PURPOSE Subthreshold micropulse laser irradiation has been used for the treatment of retinal edema; however, there are few reports about the mechanism of its therapeutic effect. In this study, we compared threshold short pulse and subthreshold micropulse laser irradiation in mice and investigated their mechanism. METHODS Nine to 12-week-old male C57BL/6J mice were used in this study. After general anesthesia, threshold short pulse or subthreshold micropulse laser irradiation was performed on the right eye using IQ577. Enucleation was performed 24 h after the laser irradiation, and histological and gene expression analyses were carried out. RESULTS Coagulation spots and atrophy of the retinal pigment epithelium were observed after threshold short pulse laser irradiation but not after subthreshold micropulse laser irradiation. Twenty-four hours after laser, aquaporin (AQP) 1, 2, 7, and 11 levels were significantly elevated by 1.7- to 3-fold in the threshold short pulse laser group compared with non-treated control group. AQP 3 was increased significantly and prominently by 100-fold. VEGF-A and VEGFR2 were upregulated 1.5- and 2.3-fold, respectively. In the subthreshold micropulse laser group, AQP 3 was increased by 6-fold compared with the non-treated control group. Angiopoietin-1 and the adrenomedullin (AM) receptor CLR were decreased by 0.6-fold and 0.5-fold, respectively. CONCLUSION Threshold short pulse laser irradiation caused retinal damage and prominent changes in the expression of various genes. Contrarily, subthreshold micropulse laser irradiation did not induce retinal damage; it upregulated AQP 3, which might have improved retinal edema by drainage of subretinal fluid.

中文翻译：

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亚阈值微脉冲激光照射视网膜的治疗机制研究。

目的亚阈值微脉冲激光照射已被用于治疗视网膜水肿。然而，关于其治疗作用机理的报道很少。在这项研究中，我们比较了小鼠阈值短脉冲和亚阈值微脉冲激光辐照，并研究了它们的作用机理。方法采用9至12周龄的雄性C57BL / 6J小鼠。全身麻醉后，使用IQ577对右眼进行阈值短脉冲或亚阈值微脉冲激光照射。激光照射后24小时进行去核，并进行组织学和基因表达分析。结果阈值短脉冲激光照射后观察到视网膜色素上皮的凝结斑点和萎缩，而亚阈值微脉冲激光照射后未观察到。激光治疗后二十四小时，阈值短脉冲激光治疗组与未治疗的对照组相比，水通道蛋白（AQP）1、2、7和11的水平显着提高了1.7到3倍。AQP 3显着增加了100倍。VEGF-A和VEGFR2分别上调了1.5倍和2.3倍。在亚阈值微脉冲激光组中，与未治疗的对照组相比，AQP 3增加了6倍。血管生成素-1和肾上腺髓质素（AM）受体CLR分别降低了0.6倍和0.5倍。结论阈值短脉冲激光照射引起视网膜损伤和各种基因表达的显着变化。相反，亚阈值微脉冲激光辐照并未引起视网膜损伤；它上调了AQP 3，