Thompson Robert W, Choi David M, Price Marianne O, Potrezbowski Laurie, Price Francis W
Price Vision Group, 9002 N. Meridian St., Suite 100, Indianapolis, IN 46260, USA.
J Refract Surg. 2003 Sep-Oct;19(5):507-15. doi: 10.3928/1081-597X-20030901-05.
Studies show significant variability in the thickness of laser in situ keratomileusis (LASIK) corneal flaps cut by various microkeratomes. Most studies of corneal flap thickness are based on contact ultrasonic pachymetry measurements taken during the surgical procedure. This study reports a technique to obtain reproducible corneal flap thickness and residual stromal bed thickness measurements using noncontact optical coherence tomography (OCT) following LASIK.
The corneal flap thicknesses of 26 eyes of 15 patients were measured following LASIK in which the flap was created using the Amadeus microkeratome: 160-microm head, 9.5-mm ring, 4.0-mm/s translation speed, 8000 oscillations/m, and full vacuum. Zeiss Humphrey OCT-2 line scans were performed on postoperative days 1 and 7. The raw data from three scans for each eye and day were exported to Microsoft Excel for processing, averaging, and analysis.
The OCT corneal flap thickness and residual stromal bed thickness measurements correlated well with ultrasonic pachymetry measurements performed during surgery (R2 = .92). The OCT technique yielded reproducible results, as the variance for repeated scans was only 2.5% of the variance between eyes. In bilateral cases a single blade was used for both eyes. The mean flap thickness of 15 first eyes was significantly greater than that of the 10 second eyes: 181 +/- 31 microm vs. 143 +/- 41 microm (P < .01). A positive correlation was found between the preoperative pachymetry and corneal flap thickness.
The OCT scan averaging technique is a reproducible, noncontact postoperative method for measuring corneal flap and residual stromal bed thicknesses following LASIK.
研究表明，各种微型角膜刀切割的准分子原位角膜磨镶术（LASIK）角膜瓣厚度存在显著差异。大多数关于角膜瓣厚度的研究是基于手术过程中进行的接触式超声测厚测量。本研究报告了一种在LASIK术后使用非接触式光学相干断层扫描（OCT）获得可重复的角膜瓣厚度和剩余基质床厚度测量值的技术。
对15例患者的26只眼进行LASIK手术，使用阿玛迪斯微型角膜刀制作角膜瓣：160微米刀头、9.5毫米环、4.0毫米/秒平移速度、8000次振荡/分钟和全真空。在术后第1天和第7天进行蔡司汉弗莱OCT-2线扫描。将每只眼和每天三次扫描的原始数据导出到Microsoft Excel进行处理、平均和分析。
OCT测量的角膜瓣厚度和剩余基质床厚度与手术期间进行的超声测厚测量结果相关性良好（R2 = 0.92）。OCT技术产生了可重复的结果，因为重复扫描的方差仅为两眼之间方差的2.5%。在双侧病例中，两只眼睛使用同一把刀片。15只第一眼的平均瓣厚度显著大于10只第二眼：181±31微米对143±41微米（P < 0.01）。术前测厚与角膜瓣厚度之间存在正相关。
OCT扫描平均技术是一种可重复的、非接触式的LASIK术后测量角膜瓣和剩余基质床厚度的方法。
