|
Other common
name(s): light boxes, bright light treatment, ultraviolet
light therapy, UV, ultraviolet blood irradiation, colored light
therapy, chromatotherapy
Scientific/medical
name(s): phototherapy, ultraviolet phototherapy,
photopheresis, extracorporeal photochemotherapy, photodynamic therapy
Description
Light therapy involves the use of visible light or nonvisible
ultraviolet light to treat a variety of conditions.
Overview
Some forms of light therapy, such as light boxes, ultraviolet
(UV) light therapy, and photodynamic therapy, are used in conventional
medicine. However, available scientific evidence does not support
claims that alternative uses of light or color therapy are effective in
treating cancer or curing other illnesses.
How is it promoted for use?
Conventional medical professionals may prescribe the use of
light boxes, photopheresis, photodynamic therapy, or UV light therapy
for the treatment of conditions for which studies have shown the
methods to be safe and effective. For example, the use of light boxes
to mimic sunlight is a proven medical treatment for seasonal affective
disorder (SAD). Ultraviolet (UV) light therapy is used to treat
psoriasis and cutaneous T-cell lymphoma (a type of cancer that first
appears on the skin). Photodynamic therapy is helpful in treating
certain cancers or precancers of the skin, esophagus, and lungs, and is
now being tested against other types of cancer. A special form of UV
blood irradiation, called photopheresis or extracorporeal
photochemotherapy, also inhibits T-cell lymphoma and may be helpful for
other conditions.
However, several types of light therapy are also promoted for
alternative uses. These include light boxes (or special bright lamps
and visors), UV light or sun lamp therapy, most types of colored light
therapy (chromatotherapy), and UV blood irradiation.
Colored light therapy: Supporters of colored light therapy
(also called chromatotherapy) claim that colored light relieves a
number of conditions, including sleep disorders, shoulder pain,
diabetes, impotence, and allergies. Practitioners of one system of
chromatotherapy believe that shining colored lights on the body harms
cancer cells.
Light box therapy: Light box therapy is also sometimes called
bright light therapy and can employ light boxes, bright lamps, or light
visors. Proponents claim it relieves high blood pressure, insomnia,
premenstrual syndrome, migraine headaches, carbohydrate cravings,
hyperactivity in children, and that it improves sexual functioning.
UV light: Proponents of UV light therapy, which is sometimes
marketed as sun lamps, claim that it neutralizes toxins in the body and
cures or helps immune system disorders, bacterial infections, AIDS,
colds, bug bites, and cancer.
UV blood irradiation: Proponents of UV blood irradiation claim
that UV light exposure kills germs such as viruses, bacteria, and fungi
inside the body and that it neutralizes toxins in the blood. Some claim
that even a small amount of UV-treated blood can reenter the
circulatory system of the patient and stimulate the immune system to
increase attacks against invaders, including cancer cells.
What does it involve?
Colored light therapy involves the use of colored lights such
as blue, red, and violet lights that the practitioner shines directly
on the patient. In some cases, the patient purchases the device and
uses it at home. Sometimes the lights flash in patterns.
One type of colored light therapy is used in conventional
medicine for newborns who have a buildup of a waste product called
bilirubin in the blood. The infant’s skin is exposed to a
special blue light, usually for several days. This helps the bilirubin
to break down into a substance that is easier for the baby to excrete.
Light boxes contain lights that simulate the wavelengths of
sunlight. Patients undergoing this kind of therapy sit in front of the
light box or special bright lamp for a prescribed amount of time each
day. The person may read or do other tasks during the light exposure,
but must sit close enough to the light to receive its full effect. The
amount of time required will vary according to the person and the
strength of light being used. For most people with SAD, light treatment
is used early in the morning from thirty minutes to two hours each day.
A brighter light may require less time exposure.
In ultraviolet light therapy, the eyes and unaffected skin are
protected while the patient is exposed to UV light for a prescribed
length of time. Conventional treatment for psoriasis may involve the
use of UV light and drugs that make one’s skin sensitive to
the light. A new type of UV light, called narrow-band UV light, is also
being used now and may be more effective.
Ultraviolet blood irradiation is called photopheresis or
extracorporeal photochemotherapy in conventional medicine and is mainly
used to inhibit T-cell lymphoma. It may also be helpful for other
conditions. During this procedure, blood is removed from the patient
and separated into different types of cells. About a pint of blood,
mostly white blood cells, is treated with a special drug to make it
make it more sensitive to light. It is then treated with UV light, and
the blood is infused back into the patient. This procedure is
considered a form of immunotherapy and takes from three to five hours.
In the alternative treatment setting, a small tube of blood is removed,
treated with UV rays, and infused back into the patient.
Photodynamic therapy is used in conventional medicine for
certain types of cancer. The patient is given a drug to make cancer
cells more sensitive to light. The tumor area is then exposed to laser
or another type of light.
What is the history behind it?
Interest in the relationship between light and health dates
back centuries. All forms of light therapy now in use started during
the 20th century. The first reports of ultraviolet blood irradiation
date back to the 1930s.
What is the evidence?
Available scientific evidence does not support claims that
light box therapy can cure cancer; however, it does have some medically
accepted uses. Light box therapy has been shown to be effective in
treating seasonal affective disorder (SAD), a type of depression caused
by insufficient exposure to bright light. Some researchers are testing
light therapy to see if it helps other types of depression. Early
findings suggest it may be helpful given alone or with medicines. It
may also be helpful for shift workers and those traveling to different
time zones in helping to reset their internal clocks.
Ultraviolet light therapy (phototherapy) is commonly used to
treat psoriasis. There is also evidence that UV light therapy inhibits
the growth of cutaneous T-cell lymphoma. Researchers have found that it
has resulted in long-term remission and cure among many patients in the
early stage of the disease and prolonged survival even in patients
treated later in disease. Early studies suggest that it may also be
helpful for people with atopic dermatitis (an allergic skin condition)
and vitiligo (uneven pigment in the skin). However, available
scientific evidence does not support other health claims for UV light
therapy.
Colored light therapy has been advocated since the early
twentieth century for nearly every imaginable purpose. At least one
maker of spectro-chrome (color) therapy devices has been prosecuted for
making false claims. However, blue light has been used for years to
treat newborns with high bilirubin levels and has proven to be very
effective. The light helps to break down the bilirubin into a form that
is easier to excrete from the body. At this time, available scientific
evidence does not support claims that any other type of colored light
therapy is effective in treating cancer or other illnesses.
Ultraviolet blood irradiation treatment is approved by the
U.S. Food and Drug Administration (FDA) for treating T-cell lymphoma
involving the skin. Photopheresis is sometimes used conventionally when
organ transplant rejection or graft-versus-host disease (a complication
related to bone marrow or stem cell transplants) does not respond to
usual conventional treatments. Some clinical trial results look
promising for the treatment of immune system diseases such as multiple
sclerosis, systemic sclerosis, rheumatoid arthritis, lupus, and type 1
diabetes. Available scientific evidence does not support claims for
alternative uses of UV blood irradiation.
Are there any possible problems or
complications?
Light therapy that involves only visible light (light boxes
and colored light therapy) is generally considered safe. Light therapy
for depressive disorders can push a few people into a hyperactive state
called mania, which may pose some risk. Light or light box therapy
should not be confused with a tanning bed or sun lamp, which is not a
medical therapy and is dangerous because of high levels of ultraviolet
radiation. Any treatment that exposes the patient to ultraviolet
radiation presents some danger, including premature aging of the skin
and an increased risk for skin cancer later in life.
Patients may be at higher risk of sunburn the day of UV
treatment and are advised to avoid natural sunlight. Those having
long-term UV light treatment for psoriasis or other conditions may have
a greater-than-average number of cataracts and skin-related problems,
including cancer.
Relying on unproven uses of light therapy while delaying or
avoiding conventional therapy for cancer can have serious consequences.
Additional Resources
More information from your American Cancer
Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be found on
our Web site (www.cancer.org)
or ordered from our toll-free number (1-800-ACS-2345).
References
American Cancer Society. Questionable methods of cancer
management: electronic devices. CA
Cancer J Clin. 1994;44:115-127.
Boivin DB, James FO. Light treatment and circadian adaptation
to shift work. Ind Health.
2005;43:34-48.
Cassileth B. The
Alternative Medicine Handbook: The Complete Reference Guide to
Alternative and Complementary Therapies. New York, NY:
W.W. Norton; 1998.
Gambichler T, Breuckmann F, Boms S, Altmeyer P, Kreuter A.
Narrowband UVB phototherapy in skin conditions beyond psoriasis. J Am Acad Dermatol.
2005;52:660-670.
Golden, RN, Gaynes BN, Ekstrom RD, Hamer Rm, Jacobsen FM,
Suppes T, Wisner KL, Nemeroff CB. The efficacy of light therapy in the
treatment of mood disorders: a review and meta-analysis of the
evidence. Am J
Psychiatry. 2005;162:656-662.
Herrmann JJ, Roenigk HH Jr, Hönigsmann H. Ultraviolet
radiation for treatment of cutaneous T-cell lymphoma. Hematol Oncol Clin North Am.
1995;9:1077-1088.
Ilhan O, Arat M, Arslan O, et al. Extracorporeal
photoimmunotherapy for the treatment of steroid refractory progressive
chronic graft-versus-host disease. Transfus
Apher Sci. 2004;30:185-187.
Knobler R, Girardi M. Extracorporeal photochemoimmunotherapy
in cutaneous T cell lymphomas. Ann
N Y Acad Sci. 2001;941:123-138.
Lurie SJ, Gawinski B, Pierce D, Rousseau SJ. Seasonal
affective disorder. Am
Fam Physician. 2006;74:1521-1524.
Marques MB. Tuncer HH. Photopheresis in solid organ transplant
rejection. J Clin Apher.
2006; 21:72-77.
McGinnis KS, Shapiro M, Vittorio CC, Rook AH, Junkins-Hopkins
JM. Psoralen plus long-wave UV-A (PUVA) and bexarotene therapy: An
effective and synergistic combined adjunct to therapy for patients with
advanced cutaneous T-cell lymphoma. Arch Dermatol.
2003;139:771-775.
Photodynamic therapy for cancer: questions and answers.
National Cancer Institute Web site. Accessed at
http://www.cancer.gov/cancertopics/factsheet/Therapy/photodynamic on
May 30, 2008.
PUVA. National Psoriasis Foundation Web site. Accessed at
http://www.psoriasis.org/treatment/psoriasis/phototherapy/puva.php on
June 2, 2008.
Schwarcz J. Colorful nonsense: Dinshah Ghadiali and his
spectro-chrome device. Quackwatch Web site. Accessed at
http://www.quackwatch.org/01QuackeryRelatedTopics/spectro.html on May
30, 2008.
Triesscheijn M, Baas Pm, Schellens JH, Stewart FA.
Photodynamic therapy in oncology. Oncologist.
2006;11:1034-1044.
UVB phototherapy. National Psoriasis Foundation Web site.
Accessed at
http://www.psoriasis.org/treatment/psoriasis/phototherapy/uvb.php on
May 30, 2008.
Woltz P, Castro K, Park BJ. Care for patients undergoing
extracorporeal photopheresis to treat chronic graft-versus-host
disease: review of the evidence. Clin
J Oncol Nurs. 2006;10:795-802.
Note:
This
information may not cover all possible claims, uses, actions,
precautions, side effects or interactions. It is not intended as
medical advice, and should not be relied upon as a substitute for
consultation with your doctor, who is familiar with your medical
situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008
|
