The Institute of Optics, University of Rochester, Rochester, New York, United States Center for Visual Science, University of Rochester, Rochester, New York, United States.
The Institute of Optics, University of Rochester, Rochester, New York, United States.
Invest Ophthalmol Vis Sci. 2014 Jul 1;55(7):4603-12. doi: 10.1167/iovs.14-14373.
To determine the efficacy of intratissue refractive index shaping (IRIS) using 400-nm femtosecond laser pulses (blue light) for writing refractive structures directly into live cat corneas in vivo, and to assess the longevity of these structures in the eyes of living cats.
Four eyes from two adult cats underwent Blue-IRIS. Light at 400 nm with 100-femtosecond (fs) pulses were tightly focused into the corneal stroma of each eye at an 80-MHz repetition rate. These pulses locally increased the refractive index of the corneal stroma via an endogenous, two-photon absorption process and were used to inscribe three-layered, gradient index patterns into the cat corneas. The optical effects of the patterns were then tracked using optical coherence tomography (OCT) and Shack-Hartmann wavefront sensing.
Blue-IRIS patterns locally changed ocular cylinder by -1.4 ± 0.3 diopters (D), defocus by -2.0 ± 0.5 D, and higher-order root mean square (HORMS) by 0.31 ± 0.04 μm at 1 month post-IRIS, without significant changes in corneal thickness or curvature. Refractive changes were maintained for the duration they were tracked, 12 months post-IRIS in one eye, and just more than 3 months in the remaining three eyes.
Blue-IRIS can be used to inscribe refractive structures into live cat cornea in vivo that are stable for at least 12 months, and are not associated with significant alterations in corneal thicknesses or radii of curvature. This result is a critical step toward establishing Blue-IRIS as a promising technique for noninvasive vision correction.
使用 400nm 飞秒激光脉冲（蓝光）在活体猫角膜内直接写入折射结构，确定组织内折射率成形（IRIS）的疗效，评估这些结构在活体猫眼中的耐久性。
两只成年猫的四只眼接受了 Blue-IRIS 治疗。在 80MHz 重复率下，每只眼的角膜基质都用 100 飞秒（fs）脉冲的 400nm 光紧密聚焦。这些脉冲通过内源性双光子吸收过程局部增加角膜基质的折射率，并用于在猫角膜上刻蚀三层梯度折射率图案。然后使用光学相干断层扫描（OCT）和 Shack-Hartmann 波前感应跟踪图案的光学效果。
Blue-IRIS 图案在 1 个月后局部改变眼柱-1.4±0.3 屈光度（D）、散焦-2.0±0.5D 和高阶均方根（HORMS）0.31±0.04μm，而角膜厚度或曲率无明显变化。在 Blue-IRIS 治疗后 12 个月的一只眼和 3 个多月的其余三只眼中，折射变化持续存在，直到被跟踪。
Blue-IRIS 可用于在活体猫角膜内刻蚀折射结构，至少在 12 个月内稳定，且不伴角膜厚度或曲率半径的明显改变。这一结果是将 Blue-IRIS 确立为非侵入性视力矫正有前途技术的关键步骤。
