降眼压药物预防准分子激光原位角膜磨镶术后早期屈光回退的临床研究

Clinical study of Timolol in the prevention of myopia regression after LASIK

目的观察准分子激光原位角膜磨镶术（laser in situ keratomileusis，LASIK）的患者早期应用降眼压药对角膜前表面曲率及前房深度的影响，评价其对LANK术后角膜膨隆及屈光回退的抑制作用。方法按术前角膜厚度低于520μm、术中角膜基质床介于250—270μm的标准分为两组：第1组（用药组）15眼，术后第2天在常规用药的同时加用噻吗心安眼水；第2组（非用药组）15眼，在患者出现屈光回退时（术后1个月内）加用噻吗心安眼水。应用Orbscan-Ⅱ系统测量术后第1天、第15天及屈光回退时的前表面曲率和前房深度（晶状体前表面与角膜内皮间）。结果第2组用药后的前表面曲率较用药前降低，两组比较，差异有显著性（t=0．022）；用药后前房深度较用药前略有降低，两组比较差异有显著性（t=0．27）。第1组术后1个月内出现回退1眼（占0．67％），第2组，术后1个月内出现回退6眼（占40％），第1组术后第1天与第15天前表面曲率差值平均为（0．291±0．042）D，第2组为（0．870±0．061）D，两组差值经单因素方差分析，差异有显著性（F=7．496，P=0．023）。第1组术后第1天与第15天前房深度差值平均为（0．014±0．004）μm，第2组为（0．042±0．002）μm，经单因素方差分析，差异有显著性（F=5．171，P=0．042）。结论LASIK术后早期应用降眼压药物可以抑制眼压的升高，降低角膜膨隆及术后早期屈光回退的发生率。

Objective To observe the effect of the early application of Timolol on corneal anterior .surface curvature and to measure the depth of the anterior chamber in patients after LASIK. Methods Thirty eyes, which had a corneal thickness less than 520 μm and a comeal stroma bed in the. 250 - 270 tan range, were divided into two groups. Timolol was used on the second day after LASIK in group 1 while it was only used when regression appeared in group 2. Corneal anterior .surface curvature, and the. depth of the. anterior chamber were measured in both groups on the. first day and on the fifteenth day post-operatively, and when refractive regression appeared. Results The change in corneal anterior surface curvature after the. application of Timolol was significant （ t = 0. 022）, but the change in anterior chamber depth was not significant （t = 0.27） in group 2. Only one. eye showed regression （0.67%） in group 1, bat six eyes （40%） showed regression in group 2. The. change in corneal anterior surface curvature between the first day and the fifteenth day post- operatively was （ 0.291 ± 0. 042 ） D in group 1, and （ 0. 870 ± 0.051 ）D in group 2. The. difference between the two groups was significant （ F = 7. 496, P = 0. 023）. The change in anterior chamber depth between the first day and the fifteenth day post-operatively was （0. 014 ± 0. 004）μm in group 1, and （0.042± 0.002）μm in group 2. And the difference between the two groups was also significant （F = 5. 171, P = 0.042）. Conclusion Early application of Timolol after LASIK can decrease the morbidity of refractive regression by lowering the intraocular pressure to reduce, corneal ectasia.