de Sanctis Ugo, Angeloni Marco, Zilio Cristina, Sacco Diego, Grignolo Federico
Department of Clinical Physiopathology, Ophthalmology Institute, University of Turin, Turin, Italy.
Optom Vis Sci. 2011 Jun;88(6):697-702. doi: 10.1097/OPX.0b013e3182160763.
To investigate changes of corneal power after descemet stripping automated endothelial keratoplasty (DSAEK).
Anterior, posterior, and true-net (anterior + posterior) power of post-DSAEK and contralateral transparent corneas were measured, using the Pentacam rotating Scheimpflug camera (Oculus Wetzlar, Germany), 6 months after surgery in 23 consecutive patients who had undergone unilateral DSAEK at the same medical center. Moreover, in each cornea, Pentacam pachimetry was measured at the vertex and at 3 mm from the vertex, to calculate corneal thickness increase (CTI).
In post-DSAEK corneas, the anterior power on average decreased by -0.24 ± 0.61 diopters (D), the negative posterior power increased by -0.96 ± 0.42 D, and the true-net power decreased by -1.19 ± 0.74 D (range: +0.17 to -2.23 D). Differences vs. contralateral transparent corneas did not reach statistical significance for anterior (p = 0.09) but were significant (p < 0.001) for posterior and true-net corneal power. CTI at 3 mm from the vertex was statistically larger (p < 0.0001) in post-DSAEK corneas (mean values 0.27 ± 0.07 vs. 0.12 ± 0.05); CTI values showed a statistically significant (p < 0.05) correlation with negative posterior corneal power values in post-DSAEK (r = -0.55) and in contralateral corneas (r = -0.67).
In comparison with contralateral corneas, post-DSAEK corneas show a moderate reduction of the true-net corneal power measured by Pentacam. Knowledge of true-net corneal power changes might be useful in adjusting K values and calculating intraocular lens power, in eyes scheduled for DSAEK combined with intraocular lens implantation/exchange.
研究深板层角膜内皮移植术（DSAEK）后角膜屈光力的变化。
使用Pentacam旋转式Scheimpflug相机（德国韦茨拉尔奥culus公司），对在同一医疗中心接受单侧DSAEK手术的23例连续患者术后6个月的DSAEK术后角膜及对侧透明角膜的前表面、后表面和真实净值（前表面+后表面）屈光力进行测量。此外，在每个角膜的顶点及距顶点3mm处测量Pentacam测厚值，以计算角膜厚度增加量（CTI）。
在DSAEK术后角膜中，前表面屈光力平均降低-0.24±0.61屈光度（D），后表面负屈光力增加-0.96±0.42D，真实净值屈光力降低-1.19±0.74D（范围：+0.17至-2.23D）。与对侧透明角膜相比，前表面屈光力差异无统计学意义（p=0.09），而后表面和真实净值角膜屈光力差异有统计学意义（p<0.001）。DSAEK术后角膜距顶点3mm处的CTI在统计学上更大（p<0.0001）（平均值0.27±0.07对0.12±0.05）；CTI值与DSAEK术后（r=-0.55）及对侧角膜（r=-0.67）的后表面负角膜屈光力值存在统计学显著相关性（p<0.05）。
与对侧角膜相比，DSAEK术后角膜经Pentacam测量的真实净值角膜屈光力有适度降低。了解真实净值角膜屈光力变化可能有助于调整K值并计算计划行DSAEK联合人工晶状体植入/置换手术患者的人工晶状体屈光力。
