Thermal Evaluation of Torsional and Transverse Phacoemulsification Systems in an Artificial Chamber and Cadaver Eye
Purpose
Compare the thermal profiles of new transversal ultrasound power modulation to torsional ultrasound in an artificial chamber and cadaver eye.
Methods
Temperature increase after 30 seconds was measured at the midshaft of the needle in an artificial chamber and at the point of maximal friction in a cadaver eye. Ellips FX (transverse) was tested at 100% power, as was the Signature with micropulse settings at 6ms on and off. OZil (torsional only) was tested at 100% power both in the artificial chamber and cadaver eye. All runs were completed with aspiration blocked.
Results
Transversal FX (27.2±1.7° C) had a greater temperature increase than micropulse (13.7±0.8° C, P <0.001) and torsional (10.2±1.9° C, P <0.001). Micropulse had a greater temperature increase than torsional (P <0.001). The cadaver eye (39.6±8.5° C) had a greater temperature increase than artificial chamber for torsional (P < 0.001).
Conclusion
There was a much higher heat accumulation and potential for incisional burn with the fresh cadaver model when compared to the artificial chamber, suggesting the need for caution when using 100% torsional ultrasound with aspiration blocked. The transversal FX generated much more heat than reports for the original transversal and further study is needed to determine the incidence of incisional burn with varied power settings for this new model.