Department of Ophthalmology, Siena University, Siena, Italy.
Department of Ophthalmology, Siena University, Siena, Italy.
Am J Ophthalmol. 2014 Jun;157(6):1156-62. doi: 10.1016/j.ajo.2014.02.042. Epub 2014 Feb 26.
To assess intraoperative variation of corneal thinnest point in keratoconic patients undergoing riboflavin/ultraviolet type A (UV-A) cross-linking treatment using noncontact time-domain optical pachymetry.
Prospective, noncomparative interventional study.
Ten patients underwent epithelium-off riboflavin/UV-A corneal cross-linking at Siena University Hospital; corneal thickness was measured using optical coherence tomography at the following times: preoperatively with epithelium on; after removal of a 9-mm-diameter disc of epithelium; immediately after instillation of 2 drops of riboflavin 0.1%-dextran T 500 20% solution; after repeated instillation of riboflavin 0.1%-dextran T 500 20% solution every 2.5 minutes, at 10, 20, and 30 minutes of soaking time; at the end of the treatment after 30 minutes of UV-A exposure with the riboflavin biofilm in situ; and finally after washing the riboflavin biofilm.
The most significant decrease in thinnest point measurement was detected meanly in the first 10 minutes of corneal soaking. In this interval, the minimum recommended in various studies, a mean reduction of -79.28 μm (-17.61% of initial thinnest point value after removal of the epithelium) was recorded. No adverse events were recorded.
The study demonstrates a statistically significant intraoperative reduction in corneal thinnest point value during epithelium-off cross-linking procedure using standard riboflavin 0.1%-dextran 20% solutions. Intraoperative optical pachymetry evaluation during cross-linking should be recommended before starting UV-A irradiation, and if a thickness under 380 μm is detected, the stroma should be reexpanded with hypotonic dextran-free riboflavin solutions.
使用非接触时域光学生物测量仪评估接受核黄素/紫外线 A（UV-A）交联治疗的圆锥角膜患者术中角膜最薄点的变化。
前瞻性、非对照的干预性研究。
锡耶纳大学医院的 10 例患者行上皮下核黄素/UV-A 角膜交联术；在以下时间使用光学相干断层扫描测量角膜厚度：上皮在位时术前；去除直径 9mm 的上皮瓣后；滴入 2 滴 0.1%核黄素-右旋糖酐 T500 20%溶液后立即；每隔 2.5 分钟重复滴入 0.1%核黄素-右旋糖酐 T500 20%溶液，浸泡 10、20 和 30 分钟；在 30 分钟的 UV-A 暴露后，原位保留核黄素生物膜；最后在冲洗核黄素生物膜后。
在角膜浸泡的最初 10 分钟内，最薄点测量值的下降最为显著。在此间隔内，记录到最小推荐值，即去除上皮后的初始最薄点值的平均减少-79.28μm（-17.61%）。未记录到不良事件。
本研究表明，使用标准的 0.1%核黄素-20%右旋糖酐溶液进行上皮下交联过程中，术中角膜最薄点值会出现统计学上的显著降低。在开始进行 UV-A 照射前，交联过程中应推荐进行术中光学测厚评估，如果检测到厚度低于 380μm，则应使用不含低渗右旋糖酐的核黄素溶液重新扩张基质。
