角膜移植手术概况

角膜移植是利用异体的正常角膜组织取代混浊病变的角膜组织,使患眼复明或控制角膜病变的治疗手段.传统角膜移植分为穿透性角膜移植和板层角膜移植术,随着人们对角膜病认识程度的加深以及新技术新器材的使用,带角膜缘的板层移植联合中央部分穿透性角膜移植术、深板层角膜移植、深板层角膜内皮移植术、角膜缘移植等多种新的手术方式较之传统术式具有更好的光学效果,并大大减少了术后排斥反应、散光等并发症.此外准分子激光和飞秒激光的应用也使角膜移植术的手术效果更趋完美.同时,人工角膜移植手术为不适合传统穿透性角膜移植手术的患者提供一种新的选择.本文对准分子激光和飞秒激光应用于穿透性角膜移植、各种类型板层角膜移植以及人工角膜移植手术进行简要概述,并展望角膜移植手术的发展趋势.     

角膜内皮细胞移植

角膜内皮细胞在体外培养的条件下可以在同种异体或异种角膜后弹力层上成功生长,培养的上皮细胞的生长情况及特性与供体年龄、内皮细胞来源部位、载体材料、培养条件、以及是否应用生长因子有密切关系。人角膜内皮细胞培养的成功,以及在非人类的灵长目动物眼上的成功移植,为内皮移植技术的治疗作用提供了实验基础。培养传代的角膜内皮细胞移植到活体上后具有正常内皮细胞的功能,可以作为穿透性角膜移植的替代方法之一加以选择。     

Corneal transplantation in microphthalmic eyes

We performed corneal transplantation in nine microphthalmic eyes of five patients, who ranged in age from 1 to 63 months. The anteroposterior diameter of the eyes ranged from 12.5 to 16 mm. Complications from the surgery included superficial epithelial erosions in three eyes, leading to superficial scarring in one eye, glaucoma, and suture microabscesses. Despite these complications, seven of nine grafts have remained clear and vision developed in all eyes.     

Outcome of Corneal transplantation rejection

PURPOSE: To identify predictive factors for reversibility of corneal graft rejection. METHODS: The study design was a prospective cohort study. Among 440 consecutive penetrating keratoplasties performed at our institution, 79 grafts from 79 patients who developed signs of transplant rejection were included. Donor, recipient, surgical, and rejection variables were studied, at both univariate and multivariate levels. RESULTS: The rate of reversibility was 51% (40/79). The average postoperative time of rejection was 10.5 +/- 9.3 months, and the average time of visual acuity recovery in patients with reversible rejection was 2.4 +/- 2.3 months. In logistic regression, only two variables significantly influenced the rate of reversibility. The preoperative diagnosis (p = 0.04) influenced the rate of rejection reversibility; patients with bullous keratopathy or regraft were more likely to experience irreversible rejection than patients with keratoconus or Fuchs' dystrophy. The average graft thickness at the time of rejection diagnosis was 774 +/- 129 microm in patients with irreversible rejection and 681 +/- 118 microm in patients with reversible rejection (p = 0.001). CONCLUSION: Rejection was reversible in half of the cases. Rejection was more likely to be irreversible in patients with marked increase in graft thickness and in patients transplanted for bullous keratopathy or graft failure. Donor variables did not influence rejection reversibility.     

Corneal transplantation for herpes simplex keratitis

We conducted a retrospective study of 107 penetrating keratoplasties in 99 eyes (99 patients) performed from 1970 to 1979 at the Wills Eye Hospital. The follow-up periods ranged from one to 12 years (median, three years). Overall, 86 of the 107 transplants (80%) remained clear and 63 eyes (59%) achieved good to excellent visual acuities (20/60 or better). Preoperative vascularization was not a significant prognostic factor with regard to final visual outcome, graft clarity, or graft rejection. Herpes simplex keratitis was inactive at the time of corneal transplantation in 100 of the eyes (93%). The overall rate of recurrent dendritic keratitis after transplantation for herpes was 19%.