Skin related conditions
1. Acne vulgaris
Sunlight was previously known to improve acne conditions in many hypersensitive individuals which were thought to be due to antibacterial and other effects of the UV spectrum. But it is prevented for long term usage due to potential risks of skin damage and cancer.
Blue and red light therapy seems to be the most effective treatment for acne by reducing the number of spots by three quarters. Some acne does clear up significantly when exposed to UV light, but this is unsuitable as a long-term remedy because of the increased risk of skin cancer. A mixture of blue and red light wavelengths produced by a light box has been shown to be very effective in reducing the number of visible spots on affected areas.
Home use light boxes usually work well and are effective for people with long-term acne. They are also likely to be cheaper than dermatologist office light treatments, and can be repeated over several years for negligible cost, as opposed to once weekly or fortnightly.
Psoriasis involves the excessively fast turnover of skin layers. Application of UV radiation to the skin slows down this rapid growth of skin cells, resulting in marked improvements of the condition. Light therapy for skin conditions like psoriasis or even eczema use UVA (320-400nm waveband) or UVB (280-320nm waveband) light waves. PUVA treatment (UVA combined with orally taken psoralen) is often times used for the treatment of psoriasis. Narrow Band UVB is the 310nm wave length and is given as a light therapy treatment rather than full spectrum UVB.
3. Skin aging
Red light at 660nm induces energy levels of cells by activation of ATP in skin cells increasing the rate of production of collagen for a few days, giving a lifting effect. No permanent improvement of skin aging has been demonstrated, but completion of the healing of skin damage does seem to proceed faster.
4. Wound healing and neuropathy
Monochromic infrared light at 890nm has shown effective results through clinical studies to help restore sensation and pain reduction in patients with neuropathy and to improve circulation which ultimately increases the healing rate of non-healing ulcers. This works by the release of Nitric Oxide into the bloodstream by infrared light which aids in increasing local circulation and improvement of blood flow.
5. Premenstrual Dysphoric Disorder (PMDD)
Women's menstrual cycle is regulated by light and darkness as well as by hormones, and circumstances that upset the body clock, such as changing regular sleeping and waking patterns, jet lag, and shift work, may upset their menstrual cycle. Each month, women report symptoms such as fluid retention, weight gain, bloating, breast tenderness, poor sleep, irritability, blue moods, and other symptoms in the 3 to 5 days before their periods start, and for the first day or two of menstruation. The combination of emotional and physical symptoms is referred to as Premenstrual Dysphoric Disorder (PMDD) or Premenstrual Syndrome. Light therapy is able to promote strong daily rhythms, and can in this way assist in regulating the menstrual cycle.
Mood and Sleep related
1. Seasonal Affective Disorder (SAD)
SAD is a type of winter depression that affects approximately half a million people every winter between the months of September and April, in particular December, January and February. This disorder is caused by a biochemical imbalance in the hypothalamus due to shortened daylight hours and the lack of sunlight in the winter. For many, this is a seriously disabling neurological and psychological problem, preventing individuals from functioning normally without continuous medical treatment. For others, this condition is a mild but debilitating condition causing discomfort which is not considered as severe suffering.
Light therapy was first used to treat those with Seasonal Affective Disorder, or seasonal depression. In these cases, lack of light in the winter months, particularly in the north, contributed to depressive symptoms in many individuals. Full sunlight is preferred for SAD whereas other treatments are based upon infrared light exposure and a number of product options for the emission of this light are available which include light boxes. These products utilise high and intense artificial illumination that are effective for this disorder providing 10,000 lux or more directed angularly at the user's eyes simultaneously filtering out any harmful UV radiation. Modern light boxes are beneficial as they do not emit UV radiation thus reducing damaging effects. There are two major modes of light therapy for SAD, bright light therapy and dawn stimulation (although this will not treat the main symptoms of SAD, such as depression).
2. Non-seasonal depression
It has been proven that the use of light therapy for patients suffering from depression is as effective as it is for those suffering from SAD. A recent trial concluded that the benefits of light therapy were felt after only one week, whereas many medications took up to 8 weeks for the benefits to be felt. Also, using light therapy together with medication has superior results to either treatment on its own.
3. Delayed sleep phase syndrome
The timing of light exposure is a crucial step when treating this syndrome, light must be provided as soon after arising as possible to achieve any effect at all. Some users have responded with lights that turn on shortly before waking (dawn stimulation).
4. Postnatal depression
Many women suffer from depression during and after their pregnancies, maybe as many as 1 in 10. Studies are being conducted to show whether light therapy is useful in treating these depressed episodes, and early indications show that it is.