Scorolli L, Scorolli L, Scalinci S Z, Savini G, Meduri R
Department of Physiopathological Optics, University of Bologna, Italy.
Eur J Ophthalmol. 1996 Oct-Dec;6(4):351-5. doi: 10.1177/112067219600600401.
To evaluate the prevalence, amount and possible factors connected with the hyperopic shift after radial keratotomy.
We studied 86 eyes (51 patients) which underwent 4-8 incision radial keratotomy (delayed technique), consecutively performed by the same surgeon between February 1983 and November 1988. The diamond-bladed knife was set at 95% of the smallest paracentral ultrasonic corneal thickness measurement and the clear zone diameter was between 3.0 and 3.5 mm. Preoperative myopia ranged from -2.00 to -7.25 diopters (D). The average follow-up was 97.4 months (range 78 to 122 months).
After eight years of follow-up, the cycloplegic spherical equivalent was satisfactory: 66.2% of the eyes showed a refractive error within 0.5 D, 17.4% were myopic by more than 0.5 D and 16.2% were hyperopic by more than 0.5 D. The mean refractive error was 0.02 D (SD +/- 0.75 D). Between six months and eight years after surgery a hyperopic shift of more than 0.5 D was found in 40.6% of the eyes. The mean hyperopic shift was higher (0.78 D) in the eyes which had keratometry less than 36 D six months after surgery. Compared to the eyes with keratometry greater than 36 D (mean hyperopic shift 0.38 D), the difference was statistically significant (p < 0.02).
These results show that keratometry, measured six months postoperatively, plays a fundamental role in the stability of postsurgical refraction, as the risk of hyperopic shift is higher in eyes with keratometry < 36 D.
评估放射状角膜切开术后远视漂移的发生率、程度及相关可能因素。
我们研究了86只眼（51例患者），这些眼睛于1983年2月至1988年11月间由同一位外科医生连续进行了4 - 8切口的放射状角膜切开术（延迟技术）。钻石刀片刀设置在中央旁角膜最小超声厚度测量值的95%处，透明区直径在3.0至3.5毫米之间。术前近视度数范围为-2.00至-7.25屈光度（D）。平均随访时间为97.4个月（范围78至122个月）。
经过八年的随访，睫状肌麻痹下的等效球镜度情况良好：66.2%的眼睛屈光不正度数在0.5 D以内，17.4%的眼睛近视度数超过0.5 D，16.2%的眼睛远视度数超过0.5 D。平均屈光不正度数为0.02 D（标准差±0.75 D）。术后6个月至8年期间，40.6%的眼睛出现了超过0.5 D的远视漂移。术后6个月角膜曲率小于36 D的眼睛，其平均远视漂移更高（0.78 D）。与角膜曲率大于36 D的眼睛（平均远视漂移0.38 D）相比，差异具有统计学意义（p < 0.02）。
这些结果表明，术后6个月测量的角膜曲率对手术屈光稳定性起着重要作用，因为角膜曲率< 36 D的眼睛发生远视漂移的风险更高。
