Low-level laser therapy combined with scleral graft transplantation in the treatment of contracted socket: a clinical study.

OBJECTIVE: To analyse the efficacy of the therapeutic use of low-level laser therapy (LLLT) on the tissue repair process of allogeneic scleral grafts in patients with contracted sockets by analysing the speed of graft vascularisation and fornice depth of contraction percentage. METHODS: A retrospective chart review was performed from April 2015 to April 2021 including 39patients with socket contraction. Allogeneic scleral grafts were used to repair the sockets in all patients. They were randomly enrolled into two groups. The laser group included 18 patients treated with LLLT after the surgery, whereas the control group included 21 patients without LLLT after the surgery who healed naturally. The LLLT equipment used in the research had a wavelength of 650 nm, 10 mW power, and 3.8 J/cm2 dosimetry, and the procedure was performed once daily for 5 min over 7 days, beginning 1 week postoperatively. All patients were followed up over 6 months to examine the changes in the size of the area of the non-vascularised graft and upper and inferior fornice depth. RESULTS: The laser group presented a significantly increased speed of conjunctival vascularisation compared with the control group (P = 0.003). The fornice depth of contraction percentage was more apparent in the control group than that in the laser group (P = 0.000). CONCLUSION: LLLT accelerates conjunctival vascularisation, stimulates conjunctival incision healing within a short period, shortens the tissue repair process, reduces the local inflammatory response, and causes no significant shrinkage of the conjunctival sac.

Low-level laser therapy induces human umbilical vascular endothelial cell proliferation, migration and tube formation through activating the PI3K/Akt signaling pathway.

Low-level laser therapy (LLLT) has been recognized as a light therapy that may be used for tissue regeneration, inflammation reduction, and pain relief. We intended to evaluate the effects of LLLT on the proliferation, migration, and tube formation of HUVECs as well as their related mechanisms. HUVECs were exposed to laser irradiation under different laser parameters (irradiation dose, interval and power intensity) in order to choose the optimal parameters, which were determined by the increase in proliferation of HUVECs as follows: irradiation dose of 4.0 J/m2, interval time of 12 h and 6 times in total. The HUVEC proliferation, migration, and tube formation, and levels of angiogenesis-related genes (HIF-1α, eNOS and VEGFA) were examined following LLLT. As suggested by the obtained data, LLLT (1.0, 2.0 and 4.0 J/m2) increased the HUVEC proliferation, migration, and tube formation in dose-and time-dependent manner, accompanied with increases in the levels of HIF-1α, eNOS, and VEGFA. Furthermore, the regulatory mechanism regarding the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway was explored, phosphorylation levels of PI3K and Akt proteins were assessed by Western blot assay, which showed the enhancement of phosphorylation of PI3K, Akt, and mTOR by LLLT. The inhibitor for the PI3K/Akt axis was used to verify the involvement of PI3K/Akt signaling pathway. The obtained results suggested that the inhibition of the PI3K/Akt signaling pathway attenuated the effects of LLLT on proliferation, migration, and angiogenesis of HUVECs. In conclusion, LLLT promotes the proliferation, migration, and angiogenesis of HUVECs via activation of the PI3K/Akt signaling pathway.