Age-related Macular Degeneration (AMD) is a disease related to advancing age that affects a specific region of the retina, the macula. Two types of AMD may be diagnosed: dry or wet. For dry macular degeneration and some retinal diseases, there is a current remedy based on photobiomodulation. This treatment is known as Low-Level Light Therapy (LLLT). It uses photons – the infinitesimally small part of the luminous particles already used in the treatment of visual defects and some corneal diseases – which are also to treat retinal diseases.
What is photobiomodulation?
The mechanism of photobiomodulation (PBM) at the cellular level involves a predetermined frequency of light irradiating the mitochondria – the microscopic components of the cells designed to produce the energy necessary to carry out the cells’ own biological functions. This radiation activates mitochondrial respiration, thus promoting cell proliferation and cytoprotection, i.e., the cells’ ability to defend themselves.
How does photobiomodulation act inside the cells?
Photobiomodulation acts through the absorption of photons by photoreceptors in the target tissue. In this way, at the cellular level there are increases in energy production and in the supply of oxygen, nitric oxide and calcium which slow down the aging process, delay cell death and improve survival.
The use of photobiomodulation in medicine
Photobiomodulation is a pain-free, non-invasive process that does not produce heat, does not damage the tissue, and stimulates a cellular response. It is currently used in some areas of medicine and physiotherapy for the treatment of arthritis, for wound repair and to heal physical traumas, sprains and musculoskeletal and ligament damage. Its benefits are also increasingly being recognized for certain neurological diseases, for traumatic events such as stroke or global ischaemia, for degenerative diseases such as Alzheimer’s disease or Parkinson’s disease, and psychiatric disorders such as depression and anxiety.
Indications for Low-Level Light Therapy using photobiomodulation
Low-Level Light Therapy is indicated for the treatment of eye disease and eye damage, including cases of inflammation, oedema or deposition of drusen. It also contributes to improving wound healing following trauma or eye surgery, as well as increasing visual acuity and contrast sensitivity in patients with degenerative diseases such as dry age-related macular degeneration.
How is Low-Level Light Therapy performed?
The treatment performed at the Switzerland Eye Research Institute (SERI Lugano) uses a light capable of directing a quantity of calibrated energy onto the retina.
The entire procedure takes about ten minutes, does not require any anaesthesia or hospital stay: the patient can go home immediately after treatment. The patient is seated in front of the device, is entirely awake and does not feel any pain.
The treatment consists of four phases: a first and a third phase with the eyes open, lasting about 35 seconds each, with ocular exposure to the wavelengths of yellow pulsed light and near-infrared radiation (NIR); a second and a fourth phase with eyes closed, of 90 seconds each, with exposure to the wavelength of continuous red light. During the treatment and immediately afterwards, patients experience a dazzling sensation and a slight warming, which they report as being very pleasant.
What is the retina?
The retina is the innermost layer of the eyeball.
It is a delicate structure, in particular the peripheral part, and above all in myopic (short-sighted) patients. It can suffer degenerative phenomena that lead to thinning; this, in turn, can cause the retina itself to become separated – retinal detachment.
In particular conditions, holes, or even lacerations may form in the depth of the retina: the revealing symptom of this is usually that of seeing flashes of light or floating bodies (the so-called “floaters” or “flies”). However, the lesions are sometimes found during an eye examination even in the absence of symptoms.