Non-Linear Optical femtosecond laser device to alter corneal curvature and stiffness.

我们最近已经证明，核黄素的光激活和细胞的机械僵硬 可以使用760 nm红外飞秒激光通过双光子来实现角膜， 非线性光学(NLO)过程。NLO相对于现有技术的主要优势 技术是，交联只发生在FS的双光子焦体积内 激光，提供对面积、深度和几何形状的精确控制 可以很容易地为患者的角膜量身定做的机械坚硬的角膜 地形。我们已经进一步申请了FS激光传输系统的专利，并表明这种情况可以改变 通过将聚焦透镜的数值孔径(NA)改变为 将CXL区的侧向和轴向尺寸大大扩展到150μm的角膜 厚度。这大大加快了NLO过程，提供了更快的过程 与标准治疗相比。我们还建立了再生使用 放大的FS激光脉冲，可以实现兔角膜的机械硬化 总功率为&lt；46.1 mW，低于ANSI激光照射眼睛的热极限。 此外，我们已经在活体兔子模型中展示了我们的NLO CXL设备可以将A4 直径5 mm的中央角膜区域，产生1-2个屈光度的角膜扁平化。 我们进一步开发了一种FS角膜上皮微加工方法，以增强 化学品穿透上皮而不会在或之前造成上皮损伤 在程序之后，从而避免了标准协议的重大不良影响。有了这个 现在有了新技术，我们准备开发一种临床原型，它将允许 该装置用于治疗圆锥角膜和低度近视、远视、老花眼。 和散光。

We have recently shown that photo-activation of riboflavin and mechanical stiffening of the cornea can be achieved using 760 nm infrared Femtosecond laser light through a two photon, nonlinear optical (NLO) process. The primary advantage of NLO over the existing technology is that cross linking occurs only within the two-photon focal volume of the FS laser light, providing precise control over the area, depth and geometry of the mechanically stiffened cornea that can be easily tailored to the patient's corneal topography. We have further patented an FS laser delivery system and shown that can vary the two-photon focal volume by changing the numerical aperture (NA) of the focusing lens to greatly expand the lateral and axial dimensions of the CXL region up to 150 μm of the corneal thickness. This greatly speeds up the NLO process, providing a more rapid procedure compared to that of standard treatments. We have also established that using regeneratively amplified FS laser pulses, mechanical stiffening of rabbit corneas can be achieved with an overall power of <46.1 mW, below the ANSI thermal limits for laser exposure to the eye. Additionally, we have shown in a live rabbit model that our NLO CXL device can crosslink a 4 mm diameter central corneal region in 5 minutes and produce 1-2 diopters of corneal flattening. We have further developed an FS corneal epithelial micromachining method to enhance penetration of chemicals through the epithelium without producing epithelial damage before or after the procedure, thus avoiding the major adverse effects of standard protocols. With this novel technology now in hand, we are ready to develop a clinical prototype that will allow for the testing of this device to treat keratoconus and low degrees of myopia, hyperopia, presbyopia and astigmatism.