*Cornea Service, Massachusetts Eye and Ear Infirmary, Boston, MA; †Department of Ophthalmology, Harvard Medical School, Boston, MA; ‡Ophthalmic Pathology, Massachusetts Eye and Ear Infirmary, Boston, MA; and §Schepens Eye Research Institute, Boston, MA.
Cornea. 2014 Feb;33(2):184-90. doi: 10.1097/ICO.0000000000000029.
The aim of this study was to assess the possibility of light damage to the retina by a surgical microscope during implantation of a Boston Keratoprosthesis (B-KPro) in rabbits.
The retinal irradiance from a Zeiss OPMI Lumera S7 operating microscope was measured at the working distance (16.5 cm). Light transmittance through an isolated B-KPro was measured. A B-KPro was implanted into 1 eye of 12 rabbits with the optic covered during the procedure. The operated eyes were then continuously exposed to a fixed light intensity under the microscope for 1 hour. Fluorescein angiography was carried out on days 2 and 9 postsurgery, after which the animals were euthanized. Further, we compared the potential of these retinal exposures to well-accepted light safety guidelines applicable to humans.
Light transmittance of B-KPro revealed a blockage of short wavelengths (<390 nm) and of long wavelengths (1660-1750 nm) of light. In addition, the surgical microscope filtered a part of the blue, ultraviolet, and infrared wavelengths. Neither fluorescein angiography nor a histological examination showed any morphological retinal changes in our rabbits. Moreover, the retinal exposures were well below the safety limits.
Modern surgical microscopes have filters incorporated in them that block the most damaging wavelengths of light. The B-KPro is made of 100% poly(methyl methacrylate), which makes it in itself a blocker of short wavelengths of light. No damage could be demonstrated in the animal study, and the retinal exposures were well below the safety limits. Together, these results suggest that light exposures during B-KPro surgery present a low risk of photochemical damage to the retina.
本研究旨在评估在兔眼行 Boston 角膜镜（B-KPro）植入术时手术显微镜对视网膜造成光损伤的可能性。
在工作距离（16.5 厘米）处测量 Zeiss OPMI Lumera S7 手术显微镜的视网膜辐照度。测量隔离 B-KPro 的光透过率。将 B-KPro 植入 12 只兔子的 1 只眼，手术过程中遮盖光学镜。然后，将手术眼在显微镜下持续暴露于固定光强 1 小时。术后第 2 天和第 9 天进行荧光素血管造影，之后处死动物。此外，我们比较了这些视网膜暴露的潜在风险与适用于人类的公认的光安全指南。
B-KPro 的光透过率显示短波长（<390nm）和长波长（1660-1750nm）的光被阻断。此外，手术显微镜过滤了部分蓝光、紫外线和红外线。我们的兔子在荧光素血管造影或组织学检查中均未显示任何形态学视网膜改变。此外，视网膜暴露量远低于安全限值。
现代手术显微镜内置有滤光片，可以阻挡最具损伤性的光波。B-KPro 由 100%聚甲基丙烯酸甲酯制成，本身就是短波长光的阻挡物。动物研究未发现任何损伤，视网膜暴露量远低于安全限值。这些结果表明，B-KPro 手术过程中的光暴露对视神经的光化学损伤风险较低。
