Ishikawa T, Park S B, Cox C, del Cerro M, Aquavella J V
Cornea Research Laboratory, University of Rochester Medical Center, NY.
J Refract Corneal Surg. 1994 Jul-Aug;10(4):417-22.
For the correction of myopia, small amounts of corneal tissue--including corneal nerves--are removed, resulting in flattening of the central cornea.
We studied the changes in corneal sensation in five regions of the cornea following photorefractive keratectomy at varying depths. We examined and compared the recovery of sensation in 17 sighted myopic eyes, with preoperative refractive ranges from -1.00 to -7.25 D. Eyes were divided into shallow (0 to 30 microns) or deep (31 to 70 microns) ablation groups depending on the attempted laser correction. Corneal sensation was measured in the central ablated area and the temporal, inferior, nasal, and superior unablated regions preoperatively and at 1, 3, and 6 months postoperatively.
Central and inferior sensation were significantly reduced in the deep ablations at 1 month and continued in the central cornea 6 months postoperatively. There were no overall differences in the sensations in the unablated nasal, temporal, and superior regions between either group or over time. There was a significant second order trend (p = .034) in these three regions, indicating a sharper increase in sensation from baseline in the deeper group at 1 month than the gradual upward trend of the shallow group.
Corneal sensation of both the central ablated area and the unablated peripheral cornea is decreased after deep anterior stromal excimer laser ablations and does not recover within 1 month. Although the deeper group showed isolated areas in the periphery of significant second order trends in sensation, the overall trends were not large, indicating no significant anesthetic effect. Fluctuations in sensation can be detected in the five regions even 6 months after excimer laser keratectomy. The clinical importance of these data remain to be defined.
为矫正近视，需去除少量角膜组织（包括角膜神经），从而导致中央角膜变平。
我们研究了不同深度的准分子激光原位角膜磨镶术（PRK）后角膜五个区域的角膜感觉变化。我们检查并比较了17只近视患者眼的感觉恢复情况，术前屈光范围为-1.00至-7.25D。根据尝试的激光矫正，将眼睛分为浅层（0至30微米）或深层（31至70微米）消融组。在术前以及术后1、3和6个月测量中央消融区域以及颞侧、下方、鼻侧和上方未消融区域的角膜感觉。
深层消融术后1个月中央和下方感觉显著降低，术后6个月中央角膜仍持续降低。两组间以及随时间推移，未消融的鼻侧、颞侧和上方区域的感觉无总体差异。这三个区域存在显著的二阶趋势（p = 0.034），表明深层组在1个月时感觉较基线的增加比浅层组的逐渐上升趋势更明显。
深层前基质准分子激光消融术后，中央消融区域和未消融的周边角膜的角膜感觉均降低，且1个月内未恢复。尽管深层组在周边出现了感觉显著二阶趋势的孤立区域，但总体趋势不大，表明无显著麻醉效应。即使在准分子激光角膜切削术后6个月，仍可在五个区域检测到感觉波动。这些数据的临床重要性仍有待确定。
