Thermal evaluation of two phacoemulsification systems

Area of Science:

• Ophthalmology
• Surgical Technology

Background:

• Phacoemulsification uses ultrasound energy to remove cataracts.
• Different ultrasound modalities (transversal, torsional, micropulse) have varying thermal profiles.
• Understanding heat generation is crucial for preventing intraoperative complications like incisional burns.

Purpose of the Study:

• To compare the thermal profiles of new transversal ultrasound power modulation (Ellips FX) against torsional ultrasound (OZil) and micropulse settings (Signature).
• To evaluate heat accumulation in both an artificial chamber and a cadaver eye model.

Main Methods:

• Laboratory investigation measuring temperature increase after 30 seconds.
• Tested Ellips FX (transverse) and Signature (micropulse) at 100% power, and OZil (torsional) at 100% power.
• Temperature was measured using a microthermistor probe on the phacoemulsification sleeve with aspiration blocked.

Main Results:

• Transversal FX demonstrated significantly greater temperature increase than both micropulse and torsional ultrasound (p < 0.001).
• Micropulse settings also showed a greater temperature increase compared to torsional ultrasound (p < 0.001).
• The cadaver eye model exhibited higher temperature increases than the artificial chamber for torsional ultrasound (p < 0.001).

Conclusions:

• Higher heat accumulation in the cadaver model suggests a potential risk for incisional burns, particularly with 100% torsional ultrasound and blocked aspiration.
• The new transversal FX model generates more heat than previously reported, necessitating further investigation into its incisional burn risk.
• While micropulse settings generated more heat than historical data, improved efficiency may mitigate the risk of incisional burns.