rate and vacuum are
not independent in a vacuum pump
system (Venturi).

55. •By aspiration flow rate, or simply “aspiration,”
I mean the rate at which fluid and particles
come to the ultrasound tip.
•Higher aspiration means faster flow and faster
movement of nuclear and epinuclear pieces to
the tip.
• Aspiration flow rate determines how quickly
fluid and materials come to the tip.
• Vacuum occurs only when the tip is occluded
and helps to remove material at the tip.

56. • Once the nucleus is at the tip, ultrasound
power is responsible for emulsifying it into a
small enough piece to fit through the tip and
travel through the
•bore of the ultrasound handle.
• The surgeon must choose a power level that
is
•just enough to break up the nuclear
fragment into small enough chunks to be
vacuumed through the tip.

57. • The surgeon must also choose between longitudinal
• ultrasound power and torsional ultrasound.
• delivers an axial cutting force that will tend
to push nuclear piece away from the tip and
create a “tunnel-like” cavity into the tissue,
much like a jackhammer.
,
•is produced by side-to-side oscillation of
phaco tip, and delivers ultrasound force to a
larger region of tissue.

60. •More the angulation, the
lesser the holding power
but cutting power is more.
•60° tip is a sharper tapered
tip making occlusion
difficult. But is useful for
grooving hard cataracts.
•Entering into the anterior
chamber is easy with the
60° tip and progressively
harder with a 15° or a 0° tip.

61. Mechanism of Emulsification
•actual mechanism of
emulsification is Jack-
hammer & Cavitation
•jackhammer effect is
physical striking of the
needle against the nucleus.
•It requires that the nucleus
should be fixed as for the
bombarding action to be
effective.

62. Cavitation
• phaco needle, moving through a liquid
medium at ultrasonic speeds, gives rise to
intense zones of high and low pressure.
•Low pressure, created with backward
movement of the tip, pulls dissolved gases
out of solution, producing micro bubbles.
•Forward tip movement then creates an
equally intense zone of high pressure.
•This initiates compression of the micro
bubbles until they implode.

63. •At the moment of implosion, the bubbles
create a temperature of 7204˚C degrees
and a shock wave of 5,171,100 mbar.
•Of the micro bubbles created, 75%
implode, amassing to create a powerful
shock wave radiating from phaco tip in
direction of bevel with annular spread.
•The energy created by cavitation exists
for no more than 4 milliseconds and is
present only in the immediate vicinity of
the phaco tip and within its lumen.

64. • cavitation is instrumental in clearing nuclear
fragments within phaco needle, preventing
repetitive needle clogging.
• angle of the bevel of the phaco needle
governs direction of generation of shock
wave and micro bubbles.
• disadvantage of this wave is that it may push
nuclear pieces away if the hold is not good
and thus decrease the Jack-hammer effect.
•Phacoemulsification is most efficient when
both the jackhammer effect and cavitation
energy are combined.

65. •Once the ultrasound has “handled” the
nuclear fragment, it is the vacuum that
determines how quickly the fluid or
particle will make its way through
•the tip.
•Softer nuclear and epinuclear pieces
need less vacuum to pull the tissue
through the ultrasound tip.
• Harder and denser nuclei need higher
vacuum levels to draw them through tip.

66. •Vacuum rise occurs when the ultrasound
hand piece tip is occluded. Maximum
vacuum is generated when the tip is
completely occluded
• Use the pulse setting when you want
slower, more controlled nuclear removal.
•Use burst mode for maximum speed and
efficiency.
•Use the epinuclear setting for epinucleus
removal.

68. DIVIDE AND CONQUER PHACO
•Nuclear fracturing techniques, have
facilitated cataract surgery immensely,
allowing for safer and more efficient
means of nucleus removal.
•fundamental principle underlying all
nuclear-fracturing techniques is the
creation of “breaks” to divide the lens
into smaller fragments for controlled
removal through a small incision.

69. •Gimbel first to propose a Approach with
the “divide and conquer” nucleofractis
phaco technique.
• This method involves the creation of 2
deep grooves in nucleus that Intersect
centrally and are then cracked into 4
quadrants.
•These smaller sections of lens can be
brought away from the capsule into a
“safe zone” for emulsifi cation and
removal

70. DIVIDE-AND-CONQUER TECHNIQUE
•The initial nuclear groove formation
requires the use of a moderate degree
of phaco energy with low aspiration
and vacuum settings.
•Quadrant removal requires higher
aspiration and vacuum settings to allow
the phaco tip to engage the lens
fragments.

71. Grooving Technique
•create a sulcus that is 90% of the depth of
the lens. The sulcus depth is the most
important aspect for facilitating a
complete crack at the base of the lens.
•Groove length is not as important and
should not extend into the far lens
periphery. A good rule of thumb is to limit
the length of the groove to the length of
capsulorrhexis.

72. •Creation of the initial sulcus is best
achieved using a moderate degree of
phaco energy with low aspiration and
vacuum settings.
setting of
of , and
setting of
•create a groove that is
•1.5 phaco tips wide and 3 TIPS deep.
•The standard phaco tip is 1.2 mm in
diameter, thus yielding a groove that is
1.8 mm × 3.6 mm centrally.

74. •The average lens has a diameter of 9
mm and a thickness of 4.5 mm
centrally. The rationale for limiting
the length of the initial groove is that
the lens thickness and the proximity
of the posterior capsule decrease in
the periphery.
•The goal of grooving should be to
achieve 90% depth centrally with a
length of approximately 6 mm

75. Cracking Technique &Bisection of Two Halve
• Goal: Nucleofractis of the nuclear plate and
rim and the remaining nuclear material
• It is important to achieve a complete
separation of the posterior nucleus.
• A complete crack of the periphery is not as
important (leaving a portion of the cortex and
epinucleus intact is not problematic).
• The phaco tip and second instrument must be
positioned deep in the groove, and the second
instrument is rotated to simulate a paddle-
like movement while the phaco tip is moved in
the opposite direction to create a crack

76. INITIAL
SCULPTING OF
A TRENCH OR
TROUGH

77. DOWN SLOPE TECHNIQUE
STARTS WITH TRENCH OR
TROUGH SCULPTED TO
JUST PAST THE CENTER
OF LENS SURFACE AND
THEN NUDGE THE LENS
INFERIORLY AND
CONTINUE SCULPTING OF
MORE SUPERIOR PART

78. POSTERIOR
PLACEMENT OF TWO
INSTRUMENTS FOR
BIDIRECTIONAL
FRACTURING
INAPPROPRIATE
ANTERIOR PLACEMENT
OF INSTRUMENTS ,
RESULTING IN
INEFFECTIVE
FRACTURING

81. • Achieving a consistent, even crack of the
posterior cataract is an important piece in
mastering the divide-and-conquer
technique. complete posterior crack
reflects that entire nuclear component of
the lens has been thoroughly bisected.
Extension of crack into far periphery is
not nearly as vital because peripheral
cortex and epinucleus can be easily
divided with a second instrument during
quadrant removal
• initial crack described here is performed
after formation of the initial groove

82. CRATER DIVIDE AND
CONQUER TECHNIQUE
IN DENSE AND
BRUNESCENT
CATARACTS IS
FACILITATED BY
EMULSIFICATION OF A
DEEP AND WIDE
CENTRAL CRATER OF
NUCLEUS

83. USING THE
CYCLODIALYSIS
SPATULA AND
THE PHACO TIP ,
RESULTANT
PERIPHERAL
NUCLEAR RIM IS
FRACTURED

84. NUCLEUS IS
ROTATED AND A
SECOND
FRACTURE IS
MADE . THE
SECTION IS LEFT IN
PLACE ENSURING
STABILISATION OF
NUCLEUS AND
CAPSULE

88. Quadrant Removal
•Goal: Rotation, reposition, and removal
of nucleus
•Engage the quadrants in the region of
the nucleus (the middle portion of the
cataract). Occlude the tip and pull the
fragment centrally. Once the phaco tip
and nuclear fragment are positioned
centrally and at the level of the Iris ,
quadrant can be safely removed

90. • settings for quadrant removal are phaco
power setting of 20% to 60%, vacuum of
350 mm Hg, and aspiration of 25 mm Hg
• present posterior edge of the fragment to
the phaco tip by gently lifting fragment
with second instrument & engaging piece
with higher vacuum and higher flow rates
and drawing it into the pupillary center
• The phaco tip is used to impale the fragment,
the vacuum is then allowed to increase, and
piece is drawn into pupillary plane. The second
instrument remains under segments being
emulsified in order to protect posterior capsule

91. PHACO SUMMARY
• 1. Create a nuclear groove that is 90% of the depth
of the lens. sulcus depth is the most important
aspect for facilitating crack at the base of the lens.
• 2. Groove length is not as important as groove depth
and should not extend into the far lens periphery. A
good rule of thumb is to limit the length of the
groove to the length of the capsulorrhexis.
• 3. Cracking of the posterior aspect of the lens is
more important than cracking the periphery.
• 4. In general, create a groove that is 1.5 phaco tips
wide and 3 deep.

92. • 1. Aspiration flow rate determines how
quickly fluid and materials come to tip.
•2. Vacuum occurs only when the tip is
occluded and helps to remove material at the
tip.
•3. Use the pulse setting when you want
slower, more controlled nuclear removal.
• 4. Use burst mode for maximum speed and
efficiency.
• 5. Use epinuclear setting for epinucleus
removal

94. BIMANUAL
IRRIGATION
AND
ASPIRATION IS
BETTER

96. ECCE

97. ECCE
TECHNIQUE

100. PLANE THREE OF
INCISION
PENETRATION
INTO ANTERIOR
CHAMBER USING
A DISPOSABLE
PHACO BLADE

101. ANTERIOR
CAPSULOTOMY
BEND A 27 G
DISPOSABLE NEEDLE
ANTO CONFIGURATION
SHOWN IN INSET .
ATTACH THE NEEDLE
TO A SMALL SYRINGE ,
WHICH SERVES AS A
HANDLE

102. EXTEND PLANE THREE OF INCISION
WITH CRESCENT BLADE

111. FEMTOSECOND LASER ASSISTED
CATARACT SURGERY
•Femtosecond laser provides an
ultrafast burst of energy.
•Argon, excimer, and Nd: YAG lasers:
nanosecond (10 -9 ) pulses
•Femtosecond: 10 -15 second

112. FEMTOSECOND LASER ASSISTED
CATARACT SURGERY
• Excimer: “ ”
• Argon: “ ”
• Nd: YAG and Femtosecond: “ t”.
• Their light energy can be absorbed by
optically clear tissue and create
“microcavitation bubbles” that cause an
acoustic shock wave that incises the
target tissue.

113. Femtosecond laser first FDA
approved for LASIK flaps in 2001
and then approved for cataract
surgery In 2010.
Optimedica catalys

114. With guidance systems OCT or
Scheimpflug-like technology FEMTO
CATARACT is used to make:
 Cataract clear corneal
and limbal relaxing incisions

 ;
a pretreatment prior to phaco
&/or irrigation /aspiration

115. Status of femto catarct
• Does only 3 steps
•Even in phaco itself first two steps incision
and capsulorhexis are done by blade or
needle or forceps .
•3rd step actual nuclear emulsification it is
not better than phaco and for aspiration
anyway phaco has to be used ; then why not
the 3rd complete step to be done completely
by one time tested , economical and time
efficient phaco machine

116. Status of femto catarct
• femtolaser is practically not
useful at this juncture .
• So phaco is superior to femto
phaco

117. THANK YOU
DR DINESH
DR SONALEE