De Bernardo Maddalena, Borrelli Maria, Imparato Roberto, Rosa Nicola
Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy.
Department of Ophthalmology, University Hospital Duesseldorf, Duesseldorf, Germany.
J Ophthalmol. 2020 Apr 1;2020:1916369. doi: 10.1155/2020/1916369. eCollection 2020.
To check if a regression formula, IOLMaster-derived, to calculate the real corneal power after photorefractive keratectomy (PRK), can give reliable results utilizing the Pentacam.
Pre- and postoperative IOLMaster, Km, and Pentacam K readings were measured. Patients who had myopic PRK were divided into two groups: the first group (108 eyes) was utilized to check which of the preop Pentacam K readings (P-Kpre) better fitted with the preop IOLMaster measurements; in the second group (120 eyes), the real K (Kr), obtained adding the effective treatment to the P-Kpre, were compared with the K readings calculated with the IOLMaster-derived formula (Kc). Moreover, an attempt to find a different formula utilizing the P-Kpre was made.
In group 1, the best correlation was found between IOLMaster Km and Pentacam equivalent K readings (r2 0.9519). In group 2, the comparison between Kr and Pentacam postop Km showed 69 eyes (57%) with differences >0.5 D and 38 eyes (31%) with differences >1 D, ( < 0.001). The comparison between Kr and Kc showed 55 eyes (45%) with differences >0.5 D and 22 eyes (18%) with differences >1 D, ( < 0.001). Moreover, a regression formula K = EKR - [ETcp + (0.8114 ∗ ETcp - 0.2031)] was obtained in order to calculate the K readings to be used with the Pentacam in the IOL power calculation in case the effective treatment is known.
K calculated with the new formula could be used in patients that underwent refractive corneal surgery in case a Pentacam device is used, pending further studies conducted in clinical practice to establish its accuracy and effectiveness. This study further proves that data obtained from different machines cannot be used interchangeably.
检验一种通过IOLMaster得出的、用于计算准分子激光原位角膜磨镶术（PRK）后真实角膜屈光力的回归公式，利用眼前节分析系统（Pentacam）能否得出可靠结果。
测量术前和术后IOLMaster、角膜曲率计读数（Km）以及Pentacam角膜曲率读数。接受近视PRK的患者被分为两组：第一组（108只眼）用于检验术前哪一个Pentacam角膜曲率读数（P-Kpre）与术前IOLMaster测量值拟合度更佳；第二组（120只眼）将通过在P-Kpre基础上加上有效治疗量得出的真实角膜曲率（Kr）与用IOLMaster得出的公式计算出的角膜曲率读数（Kc）进行比较。此外，尝试利用P-Kpre找出一个不同的公式。
在第一组中，IOLMaster Km与Pentacam等效角膜曲率读数之间相关性最佳（r2 0.9519）。在第二组中，Kr与Pentacam术后Km比较显示，69只眼（57%）差异>0.5 D，38只眼（31%）差异>1 D（P<0.001）。Kr与Kc比较显示，55只眼（45%）差异>0.5 D，22只眼（18%）差异>1 D（P<0.001）。此外，得出一个回归公式K = EKR - [ETcp + (0.8114 * ETcp - 0.2031)]，以便在已知有效治疗量的情况下计算眼前节分析系统在人工晶状体屈光力计算中使用的角膜曲率读数。
在使用眼前节分析系统的情况下，对于接受角膜屈光手术的患者，用新公式计算出的角膜曲率可在临床实践中进行进一步研究以确定其准确性和有效性之前使用。本研究进一步证明，从不同仪器获得的数据不能互换使用。
