Bleckmann H, Holak S
Eye Department of DRK Kliniken Westend, Spandauer Damm 130, 14050, Berlin, Germany.
Graefes Arch Clin Exp Ophthalmol. 2006 Apr;244(4):502-6. doi: 10.1007/s00417-005-0068-6. Epub 2005 Aug 17.
The purpose was to evaluate the validity of implantation of the artificial cornea (AlphaCor) in human corneas considered too high risk for penetrating keratoplasty with donor tissue.
Four keratoprostheses, made from poly(2-hydroxyethyl methacrylate) (PHEMA) with a porous skirt and a transparent optical part, were implanted into the cornea of four patients. Keratocytes invading the skirt provide a watertight fixation with the scarred corneal tissue. Deep to the clear optical part, the posterior corneal lamella was excised to a diameter of 3.5 mm before the device was implanted, and the anterior lamella was trephined similarly 3 months after AlphaCor implantation.
The eyes selected to receive an artificial cornea had significant neovascularisation, and 0-3 previous failed grafts. Follow-up for 6 months revealed best visual acuity between 20/400 and 20/50. Factors limiting the visual acuity outcome were optic atrophy and age-related macular disease. One patient underwent an extracapsular cataract extraction after the device was implanted, as a senile cataract was then noted. One complication occurred, a central corneal stromal melt, which was managed by covering with a 9-mm donor lamella.
The flexible device AlphaCor may provide a substitute for donor corneal tissue in desperate cases. Advantages include the simple implantation technique, which avoids trauma to the surrounding structures. Visual acuity results may be limited by pre-existing pathology, but it appears that a patient's visual potential can be achieved. Further follow-up to exclude long-term complications is required.
本研究旨在评估人工角膜(AlphaCor)植入对于那些因供体组织进行穿透性角膜移植术风险过高的人类角膜的有效性。
将四个由聚甲基丙烯酸羟乙酯(PHEMA)制成的角膜假体植入四名患者的角膜,这些假体带有多孔裙边和透明光学部分。侵入裙边的角膜细胞与瘢痕化的角膜组织形成水密固定。在植入装置前,在透明光学部分的深层切除直径为3.5毫米的后角膜板层,在AlphaCor植入3个月后,类似地环钻切除前角膜板层。
入选接受人工角膜的眼睛有明显的新生血管,且之前有0至3次移植失败。6个月的随访显示最佳视力在20/400至20/50之间。限制视力结果的因素是视神经萎缩和年龄相关性黄斑疾病。一名患者在植入装置后因发现老年性白内障而接受了囊外白内障摘除术。发生了一种并发症,即中央角膜基质溶解,通过覆盖一片9毫米的供体角膜板层进行处理。
柔性装置AlphaCor在绝望情况下可能为供体角膜组织提供替代。优点包括简单的植入技术,可避免对周围结构造成创伤。视力结果可能受既有病变限制,但似乎可以实现患者的视觉潜能。需要进一步随访以排除长期并发症。