Bernard Aurélien, He Zhiguo, Gauthier Anne Sophie, Trone Marie Caroline, Baubeau Emmanuel, Forest Fabien, Dumollard Jean Marc, Peocʼh Michel, Thuret Gilles, Gain Philippe
*Corneal Graft Biology, Engineering and Imaging laboratory, EA2521, SFR143, Faculty of Medicine, University Jean Monnet, Saint-Etienne, France; †Department of Ophthalmology, University Hospital, Besançon, France; ‡Department of Ophthalmology, University Hospital, Saint-Etienne, France; §Manutech Ultrafast Surfacing Design, Pole Optique Rhône-Alpes, Saint-Etienne, France; ¶Department of Pathology, University Hospital, Saint-Etienne, France; and ‖Institut Universitaire de France, Boulevard Saint-Michel, Paris, France.
Cornea. 2015 Feb;34(2):209-17. doi: 10.1097/ICO.0000000000000314.
Stromal surface quality of endothelial lamellae cut for endothelial keratoplasty with a femtosecond laser (FSL) with epithelial applanation remains disappointing. Applanation of the endothelial side of the cornea, mounted inverted on an artificial chamber, has therefore been proposed to improve cut quality. We compared lamellar quality after FSL cutting using epithelial versus endothelial applanation.
Lamellae were cut with an FSL from organ-cultured corneas. After randomization, 7 were cut with epithelial applanation and 7 with endothelial applanation. Lamellae of 50-, 75-, and 100-μm thickness were targeted. Thickness was measured by optical coherence tomography before and immediately after cutting. Viable endothelial cell density was quantified immediately after cutting using triple labeling with Hoechst/ethidium/calcein-AM coupled with image analysis with ImageJ. The stromal surface was evaluated by 9 masked observers using semiquantitative scoring of scanning electronic microscopy images. Histology of 2 samples was also analyzed before lamellar detachment.
Precision (difference in target/actual thickness) and thickness regularity [coefficient of variation (CV) of 10 measurements] were significantly better with endothelial applanation (precision: 18 μm; range, 10-30; CV: 11%; range, 8-12) than with epithelial applanation (precision: 84 μm; range, 54-107; P = 0.002; CV: 24%; range, 13-47; P = 0.001). Endothelial applanation provided thinner lamellae. However, viable endothelial cell density was significantly lower after endothelial applanation (1183 cells/mm2; range, 787-1725 versus 1688 cells/mm2; range, 1288-2025; P = 0.018).
FSL cutting of endothelial lamellae using endothelial applanation provides thinner more regular grafts with more predictable thickness than with conventional epithelial applanation but strongly reduces the pool of viable endothelial cells.
使用带有上皮压平装置的飞秒激光（FSL）进行内皮角膜移植术时，内皮薄片的基质表面质量仍不尽人意。因此，有人提出将角膜内皮面倒置安装在人工房上进行压平，以提高切割质量。我们比较了使用上皮压平与内皮压平的飞秒激光切割后的薄片质量。
用飞秒激光从器官培养的角膜上切割薄片。随机分组后，7片采用上皮压平切割，7片采用内皮压平切割。目标厚度为50、75和100μm。在切割前和切割后立即通过光学相干断层扫描测量厚度。切割后立即使用Hoechst/溴化乙锭/钙黄绿素-AM三重标记结合ImageJ图像分析对存活的内皮细胞密度进行定量。由9名蒙面观察者使用扫描电子显微镜图像的半定量评分对基质表面进行评估。在薄片分离前还对2个样本进行了组织学分析。
内皮压平的精度（目标/实际厚度差异）和厚度均匀性[10次测量的变异系数（CV）]明显优于上皮压平（精度：18μm；范围10 - 30；CV：11%；范围8 - 12）（精度：84μm；范围54 - 107；P = 0.002；CV：24%；范围13 - 47；P = 0.001）。内皮压平产生的薄片更薄。然而，内皮压平后存活的内皮细胞密度明显更低（1183个细胞/mm²；范围787 - 1725，而1688个细胞/mm²；范围1288 - 2025；P = 0.018）。
使用内皮压平的飞秒激光切割内皮薄片可提供比传统上皮压平更薄、更规则且厚度更可预测的移植物，但会大大减少存活内皮细胞数量。
