使用MEL 90 行LASIK矫正混合散光的结果

Reinstein, D. Z., Carp, G. I., Archer, T. J., Day, A. C., & Vida, R. S. (2018). Outcomes for mixed cylinder LASIK with the MEL 90® excimer laser. Journal of Refractive Surgery, 34(10), 672-680.

报告使用MEL 90的Triple-A切削模式进行混合散光的LASIK矫正术后结果。

回顾性分析2013年7月至2016年10月期间接受MEL 90的Triple-A切削模式行LASIK矫正混合散光的所有眼数据。术后随访1年。通过Alpins方法进行标准结果分析和矢量分析。

共计纳入接受MEL 90的LASIK矫正混合散光的105只眼（82名患者）。平均年龄40±11岁（范围：18至65岁）。平均等效球镜度+0.30 ± 0.90 D（范围：-2.30至+1.75 D）。平均柱镜度为-2.93 ± 1.47 D（范围：-0.75至-7.00 D）。

▲105眼的混合散光矫正术后屈光结果九连图，患眼均接受MEL 90的LASIK矫正，使用Triple-A切削模式的500 Hz频率。

*图I显示误差角小，再加上图H的分析结果，本文推荐MEL 90的LASIK矫正混合散光术前，散光nomogram为降低12%的混合散光幅度。

▲亚组分析散光矫正效果。A.近视为主的混合散光（球镜为负散光的25%及以下）；B.混合散光（球镜为负散光的25%至75%之间）；C.远视为主的混合散光（球镜为负散光的75%及以上）。

注：近视为主的混合散光矫正指数几何平均值1.06，混合散光1.16，远视为主的混合散光1.13。

81%的眼术前最佳矫正远视力(CDVA)为20/20或更高。69%的眼术后裸眼远视力(UDVA)为20/20或更高，86%的眼为20/25或更高。相对目标屈光度的平均术后等效球镜度为-0.21 ± 0.38 D（范围：-1.25至+1.13 D），其中83%在±0.50 D内。平均术后柱镜度为-0.57 ± 0.41 D（范围：0.00至-1.75 D)。矫正指数的几何平均值为1.12，成功指数的几何平均值为0.25。误差角的算术平均值为-0.6° ± 4.2°（范围：-13.5°至9.5°），平均绝对值为2.9° ± 3.0°（范围：0.0°至13.5°）。3%的眼有1行CDVA丢失，无1只眼有2行及以上CDVA丢失。术后3、6、12和18 cpd的对比敏感度略有增加（P < .05）。

使用MEL 90行LASIK矫正高达-7.00 D的混合散光术后一年的结果表明了其优异的有效性、安全性和可预测性。矢量分析显示，散光幅度有12%的过矫。鉴于误差角表明的的高准确度，可以应用nomogram来减少过矫，以进一步改善裸眼远视力结果。

▪ 对于MEL 90的LASIK矫正混合散光，本文提到的散光nomogram为术前降低12%散光幅度;

▪ 亚组分析显示，近视为主的混合散光过矫程度更低而其它类型过矫程度更高；因此建议术前nomogram计算在正柱镜形式下进行，进一步降低术前远视性的等效球镜度，从而减少过矫，例如：

✓ 术前验光：+4.00 / -5.50 x 65

✓ 转换为正柱镜形式：-1.50 / +5.50 x 155

✓ 使用文中建议的散光nomogram：-1.50 / +4.91 (+5.50 ÷ 1.12) x 155

▪ Nomogram通常根据术式、设备、术中操作流程与习惯、验光标准、环境温湿度和患者个体因素等有关，通过临床实践后回归分析可以得到个性化的nomogram；

▪ 蔡司免费提供Nomogram分析服务：为了更加准确的分析，建议提供同一位医生手术的至少60眼随访3个月以上的主观验光数据。

To report the outcomes of LASIK for mixed cylinder using the Triple-A ablation profile with the MEL 90 excimer laser (Carl Zeiss Meditec, Jena, Germany).

This was a retrospective analysis of all eyes treated by LASIK for mixed cylinder using the Triple-A ablation profile with the MEL 90 laser between July 2013 and October 2016. Patients were observed for 1 year after surgery. Standard outcomes analysis and vector analysis by the Alpins method were performed.

The database review identified 105 eyes (82 patients) treated by LASIK for mixed cylinder using the MEL 90 laser. Mean age was 40 ± 11 years (range: 18 to 65 years). Mean attempted spherical equivalent was +0.30 ± 0.90 diopters (D) (range: -2.30 to +1.75 D). Mean cylinder was -2.93 ± 1.47 D (range: -0.75 to -7.00 D). Preoperative corrected distance visual acuity (CDVA) was 20/20 or better in 81% of eyes. Postoperative uncorrected distance visual acuity was 20/20 or better in 69% and 20/25 or better in 86% of eyes. Mean postoperative spherical equivalent relative to the intended target was -0.21 ± 0.38 D (range: -1.25 to +1.13 D), with 83% within ±0.50 D. Mean postoperative cylinder was -0.57 ± 0.41 D (range: 0.00 to -1.75D). Geometric mean was 1.12 for the correction index and 0.25 for the index of success. For angle of error, the arithmetic mean was -0.6° ± 4.2° (range: -13.5° to 9.5°) and the absolute mean was 2.9° ± 3.0° (range: 0.0° to 13.5°). There was loss of one line of CDVA in 3% of eyes and no eyes lost two or more lines CDVA. There was a small increase in contrast sensitivity after surgery at 3, 6, 12, and 18 cycles per degree (P < .05).

One-year outcomes of LASIK using the MEL 90 laser for mixed cylinder up to -7.00 D demonstrated excellent efficacy, safety, and predictability. Vector analysis found a 12% overcorrection in magnitude of refractive cylinder. Given the high accuracy for angle of error, a nomogram could be applied to reduce the overcorrection and further improve the uncorrected distance visual acuity outcomes