Table 3:
Laser versus non-coherent comparison trials 1982–1996
| Study | Study type | Parameters (non-laser) | Parameters (laser) | Results |
|---|---|---|---|---|
| Haina (1982) [72] | Rat | 630nm; 4 J/cm2 | 633 nm; 90 mW; 50 mW/cm2; 0.5, 1.5, 4, 10 or 20 J | Both He-Ne laser and non-coherent red light with similar parameters increased granulation tissue in wounds significantly, but He-Ne laser had a notably more pronounced effect. |
| Muldiyarov (1983) [73] | Rat | “Ordinary incandescent lamp with a simple red filter” | 633 nm; 1 – 1.5 mW/cm2; 120 sec | He-Ne laser decreased synovitis, while ordinary red light had no effect. |
| Berki (1988) [74] | In vitro, lymphoid cels and macrophages | 633 nm; 5.6 mW; 0.14 – 14.0 J/cm2 | 633 nm; 5.6 mW; 1 J; 0.14 – 28.0 J/cm2; 180 sec | Laser light appeared to kill cells on higher doses, while non-coherent filtered light from xenon arc lamp with similar parameters didn’t have this effect in this study. |
| Rosner (1993) [75] | Rat | 904 nm; 10 or 15 mW; 2 min | 633 nm; 3.5–10.5 mW; 1–10 min; many experimental groups with different dose parameters | He-Ne laser showed beneficial effects on the action potential amplitude with several of the studied parameters, although there were also multiple ineffective parameters. The non-coherent light did not show beneficial effects with the studied parameters. There were also some groups treated with He-Ne laser or non-coherent light that showed lower action potential amplitude than the nonirradiated controls |
| Laakso (1994) [76] | Human, RCT, double-blind | 660 nm; 9.5 mW; 1 or 5 J/cm2 | 670 nm; 10 mW; 1 or 5 J/cm2 | It was reported that (only) coherent light was able to potentiate the plasma levels of ACTH and β-endorphin. However, while there were some statistically significant changes in individual timepoints, the changes didn’t follow any clear patterns and the magnitude of changes was relatively low to make clear clinical interpretations. |
| Antipa (1996) [77] | Human | 750 nm; 9 mW; 1.08 J/cm2; 0.50 cm2; 60 s | 720 nm; 3 mW; 1.08 J/cm2; 0.50 cm2; 180 s | Laser light had better efficacy (66.7%) than noncoherent light (52%) and placebo light (36.4%). However, the difference between laser and noncoherent light was not statistically significant |