PURPOSE: To compare corneal incision temperature changes and heat-generation patterns between two phacoemulsification systems with different operating frequencies and modes, using an ex vivo porcine eye model.

METHODS: Three ex vivo porcine eyes were used. A 2.4-mm clear corneal incision was created with a keratome. Stellaris Elite with the Attune handpiece (Bausch + Lomb; 28.5 kHz, up to 150 µm stroke) and a 1.8-mm MICS needle and sleeve was compared to Centurion (Alcon) with the Ozil handpiece and Balanced Tip needle and sleeve (44.5 kHz, up to 90 µm longitudinal stroke; 32 kHz torsional). For each system, phaco power was activated using room-temperature BSS under 450 mmHg vacuum and 50 mmHg infusion pressure at 25%, 50%, and 100% power. For each power level, three repetitions were performed. Corneal incision temperature was recorded from baseline using a FLIR A325sc thermal imager focused on the incision. Temperature rise (ΔT) was calculated as the average increase from baseline. System comparisons were performed using two-sample t-tests (α=0.05).

RESULTS: Stellaris Elite/Attune produced consistently lower corneal incision temperature increases than Centurion/Ozil. Mean ΔT (°C) at 25%, 50%, and 100% power was 1.4, 2.6, and 2.5 °C for Stellaris Elite/Attune, versus 2.8, 5.5, and 9.1 °C for Centurion longitudinal mode (all p<0.01), and 3.2 p><0.01), 4.4 p><0.05), and 3.2 c p="0.065)" for centurion torsional mode. stellaris elite attune was 50-73 lower than centurion longitudinal and 22-56 lower than centurion torsional across 25-100 power. temperature distribution along the sleeve also differed: stellaris elite attune showed maximal heating further from the incision whereas centurion ozil exhibited higher temperatures near the corneal incision and around the sleeve hub.>

CONCLUSIONS: In this ex vivo model, the lower-frequency longitudinal phacoemulsification system (Stellaris Elite/Attune) produced smaller corneal incision temperature increases than the higher-frequency longitudinal and torsional modes of Centurion/Ozil. Differences in needle design, including the shorter MICS needle versus the Balanced Tip needle, likely contributed to both the magnitude and location of the thermal load. These findings suggest that operating frequency, mode of energy delivery, and needle geometry all influence thermal distribution at the corneal incision and may affect thermal safety margins during phacoemulsification.