Inoue Y
Department of Opthalmology, Faculty of Medicine, Tottori University, Yonago, Japan.
Semin Ophthalmol. 2001 Sep;16(3):113-8. doi: 10.1076/soph.16.3.113.4202.
Corneal diseases subject to keratoplasty are often combined with a certain degree of cataract. Therefore, appropriate strategies for the management of cataract are mandatory. One strategy is a sequential procedure performing cataract surgery after keratoplasty. Though this procedure enables us to estimate IOL power accurately, there are several drawbacks including multiple procedures, slow visual rehabilitation and endothelial damage during cataract surgery. On the other hand, triple procedure, consisting of penetrating keratoplasty, extracapsular lens extraction and IOL implantation, has several advantages, such as single procedure, rapid visual rehabilitation and no additional endothelial trauma. How-ever, open sky procedure may be accompanied by uncontrollable vitreous pressure followed by posterior capsule rupture and difficulty of IOL implantation, while the worst outcome may be expulsive hemorrhage. Combined core vitrectomy preceding corneal trephination is contrived to solve this problem. This procedure is simply performed from a single sclerotomy 3.5-4.01 mm posterior to the corneal limbus with a vitreous cutter under the external pressure to the eye, and vitreous pressure is sufficiently lowered to allow the following procedures to be done very safely. Another problem with triple procedure is the calculation of IOL power. This problem is caused by unpredictable keratometer readings after keratoplasty. Several methods for calculating IOL power in triple procedure are also discussed.
需要进行角膜移植的角膜疾病常常合并有一定程度的白内障。因此,必须采取适当的白内障治疗策略。一种策略是在角膜移植术后进行白内障手术的序贯手术。尽管这种手术能让我们准确估算人工晶状体的度数,但也存在一些缺点,包括多次手术、视力恢复缓慢以及白内障手术过程中的内皮损伤。另一方面,三联手术,即穿透性角膜移植术、囊外晶状体摘除术和人工晶状体植入术,有几个优点,比如单次手术、视力快速恢复且无额外的内皮创伤。然而,开放式手术可能会伴有无法控制的玻璃体压力,继而导致后囊破裂和人工晶状体植入困难,而最糟糕的结果可能是驱逐性出血。在角膜环钻术之前联合进行核心玻璃体切除术旨在解决这个问题。该手术只需在角膜缘后方3.5 - 4.01毫米处通过一个巩膜切口,在对眼球施加外部压力的情况下用玻璃体切割器进行操作,玻璃体压力会充分降低,从而能非常安全地进行后续手术。三联手术的另一个问题是人工晶状体度数的计算。这个问题是由角膜移植术后角膜曲率计读数不可预测导致的。本文还讨论了三联手术中计算人工晶状体度数的几种方法。