Gokmen Fusun, Jester James V, Petroll W Matthew, McCulley James P, Cavanagh H Dwight
Department of Ophthalmology, University of Texas Southwestern Medical Center at Dallas, USA.
J Cataract Refract Surg. 2002 Jun;28(6):962-70. doi: 10.1016/s0886-3350(02)01275-0.
To measure flap thickness in laser in situ keratomileusis (LASIK) patients using in vivo confocal microscopy through-focusing (CMTF) and compare measured versus intended flap thickness achieved by 2 microkeratomes, the Automated Corneal Shaper(R) (ACS) (Chiron Bausch & Lomb) and the Hansatome (Bausch & Lomb).
Department of Ophthalmology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA.
Twenty-seven eyes of 27 patients were examined by in vivo CMTF 3 to 12 months after LASIK was performed with the ACS (12 patients) or Hansatome (15 patients) microkeratome. The central cornea was scanned, and the epithelium, flap, stroma, and total corneal thickness were measured. Normalized flap thickness (NFT) was also calculated to account for changes in epithelial thickness that may have occurred postoperatively.
The mean posterior stromal thickness was 341.1 microm +/- 53.9 (SD) (range 233 to 431 microm) in the ACS group and 320.3 +/- 42.3 microm (range 258 to 382 microm) in the Hansatome group. The mean nonnormalized flap thickness was 132.7 +/- 12.5 microm (range 11 to 151 microm) in the ACS group and 167.4 +/- 21.4 microm (range 141 to 209 microm) in the Hansatome group. The NFT was 129.6 +/- 9.5 microm and 158.4 +/- 22.1 microm, respectively. Both microkeratomes cut significantly less than intended (P <.05); however, the ACS cut a thinner-than-intended thickness in all cases, and the Hansatome cut thicker than intended in 13% of cases. The Hansatome also showed significantly greater variability in flap thickness than the ACS (P <.05).
A significant difference in precision was noted between the 2 microkeratomes. The findings emphasize the importance of performing thickness measurements and the usefulness of in vivo CMTF in making these determinations to ensure the safety and effectiveness of LASIK.
使用体内共焦显微镜聚焦测量法（CMTF）测量准分子原位角膜磨镶术（LASIK）患者的角膜瓣厚度，并比较使用两种微型角膜刀，即自动角膜成形器（ACS）（Chiron博士伦公司）和汉森刀（博士伦公司）所获得的测量角膜瓣厚度与预期角膜瓣厚度。
美国得克萨斯州达拉斯市得克萨斯大学西南医学中心眼科。
对27例患者的27只眼在使用ACS（12例患者）或汉森刀（15例患者）微型角膜刀进行LASIK术后3至12个月，通过体内CMTF进行检查。扫描中央角膜，测量上皮、角膜瓣、基质和角膜总厚度。还计算了标准化角膜瓣厚度（NFT），以考虑术后可能发生的上皮厚度变化。
ACS组平均后基质厚度为341.1微米±53.9（标准差）（范围233至431微米），汉森刀组为320.3±42.3微米（范围258至382微米）。ACS组平均非标准化角膜瓣厚度为132.7±12.5微米（范围11至151微米），汉森刀组为167.4±21.4微米（范围141至209微米）。NFT分别为129.6±9.5微米和158.4±22.1微米。两种微型角膜刀切割的厚度均明显小于预期（P<.05）；然而，ACS在所有病例中切割的厚度均比预期薄，而汉森刀在13%的病例中切割的厚度比预期厚。汉森刀在角膜瓣厚度上的变异性也明显大于ACS（P<.05）。
两种微型角膜刀在精度上存在显著差异。这些发现强调了进行厚度测量的重要性以及体内CMTF在进行这些测定以确保LASIK手术安全性和有效性方面的有用性。
