ABSTRACT
@#AIM: To explore the mechanism of rejection of bioengineered keratoplasty by the laser confocal microscope and immunopathological studies.<p>METHODS: Retrospective case study. Five patients(5 eyes)who underwent bioengineered keratoplasty for infectious keratitis from Sep.2018 to Dec.2020 and were immunologically rejected included. All observers were monocular. Slit-lamp was used to examine corneal transparency and corneal neovascularization. The cornea was dynamically observed under laser confocal microscopy, the density of subepithelial langerhans cells and stromal inflammatory cells was recorded after graft rejection, and the contralateral eye was used as the control group for statistical analysis. The infiltration and distribution of CD4<sup>+</sup> cells, CD8<sup>+</sup> cells and inflammatory cells were observed after immunohistochemical staining of bioengineered corneas during corneal allograft.<p>RESULTS: Confocal laser microscopy showed that a large number of langerhans cells were activated under the corneal epithelium of the intraoperative eye, and the activation ratio was significantly different from that of the contralateral eye(χ<sup>2</sup>=38.29, <i>P</i><0.001). The stromal layer was rich in inflammatory cells, which was significantly different from that of the contralateral eye(<i>t</i>=32.5, <i>P</i><0.05). Immunohistochemical staining and HE staining were performed on the bioengineering corneal tissue. CD4<sup>+</sup> and CD8<sup>+</sup> cells were observed in all corneal stromal layers, and only one case had a large number of eosinophils.<p>CONCLUSION: Immunopathology of rejection after bioengineered keratoplasty confirmed that T-cell-mediated cellular immunity plays an important role in the pathogenesis, and hypersensitivity to xenoantigen may be involved in it.
ABSTRACT
@#AIM: To observe the efficacy of bioengineered cornea in the lamellar keratoplasty treatment of infectious keratitis, and to evaluate the clinical value and significance.<p>METHODS: Totally 35 eyes in 35 patients with infectious keratitis requiring surgical treatment in our hospital were divided into three groups: the observation group(<i>n</i>=15)received lamellar keratoplasty with bioengineered cornea; the control group 1(<i>n</i>=10)received lamellar keratoplasty with conserved human cornea; the control group 2(<i>n</i>=10)received autogenous conjunctival flap covering for corneal ulcer. The vision, infection control and corneal transparency were observed lasting for 3-20mo.<p>RESULTS: In the observation group, corneal infection was controlled in 15 eyes after operation and except for 1 eye with cornea opacity during follow-up, the other 14 eyes remained basically transparent. In the control group 1, 9 corneal grafts were transparent, except for 1 eye of viral keratitis experienced corneal opacity because of virus recurrence. In the control group 2, corneal ulcer was scar recoveried in 9 eyes, except for 1 eye of aggravated fungal corneal ulcer infection with later removing of eye content.<p>CONCLUSION: Bioengineered cornea is a novel alternative material of human cornea, which plays a significant role in resolving the contradiction between the increasing keratopathy and donor cornea shortage.