Hille K, Hille A, Ruprecht K W
Klinik für Augenheilkunde, Universitätskliniken des Saarlandes, Kirrberger Strasse 1, 66421 Homburg/Saar, Germany.
Graefes Arch Clin Exp Ophthalmol. 2006 Jun;244(6):696-704. doi: 10.1007/s00417-005-0092-6. Epub 2005 Nov 19.
Corneal grafts or limbal stem cell transplantation are often unsuccessful in patients with severe ocular surface disorders such as severe dry eye syndrome, symblepharon or diffuse vascularisation. In those patients, a keratoprosthesis (KPro) may be an alternative for the recovery of vision. Various KPro differ from each other in the material of the haptic that supports the optic cylinder. The haptic may be made of biocompatible or biological material such as tibia bone (TKPro) or dentine and alveolar bone (osteo-odonto-keratoprosthesis, OOKP). On the basis of our experience, we wanted to comment on the value of different KPro.
Over the last 10 years we have implanted a total of 35 KPro, 29 with biological haptic (25 OOKP and four TKPro), and six KPro with biocompatible haptic (one Legais KPro, five Pintucci KPro). A follow up examination was carried out approximately every6 months.
The patients gained a visual acuity of > or =0.9 in 20.6%, of > or =0.5 in 52.9%, of > or =0.2 in 61.8% and a significant improvement in visual acuity in 76.5%, respectively. There was no significant difference between the various types of KPro concerning the best postoperative visual acuity. All patients showing poor improvement had a pre-existing end stage secondary glaucoma or other retinal damage. The median follow-up was 2.9 years (maximum 8) for OOKP, 1 year for TKPro, 1 year (maximum 2) for Pintucci Kpro and 6 month for Legeais KPro. During this period, only one of the KPro with biological haptic was lost (one TKPro after 1 year), compared with four out of six of the KPro with biocompatible haptic (P<0.0001).
Fixation of the KPro by a root of the patient s own tooth (OOKP) leads to the best results in the long-term follow up, as our results as well as the literature demonstrate. As long as a KPro is in place, the visual acuity is as good as the retinal function. For the ranking of different types of KPro, the percentage and the duration of the anatomic success are most important. The comparability of the various KPro results may be limited, since the patients were not randomised and the four groups differ in number.
对于患有严重眼表疾病（如严重干眼症、睑球粘连或弥漫性血管化）的患者，角膜移植或角膜缘干细胞移植往往不成功。在这些患者中，人工角膜（KPro）可能是恢复视力的一种选择。各种人工角膜在支撑视柱的触觉材料上彼此不同。触觉部分可由生物相容性材料或生物材料制成，如胫骨（TKPro）或牙本质和牙槽骨（骨-牙-角膜移植术，OOKP）。基于我们的经验，我们想对不同人工角膜的价值进行评论。
在过去10年中，我们共植入了35枚人工角膜，其中29枚采用生物触觉材料（25枚OOKP和4枚TKPro），6枚采用生物相容性触觉材料（1枚Legais人工角膜，5枚Pintucci人工角膜）。大约每6个月进行一次随访检查。
患者的视力分别在20.6%的情况下提高到≥0.9，52.9%的情况下提高到≥0.5，61.8%的情况下提高到≥0.2，76.5%的情况下视力有显著改善。不同类型的人工角膜在术后最佳视力方面没有显著差异。所有视力改善不佳的患者都预先存在终末期继发性青光眼或其他视网膜损伤。OOKP的中位随访时间为2.9年（最长8年），TKPro为1年，Pintucci人工角膜为1年（最长2年），Legais人工角膜为6个月。在此期间，采用生物触觉材料的人工角膜中仅1枚丢失（1枚TKPro在1年后），而采用生物相容性触觉材料的6枚人工角膜中有4枚丢失（P<0.0001）。
正如我们的结果以及文献所表明的，通过患者自身牙齿根部（OOKP）固定人工角膜在长期随访中能取得最佳效果。只要人工角膜在位，视力就与视网膜功能一样好。对于不同类型人工角膜的排名，解剖学成功的百分比和持续时间最为重要。由于患者未进行随机分组且四组数量不同，各种人工角膜结果的可比性可能有限。
