Stulting R D, Thompson K P, Waring G O, Lynn M
Department of Ophthalmology, Emory University School of Medicine, Atlanta, GA 30322, USA.
Ophthalmology. 1996 Sep;103(9):1357-65. doi: 10.1016/s0161-6420(96)30496-x.
The authors prospectively investigated the effect of excimer laser photorefractive keratectomy (PRK) for myopia on the corneal endothelium.
Quantitative computer-assisted morphometric analysis of central and peripheral corneal endothelial cells was performed on 142 myopic eyes before and at 3 months, 1 year, and 2 years after PRK. The mean age of the subjects was 37 years (range, 21-66 years). Ninety-one (64%) of them had a history of contact lens wear. Mean attempted correction was -3.9 diopters (range, -1.6 to -6.0 diopters).
The mean preoperative endothelial cell density was 2660 cells/mm2 centrally and 2776 cells/mm2 peripherally. There was no change in central endothelial cell density at any of the postoperative examinations. The peripheral cell density decreased 4.1% (P = 0.003) at 3 months and 6.2% (P = 0.0001) at 1 year. However, the peripheral cell density was not significantly different from the preoperative value at 2 years. The peripheral coefficient of variation of cell size was 7.8% lower 2 years postoperatively than it was preoperatively, and this improvement was attributable to cessation of contact lens wear after PRK. The decrease in peripheral endothelial cell density at 1 year correlated with the amount of attempted correction, but there was no correlation between attempted correction and the change in central or peripheral endothelial cell density 2 years postoperatively.
For the correction of up to 6.0 D of myopia, PRK causes no detectable changes in central corneal endothelial cell density, but it does cause a transient, modest loss of peripheral corneal endothelial cells at 1 year. Variations in endothelial cell shape caused by contact lens wear resolve after PRK.
作者前瞻性地研究了准分子激光屈光性角膜切削术（PRK）治疗近视对角膜内皮的影响。
对142只近视眼睛在PRK术前、术后3个月、1年和2年进行中央和周边角膜内皮细胞的定量计算机辅助形态学分析。受试者的平均年龄为37岁（范围21 - 66岁）。其中91只眼（64%）有佩戴隐形眼镜史。平均预期矫正度数为-3.9屈光度（范围-1.6至-6.0屈光度）。
术前中央内皮细胞密度平均为2660个细胞/mm²，周边为2776个细胞/mm²。术后任何一次检查中，中央内皮细胞密度均无变化。周边细胞密度在术后3个月下降了4.1%（P = 0.003），在1年时下降了6.2%（P = 0.0001）。然而，2年时周边细胞密度与术前值无显著差异。术后2年周边细胞大小变异系数比术前低7.8%，这种改善归因于PRK后停止佩戴隐形眼镜。1年时周边内皮细胞密度的下降与预期矫正量相关，但术后2年预期矫正量与中央或周边内皮细胞密度的变化之间无相关性。
对于矫正高达6.0 D的近视，PRK不会引起中央角膜内皮细胞密度的可检测变化，但在1年会导致周边角膜内皮细胞短暂、适度的丢失。由隐形眼镜佩戴引起的内皮细胞形状变化在PRK后会消失。
