Continuous vs Pulsed Oscillatory Ultrasound in cataract phacoemulsification The authors have not financial interest in the subject matter of this poster.

Asociación para Evitar la Ceguera en México García - Ramírez Laura MD, Cervantes - Coste Guadalupe MD, Velasco - Barona Cecilio MD, Asociación para Evitar la Ceguera en México *adrygarcia09@hotmail.com

Objective To compare the effectiveness between continuous versus pulsed oscillatory ultrasound, in cataract removal with phacoemulsification.

Methods Prospective study of 20 eyes with nuclear cataract N2 or N3 (LOCS III). Cataract surgery was performed by one surgeon (CFB) with oscillatory ultrasound (INFINITI Vision System®) and “stop and chop” technique.

Methods The nucleous was divided in 2 halves. The first fragment was emulsified with continuous oscillatory or pulsed ultrasound in a randomized mode. All parameters were the same for both ultrasound modalities. Amplitude 80%, vaccum 380mmHg, aspiration 40cc/min , dynamic rise 1, bottle height 110cm. At the end of the surgery, metrics for each half was recorded.

Methods Figure 1 y 2. Metrics recorded for continuous torsional ultrasound. Figure 3 y 4. Metrics recorded for pulsed torsional ultrasound.

Results We studied 20 patients, (12) 60 % female and (8) 40% male, older than 30 years old. Of the studied eyes, 14 (70%) were rigth eyes and 6(30%) were right eyes.

Results Continuous oscillatory ultrasound Pulsed oscillatorory P UST 32.25 sec ± 9.78 17.70 sec ± 6.76 <0.5 CDE 5.84 ± 2.83 3.84 ± 1.50 <0.004 UST : ultrasound time CDE: cumulated dissipated energy

Results Graphic No. 1 Relation between the ultrasound time reported with the two modalities. (P<0.5) Graphic No. 2 Relation of cumulated dissipated energy reported with the two modalities. (P< 0.004)

Conclusion Pulsed oscillatory ultrasound is more effective than the continuous oscillatory mode, in cataract removal (N2 or N3 LOCSIII) with phaco surgery.