Kanellopoulos Anastasios John, Asimellis George
Laservision.gr Eye Institute, Athens, Greece ; New York University School of Medicine, Department of Opthalmology, NY, NY, USA.
Clin Ophthalmol. 2013;7:1385-96. doi: 10.2147/OPTH.S44745. Epub 2013 Jul 18.
The purpose of this study was to compare the safety and efficacy of two alternative corneal topography data sources used in topography-guided excimer laser normalization, combined with corneal collagen cross-linking in the management of keratoconus using the Athens protocol, ie, a Placido disc imaging device and a Scheimpflug imaging device.
A total of 181 consecutive patients with keratoconus who underwent the Athens protocol between 2008 and 2011 were studied preoperatively and at months 1, 3, 6, and 12 postoperatively for visual acuity, keratometry, and anterior surface corneal irregularity indices. Two groups were formed, depending on the primary source used for topoguided photoablation, ie, group A (Placido disc) and group B (Scheimpflug rotating camera). One-year changes in visual acuity, keratometry, and seven anterior surface corneal irregularity indices were studied in each group.
Changes in visual acuity, expressed as the difference between postoperative and preoperative corrected distance visual acuity were +0.12 ± 0.20 (range +0.60 to -0.45) for group A and +0.19 ± 0.20 (range +0.75 to -0.30) for group B. In group A, K1 (flat keratometry) changed from 45.202 ± 3.782 D to 43.022 ± 3.819 D, indicating a flattening of -2.18 D, and K2 (steep keratometry) changed from 48.670 ± 4.066 D to 45.865 ± 4.794 D, indicating a flattening of -2.805 D. In group B, K1 (flat keratometry) changed from 46.213 ± 4.082 D to 43.190 ± 4.398 D, indicating a flattening of -3.023 D, and K2 (steep keratometry) changed from 50.774 ± 5.210 D to 46.380 ± 5.006 D, indicating a flattening of -4.394 D. For group A, the index of surface variance decreased to -5.07% and the index of height decentration to -26.81%. In group B, the index of surface variance decreased to -18.35% and the index of height decentration to -39.03%. These reductions indicate that the corneal surface became less irregular (index of surface variance) and the "cone" flatter and more central (index of height decentration) postoperatively.
Of the two sources of primary corneal data, the Scheimpflug rotating camera (Oculyzer™) for topography-guided normalization treatment with the WaveLight excimer laser platform appeared to provide more statistically significant improvement than the Placido disc topographer (Topolyzer™). Overall, the Athens protocol, aiming both to halt progression of keratoconic ectasia and to improve corneal topometry and visual performance, produced safe and satisfactory refractive, keratometric, and topometric results. The observed changes in visual acuity, along with keratometric flattening and topometric improvement, are suggestive of overall postoperative improvement.
本研究旨在比较在使用雅典方案进行圆锥角膜治疗中，用于地形引导准分子激光标准化的两种替代角膜地形图数据源的安全性和有效性，该方案结合了角膜胶原交联，即普拉西多盘成像设备和眼前节分析成像设备。
对2008年至2011年间连续接受雅典方案治疗的181例圆锥角膜患者进行术前及术后1、3、6和12个月的视力、角膜曲率测量和角膜前表面不规则指数研究。根据用于地形引导光消融的主要数据源分为两组，即A组（普拉西多盘）和B组（眼前节分析旋转相机）。研究每组患者术后一年的视力、角膜曲率测量和七个角膜前表面不规则指数的变化。
A组术后与术前矫正远视力差值表示的视力变化为+0.12±0.20（范围+0.60至-0.45），B组为+0.19±0.20（范围+0.75至-0.30）。在A组中，K1（平角膜曲率）从45.202±3.782D变为43.022±3.819D，变平了-2.18D，K2（陡角膜曲率）从48.670±4.066D变为45.865±4.794D，变平了-2.805D。在B组中，K1（平角膜曲率）从46.213±4.082D变为43.190±4.398D，变平了-3.023D，K2（陡角膜曲率）从50.774±5.210D变为46.380±5.006D，变平了-4.394D。对于A组，表面方差指数降至-5.07%，高度偏心指数降至-26.81%。在B组中，表面方差指数降至-18.35%，高度偏心指数降至-39.
