超音波白内障手術における高頻回パルス発振の有用性

Usefulness of the high frequency pulse mode in cataract surgery by phacoemulsification and aspiration

加齢白内障93眼に超音波手術を行い，パルス発振と連続発振による超音波積算値と核処理時間を比較した。パルス発振では，連続発振よりも超音波積算値が減少した。核処理時間については毎秒15パルス（pps）の低頻回パルス発振では連続発振よりも延長し，70 ppsの高頻回パルス発振では連続発振と同等であった。オンタイムが極端に短くなると，4msecの高頻回パルス発振のほうが12msecの低頻回パルス発振よりも核処理時間が延長した。高頻回パルス発振は，ある程度のオンタイムを維持する必要があるが，超音波使用量を減少し，乳化効果を改善する可能性がある。

During phacoemulsification-aspiration on 93 eyes,we compared the pulse mode and continuous mode regarding cumulative energy of ultrasound and the time needed to emulsify the lens mucleus. The cumulative energy of ultrasound was less for pulse mode than continuous mode. The time needed to emulsify the lens nucleus was longer when using low-frequency pulse mode of 15 pulses per second（PPS）than continuous mode. It was the same for high-frequency pulse mode of 70 pps as continuous pulse mode. When the on-time became extremely short,the time needed to emulsify the nucleus was longer with 4 msec high-frequency mode than 12 msec low-frequency mode. High-frequency mode resulted in lesser cumulative energy with improved emulsification. It is necessary,thougt,to maintain on-time at a certain level.