Low-Level Light Therapy of the Eye and Brain

Introduction

Low-Level Light Therapy (LLLT) is a technology that uses light in the wavelength range of 600–1070 nm to stimulate biological processes at the cellular level without causing heat or tissue damage. This research focuses on the effects of LLLT on the eyes and brain , which are organs that are sensitive to light and have the potential to respond to light stimulation at the molecular level. This study aimed to evaluate the biological mechanisms, efficacy, and safety of LLLT in restoring neuronal function and treating central nervous system and visual disorders.

Method of study

This research is a systematic literature review. It compiles data from clinical research and laboratory experiments related to the use of LLLT on the eyes and brain in humans and experimental animals.

The scope of the study is divided into two main parts:

1. Ocular LLLT (Eye Therapy): It uses light in the range of 670 nanometers to stimulate the retina and reduce the degeneration of photoreceptor cells.

2. Transcranial LLLT (Transcranial Neurotherapy): Near-infrared light (810–1070 nm) is used to stimulate the brain in patients with traumatic brain injury, stroke, and dementia.

Study results

🔹 Effects on the eyes

• 670 nm light irradiation increases mitochondrial function in retinal cells.

• Reduces oxidative stress and reduces the death rate of photoreceptor cells.

• Restoration of vision was observed in experimental animals with retinal degeneration.

🔹 Effects on the brain

• Near-infrared light (810–1070 nm) can partially penetrate the skull and stimulate the activity of neurons in the cerebral cortex.

• Increase blood flow and oxygen to the brain

• It has been reported to aid recovery in patients after traumatic brain injury and stroke.

• Some studies have found that LLLT can relieve depression and improve concentration.

Mechanism of action

Low-energy light stimulation works through the following key mechanisms:

• Stimulation of the enzyme Cytochrome c oxidase in mitochondria → Increases energy production (ATP)

• Reduces inflammation (anti-inflammatory effect) by reducing the production of cytokines.

• Stimulates the formation of new nerve cells (neurogenesis) and the formation of new blood vessels (angiogenesis).

• Prevents neuronal cell death (anti-apoptotic effect)

Summary of results

From evidence in many research studies, it was found that

• LLLT is a highly potential technique for treating eye and brain disorders.

• It is very safe if used in the right amount of energy.

• It can be used in conjunction with other treatment methods without causing serious side effects.

However, further clinical studies are needed to determine the optimal energy dose (dosimetry) and treatment frequency that produce the best results in humans.

References

Hamblin, M.R. (2016). Low-level light therapy of the eye and brain. Eye and Brain, 8, 23–37. https://doi.org/10.2147/EB.S101472