PURPOSE To compare 2 ultrasound (US) frequencies for phacoemulsification for moderate to hard cataract to determine a frequency that makes phacoemulsification safer and more efficacious. SETTING Post Graduate Institute of Medical Education and Research, New Delhi, India. DESIGN Randomized controlled trial. METHODS Patients with grade 4.0 to 6.9 senile cataract were randomized to 2 groups. Group A had lower frequency (28 kHz) phacoemulsification, and Group B had higher frequency (42 kHz) phacoemulsification. The effective phacoemulsification time (EPT) and estimated fluid usage (EFU) were compared intraoperatively. The endothelial parameters were assessed over 1 year. RESULTS Both groups comprised 80 patients. The groups were matched for age (P = .533), sex (P = .263), and nuclear grade (nuclear color, P = .496; nuclear opalescence, P = .622). Group B had significant reductions in EPT (P = .008) and EFU (P = .004) compared with Group A. Postoperatively, the endothelial cell density (ECD) was significantly higher in Group B at 1 month (P = .004), 3 months (P = .003), 6 months (P = .004), 9 months (P = .002), and 1 year (P = .003). The percentages of ECD loss were also significantly lower in Group B; the difference was statistically significant up to 1 year postoperatively even after adjustments for age, grade of cataract, EPT, and EFU. CONCLUSION Higher frequency phacoemulsification was associated with a lower EPT and EFU as well as better endothelial preservation than a lower frequency.

中文翻译：

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使用2个超声频率比较有效超声乳化时间和角膜内皮细胞损失。

目的比较中度至硬性白内障超声乳化超声的2种超声（US）频率，以确定使超声乳化更安全，更有效的频率。地点印度新德里，医学教育与研究研究生学院。设计随机对照试验。方法将4.0至6.9级老年性白内障患者随机分为两组。A组的超声乳化频率较低（28 kHz），B组的超声乳化频率较高（42 kHz）。术中比较了有效超声乳化时间（EPT）和估计的液体使用量（EFU）。评估了一年以上的内皮参数。结果两组均包括80例患者。各组的年龄（P = .533），性别（P = .263）和核级（核颜色，P = .496；核乳光，P = .622）匹配。与A组相比，B组的EPT（P = .008）和EFU（P = .004）明显降低。术后，B组在1个月时的内皮细胞密度（ECD）明显更高（P = .004） ，3个月（P = .003），6个月（P = .004），9个月（P = .002）和1年（P = .003）。B组中ECD丢失的百分比也显着降低；即使在调整了年龄，白内障等级，EPT和EFU之后，直至术后1年，差异仍具有统计学意义。结论较高频率的超声乳化与较低频率的EPT和EFU以及更好的内皮保存有关。004），3个月（P = .003），6个月（P = .004），9个月（P = .002）和1年（P = .003）。B组中ECD丢失的百分比也显着降低；即使在调整了年龄，白内障等级，EPT和EFU之后，直至术后1年，差异仍具有统计学意义。结论较高频率的超声乳化与较低频率的EPT和EFU以及更好的内皮保存有关。004），3个月（P = .003），6个月（P = .004），9个月（P = .002）和1年（P = .003）。B组中ECD丢失的百分比也显着降低；即使在调整了年龄，白内障等级，EPT和EFU之后，直至术后1年，差异仍具有统计学意义。结论较高频率的超声乳化与较低频率的EPT和EFU以及更好的内皮保存有关。