二次穿透性角膜移植术的临床研究

Clinical research of repeat penetrating keratoplasty

目的对穿透性角膜移植术后植片混浊的原因及二次穿透性角膜移植术的临床技巧及疗效进行初步研究。方法回顾性研究，对40例因植片混浊行二次穿透性角膜移植术的患者，对原发病、植片混浊原因和两次手术时间二次移植的植片的大小进行分析，随访观察植片透明度、视力及免疫排斥情况。结果感染性角膜炎居原发病首位。免疫排斥反应为植片混浊的主要原因，其次为植片感染性角膜炎复发、再发或继发。10例因植片感染于6个月及以内更换植片，30例因植片混浊于6个月以上更换植片。5例原直径过大而采用小直径植片；29例原直径≤8．25mm而采用等直径植片；6例因复发感染累及植片周边而扩大植片直径。随访32例植片（≤8．25mm）透明，视力较术前明显提高。8例植片混浊，其中5例混浊由免疫排斥所致。结论造成二次穿透性角膜移植术的主要原因为植片免疫排斥和感染性角膜炎复发、再发或继发，据植片混浊不同病因采取不同直径的二次植片可有效减低免疫排斥反应发生率及治疗原发病复发或再发，延长植片透明时间。

Objective To investigate the factors of allograft opacity after penetrating keratoplasty and evaluate the efficacy of repeat penetrating keratoplasty by individual clinical technique.Methods Forty cases suffered from allograft opacity after penetrating kcratoplasty were treated by repeat penetrating keratoplasty.Primary disease and causes of allograft opacity were explored preoperatively.Donor allografts with the diameters of smaller than, equal to or larger than primary grafts according to causes of allograft opacity and the diameters of primary grafts were adopted during the operation.The transparency of corneal implants, visual acuity and immunological rejection were observed.Results Infectious keratitis was the dominant disease among protopathy.lmmunological rejection was the major factor that caused allograft opacity, and the secondary factor was relapsed infectious keratitis of allograft.Ten opaque grafts caused by infectious keretitis received repeat PKP with or within 6 months; 30 opaque grafts followed immunological rejection received repeat PKP above 6 months.Five eyes with large primary grafts received smaller diameter of allogafts.Twenty-nine opaque grafts smaller than 8.25mm received equal diameters of allografts.Six opaque grafts followed by relapsed infectious focus involved periphery recipient bed must be enlarged the plant bed.During the follow-up period, 32 allografts with the diameter smaller than 8,25mm kept transparent, the visual acuities were better than that of before operation.Eight repeat allogafts were opaque, in which 5 were caused by immunological rejection.Conclusions The main reason of repeat penetrating keratoplasty is allograft immunological rejection and recurred infectious keratitis.It can effectively reduce the incidence of immunological rejection, treat relapsed primary infection and prolong the survival time of repeat graft by adopting different diameters of repeat grafts according to different causes of allografts opacity.