基于屈光手术的角膜切削模型和临床测量的波前像差数据,分析了矫正近视散光的常规屈光手术中切削偏心对波前像差的影响。结果表明,切削偏心主要会引起彗差的增大,引入彗差与偏心程度成线性关系,与被矫正的近视散光的屈光度也近似成线性关系。3-5阶像差中,除彗差以外的其它高阶像差并不会随着切削偏心的增大而显著增大。屈光手术后高阶像差的增大主要是切削偏心、激光斜入射和角膜愈合反应等多重因素导致的。

波前像差的客观验光准确度对眼科临床应用有重要的意义。基于实测人眼的波前像差数据,计算波前像差曲面图的曲率分布,得到人眼在瞳孔平面位置的屈光度。通过波前传播,计算得到眼镜镜片所处位置的屈光度。该方法包含了高阶像差对人眼屈光度的影响,分析该屈光度与主观验光屈光度间的差异发现,4 mm瞳孔直径下的波前验光结果与主观验光结果差异较小,平均球度差异为0.06D,平均柱度和柱度角的差异分别为-0.07D和0.62°。结果表明,利用4 mm瞳孔直径下的曲率分布图验光结果可以较准确的预测主观验光结果。

In order to determine the appropriate treatment interval, 267 patients who underwent 3 sessions of treatment with Q-switched alexandrite laser were divided into 4 groups according to treatment interval, and their clinical responses were compared. Among them, 187 were asked about the process of pigment fading. Moreover, light and transmission electron microscopy were performed. It was noted that the clinical response of the 5-6 month interval group was significantly better than that of the 3-4 month group, but showed no significant difference from that of the 7-8 or >=9 month group. 80.21% of investigated patients stated that marked pigment fading could no longer be observed 7 months after irradiation. 4 months after irradiation, the degenerated melanosomes and cell debris were still scattered among collagen fibers, scavenged gradually by macrophage. In conclusion, an appropriate treatment interval is 5-6 months.