穿透性角膜移植术后角膜植片内皮慢性失功的临床分析

The analysis of chronic corneal allograft endothelial dysfunction after penetrating keratoplasty

目的探讨圆锥角膜行穿透性角膜移植(PK)术后角膜植片内皮慢性失功的临床特点。设计回顾性病例系列。研究对象圆锥角膜患者PK术后角膜植片内皮慢性失功148例(163眼)。方法所有患者实施PK术,采用非接触式角膜内皮显微镜、A型超声测厚仪和眼前节OCT扫描系统对角膜植片进行评价。主要指标中央角膜内皮细胞密度(ECD)、六边形细胞百分率、内皮细胞丢失率、内皮细胞形态、中央角膜厚度(CCT)及最佳矫正视力。结果PK术后3年内患者植片ECD呈下降趋势,内皮细胞年丢失率为14.2%±10.9%。术后1.5年较术后1年的ECD有明显下降(P=0.002)。术后不同时间点的植片内皮六边形细胞百分率均在50%以上,CCT在500μm以上,各组间比较无统计学差异(P=0.869)。PK术后5年以上复查,患者角膜植片ECD仍呈下降趋势,但个体差异性较大,多数患者的六边形细胞百分率仍在50%以上,内皮细胞面积增大是局部性的,CCT保持在500μm以上。150例未发生排斥的角膜植片除2例发生植片混浊外,其余均保持透明,患者术后最佳矫正视力提高。结论ECD的超生理下降和局部内皮细胞面积增大是PK术后角膜植片内皮慢性失功的主要临床表现。内皮慢性失功的发展存在个体差异性,且在同一个体不同时期发展程度亦有不同。

Objective To explore the clinical characteristics of chronic corneal allograft endothelial dysfunction after penetrating keratoplasty （PK） for keratoconus. Design Retrospective case series. Partidpants 148 cases （163 eyes） of keratoconus with chronic corneal allograft endothelial dysfunction after PK. Methods All cases treated with PK were analyzed by non-contact specular microscope, ultrasound corneal pachymetry and optical coherence tomography system. Main Outcome Measures Central corneal endothelial cell density （ECD）, percentage of hexagonal cells, the rate of endothelial cell loss, morphologic changes of endothelial cell, central corneal thickness （CCT） and best corrected visual acuity （BCVA）. Results ECD was decreased during three years after PK. The annual rate of endothelial cell loss was 14.2%＋10.9%. The difference of ECD was significant between 1 year and 1.5 years after PK （P=0.002）. At different time of three years after PK, percentages of hexagonal cells were above 50% and CCTs were above 500μm with no significant difference（P=0.869 ）. ECD appeared decreasing above five years after PK, but there were much significances between different patients. In majority of those patients, percentages of hexagonal cells were above 50%, enlargement of area of endothelial cell were local,and CCTs were still above 500 μm. In 150 grafts without immunologic rejection, 2 grafts become opaque, but others remain transparent and BCVA enhanced. Conclusions Ultra-physiological descent of ECD and enlargement of area of endothelial cell are main clinical manifestations of chronic corneal allograft endothelial dysfunction after PK. There are individual differences during the development of chronic allograft endothelial dysfunction. Different extent of dysfunction exists in same individual at different time.