深低温冻存及新鲜角膜用于穿透性角膜移植的对比研究

Comparing Cryopreserved with Fresh Corneas on Clinical Application in Penetrating Keratoplasty

目的:进一步探讨深低温保存角膜用于穿透性角膜移植术的价值及比较它与新鲜角膜各自的特点。方法:选择36例属优良组的角膜白斑,随机分2组,分别采用新鲜及深低温保存角膜为供体,行穿透性角膜移植术,观察术后植片愈合及泪膜恢复情况,检测角膜厚度、内皮细胞密度及视力恢复情况等。结果:采用新鲜及深低温保存角膜为供体,术后泪膜破裂时间（Break-up time,BUT）恢复正常的时间平均为（4.7±0.3）月（2～6月）及平均为（5.6±0.4）月（2～8月）;泪液分泌试验（SchirmirTest）恢复正常的时间平均为（2.1±0.3）月（1～4月）及平均为（1.7±0.5）月（1～3.5月）;移植片厚度平均为0.62mm（0.56～0.68mm）及平均为0.59mm（0.54～0.62 mm）;趋于稳定后的视力分别为0.46±0.03及0.44±0.05;排斥反应发生率分别为20％及19％;二组间均无显著性差异（P>0.05）。但前组术后植片上皮完整,植片始终透明,而后组术后植片上皮缺损,约3～5天才修复,植片出现2～3周暂时性水肿;前组植片内皮细胞密度平均为2 135个/mm2（2 043～2210）,后组平均为1672个/mm2（1240～1860个/mm2）,二组间有显著性差异（P<0.01）。结论:深低温保存角膜用于穿透性角膜移植术后在植片透明率、角膜厚度。

Purpose: To evaluate the role of cryopreserved corneas on penetrating keratoplasty (PKP) by comparing them with fresh corneas on clinical application. Methods: Third-six excellent condition patients were chosen and randomly divided into two groups. They were performed PKP by using fresh and cryopreserved corneas respectively. The graft transparency, epithelial healing speed of graft, tear membrane, graft thickness, endothelium density and visual acurity were emphasized respectively. Results: When fresh and cryopreserved corneas were used on PKP as the donor respectively, postoperative time to recover normal break-up time (BUT) was two to six months average (4. 7±0. 3) months and two to eight months, average (5. 6±0. 4) months and time to recover normal Schirmer' test was one to four months average (2.1±0. 3) months and 1 ~ 3. 5 months, average (1.7±0. 5) months. The graft's thickness, stablized visual acurity and graft' s rejective rate were 0.56~0.68 mm (average 0.62 mm) vs 0. 54~0. 62 mm (average 0. 59 mm), (0. 46±0. 03) vs (0. 44±0. 05) and 20% vs 19% respectively when fresh vs cryoperserved corneas. No statistical significance between fresh and cryopreserved corneas ( P > 0. 05). But the grafts behaved intact epitheli-um and continuing transparency when fresh corneas as donors, while the graft' s epithelial defects healed after three to five days of the operation and edematous grafts were re-clear after two to three weeks of the operation when cryopreserved corneas as donors. Graft's endothelium density in fresh corneas group 2 043 ~2 210 cells/mm2 (average 2 135 cells/mm2) was high than in cryopreserved corneas 1 240-1 860cells/mm2 (average 1 672 cells/mm2) (P < 0. 01).Conclusion: There were no statistical significance on the transparent rate of grafts, grafts thickness, visual acurity and graft' s rejective rate between fresh and cryopreserved corneas. But graft's epithelium healing was delayed and endothelium density was lower when cryopreserved corneas as donors. Eye Science 2001; 17: 68 - 71.