玻璃体切除术后的白内障超声乳化术

目的 描述在曾做玻璃体切除眼再施行超声乳化白内障摘出术中的特征及其并发症和视力结果。方法 回顾研究了作者3年内30眼曾做玻璃体切除术后再施行白内障手术。资料包括术前特征，术中发现。术后并发症及视力。结果 在所有做过玻璃体切除的术眼，均可发现术中有晶状体悬韧带松弛、前房异常加深和散瞳。有些术眼在初期前房加深后，还相反可见前房变浅和缩瞳(灌注偏差综合征)，未见有何严重威胁视力的并发症发生，最后视力较术前多有明显增进。结论 在已施行玻璃体切除眼上再做白内障手术存在有特殊的问题，包括丧失玻璃体支持，后囊膜不稳定及悬韧带脆弱等。为减少前房深度的突然改变，应将灌流液瓶的高度降低，在前房深度异常波动时，超声乳化头应放置在虹膜平面之前，且避免在囊袋内作超声乳化术。

Cataract extraction with phacoemulsification following pars plana vitrectomy

Objective To describe the intraoperative characteristics of phacoemulsification cataract extraction in eyes that had undergone pars plana vitrectomy(PPV)and to determine the complications and visual outcomes.Methods A retrospective study of 30 consecutive cataract operations on vitrectomised eyes per-formed in a three years period by a single surgeon.Data were collected on preoperative characteristics,intraoperative observations,postoperative complications and visual acuities.The mean interval from PPV to phacoemulsification was 20 months(10 to 36 months).Results Zonular laxity with abnormal deepening of anterior chamber and mydriasis was noted in all eyes that had undergone pars plana vitrectomies.In some eyes,the initial deepening of the anterior chamber was accompanied by paradoxical shallowing with miosis(the "infusion deviation syndrome").No sight threatening complications was encountered and final visual acuity was improved.Conclusions Cataract surgery in the vitrectomised eye presents a special challenge,which incude the loss of vitreous support,unstable posterior capsules,weakened zonules.A lower infuaion bottle height may guard against sudden changes in anterior chamber depth.It is necessary that one should keep the phaco tip anterior to the iris plane and avoid in-the-bag phacoemulsification if abnormal fluctuation of the anterior chamber depth are encountered.