Patel Sanjay V, McLaren Jay W, Kittleson Katrina M, Bourne William M
Department of Ophthalmology, Mayo Clinic, Rochester, MN 55905, USA.
Arch Ophthalmol. 2010 Nov;128(11):1413-9. doi: 10.1001/archophthalmol.2010.253.
To compare changes in subbasal nerve density and corneal sensitivity after laser in situ keratomileusis (LASIK) with the flap created by a femtosecond laser (bladeless) vs a mechanical microkeratome.
In a randomized paired-eye study, 21 patients received myopic LASIK with the flap created by a femtosecond laser in one eye and by a mechanical microkeratome in the fellow eye. Eyes were examined before and at 1, 3, 6, 12, and 36 months after LASIK. Central subbasal nerve density was measured by using confocal microscopy. Corneal mechanical sensitivity was measured by using a gas esthesiometer and was expressed as the ratio of mechanical threshold in eyes that received LASIK to mechanical threshold in concurrent control eyes.
Subbasal nerve density and corneal sensitivity did not differ between methods of flap creation at any examination. Mean (SD) nerve density was decreased at 1 month (bladeless, 974 [2453] μm/mm(2); microkeratome, 1308 [2881] μm/mm(2)) compared with the preoperative examination (bladeless, 10,883 [5083] μm/mm(2), P < .001; microkeratome, 12,464 [6683] μm/mm(2), P < .001) and remained decreased through 12 months (P < .001). Mechanical threshold ratios did not differ from that at the preoperative examination through 36 months for either LASIK treatment; when all LASIK eyes were combined, the mechanical threshold ratio was transiently higher (decreased sensitivity) at 1 month (1.29 [0.85]) compared with the preoperative examination (0.89 [0.73], P = .05).
The planar configuration of the femtosecond laser flaps is not associated with faster reinnervation compared with the microkeratome flaps. The prolonged decrease in subbasal nerve density after LASIK is not accompanied by a prolonged decrease in corneal sensitivity.
clinicaltrials.gov Identifier NCT00350246.
比较飞秒激光（无刀）制作角膜瓣与机械微型角膜刀制作角膜瓣的准分子原位角膜磨镶术（LASIK）后角膜基质下神经密度和角膜敏感性的变化。
在一项随机双眼配对研究中，21例患者一只眼接受飞秒激光制作角膜瓣的近视LASIK手术，另一只眼接受机械微型角膜刀制作角膜瓣的手术。在LASIK术前及术后1、3、6、12和36个月对眼睛进行检查。使用共焦显微镜测量中央角膜基质下神经密度。使用气体感觉计测量角膜机械敏感性，并将其表示为接受LASIK手术的眼睛的机械阈值与同期对照眼睛的机械阈值之比。
在任何检查中，两种制作角膜瓣的方法在角膜基质下神经密度和角膜敏感性方面均无差异。与术前检查相比（飞秒激光组，10883 [5083] μm/mm²，P <.001；机械微型角膜刀组，12464 [6683] μm/mm²，P <.001），1个月时平均（标准差）神经密度降低（飞秒激光组，974 [2453] μm/mm²；机械微型角膜刀组，1308 [2881] μm/mm²），并且在12个月内一直降低（P <.001）。两种LASIK治疗方法在36个月内的机械阈值比与术前检查相比均无差异；当所有接受LASIK手术的眼睛合并计算时，1个月时的机械阈值比（敏感性降低）与术前检查相比（0.89 [0.73]，P =.05）短暂升高（1.29 [0.85]）。
与机械微型角膜刀制作的角膜瓣相比，飞秒激光制作的角膜瓣的平面结构与更快的神经再支配无关。LASIK术后角膜基质下神经密度的长期降低并未伴随着角膜敏感性的长期降低。
clinicaltrials.gov标识符NCT00350246。
