tailieunhanh - Cataract and Refractive Surgery - part 5

Đối với đánh giá của mặt phẳng phân cắt của EpiLASIK giác mạc của con người mà không phù hợp cho việc cấy ghép được lấy từ ngân hàng mắt Bristol. Các nút corneo-scleral được đặt trong một khoang phía trước nhân tạo | Histology of the EpiLASIK Cut 67 Fig. Histology after EpiLA-SIK light microscopy tecture is consistently delivered in an optimal alignment for separation. stromal bed appeared to be very smooth with smooth cutting edges Fig. . Histology of the EpiLASIK Cut For the evaluation of the cleavage plane of Epi-LASIK human corneas that were not suitable for transplantation were obtained from the Bristol eye bank. The corneo-scleral buttons were placed in an artificial anterior chamber. EpiLASIK cuts were performed on these human corneas with the EpiVision microkeratome Gebauer Cooper-Vision . In 5 eyes the epithelium and the stromal beds were embedded for light and electron microscopy in paraformaldehyde. In 5 corneas the epithelium was used to test for cell viability with Trypan blue. Light Microscopy For light microscopic examinations the epithelial flaps were embedded immediately after the separation. The epithelial flap showed that the epithelium was uniformly thick along its entire length. The epithelial layer retained its typical stratification and integrity. There was no disruption of the basal membrane in any of the specimens. The Transmission Electron Microscopy The epithelial flap and the stromal bed for transmission electron microscopy were embedded in glutaraldehyde. The flap demonstrated that the epithelial layer was separated beneath the level of the basement membrane between the lamina lucida and Bowman s membrane. The epithelium consisted of healthy-looking cells with intact basal membrane. The intracellular organelles and intercellular desmosomal connections looked very healthy and there are no evident morphological abnormalities. Basal epithelial cells rested on the prominent basal lamina which consisted of an apparently structureless lamina lucida and an electron-dense lamina densa with occasional focal disruptions. In some places the disruptions were associated with the formation of small blebs surrounded by a cell membrane.