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Cataracts
Figure 3: Infusion-assisted ‘Hybrid Phaco’ with the SofPort silicone. Recent long-term studies suggest that after-cataract
®
easyTip CO-MICS Micro-co-axial Phaco Tip and a Tight-
and yttrium–aluminium–garnet (YAG) rates, due to the particular
fit Low-resistance Infusion Spatula (Geuder, Germany)
material and design properties, will be significantly lower with the
Fluid-assisted (‘hybrid’) microphaco three-piece silicone IOL compared with the one-piece acrylic models.
10
‘High-flow’-infusion spatula and
easyTip
®
CO-MICS by Oertli Micro-incision Cataract Surgery
Through Sub-2mm Incisions
Phaco Instrumentation
MICS requires new technologies and surgical techniques if the efficacy
Low-resistance shaft
> mass influx
and safety of phaco are to be preserved. For phaco, a micro-co-axial or
a bi-axial approach can been chosen. For several years, the bi-axial
approach has been the only choice for real micro-incision phaco
through incisions smaller than 2mm. Recent improvements in
phaco needle manufacturing technology have allowed implementation
of the SSSB design into a co-axial micro-tip – easyTip
®
CO-MICS by
Oertli (see Figure 1, right). This needle allows co-axial micro-phaco
Figure 4: Modified ‘Divide and Conquer’ Technique
(MPE) through incisions as small as 1.4mm when used with
for easyTip
®
CO-MICS Micro-co-axial Phaco Tip with or
without Infusion Assistance
trumpet-shaped incisions. Clinical studies have demonstrated its
efficacy and safety. However, inflow remains the limiting factor for high-
easyTip
®
CO-MICS – phaco technique:
fluidic settings. To compensate for this, infusion-assisted or hybrid
direct crack and conquer
phaco
11
has been introduced and evaluated by the author. In place of a
phaco spatula, a special infusion spatula is inserted through the side-
port, which supplements the infusion inflow and allows for
1. ‘Direct crack’ the manipulation of the cataractous lens during work-up and aspiration
(see Figures 3 and 4). The additional fluid supply allows the use of
excessive vacuum and flow settings for maximum phaco efficiency
while at the same time preserving a ‘rock-solid’ chamber. The safety
limits were elaborated in an experimental setting. Vacuum limits of
600mmHg and flow rates of up to 50mmHg have been demonstrated to
be safe. In a clinical study comparing the easyTip
®
CO-MICS tip standard
and hybrid techniques, less than half the phaco energy was required
2. Conquer
when infusion assistance was used. While allowing for phaco through
incisions as small as those used with bi-axial MPEs, co-axial MPE with
SSSB tips offers the following advantages, especially when infusion-
Standard: Infusion-assisted:
assisted: no incision leakage, which optimises chamber stability; no
20ml/min, 400mmHg >40ml/min, 600mmHg
tissue damage by the oscillating needle, which preserves the self-
Figure 5: The Dilemma of Sleeveless Bi-axial
sealing ability of the incision; abundant infusion supply, allowing for
Micro-phaco work with excessive flow, which optimises followability and needle
occlusion; and usage of SSSB tip technology, which optimises
The dilemma of sleeveless bi-axial microphaco: holdability and energy output while suppressing post-occlusion surge.
tissue ‘oar-locking’ versus wound leakage
Thus, maximum efficiency and safety are provided while optimally
preserving the tissue integrity and valve function of the incision.
Sleeve-armed Co-axial or Sleeveless Bi-axial
Microphaco – Which Way to Go?
Proponents of sleeveless bi-axial phaco argue that it requires a smaller
incision and improves the flow characteristics in the anterior chamber.
Although bi-axial MPE is feasible, there are a number of downsides: in
order to maintain a deep and stable chamber while using high fluidics,
Tight wound fit Loose wound fit
incision leak must be minimised. Sleeveless phaco needles tend to
‘oar-lock’ a tight CCI, or allow for continuous collateral wound leak
funnel-shaped incision alleviates docking for insertion. However, the with a wider CCI, which varies according to the changing angle of the
unfolding IOL exerts considerable stress on Descemet’s membrane, instrument approach (see Figure 5). There is no way of designing and
which may compromise the self-sealing properties of the corneal lip. A sizing a CCI that seals the wound and spares tissue at the same time.
trumpet-shaped incision makes appropriate docking more demanding, Histological studies have demonstrated that both the stromal tunnel
but minimises the stress on the corneal lip. Therefore, the latter is and the corneal valve are compromised in their morphology and
definitely preferable for the experienced surgeon. Alternatively, function.
12,13
A soft-silicone sleeve snugly adapts to the slit incision and
pre-loaded IOL injection systems have been made available that allow guarantees both atraumatic tight sealing and a greater infusion
implantation of a continuous-edge three-piece IOL through a 2.4mm throughput. The new SSSB design optimises phaco efficiency and
incision: the HOYA iSert hydrophobic acrylic and the Bausch & Lomb safety by further increasing influx while running flush with the swollen
54 EUROPEAN OPHTHALMIC REVIEW
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