Wang Jenny, Chung Jae Lim, Schuele Georg, Vankov Alexander, Dalal Roopa, Wiltberger Michael, Palanker Daniel
Stanford University, Department of Applied Physics, 452 Lomita Mall, Stanford, California 94305, United States.
Stanford University, Department of Ophthalmology, 452 Lomita Mall, Stanford, California 94305, United StatescKonyang University, Kim's Eye Hospital, Department of Ophthalmology, 136 Yeongshin-ro, Youngdeungpo-gu, Seoul 150-034, Republic of Korea.
J Biomed Opt. 2015 Sep;20(9):095005. doi: 10.1117/1.JBO.20.9.095005.
A recent study showed that 355-nm nanosecond lasers cut cornea with similar precision to infrared femtosecond lasers. However, use of ultraviolet wavelength requires precise assessment of ocular safety to determine the range of possible ophthalmic applications. In this study, the 355-nm nanosecond laser was evaluated for corneal and iris damage in rabbit, porcine, and human donor eyes as determined by minimum visible lesion (MVL) observation, live/dead staining of the endothelium, and apoptosis assay. Single-pulse damage to the iris was evaluated on porcine eyes using live/dead staining. In live rabbits, the cumulative median effective dose (ED50) for corneal damage was 231 J/cm2, as seen by lesion observation. Appearance of endothelial damage in live/dead staining or apoptosis occurred at higher radiant exposure of 287 J/cm2. On enucleated rabbit and porcine corneas, ED50 was 87 and 52 J/cm2, respectively, by MVL, and 241 and 160 J/cm2 for endothelial damage. In human eyes, ED50 for MVL was 110 J/cm2 and endothelial damage at 453 J/cm2. Single-pulse iris damage occurred at ED 50 of 208 mJ/cm2. These values determine the energy permitted for surgical patterns and can guide development of ophthalmic laser systems. Lower damage threshold in corneas of enucleated eyes versus live rabbits is noted for future safety evaluation.
最近的一项研究表明，355纳米纳秒激光切割角膜的精度与红外飞秒激光相似。然而，使用紫外波长需要精确评估眼部安全性，以确定可能的眼科应用范围。在本研究中，通过最小可见损伤（MVL）观察、内皮细胞活/死染色和凋亡检测，评估了355纳米纳秒激光对兔、猪和人类供体眼的角膜和虹膜损伤。使用活/死染色法在猪眼上评估单脉冲对虹膜的损伤。在活体兔中，通过损伤观察发现角膜损伤的累积中位有效剂量（ED50）为231 J/cm2。在287 J/cm2的较高辐射暴露下，活/死染色或凋亡中出现内皮损伤。在摘除的兔和猪角膜上，通过MVL测定的ED50分别为87和52 J/cm2，内皮损伤的ED50分别为241和160 J/cm2。在人眼中，MVL的ED50为110 J/cm2，453 J/cm2时出现内皮损伤。单脉冲虹膜损伤发生在ED50为208 mJ/cm2时。这些值确定了手术模式允许的能量，并可指导眼科激光系统的开发。摘除眼球的角膜与活体兔相比损伤阈值较低，这一点在未来的安全性评估中应予以关注。
