准分子激光屈光性角膜切削术对角膜散光的影响

The Influence of Photorefractive Keratectomyon the Corneal Astigmatism

为研究准分子激光角膜切削术（ＰＲＫ）能否引起角膜散光，用大光斑多区切削的进口准分子激光机治疗无散光高度近视７２眼和中、低度近视８１眼。经角膜地形图分析，高度和中、低度近视眼切削前后不规则散光指数无明显变化，说明ＰＲＫ不是增加角膜不规则散光的因素。术后１年，高度近视眼角膜中央３ｍｍ散光比术前增高，有显著性差异。可能与多区、大光斑多次切削时，每次切削中心不能完全重叠等因素有关。

o investigate whether excimer laser photoablation may cause corneal astigmatism, 72 eyes (37 cases) of simple high myopia and 81 eyes (43 cases) of simple mederate myopia without astigmatism were treated by photorefractive keratectomy (PRK) using excimer laser of wide area scanning and multiple zone techniques. The astigmatism values were statistically analyzed with corneal topography before PRK and 1 year after PRK. The results showed that astigmatism of central 3 mm cornea of severe myopia at 1 year after PRK was higher than that before PRK. It suggested that astigmatism might be related to multiple zone and wide area scanning for corneal ablation, and the inaccuracy of overlapping of consecutive ablation centering at the same point.