Heating retinal tissue and retinal pigment epithelium (RPE) causes a range of beneficial effects on unhealthy tissues, including elevated therapeutic heat shock protein production 1–7, downregulation of vascular endothelial growth factor (VEGF) 8, thinning of Bruch’s membrane 9, reduction of drusens 10, resolution of subretinal fluid 11–13, prevention of apoptosis 14,15 and activation of autophagy 15.

These heat-activated mechanisms pursue to reduce oxidative stress, prevent the aggregation of proteins, improve the transport of nutrients, and enhance RPEs cytoprotective mechanisms, i.e., they stimulate the natural, biological healing response of RPE 16,17. Laser-induced heat shock activates mechanisms in the RPE that could retard or even reverse the progression of major retinal diseases.

Non-damaging laser treatments aim to induce regenerative effects of temperature elevation without damaging retinal tissues. The beneficial effect of non-damaging laser treatments has been demonstrated in several clinical trials for common macular diseases such as diabetic macular edema 11,18–20, proliferative diabetic retinopathy  11,18–20, macular edema due to branch retinal vein occlusion 11,20, age-related macular degeneration (AMD) 10,21–23. central serous chorioretinopathy (CSC) 20,24–30. However, the therapeutic temperature range of the treatment is narrow, and the laser-induced temperature elevation varies between patients due to physiological differences in eye opacity, blood circulation and level of pigmentation 31,32. Personally optimized treatments would require patient-specific temperature and safety controls – a feature that Maculaser now offers for ophthalmologists.

References

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