Ophthalmology Service, Department of Clinical Neurosciences, Geneva University Hospitals, Geneva, Switzerland.
Curr Opin Ophthalmol. 2010 Jan;21(1):50-4. doi: 10.1097/ICU.0b013e328333101d.
Posterior-assisted levitation (PAL) is a surgical maneuver for dealing with rupture of the posterior capsule or zonular dehiscence with threatened or actual subluxation of the nucleus or entire lens into the vitreous during phacoemulsification. PAL is often unknown or overlooked, especially by young or inexperienced surgeons.
The advantages of PAL are, first, that it often enables completion of phacoemulsification and intraocular lens placement without conversion to an open eye with nuclear expression and second, it prevents luxation of nucleus, nuclear fragments, or the lens into the vitreous avoiding the necessity for trans pars plana vitrectomy (TPPV)-lensectomy. PAL has recently been criticized by vitreoretinal surgeons as dangerous and to be avoided. However, there is no large series or controlled study showing that the PAL maneuver is associated with an excessive complication rate as compared to cases of nuclear or lens subluxation in the vitreous managed by TPPV-lensectomy with or without previous PAL.
PAL is a simple technique that can be extremely helpful. In cases in which the PAL maneuver is unsuccessful and in cases with complete luxation of nucleus or lens into the vitreous, the patient should be referred for TPPV-lensectomy.
后辅助悬浮术（PAL）是一种处理在超声乳化过程中后囊破裂或悬韧带离断，伴有核或整个晶状体威胁性或实际半脱位进入玻璃体的手术操作。PAL 常常不被了解或忽视，尤其是在年轻或经验不足的外科医生中。
PAL 的优点首先是它通常能够完成超声乳化和人工晶状体植入，而无需转换为开放性眼核表达，其次是它可以防止核、核碎片或晶状体进入玻璃体，从而避免了经睫状体平坦部玻璃体切除术（TPPV）-晶状体切除术的必要性。最近，玻璃体视网膜外科医生批评 PAL 操作是危险的，应避免使用。然而，目前还没有大规模的系列或对照研究表明，与 TPPV-lensectomy 治疗的核或晶状体半脱位病例相比，PAL 操作与过高的并发症发生率相关，TPPV-lensectomy 治疗可伴有或不伴有先前的 PAL。
PAL 是一种简单的技术，非常有帮助。如果 PAL 操作不成功，并且核或晶状体完全脱位进入玻璃体，患者应转介进行 TPPV-lensectomy。
