This document provides an overview of instrumentation and machines used in phacoemulsification surgery. It discusses the main components of phacoemulsification machines including the console, foot pedal, handpieces, tubing, and pumps. It describes the functioning of different types of handpieces and tips as well as how the foot pedal is used to control irrigation, aspiration, and phacoemulsification power. The goal is to explain the basic setup and functioning of phacoemulsification machines to understand how they work and optimize outcomes.
3. INTRODUCTION
Phacoemulsification surgery was invented by Charles Kelman in 1962.
Phacoemulsification machines have undergone constant improvement,
ever increasing both their complexity and safety.
Phaco surgery is machine-dependent surgery so to understand
the basic functioning of the phaco machine is integral for success of phaco
surgery.
Simplicity of phaco surgery depends upon how well one knows the
machines.
4. INTRODUCTION
Complication rate is reduced with good knowledge of surgeon’s own phaco
machine.
One should give sufficient time to accustom and to customize the
parameters related to steps of phaco surgery
All phaco machines consist of a computer to generate electrical signals and
a transducer to turn these electronic signals into mechanical energy.
5. INTRODUCTION
The energy thus produced is passed through a hollow needle and is
controlled within the eye to overcome the inertia of the lens and emulsify it.
Once turned into emulsate, fluidic systems remove the emulsate, replacing
it with balanced salt solution (BSS).
7. The phacomachine broadly consists of :
1. Console
2. Foot pedal
3. Handpiece and their connections
PHACOMACHINE
8.
9. The console consists of a
computer which controls all the
functions of the machine.
It contains basic hardware and
software of the machine.
The computer generates
ultrasonic waveform and sends it
to the transducer in the form of
electronic signals.
CONSOLE
10. The setting for the various
parameters, i.e. power,
vacuum and flow rate are fed
in here.
These settings represent the
maximum level of the
parameter that will be
achievable: the further linear
control is with the foot pedal.
CONSOLE
11. Newer machines have a multi-mode panel, where multiple settings of all
variables, as is required by different surgeons,can be fed in.
The same surgeon may like to change all the variables during the surgery
and these parameters can also be fed in and can be recovered by touching
the memory button only.
Settings for different types of cataract can also be fed into the memory.
In some machines the memory can be activated by the foot switch so that
the surgeon can continue the surgery without having to look at the
console.
CONSOLE
12. PUMPS
Three types of pumps are present:
1. Diaphragmatic pump
2. Venturi pump
3. Peristaltic pump
13. DIAPHRAGMATIC PUMP
A diaphragm pump is having flexible membrane to generate vacuum.
With this pump vacuum reaches to preset level without occlusion.
This mechanism is easy to remove small pieces but safety margin is less.
14. VENTURI PUMP
There is no discrimination between vacuum and aspiration flow rate
means that both are working together.
Principle:
Compressed gas creates a negative suction force that is the vacuum inside a
closed chamber which is directly transmitted to the handpiece.
15. VENTURI PUMP
ADVANTAGES DISADVANTAGES
Surgical procedure is fast Being a fast machine the safety zone
is less
Vacuum works more efficiently and
thus holding capacity of the
machine for the tissue is better.
Catching of iris and iris chaffing
Catching of anterior and posterior
capsule is common.
16. PERISTALTIC PUMP
It is one of the most widely used pump in the practice of phaco.
Vacuum and aspiration flow rate work independently, but finally assisting
each other.
Principle:
In peristaltic pump the rotation of the rollers by the pump pinches the soft
silicon tubing, which creates a negative pressure by squeezing the fluid out of
the tube.
In this system the vacuum will be built up only when the tip is occluded.
17. PERISTALTIC PUMP
ADVANTAGES DISADVANTAGES
Safe machine According to some surgeon’s point
of view it is a slow machine.
Complicated cases can be handled
safely and in a skillful way
Chances of catching of iris, capsule
is less.
18. TUBING
Phaco machine attaches to the phaco probe via this tubing.
Two functions of the tubing are irrigation and aspiration.
These tubings are made up of silicon material which can be autoclaved or
ethylene oxide (ETO) sterilized.
With the higher end machines one can get pre sterile pouch of tubing
which is called as cassettes.
Phaco fluidics depends upon the quality of tubing.
19. TUBING
Factors determining the quality of
reusable tubing are:
Color: Yellow color indicate an old
tubing which should ideally be
changed.
Consistency of the tubing: Hard
consistency of tubing which is not
flexible should be changed.
20. TUBING
Fitting: Ends of the tubing which are
attached to the machine and
the phaco probe should not be loose.
If the ends of the tubing are not
smooth or appear damaged then
the tubing should be changed.
Cassette – in higher end machines
disposable cassette are used.
21. PHACO PROBE
It is a piezoelectric substance which converts electronic energy to
mechanical energy and thus giving the ultrasound energy under the
influence of electrical signal.
Frequency: 30,000–60,000 Hz (Commonly used are 40,000 Hz).
Different probes have different number of crystals ranging from 2-4.
More the crystal the more is stroke length and more is the power.
22. PHACO PROBE
PARTS
1. Phaco Handpiece
2. Irrigation aspiration handpiece
3. Phaco tip
4. Wrench
23. PHACO HANDPIECE
The phaco handpiece contains the
piezoelectric crystal, which is in
contact with the tip.
The tip is covered by a silicon sleeve.
The infusion fluid flows between the
tip and the sleeve cooling the former.
24. PHACO HANDPIECE
There are two openings on the sleeve
for the exit of this fluid, which should be
kept perpendicular to the tip bevel.
The proximal end of hand piece is
connected to the console with an
electric cord.
There are two more connections: one
each for the irrigation tubing and for
connecting the aspiration system.
25. PHACO HANDPIECE
Functioning of the probe is to deliver the energy which cuts the hard
part of cataract which is the nucleus.
The mechanism of working is by:
1. Jackhammer effect: It is the direct mechanical impact on the nucleus
to cut it.
2. Cavitational impact: With the gap between the phaco tip and the
nucleus the bubbles form in irrigating fluid in this gap which cuts
the tissue
26. PHACO HANDPIECE
3. Acoustic wave of fluid: This is generated by the forward movement
of the tip, can disintegrate the lens material.
Power of the machine depends upon the stroke length and the
frequency remains fixed.
27. OZIL TORSIONAL HANDPIECE
Greater Phaco Efficiency
The OZil® Torsional Handpiece features side-to-side oscillating ultrasonic
movement. The result is a wide range of benefits during
phacoemulsification procedures.
1. Reduces Repulsion
Ultrasonic oscillations cut lens material using a shearing effect
Eliminates repulsion associated with traditional ultrasound induced by the
jackhammer effect
Side-to-side movement increases cutting efficiency by emulsifying lens
material with both directions of movement
28. OZIL TORSIONAL HANDPIECE
2. Improves Followability
Lack of repulsion facilitates occlusion and effective delivery of energy
into nuclear fragments.
Improves followability and decreases dispersion of nuclear fragments
during emulsification.
Reduces irrigation fluid consumption and increases your surgical
efficiency
3. Improves Thermal Safety Profile
Operates at cooler temperatures than traditional ultrasound.
29. PHACO TIPS
The phaco tip is made of titanium and is
hollow with the distal opening functioning
as the aspiration port.
The acoustic energy produced along the
ultrasonic handpiece is then transmitted
onto the phaco tip.
The angulation of the tips may vary from
0–60°.
Tips with 60°, 45°, 30°, 15° and 0°
angulation are available.
30. PHACO TIPS
More the angulation, the lesser
the holding power but the
cutting power is more, e.g. 60°
tip is a sharper tapered tip
making occlusion difficult.
Therefore, this tip has a better
cutting and less holding power.
31. PHACO TIPS
The 45° tip has a very good cutting ability and was very popular initially as
the emphasis was then on ‘Divide and Conquer’ in which trenching (thus
cutting ability) was more important than
occlusion.
With the advent of aspiration phaco the most popular tip today is 30°. This
has adequate holding and cutting power and is useful both for trenching
and in chopping.
The 15° and 0° angulated tips are better for holding but have a poorer
cutting action.
32. SLEEVE
It is made of silicon material which
covers the phaco tip.
It protects the cornea, iris from
transmitted heat energy by the
probe.
The fluid for the irrigation flows
between the sleeve and phaco tip
thus cooling the tip.
33. SLEEVE
There are two openings 180° apart on the sleeve through which
irrigating fluid exit the sleeve.
The size of the incision depends upon of tip gauge and the sleeve.
The gauge of the phaco tip is fixed, but if you want to pass the phaco tip
by various lengths from 1.8 mm to 2.8 mm incision, it depends upon the
thickness of the sleeve.
Many companies come with different color code for the various
thicknesses of sleeves.
34. SLEEVE
The distance between the distal end of the phaco tip and that of the
sleeve (exposed part of the phaco tip) defers from case to case.
Hard cataract may need more exposed part of the tip and a softer cataract
may need a small exposed part of the tip.
Direction of irrigation fluid flow depends upon the placement of the
sleeve over the phaco tip and this finally plays a very important role in
phaco fluidics.
Sleeve is autoclaved or ETO sterilized.
35. TEST CHAMBER
It is again silicon-made and is
helpful for tuning of the machine
and before start of the case it is
useful to have an idea about the
parameters of the machine in the
test chamber.
If a small nucleus particle is stuck in
the tip or aspiration tubing, it
can be removed in the chamber
with BSS solution in the energy
mode of the machine
37. IRRIGATION-ASPIRATION (I-A) HANDPIECE
The I-A tip differs from the
phaco tip in being smooth and
rounded with a single aspiration
port on the side of the tip and
not at the end.
The aspirating port at one side
usually 0.75 mm to 1.5 mm away
from the tip.
38. IRRIGATION-ASPIRATION (I-A) HANDPIECE
The opening can be in a diameter
of 0.2, 0.3, 0.4, or 0.5 mm.
The angulations of the I-A
handpiece can be straight, 45°
bent, or has a 90° bend.
39. FOOT PEDAL
Foot pedal control is the most important
aspect of phaco.
Though the foot pedal of each machine
may have a different design, it
essentially consists of main central part
and side kicks.
The main part of the foot pedal controls
infusion, aspiration and phaco power.
40. The entire distance that the foot
pedal traverses is divided by 2
dentations into 3 excursions-
1. I (irrigation only),
2. IA (infusion and aspiration) and
3. IAP (infusion, aspiration and
phaco).
FOOT PEDAL
41. The excursion before the first dentation is the I excursion.
The excursion between the 1st and the 2nd dentation is the IA
excursion.
The excursion after the 2nd dentation is the IAP excursion.
Resistance is felt at the dentations or position where the mode changes
and it is to feel these dentations that one has to train oneself both while
depressing and while coming back up.
FOOT PEDAL
43. Familiarity with the feel of dentations of the pedal (tactile feedback)
and the sounds that the machine makes (auditory feedback) is
mandatory before attempting phacoemulsification.
Ability to move quickly from one mode to the other at the correct time is
the key to successful chopping
The point to remember is that in the I excursion, irrigation is fully on.
In the IA excursion both irrigation and aspiration are on and in the IAP
excursion, irrigation is on, aspiration is at the maximum preset, and
phaco power will depend on the amount of depression.
FOOT PEDAL
44. In the I excursion, the pinch valve opens and irrigation is switched on.
There is no gradient in this step and the irrigation is either switched fully
on or off.
In the absence of gradient, the function of this dentation is to dissociate
infusion from irrigation-aspiration.
As foot is brought back from IA/IAP excursion, stopping at this
dentation will keep the infusion on preventing the collapse of anterior
chamber.
FOOT PEDAL
45. Many steps like nuclear rotation, manipulation of nuclear fragments,
epinuclear plate etc. require a formed AC without any aspiration.
Dentation 1 to dentation 2 is the aspiration or the IA excursion.
From dentation 2 to full depression is the phaco or the ‘IAP’ excursion.
FOOT PEDAL
46. At IAP0 phaco energy delivered will be zero and at IAPmax the energy
will be maximum preset.
The delivery of phaco energy is linear both in the surgeon and the pulse
mode.
However, in panel or burst mode, as soon as foot clears IAP0, maximum
preset energy is delivered.
FOOT PEDAL
47. FOOT GRADIENT
Foot gradient is the excursion of foot pedal in mm to produce unit
power of phaco energy.
If the total foot excursion, from IAP0 to IAPmax is 10 cm i.e. 100mm
and the maximum preset phaco energy is 100%, then the foot
gradient (FG) becomes:
48. Decreasing the maximum preset
power on console increases the
foot gradient and hence the foot
control.
Therefore, phaco maximum should
be set at the minimum power
which is required for a particular
step in that grade of cataract.
49. SIDE KICK FUNCTIONS OF FOOT PEDAL
The most important sidekick function of foot pedal is reflux.
On kicking the side switch, aspiration flow rate is inverted and
the material aspirated is expelled into the AC.
Since it is not a continuous function, for further reflux, the
switch needs to be kicked again.
Inadvertent aspiration of wrong tissue (iris, capsule) can be
released by this function especially by beginners.
Editor's Notes
Blue tooth control foot pedal
Iop control pump
In some machines both the peristaltic and venturi pumps worktogether.
Methods to check an ideal phaco handpiece:Weight of the phaco probe should not be very heavyLength of the probe should not be too long or smallGrip on probe should be perfectIt should be friendly in use means to move down, up and sidewaysshould be freeThere should be no kinking of the tubing at the proximal end of thephaco probe.Holding of a phaco probe should be like a pen grip. Generally theangulation between the phaco probe and the incision ranges from0° to 30° other wise there are chances of damage to the architecture ofthe wound.
A sleeve should be changed when:Elasticity is altered and it becomes loosely fit over the phaco tipThere is difficulty while going through incisionSleeve gets torn or there is a hole in the sleeveDiscoloration of the sleeve occurs.
Test chamber gives protection to the phaco tip.When to change the test chamber:If it is torn or there is a holeDiscoloration of the test chamber