Tseng S H, Chen F K
Department of Ophthalmology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC.
Cornea. 1998 Sep;17(5):471-5. doi: 10.1097/00003226-199809000-00003.
To evaluate the morphometric and fluorophotometric characteristics of corneal endothelium after an eight-incision radial keratotomy (RK).
A total of 43 eyes of 26 patients underwent RK and 44 eyes of 23 patients were used as age-matched controls. All patients underwent specular microscopic and fluorophotometric examinations. Endothelial cell density [(ECD), cells/mm2], mean cell area [(MCA), microm2], coefficient of variation (CV) for cell area, and percentage (%) of hexagonal cells were measured by specular microscopy. Cornea-to-anterior chamber transfer coefficient (kc.ca, 10(-3) min(-1)) and corneal endothelial permeability (10(-4) cm/min) were measured by fluorophotometry.
Morphometric and fluorophotometric characteristics were similar in both the RK and control groups. Among patients in the RK group, the size of optical zone and the depth of corneal incision did not affect postoperative endothelial morphology or permeability. Those who presented for postoperative examination later than 3 months compared with those presented within 3 months of RK had lower CV for cell area; 0.28 +/- 0.04, 0.23 +/- 0.04, and 0.23 +/- 0.03, a higher percentage of hexagonal cells; 64.7 +/- 8.0, 71.7 +/- 7.8, and 72.2 +/- 6.5, and lower permeability; 5.7 +/- 1.9. 4.5 +/- 0.9, and 5.2 +/- 1.1, at <3 months, between 3 and 6 months, and >6 months after RK, respectively (all p < 0.05). In the eight cases of anisometropia, the operated eyes had a lower ECD; 3,079 +/- 429, and 3,217 +/- 495, a higher MCA; 330.6 +/- 48.1 and 317.6 +/- 50.5, and a higher endothelial permeability; 6.3 +/- 1.5 and 4.7 +/- 1.3 in the operated and unoperated eyes, respectively, at 3.4 months after RK (p < 0.05).
RK induced a minimal acute and nonprogressive endothelial loss. The transient increase in permeability within 3 months may be due to a reversible endothelial dysfunction induced by RK.
评估八切口放射状角膜切开术（RK）后角膜内皮的形态学和荧光光度学特征。
26例患者的43只眼接受了RK手术，23例患者的44只眼作为年龄匹配的对照。所有患者均接受了镜面显微镜检查和荧光光度学检查。通过镜面显微镜测量内皮细胞密度[（ECD），细胞/mm²]、平均细胞面积[（MCA），μm²]、细胞面积变异系数（CV）和六边形细胞百分比（%）。通过荧光光度法测量角膜至前房的转移系数（kc.ca，10⁻³ min⁻¹）和角膜内皮通透性（10⁻⁴ cm/min）。
RK组和对照组的形态学和荧光光度学特征相似。在RK组患者中，光学区大小和角膜切口深度不影响术后内皮形态或通透性。与RK术后3个月内进行术后检查的患者相比，术后3个月后进行检查的患者细胞面积CV较低；分别为0.28±0.04、0.23±0.04和0.23±0.03，六边形细胞百分比更高；分别为64.7±8.0、71.7±7.8和72.2±6.5，通透性更低；分别为5.7±1.9、4.5±0.9和5.2±1.1，分别在RK术后<3个月、3至6个月和>6个月时（所有p<0.05）。在8例屈光参差患者中，术后3.4个月时，手术眼的ECD较低；分别为3079±429和3217±495，MCA较高；分别为330.6±48.1和317.6±50.5，内皮通透性较高；手术眼和未手术眼分别为6.3±1.5和4.7±1.3（p<0.05）。
RK引起的急性内皮损失最小且无进展。术后3个月内通透性的短暂增加可能是由于RK诱导的可逆性内皮功能障碍所致。
