Astin C L
Moorfields Eye Hospital, London, UK.
Ophthalmic Physiol Opt. 1995 Sep;15(5):371-4.
From a research programme comparing two photorefractive keratectomy (PRK) methods, Group S using Summit ExciMed UV 200, and Group V using the VisX 20:20 excimer laser system, 10 patients from each group were recruited. They were referred 6-12 months post-PRK for lens fitting to correct resultant ametropia or irregular astigmatism. Ablation zone diameters were: Group S, 4.5 mm; Group V, 4-6 mm. For Group S, best fit rigid gas permeable (RGP) lenses generally had a back optic zone radius (BOZR) 0.10 mm steeper than the mean keratometry reading (K) and overall diameter of 9.20-10.0 mm. For Group V best fit RGP lenses generally had a BOZR of 0.20 mm steeper than the mean K. The lenses often required large diameters to improve lens centration and extra negative power to compensate for the positive power of the central tear pool. Several patients required soft lens fitting to improve comfort and some finally opted for repeat PRK.
从一项比较两种准分子激光角膜切削术（PRK）方法的研究项目中，招募了每组10名患者，其中S组使用Summit ExciMed UV 200，V组使用VisX 20:20准分子激光系统。他们在PRK术后6至12个月被转诊进行镜片适配，以矫正由此产生的屈光不正或不规则散光。消融区直径为：S组4.5毫米；V组4至6毫米。对于S组，最佳适配的硬性透气性（RGP）镜片的后光学区半径（BOZR）通常比平均角膜曲率读数（K）陡0.10毫米，总直径为9.20至10.0毫米。对于V组，最佳适配的RGP镜片的BOZR通常比平均K陡0.20毫米。这些镜片通常需要较大的直径以改善镜片的居中情况，并需要额外的负度数来补偿中央泪液池的正度数。一些患者需要佩戴软性镜片以提高舒适度，一些患者最终选择再次进行PRK。
