Comparative in vivo high-resolution confocal microscopy of corneal epithelium, sub-basal nerves and stromal cells in mice with and without dry eye after photorefractive keratectomy
Comparative in vivo high-resolution confocal microscopy of corneal epithelium, sub-basal nerves and stromal cells in mice with and without dry eye after photorefractive keratectomy
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DOI：
10.1111/j.1442-9071.2007.01543.x
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发表时间：
2007-08-01
影响因子：
4
通讯作者：
Bazan, Haydee E. P.
中科院分区：
文献类型：
--
作者：
Esquenazi, Salomon;He, Jiucheng;Bazan, Haydee E. P.
背景：本研究使用新一代高分辨率在体共聚焦显微镜，比较了两组小鼠：一组暴露在正常条件下(NC)，另一组暴露在干燥环境(DE)下，进行了准分子激光屈光性角膜切削术(PRK)联合机械刮削上皮细胞。方法：24只4~8周龄雌性Balb/C小鼠。20只小鼠在PRK前用电刷刮取双侧角膜上皮。然后，将小鼠分成两组：10只小鼠置于正常对照组。其余10只小鼠接受DE照射2周。4只小鼠作为对照。使用Heidelberg视网膜断层扫描仪II的Rostock角膜模块对角膜进行活体分析。对所有眼睛，记录每层共聚焦显微镜图像20幅，即角膜浅层和基底层、Bowman层、前后基质和内皮细胞。结果：DE组浅层上皮细胞密度较高(NC组693+/-148个/mm(2)，DE组443+/-128个/mm(2)；Mann-Whitney U检验，P=0.05)。DE组基底细胞数量较多。NC组细胞密度为986+/-198个/mm(2)，DE组为1598+/-280个/mm(2)(Mann-Whitney U检验，P<；0.05)。与NC眼相比，DE组在间质内可见明显数量的反射结构，但无明显的核。此外，DE组可见更多的珠子、神经发芽和更多的基底下神经弯曲。两组间内皮细胞密度差异无统计学意义。结论：PRK术后角膜暴露于DE，并伴有机械刮削上皮，可增加角膜上皮细胞的周转率，并与基质中较多的反射结构有关。此外，DE组可见神经珠状突起、神经发芽和基底下神经弯曲，可能是为了修复上皮水平的改变。
Background: The present study compares, using a new-generation high-resolution in vivo confocal microscope, the epithelial morphology, sub-basal nerves and stroma in two groups of mice: one exposed to normal conditions (NC) and the other to a desiccating environment (DE), following photorefractive keratectomy (PRK) with mechanical epithelial scraping.Methods: Twenty-four 4- to 8-week-old female Balb/C mice were used in this study. Twenty mice underwent bilateral corneal epithelial scraping using an electric brush prior to PRK. Then, the mice were divided in two groups: 10 mice were placed in NC. The other 10 mice were exposed to a DE for 2 weeks. Four mice served as controls. Corneas were analysed in vivo using the Rostock Cornea Module of the Heidelberg retina tomograph II. For all eyes, 20 confocal microscopic images of each layer, that is, the superficial and basal corneal epithelium, Bowman's layer, anterior and posterior stroma and the endothelium, were recorded. Epithelial and stromal cell densities and sub-basal and stromal nerves were measured and compared.Results: There was a higher density of superficial epithelial cells in the DE group (693 +/- 148 cells/mm(2) in NC group and 443 +/- 128 cells/mm(2) in DE group; Mann-Whitney U-test; P = 0.05). Higher number of basal cells were observed in the DE group. Its density was 986 +/- 198 cells/mm(2) in NC and 1598 +/- 280 cells/mm(2) in DE group (Mann-Whitney U-test; P < 0.05). Significantly higher number of reflective structures were noted within the stroma without clearly visible nuclei in the DE group compared with the NC eyes. Additionally, higher number of beads, nerve sprouts and higher tortuosity of sub-basal nerves were observed in the DE group. No difference was observed in the endothelial cell density between the groups.Conclusion: Exposure of corneas to a DE after PRK with previous mechanical epithelial scraping increases epithelial turnover and is associated with a higher number of reflective structures in the stroma. Additionally increased nerve beading, nerve sprouts and tortuosity of sub-basal nerves were observed in the DE group, possibly directed to repair the alterations observed at the epithelial level.