Effect of astigmatic keratotomy on spherical equivalent: results of the Astigmatism Reduction Clinical Trial.
Effect of astigmatic keratotomy on spherical equivalent: results of the Astigmatism Reduction Clinical Trial.
复制标题
散光角膜切开术对球面等效值的影响：散光减少临床试验的结果。
DOI：
10.1016/s0002-9394(98)00410-3
复制
发表时间：
1999
影响因子：
4.2
通讯作者：
Francis W. Price
中科院分区：
文献类型：
--
作者：
E. Faktorovich;Robert K. Maloney;Francis W. Price
EQUASE确定的效果，屈光性角膜切开术的等效球镜，作为衡量的耦合比和一个新的数量，coupling constant. METHODS在一项前瞻性多中心研究，受试者进行弓形角膜切开术在7 mm的光学区通过Lindstrom诺模图矫正散光。对95例患者的157只眼进行了术后1个月的随访检查。平均术前屈光柱镜± SEM为2.82 ± 1.17屈光度。耦合比被定义为切开的子午线的平坦度与相对子午线的陡峭度之比。耦合常数被定义为等效球镜的变化与散光矢量变化幅度的比值。根据屈光度和角膜曲率的变化计算耦合比、耦合常数和等效球镜的变化。根据屈光度的变化，耦合比为0.95 ± 0.10（平均值± SEM），耦合常数为−0.01 ± 0.03，与等效球镜的微小偏移−0.03 ± 0.07屈光度一致。根据角膜曲率的变化，耦合比为0.84 ± 0.05，耦合常数为−0.04 ± 0.02，与术后角膜曲率的轻微陡度（−0.10 ± 0.04屈光度）一致。基于折射变化的耦合比与高斯定律预测的非弹性圆顶耦合比没有统计学差异（P = .370）。切口长度和数量，实现圆柱体矫正量，年龄和性别对耦合比，耦合常数和sphere equivalent.CONCLUSION变化没有统计学显著影响角膜表现为一个非弹性表面，在弓形角膜切开术与散光减少临床试验研究诺模图。平均而言，屈光性角膜切开术对等效球镜屈光的影响最小。然而，散光角膜切开术后，不同眼睛的耦合比、耦合常数和等效球镜变化存在差异。因此，当计划同时矫正柱镜和等效球镜时，应谨慎。
PURPOSETo determine the effect of astigmatic keratotomy on spherical equivalent, as measured by the coupling ratio and a new quantity, coupling constant.METHODSIn a prospective multicenter study, subjects underwent arcuate keratotomy at a 7-mm optical zone by means of the Lindstrom nomogram for correction of astigmatism. One hundred fifty-seven eyes of 95 patients who had a follow-up examination 1 month postoperatively were studied. Mean preoperative refractive cylinder ± SEM was 2.82 ± 1.17 diopters. Coupling ratio was defined as the ratio of the flattening of the incised meridian to the steepening of the opposite meridian. Coupling constant was defined as the ratio of the change in spherical equivalent to the magnitude of the vector change in astigmatism. Coupling ratio, coupling constant, and change in spherical equivalent were calculated on the basis of change in refraction and keratometry.RESULTSOn the basis of change in refraction, coupling ratio was 0.95 ± 0.10 (mean ± SEM) and coupling constant was −0.01 ± 0.03, consistent with a minor shift in the spherical equivalent of −0.03 ± 0.07 diopter. On the basis of change in keratometry, coupling ratio was 0.84 ± 0.05 and coupling constant was −0.04 ± 0.02, consistent with minor postoperative keratometric steepening of −0.10 ± 0.04 diopter. Coupling ratio based on change in refraction was not statistically different from the coupling ratio predicted by the Gauss’ law for inelastic domes (P = .370). Incision length and number, amount of achieved cylinder correction, age, and sex had no statistically significant effect on coupling ratio, coupling constant, and change in spherical equivalent.CONCLUSIONSCornea behaved as an inelastic surface in response to arcuate keratotomy performed with the Astigmatism Reduction Clinical Trial study nomogram. On average, astigmatic keratotomy had a minimal effect on spherical equivalent refraction. There was variability, however, in coupling ratio, coupling constant, and change in spherical equivalent from eye to eye after astigmatic keratotomy. Caution is therefore advised when simultaneous correction of cylinder and spherical equivalent is planned.
影响因子：
2.4
作者：
Hsi-Chun Wang;P. Prendiville;Peter J. McDonnell;Wenji V. Chang
通讯作者：
Hsi-Chun Wang;P. Prendiville;Peter J. McDonnell;Wenji V. Chang
手术一年后放射状角膜切开术 (PERK) 研究的前瞻性评估结果。
影响因子：
13.7
作者：
Waring3rd,GO;Lynn,MJ;Gelender,H;Laibson,PR;Lindstrom,RL;Myers,WD;Obstbaum,SA;Rowsey,JJ;McDonald,MB;Schanzlin,DJ
通讯作者：
Schanzlin,DJ