Institute of Acoustics, School of Physics Science and Engineering, Tongji University, Shanghai, China.
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
Transl Vis Sci Technol. 2020 Dec 9;9(13):16. doi: 10.1167/tvst.9.13.16. eCollection 2020 Dec.
Corneal neovascularization (CNV) is the invasion of new blood vessels into the avascular cornea, leading to reduced corneal transparency and visual acuity, impaired vision, and even blindness. Current treatment options for CNV are limited. We developed a novel treatment method, termed photo-mediated ultrasound therapy (PUT), that combines laser and ultrasound, and we tested its feasibility for treating CNV in a rabbit model.
A suture-induced CNV model was established in New Zealand White rabbits, which were randomly divided into two groups: PUT and control. For the PUT group, the applied light fluence at the corneal surface was estimated to be 27 mJ/cm at 1064-nm wavelength with a pulse duration of 5 ns, and the ultrasound pressure applied on the cornea was 0.43 MPa at 0.5 MHz. The control group received no treatment. Red-free photography and fluorescein angiography were utilized to evaluate the efficiency of PUT. Safety was evaluated by histology and immunohistochemistry. For comparison with the PUT safety results, conventional laser photocoagulation (LP) treatment was performed with standard clinical parameters: 532-nm continuous-wave (CW) laser with 0.1-second pulse duration, 450-mW power, and 75-µm spot size.
In the PUT group, only 1.8% ± 0.8% of the CNV remained 30 days after treatment. In contrast, 71.4% ± 7.2% of the CNV remained in the control group after 30 days. Safety evaluations showed that PUT did not cause any damage to the surrounding tissue.
These results demonstrate that PUT is capable of removing CNV safely and effectively in this rabbit model.
PUT can remove CNV safely and effectively.
角膜新生血管（CNV）是指新血管侵入无血管的角膜，导致角膜透明度和视力下降、视力受损，甚至失明。目前治疗 CNV 的选择有限。我们开发了一种新的治疗方法，称为光介导超声治疗（PUT），它结合了激光和超声，并在兔模型中测试了其治疗 CNV 的可行性。
在新西兰白兔中建立缝线诱导的 CNV 模型，将其随机分为两组：PUT 组和对照组。对于 PUT 组，角膜表面的应用光剂量估计为 1064nm 波长 5ns 脉冲时为 27mJ/cm2，施加在角膜上的超声压力为 0.5MHz 时为 0.43MPa。对照组未接受治疗。用眼底照相和荧光素血管造影评估 PUT 的疗效。通过组织学和免疫组织化学评估安全性。为了与 PUT 安全性结果进行比较，采用标准临床参数进行常规激光光凝（LP）治疗：532nm 连续波（CW）激光，脉冲持续时间 0.1 秒，功率 450mW，光斑尺寸 75µm。
在 PUT 组中，治疗 30 天后只有 1.8%±0.8%的 CNV 残留。相比之下，对照组在 30 天后仍有 71.4%±7.2%的 CNV 残留。安全性评估表明，PUT 不会对周围组织造成任何损伤。
这些结果表明，在本兔模型中，PUT 能够安全有效地去除 CNV。
Yvonne
