Department of Ophthalmology, Stanford University School of Medicine, Stanford, California, USA.
Retina. 2011 Feb;31(2):380-8. doi: 10.1097/IAE.0b013e3181e76da6.
To evaluate the safety, selectivity, and healing of retinal lesions created using a continuous line scanning laser.
A 532-nm Nd:YAG laser (PASCAL) with retinal beam diameters of 40 μm and 66 μm was applied to 60 eyes of 30 Dutch-belted rabbits. Retinal exposure duration varied from 15 μs to 60 μs. Lesions were acutely assessed by ophthalmoscopy and fluorescein angiography. Retinal pigment epithelial (RPE) flatmounts were evaluated with live-dead fluorescent assay. Histological analysis was performed at 7 time points from 1 hour to 2 months.
The ratios of the threshold of rupture and of ophthalmoscopic visibility to fluorescein angiography visibility (measures of safety and selectivity) increased with decreasing duration and beam diameter. Fluorescein angiography and live-dead fluorescent assay yielded similar thresholds of RPE damage. Above the ophthalmoscopic visibility threshold, histology showed focal RPE damage and photoreceptor loss at 1 day, without inner retinal effects. By 1 week, photoreceptor and RPE continuity was restored. By 1 month, photoreceptors appeared normal.
: Retinal therapy with a fast scanning continuous laser achieves selective targeting of the RPE and, at higher power, of the photoreceptors without permanent scarring or inner retinal damage. Continuous scanning laser can treat large retinal areas within standard eye fixation time.
评估使用连续线扫描激光治疗视网膜病变的安全性、选择性和愈合情况。
使用 532nmNd:YAG 激光（PASCAL），视网膜光束直径分别为 40μm 和 66μm，对 30 只荷兰垂耳兔的 60 只眼进行治疗。视网膜暴露时间从 15μs 到 60μs 不等。通过检眼镜和荧光素血管造影术对急性损伤进行评估。使用活死荧光检测法对视网膜色素上皮（RPE）平片进行评估。在 1 小时至 2 个月的 7 个时间点进行组织学分析。
破裂阈值和眼底可见性与荧光素血管造影可见性的比值（安全性和选择性的衡量标准）随着持续时间和光束直径的减小而增加。荧光素血管造影和活死荧光检测得出的 RPE 损伤阈值相似。在眼底可见性阈值以上，组织学显示在第 1 天出现局灶性 RPE 损伤和光感受器丧失，而无内层视网膜影响。在第 1 周，光感受器和 RPE 的连续性得到恢复。在第 1 个月，光感受器看起来正常。
使用快速扫描连续激光进行视网膜治疗，可以选择性地靶向 RPE，并在更高的功率下靶向光感受器，而不会造成永久性瘢痕或内层视网膜损伤。连续扫描激光可以在标准眼固视时间内治疗大的视网膜区域。
