Daniele Tognetto MD, Pia Leon MD,Paolo Cecchini MD, Silvia Rinaldi MD, Giuseppe Ravalico MD

The Authors have no proprietary interest in any products or devices discussed in this presentation

University Eye Clinic of Trieste (Italy)Head: Prof. Giuseppe Ravalico

Phaco Tip Displacement and Working Frequencies of different Phaco Machines

Aim of the study:

Step 1. determine the working frequency of the phaco machines

Step 2. evaluate the extent of the longitudinal stroke of the phaco machines

Step 3. analyze the shape and the dynamics of the stroke of two phaco machines working with lateral tip movements

AMO Signature Ellips FX

Alcon Infiniti Ozyl Torsional

Bausch&LombStellaris

Phaco machines analyzed

Step 1- Working frequencyVideo wet stroke fixture

Transparent BSS filled chamber

High magnification videocamera

Micrometric fixture

Strobo light source

Phaco handpiece

PHACO MACHINE Working FrequencyAlcon Infiniti OZil

Longitudinal 43.61 Hz

Torsional 31.62 Hz

Abbott Signature Whitestar

Ellips longitudinal 29.05 Hz

Ellips FX 38.00 Hz

Baush&Lomb Stellaris 28.75 Hz

Step 1- Results Working frequency

x y

y

x

Camera

Step 2 -Tip dynamics Video wet stroke fixture

Transparent BSS filled chamber

High magnification videocamera

Micrometric video controller

X and Y superimposed measurement lines

External peristaltic pump

Light source

A shiny spot is used as a surface landmark which generates a visible trace varying in shape and length according to the tip movement

Phaco handpiece

Longitudinal tip movement at rising phaco power

Step 2 - Results U/S Longitudinal

AMO Signature Ellips FX

Alcon Infiniti OZil Torsional

■ X and Y components of tip movement■ Different power settings (10 to 100%)■ Bent tip (end of tip and at incision)

Side-to-side movement is an emerging phaco technology and an effective alternative

to conventional lungitudinal U/S

Step 3 – New phaco modalities

Longitudinal and lateral movement at rising phaco power

Infiniti Ozil- Virtually no longitudinal movement- Linear increase at rising power

Ellips FX- Both longitudinal and lateral components, drawing an elliptic pattern- Linear increase of movement up to about 40% then tending to a plateau

Step 3 Results – New phaco modalities

Reduced movement at incision for both machines (especially for Alcon OZil)

Alcon OZil

A single movement variable was mathematically calculated from longitudinal and lateral movement taking into account the working frequency

Infiniti OZil: Linear increase of stroke

Ellips FX: Linear increase to about 40% then tending to a plateau

Step 3 Results – Normalized stroke

CONCLUSIONS

Step 1 - Working Frequency

The knowledge of the working frequency is important to compare

the different machines in terms of delivered phaco energy

Step 2 - U/S Longitudinal

A different movement behaviour has been observed

■ Alcon Infiniti: highest frequency, lowest stroke extension■ AMO Signature: lower frequency, higher stroke extension■ Bausch&Lomb Stellaris: lower frequency, highest stroke

exstension

CONCLUSIONS

Step 3 - Torsional and transversal mode

■ Infiniti OZil: - Horizontal stroke with linear power delivery

- Longitudinal stroke almost absent

■ Ellips FX: - Mostly horizontal stroke up to 40%- Mostly longitudinal stroke tending to a

plateau over 40% power

The stroke dynamic is an important variable affecting phaco cutting efficiency

Its knowledge is crucial to exploit the advantages of these new phaco devices