Torsional phacoemulsification represents a clear advance on
traditional lens extraction modalities due to its
enhanced efficiency, ease of use and robust safety profile,
according to a number of investigators.

Speaking at the XXV Congress of the ESCRS, several surgeons highlighted the benefits of using the OZil torsional handpiece (Alcon) in their cataract procedures and suggested it will eventually come to supplant traditional longitudinal phaco.

“The inherent properties of torsional phacoemulsification
with OZil eliminates repulsive forces, increases followability,
decreases the need for higher vacuum and facilitates a stable
anterior chamber,” said Noshir Shroff MD, New Delhi, India.
Dr Shroff said he had been particularly impressed with
OZil's performance in dealing with brunescent cataracts.
“We frequently encounter these types of hard cataracts in
India, but torsional phacoemulsification makes the surgeon's
job so much easier. In our clinical experience, OZil delivers
excellent visual outcomes and minimal complications,” he said.
As a new cataract removal modality on the Infiniti Vision
System (Alcon), OZil incorporates a combination of handpiece,
hardware and software enhancements. By using ultrasonic
oscillations of an angulated or curved needle, torsional
phacoemulsification dramatically alters both the energy profile
of the tip and the reaction of the lens material contacted by
the vibrating needle.

Unlike traditional ultrasound, there is no forward and
backward movement of the tip with torsional ultrasound. In
the torsional mode, the handpiece oscillates from side to side
at approximately 32,000 times per second.These oscillations
are much faster and because they happen at a lower frequency
than longitudinal phaco, there are approximately 20 per cent
energy savings and less risk of thermal burn, according to
surgeons who are familiar with the technology.
The side-to-side motion of the OZil handpiece shears off
nucleus pieces without repelling them, thereby eliminating
'chatter' or repulsion and improving followability, according to
Richard Packard MD, FRCS, FRCOphth.

“What happens is that all of the crucial action takes place at
the tip end.The geometry of the curved tip used in a side-toside
displacement causes what I believe to be more efficient
cutting.The tip seems to create a shearing effect in the tissue
that you are trying to remove.With longitudinal phaco, we are
essentially pushing at the nucleus using compression and it only
cuts when a forward movement is employed.With torsional
phacoemulsification, surgeons get the benefit of cutting both
right and left,” he said.

Dr Packard also noted that the traditional phaco method is
associated with excessive heat production at the incision site,
which carries with it the potential danger for wound burn.
Torsional ultrasound, on the other hand, generates two to
three times less heat at the same power level and there is no
risk of wound burn, even using 100 per cent continuous
torsional ultrasound, he added.

The superior performance of OZil was also confirmed by
the results of a clinical trial comparing torsional and
conventional phacoemulsification carried out by Abhay
Vasavada, MBBS, MS, FRCS, of the Iladevi Cataract & IOL
Research Centre,Ahmedabad, India.
Dr Vasavada presented results of a randomised prospective
study of 360 eyes divided into three equal groups: group one
with continuous torsional using OZil and maximum amplitude
at 100 per cent, group two with microburst and traditional
longitudinal ultrasound on the Infiniti system and group three
with microburst and longitudinal ultrasound with the Legacy
Everest system.

Dr Vasavada noted that surgical clock time, fluid volume, and
endothelial cell loss were significantly less with torsional
phacoemulsification. Furthermore, there was less incidence of
corneal edema at one day postop for patients treated with
OZil, he said.