Phototherapy
53,435 views
56 slides
Sep 08, 2016
Slide 1 of 56
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
About This Presentation
Phototherapy, also known as light therapy is a therapeutic method that is done with the non-ionizing portions of the electromagnetic spectrum. The objective of phototherapy is to heal a clinical condition, minimizing the adverse effects. Light contains energy in the form of photons. Light absorbing ...
Slide Content
Kavya Liyanage
Phototherapy
Phototherapy
Objectives
1Introduction
2History of phototherapy
3Phototherapy in Neonatal Jaundice
3.1BilirubinMetabolism
3.2Jaundice
3.3Phototherapy as a Treatment of Choice
3.4Mechanism of Action
3.5Best Indications
4Applications in the Field of Dermatology
4.1Mechanism of Action
4.1.1 Vitiligo
4.1.2 Psoriasis
4.1.3 Eczema
Cont.
1Introduction
2History of phototherapy
3Phototherapy in Neonatal Jaundice
3.1BilirubinMetabolism
3.2Jaundice
3.3Phototherapy as a Treatment of Choice
3.4Mechanism of Action
3.5Best Indications
4Applications in the Field of Dermatology
4.1Mechanism of Action
4.1.1 Vitiligo
4.1.2 Psoriasis
4.1.3 Eczema
Cont.
Cont.
5 Applications in the Field of Psychiatry
5.1Mechanism of Action
5.2Best Indications
5.2.1Wavelength
5.2.2Irradiance and Duration
5.3Jet Lag
5.4Shift Work Sleep Disorder
5.5Delayed Sleep Phase Syndrome
5.6Advanced Sleep Phase Syndrome
5.7Adverse Effects
5.8Light Sources
6Photodynamic Therapy
5 Applications in the Field of Psychiatry
5.1Mechanism of Action
5.2Best Indications
5.2.1Wavelength
5.2.2Irradiance and Duration
5.3Jet Lag
5.4Shift Work Sleep Disorder
5.5Delayed Sleep Phase Syndrome
5.6Advanced Sleep Phase Syndrome
5.7Adverse Effects
5.8Light Sources
6Photodynamic Therapy
Introduction
Phototherapy, also known as light therapy is a
therapeutic method that is done with the non-ionizing
portions of the electromagnetic spectrum.
The objective of phototherapy is to heal a clinical
condition, minimizing the adverse effects.
Light contains energy in the form of photons.
Light absorbing molecules or chromophorescan utilize
the light energy can make a certain change.
Phototherapy, also known as light therapy is a
therapeutic method that is done with the non-ionizing
portions of the electromagnetic spectrum.
The objective of phototherapy is to heal a clinical
condition, minimizing the adverse effects.
Light contains energy in the form of photons.
Light absorbing molecules or chromophorescan utilize
the light energy can make a certain change.
Cont.
Sunlight is known to have a healing power from the
ancient times.
With this concept, by the development of modern
science, the power of artificial light has been using in
treating certain clinical conditions such as given as in
dermatitis, psoriasis, common acne, eczema, seasonal
affective disorders, vitiligo, neonatal jaundice, circardian
rhythm disorders etc.
Modern phototherapy light sources include sunlight,
fluorescent light, halogen spotlight, fibre-optic system,
light emitting diodes (LEDs) and etc.
Sunlight is known to have a healing power from the
ancient times.
With this concept, by the development of modern
science, the power of artificial light has been using in
treating certain clinical conditions such as given as in
dermatitis, psoriasis, common acne, eczema, seasonal
affective disorders, vitiligo, neonatal jaundice, circardian
rhythm disorders etc.
Modern phototherapy light sources include sunlight,
fluorescent light, halogen spotlight, fibre-optic system,
light emitting diodes (LEDs) and etc.
History of phototherapy
Early Egyptians and Indians had used sunlight for treating
several skin disorders.
The very first use of the light as a medical treatment in the
history was as a treatment for the skin disease vitilgo, by
ancient Indians.
This particular disease causes loss of pigmentation of the
skin, whereas it was treated with exposure to sunlight, after
applying seeds of photosensitizing Psoralea.
So, when applied it on the non-pigmented areas of the skin
and made them expose to the sun, the re-pigmentation
occurs.
The ancient people had done this therapy with natural
sunlight.
Early Egyptians and Indians had used sunlight for treating
several skin disorders.
The very first use of the light as a medical treatment in the
history was as a treatment for the skin disease vitilgo, by
ancient Indians.
This particular disease causes loss of pigmentation of the
skin, whereas it was treated with exposure to sunlight, after
applying seeds of photosensitizing Psoralea.
So, when applied it on the non-pigmented areas of the skin
and made them expose to the sun, the re-pigmentation
occurs.
The ancient people had done this therapy with natural
sunlight.
Cont.
It was in the 19
th
century that the use of artificial light
sources for phototherapy happened.
Prof. NielsRybergFinsen is known as the father of
phototherapy.
He turned a new page in the field of medicine, by his work
on treating for lupus vulgaris, a skin infection caused by
Mycobacterium tuberculosis, with concentrated light rays.
This therapy was done with natural sunlight and ultraviolet
radiation from a carbon arc.
Hence, he was the Nobel Prize winner in Physiology and
Medicine in 1903, for his remarkable work. Since then,
many works in the pathway of phototherapy have been
done.
It was in the 19
th
century that the use of artificial light
sources for phototherapy happened.
Prof. NielsRybergFinsen is known as the father of
phototherapy.
He turned a new page in the field of medicine, by his work
on treating for lupus vulgaris, a skin infection caused by
Mycobacterium tuberculosis, with concentrated light rays.
This therapy was done with natural sunlight and ultraviolet
radiation from a carbon arc.
Hence, he was the Nobel Prize winner in Physiology and
Medicine in 1903, for his remarkable work. Since then,
many works in the pathway of phototherapy have been
done.
Phototherapy in Neonatal Jaundice
Jaundice, hyperbilirubinaemiaor icterusis a condition
that results from elevated serum bilirubinlevels.
This condition manifests as a yellowish discolouration of
skin and mucous membranes.
Jaundice, hyperbilirubinaemiaor icterusis a condition
that results from elevated serum bilirubinlevels.
This condition manifests as a yellowish discolouration of
skin and mucous membranes.
BilirubinMetabolism
Bilirubinpigment is a product of haemedegradation
pathway.
Bilirubinis in two forms, unconjuatedand conjugated
forms, depending on its solubility in plasma.
The unconjugatedbilirubin, produced in the reticulo-
endothelial system, is lipid soluble and is transported to
the liver by binding with albumin.
Bilirubinpigment is a product of haemedegradation
pathway.
Bilirubinis in two forms, unconjuatedand conjugated
forms, depending on its solubility in plasma.
The unconjugatedbilirubin, produced in the reticulo-
endothelial system, is lipid soluble and is transported to
the liver by binding with albumin.
Cont.
In the liver hepatocytes, the unconjugatedform of
bilirubinconjugates with glucuronicacids and known as
the conjugated form.
It is the soluble form in plasma.
The conjugated bilirubinis secreted into bile and the
later is released to the gut.
Some of the conjugated bilirubinis reabsorbed into the
circulation as unconjugatedbilirubin, the process of
recycling biirubin, known as enterohepaticcirculation.
In the liver hepatocytes, the unconjugatedform of
bilirubinconjugates with glucuronicacids and known as
the conjugated form.
It is the soluble form in plasma.
The conjugated bilirubinis secreted into bile and the
later is released to the gut.
Some of the conjugated bilirubinis reabsorbed into the
circulation as unconjugatedbilirubin, the process of
recycling biirubin, known as enterohepaticcirculation.
Jaundice
In the newborns, foetal haemoglobin is replaced by adult
haemoglobin.
Hence, the red blood cell haemolysis occurs more and
billirubinformation occurs in high rates in them.
This results in both unconjugatedand conjugated forms
of bilirubin.
Indeed, the immaturity of the hepatic metabolic
pathway too leads to increased levels of bilrubin.
As such, neonates are more prone to get
hyperbilirubinaemicconditions.
In the newborns, foetal haemoglobin is replaced by adult
haemoglobin.
Hence, the red blood cell haemolysis occurs more and
billirubinformation occurs in high rates in them.
This results in both unconjugatedand conjugated forms
of bilirubin.
Indeed, the immaturity of the hepatic metabolic
pathway too leads to increased levels of bilrubin.
As such, neonates are more prone to get
hyperbilirubinaemicconditions.
Cont.
Neonatal jaundice can be either physiological or
pathological.
The physiological jaundice occurs in the first week of life,
usually within the 2-5 days after delivery.
Also, this returns back to normal in 10-14 days after
birth.
If the signs of jaundice appear within the 48 hours after
birth, it is due to a pathological reason and is the
pathological jaundice
Neonatal jaundice can be either physiological or
pathological.
The physiological jaundice occurs in the first week of life,
usually within the 2-5 days after delivery.
Also, this returns back to normal in 10-14 days after
birth.
If the signs of jaundice appear within the 48 hours after
birth, it is due to a pathological reason and is the
pathological jaundice
Cont.
One severe complication of neonatal jaundice is
kernicterus.
When the unconjugatedbiilirubinis elevated in the
blood, those bilirubinmolecules can cross the immature
neonatal blood brain barrier and get deposited in the
basal ganglia.
This causes irreversible damage to the brain tissue,
resulting in kernicterus.
Therefore, it is important to treat this neonatal
hyperbilirubinaemiabefore the complications take place.
One severe complication of neonatal jaundice is
kernicterus.
When the unconjugatedbiilirubinis elevated in the
blood, those bilirubinmolecules can cross the immature
neonatal blood brain barrier and get deposited in the
basal ganglia.
This causes irreversible damage to the brain tissue,
resulting in kernicterus.
Therefore, it is important to treat this neonatal
hyperbilirubinaemiabefore the complications take place.
Phototherapy as a Treatment Of Choice
Phototherapy is the treatment of choice of most of the
clinicians. It is detected as jaundice in neonates when
the serum bilirubinlevel is more than 5 mg/dl.
When this level israisedabove the required level
according to the days of life, the neonate is prescribe for
a phototherapy treatment along with breast feeding.
Exchange blood transfusion is the other treatment
option if the phototherapy is ineffective in severe
jaundice conditions.
Phototherapy is the treatment of choice of most of the
clinicians. It is detected as jaundice in neonates when
the serum bilirubinlevel is more than 5 mg/dl.
When this level israisedabove the required level
according to the days of life, the neonate is prescribe for
a phototherapy treatment along with breast feeding.
Exchange blood transfusion is the other treatment
option if the phototherapy is ineffective in severe
jaundice conditions.
Mechanism of Action
Some bilirubin, are present in the interstitial spaces and
superficial capillaries of the skin, subcutaneous tissues.
During the phototherapy, these molecules are exposed
to light.
The photons of energy are absorbed by the pigment,
bilirubin.
This leads to a sequence of photochemical reactions;
configurationalisomerisation, structural isomerisation
and photo-oxidation.
Some bilirubin, are present in the interstitial spaces and
superficial capillaries of the skin, subcutaneous tissues.
During the phototherapy, these molecules are exposed
to light.
The photons of energy are absorbed by the pigment,
bilirubin.
This leads to a sequence of photochemical reactions;
configurationalisomerisation, structural isomerisation
and photo-oxidation.
Cont.
This energy converts bilirubininto its nontoxic isomers
such as photobilirubin(4Z, 15E biliirubin), lumilirubin
which are more polar and thus water soluble.
These photo-isomers can be eliminated from the body
more easily without undergoing the process of
conjugation in the liver.
Indeed, since they are water soluble, transporter proteins
are not required.
But the photobilirubinis reversible to naive bilirubin
while the lumirubinis irreversible.
This energy converts bilirubininto its nontoxic isomers
such as photobilirubin(4Z, 15E biliirubin), lumilirubin
which are more polar and thus water soluble.
These photo-isomers can be eliminated from the body
more easily without undergoing the process of
conjugation in the liver.
Indeed, since they are water soluble, transporter proteins
are not required.
But the photobilirubinis reversible to naive bilirubin
while the lumirubinis irreversible.
Cont.
Hence, the former isomer can enter the entero-hepatic
circulation and less amount is excreted.
As formation of lumirubinis the rate limiting step, less
amount of lumirubinis formed.
But it is cleared from the body more effectively.
Excretion of bilirubinisomers from the body, especially
lumirubin, declines the elevated serum bilirubinand thus
reduces the risk of kernicterus.
Hence, the former isomer can enter the entero-hepatic
circulation and less amount is excreted.
As formation of lumirubinis the rate limiting step, less
amount of lumirubinis formed.
But it is cleared from the body more effectively.
Excretion of bilirubinisomers from the body, especially
lumirubin, declines the elevated serum bilirubinand thus
reduces the risk of kernicterus.
Best Indications
When administrating the therapy, the dose depends on
the wavelength of the light source, irradiance of the light
and the distance between the light source and the infant.
Higher the irradiance of the light is, higher the efficiency
of the therapy.
Relatively a narrow wavelength range (400-520 nm) is
very effective with a peak wavelength of 460±10 nm for
the photoisomerizationof bilirubin.
This is range that belongs to the blue light.
When administrating the therapy, the dose depends on
the wavelength of the light source, irradiance of the light
and the distance between the light source and the infant.
Higher the irradiance of the light is, higher the efficiency
of the therapy.
Relatively a narrow wavelength range (400-520 nm) is
very effective with a peak wavelength of 460±10 nm for
the photoisomerizationof bilirubin.
This is range that belongs to the blue light.
Cont.
When the light source is near the neonate, the intensity
of it is more.
But some sources like halogen phototherapy lamps, it
may give burns if the source is closer to the skin than the
recommended distance.
For a faster decline in the serum bilirubinlevel, large
body area can be exposed to light.
When giving the therapy, the eyes and genitalia of the
baby must not be exposed to the light.
When the light source is near the neonate, the intensity
of it is more.
But some sources like halogen phototherapy lamps, it
may give burns if the source is closer to the skin than the
recommended distance.
For a faster decline in the serum bilirubinlevel, large
body area can be exposed to light.
When giving the therapy, the eyes and genitalia of the
baby must not be exposed to the light.
Commercially Available Light Sources
Fibreopticblankets
Fluorescent tubes
Halogen spot lights
Gallium nitride light emitting diodes (LEDs)
Fibreopticblankets
Fluorescent tubes
Halogen spot lights
Gallium nitride light emitting diodes (LEDs)
Applications in the Field of Dermatology
Ultraviolet (UV) part of the light spectrum consists of
light of long, medium and short wavelength.
These waves are known as
UVA (wavelength more than 320 nm)
UVB (wavelength between 290-320 nm)
UVC (wavelength less than 290 nm)
Ultraviolet (UV) part of the light spectrum consists of
light of long, medium and short wavelength.
These waves are known as
UVA (wavelength more than 320 nm)
UVB (wavelength between 290-320 nm)
UVC (wavelength less than 290 nm)
Cont.
Though most of the UVC is absorbed by the ozone layer,
the UVA and UVB penetrate the atmosphere and reach
the skin.
This particular light is harmful for the normal skin.
In comparison, UVA is more harmful than UVB.
It may cause mutations, skin malignancy, premature skin
aging and also cause cataract in eye lens.
White skinned people are more vulnerable for these
effects.
Though most of the UVC is absorbed by the ozone layer,
the UVA and UVB penetrate the atmosphere and reach
the skin.
This particular light is harmful for the normal skin.
In comparison, UVA is more harmful than UVB.
It may cause mutations, skin malignancy, premature skin
aging and also cause cataract in eye lens.
White skinned people are more vulnerable for these
effects.
Cont.
Even though both UVA and UVB are potentially harmful,
they have ability to suppress cutaneousinflammation.
This scientific phenomenon has used in phototherapy in
treating dermatological problems.
Indeed, these are capable of suppressing the
immunoreactivityof the whole system.
So that, non affected areas and high risk areas like eyes
and scrotum are not exposed to this light.
Even though both UVA and UVB are potentially harmful,
they have ability to suppress cutaneousinflammation.
This scientific phenomenon has used in phototherapy in
treating dermatological problems.
Indeed, these are capable of suppressing the
immunoreactivityof the whole system.
So that, non affected areas and high risk areas like eyes
and scrotum are not exposed to this light.
Cont.
Several types of light treatment are used in the field.
Narrow band UVB in the range of 310-315 nm, with a
peak at 311 nm is usually chosen as the therapeutic
spectrum.
As UVA is less effective, it is used along with Psoralen, a
photo-sensitizing chemical, in the method known as
photo chemotherapy (PUVA).
Sometimes, a combination of UVA and UVB is given.
Several types of light treatment are used in the field.
Narrow band UVB in the range of 310-315 nm, with a
peak at 311 nm is usually chosen as the therapeutic
spectrum.
As UVA is less effective, it is used along with Psoralen, a
photo-sensitizing chemical, in the method known as
photo chemotherapy (PUVA).
Sometimes, a combination of UVA and UVB is given.
Cont.
In some dermatological problems such as vitiligo,
psoriasis, common acne and eczema, phototherapy is a
choice of treatment.
In some dermatological problems such as vitiligo,
psoriasis, common acne and eczema, phototherapy is a
choice of treatment.
Mechanism of Action
Narrow-band UVB, to which the skin is exposed, is
absorbed by the DNA and urocanicacid. It alters the
antigen presenting cell activity.
This narrow-band radiation is less potent than the broad-
band UVB. But the former has relatively more
suppressive effect than the latter on systemic immune
responses.
Narrow-band UVB, to which the skin is exposed, is
absorbed by the DNA and urocanicacid. It alters the
antigen presenting cell activity.
This narrow-band radiation is less potent than the broad-
band UVB. But the former has relatively more
suppressive effect than the latter on systemic immune
responses.
Mechanism of Action In Vitiligo
A common autoimmune disorder, vitiligocauses
depigmentationof the skin due to the loss of
melanocytes.
In this condition, PUVA or narrow-band UVB is used for
the phototherapy treatment.
In both cases, the UV light stimulates the amelanotic
melanocytesin the skin.
Then they get activated and proliferation occurs, leading
to the production of melanin.
This melanin migrates outward to adjacent depigmented
areas and causes perifolliclarrepigmentation.
A common autoimmune disorder, vitiligocauses
depigmentationof the skin due to the loss of
melanocytes.
In this condition, PUVA or narrow-band UVB is used for
the phototherapy treatment.
In both cases, the UV light stimulates the amelanotic
melanocytesin the skin.
Then they get activated and proliferation occurs, leading
to the production of melanin.
This melanin migrates outward to adjacent depigmented
areas and causes perifolliclarrepigmentation.
Mechanism of Action In Psoriasis
Psoriasis is a common paplo-squamousdisorder that is
characterised by well demarcated red scary plaques.
In this condition, the skin becomes inflamed and
hyperproliferationof the skin occurs.
In psoriasis like conditions, the narrow-band decreases
lymphocyte proliferation
natural killer cell activity
cytokine production (IL-2, IL-10)
suppressing the immune activity of the body.
Psoriasis is a common paplo-squamousdisorder that is
characterised by well demarcated red scary plaques.
In this condition, the skin becomes inflamed and
hyperproliferationof the skin occurs.
In psoriasis like conditions, the narrow-band decreases
lymphocyte proliferation
natural killer cell activity
cytokine production (IL-2, IL-10)
suppressing the immune activity of the body.
Mechanism of Action In Eczema
Eczema is a kind of dermatitis which can be seen over a
large proportion of the skin.
This condition is also treated with narrow-band UVB
phototherapy similarly as in psoriasis.
Eczema is a kind of dermatitis which can be seen over a
large proportion of the skin.
This condition is also treated with narrow-band UVB
phototherapy similarly as in psoriasis.
Applications in the Field of Psychiatry
According to the records of the history, bright light was
used to treat patients with the winter seasonal affective
disorder, for the first time in 1984, in the field of
psychiatry.
According to the records of the history, bright light was
used to treat patients with the winter seasonal affective
disorder, for the first time in 1984, in the field of
psychiatry.
Cont.
Circadian rhythm cycle is an endogenously generated
biological clock. This cycle is roughly of 24 hours.
By the influence of biological and environmental cues or
zeitgebers, physiological and behavioural aspects of the
circadian cycles of animals and humans are modulated.
The most important zeitgebersregulating the circadian
and seasonal rhythm of mammals is the light-dark cycle.
Circadian rhythm cycle is an endogenously generated
biological clock. This cycle is roughly of 24 hours.
By the influence of biological and environmental cues or
zeitgebers, physiological and behavioural aspects of the
circadian cycles of animals and humans are modulated.
The most important zeitgebersregulating the circadian
and seasonal rhythm of mammals is the light-dark cycle.
Cont.
An “oscillator” in the suprachiasmaticnucleus of the anterior
hypothalamus senses the environmental light via its special
neuronal pathway with the retina of the eye, the retino-
hypothalamic pathway.
Studies have shown that a sufficient light intensity indeed
influences the human circadian rhythm cycle.
This rhythmicityis sometimes melatonin dependent.
Melatonin is a hormone secreted by the pineal gland which
involves in timing signals to coordinate events with light-dark
cycle.
However, the bright light is a stronger exogenous factor that
effects on the endogenous biological rhythm.
An “oscillator” in the suprachiasmaticnucleus of the anterior
hypothalamus senses the environmental light via its special
neuronal pathway with the retina of the eye, the retino-
hypothalamic pathway.
Studies have shown that a sufficient light intensity indeed
influences the human circadian rhythm cycle.
This rhythmicityis sometimes melatonin dependent.
Melatonin is a hormone secreted by the pineal gland which
involves in timing signals to coordinate events with light-dark
cycle.
However, the bright light is a stronger exogenous factor that
effects on the endogenous biological rhythm.
Cont.
Light therapy is an effective treatment option for the
disorders with disturbances in the circadian rhythm. Jet
lag, shift work sleep disorder, delayed sleep phase
syndrome and advanced phase sleeping syndrome are
some of the examples for such disorders.
Light therapy is an effective treatment option for the
disorders with disturbances in the circadian rhythm. Jet
lag, shift work sleep disorder, delayed sleep phase
syndrome and advanced phase sleeping syndrome are
some of the examples for such disorders.
Cont.
These sleeping disorders are due to the changes in the
circadian cycle. As a treatment option, the 24 hours clock
of the body can be “re-set” by the aid of bright light
therapy. In this case, the patient’s sleeping patterns are
synchronized as he or she desires to match with the daily
routine of the particular person.
These sleeping disorders are due to the changes in the
circadian cycle. As a treatment option, the 24 hours clock
of the body can be “re-set” by the aid of bright light
therapy. In this case, the patient’s sleeping patterns are
synchronized as he or she desires to match with the daily
routine of the particular person.
Mechanism of Action
The activation of ocular photoreceptors exclusively
mediates the light treatment of circadian rhythm cycle.
The blue light sensitive photo-pigment melanopsin.
It is in specialised ganglioniccells of the retina, directly
projects to the circadian clock in the suprachiasmatic
nucleus.
The treatment efficiency depends on the wavelength
and the dose of the light, indeed the time of the day that
the light is administered.
The activation of ocular photoreceptors exclusively
mediates the light treatment of circadian rhythm cycle.
The blue light sensitive photo-pigment melanopsin.
It is in specialised ganglioniccells of the retina, directly
projects to the circadian clock in the suprachiasmatic
nucleus.
The treatment efficiency depends on the wavelength
and the dose of the light, indeed the time of the day that
the light is administered.
Wavelength
Human eye uses three cone types in order to sense light
in three colour bands.
The photo-pigments of the cones have maximum
absorption at certain wavelengths.
This absorption occurs with maximum efficacy at a
wavelength of 555 nm in the green light area.
With regarding the primary mediating effect of the
melanopsin, exposure to bright monochromic blue light
(460 nm) is more effective than green light (555 nm).
Human eye uses three cone types in order to sense light
in three colour bands.
The photo-pigments of the cones have maximum
absorption at certain wavelengths.
This absorption occurs with maximum efficacy at a
wavelength of 555 nm in the green light area.
With regarding the primary mediating effect of the
melanopsin, exposure to bright monochromic blue light
(460 nm) is more effective than green light (555 nm).
Cont.
But the peak sensitivity of the three cone photo-optic
visual system is in the green area.
This process is for the phase resetting of the circadian
cycle and for the suppression of night time release of
melatoninehormone by the pineal gland.
Therefore, the blue enriched light is effective in treating
the circadian sleeping disorders as compared to longer
wavelength light.
But the peak sensitivity of the three cone photo-optic
visual system is in the green area.
This process is for the phase resetting of the circadian
cycle and for the suppression of night time release of
melatoninehormone by the pineal gland.
Therefore, the blue enriched light is effective in treating
the circadian sleeping disorders as compared to longer
wavelength light.
Irradiance and Duration
The irradiance and the duration of the light stimulus are
the facts that are important in considering the dose of
the light therapy.
In studies regarding this matter, only the exposure to
bright artificial light (2,500-10,000 lux) has been shown
to improve the circadian cycle and the behavioural
aspect.
In comparison of the intensity of the light administrated,
bright light shows more effective changes in re-
synchronizing the rhythm if preceded with dim light.
The irradiance and the duration of the light stimulus are
the facts that are important in considering the dose of
the light therapy.
In studies regarding this matter, only the exposure to
bright artificial light (2,500-10,000 lux) has been shown
to improve the circadian cycle and the behavioural
aspect.
In comparison of the intensity of the light administrated,
bright light shows more effective changes in re-
synchronizing the rhythm if preceded with dim light.
Cont.
The magnitude and direction of phase synchronising rely
upon the circadian phase at which the stimulus of light is
applied.
Generally, this cycle is most sensitive during the actual
night time.
So that, the light therapy is more appropriate to be given
shortly after awakening and shortly before bedtime.
The magnitude and direction of phase synchronising rely
upon the circadian phase at which the stimulus of light is
applied.
Generally, this cycle is most sensitive during the actual
night time.
So that, the light therapy is more appropriate to be given
shortly after awakening and shortly before bedtime.
Jet Lag
Jet lag or Rapid time zone change syndrome is seen in
the people who travel across time zones.
They present with excessive sleepiness and lack of
daytime alertness.
In this case, the eastward travellers show difficulty in
waking in the morning, while the westward ones are
having early morning awakenings.
Jet lag or Rapid time zone change syndrome is seen in
the people who travel across time zones.
They present with excessive sleepiness and lack of
daytime alertness.
In this case, the eastward travellers show difficulty in
waking in the morning, while the westward ones are
having early morning awakenings.
Cont.
The desired outcome of the phototherapy in the
eastward travellers is to phase advance shift the cycle
while that of the westward travellers is to phase delay
shift the cycle.
Therefore, in treating the eastward travellers, morning
bright light therapy after waking time (home time zone)
and dim light prior to bedtime is administered.
Evening bright light therapy prior to bedtime (home time
zone) and dim light after wake time is treatment method
suitable for the westward travellers.
The desired outcome of the phototherapy in the
eastward travellers is to phase advance shift the cycle
while that of the westward travellers is to phase delay
shift the cycle.
Therefore, in treating the eastward travellers, morning
bright light therapy after waking time (home time zone)
and dim light prior to bedtime is administered.
Evening bright light therapy prior to bedtime (home time
zone) and dim light after wake time is treatment method
suitable for the westward travellers.
Shift Work Sleep Disorder
This particular disorder results in people who frequently
rotates work shifts and work at night.
They are having excessive sleepiness during the wake
time, and desire to have a large phase delay shift.
They should be administered bright light therapy in the
evening and dim light after work.
This particular disorder results in people who frequently
rotates work shifts and work at night.
They are having excessive sleepiness during the wake
time, and desire to have a large phase delay shift.
They should be administered bright light therapy in the
evening and dim light after work.
Delayed Sleep Phase Syndrome
Patients with this condition may fall asleep lately and
they have difficulty to wake up in the morning in order to
involve in day-today routine.
Their goals of the therapy would be earlier sleep-wake
times and to have a phase advance shift.
Therefore, morning bright light after wake time and dim
light prior to bedtime should be administrated.
Patients with this condition may fall asleep lately and
they have difficulty to wake up in the morning in order to
involve in day-today routine.
Their goals of the therapy would be earlier sleep-wake
times and to have a phase advance shift.
Therefore, morning bright light after wake time and dim
light prior to bedtime should be administrated.
Advanced Sleep Phase Syndrome
This advanced sleep phase syndrome is commonly seen
among adults.
These people go to sleep early (6.00-9.00 p.m.) and they
wake up earlier than desired, around 2.00-5.00 a.m. .
So that, required effect is to have a phase delay shift,
following a later sleep-wake times.
Phototherapy treatment is given as evening bright light
therapy prior to bedtime and dim light after wake time.
This advanced sleep phase syndrome is commonly seen
among adults.
These people go to sleep early (6.00-9.00 p.m.) and they
wake up earlier than desired, around 2.00-5.00 a.m. .
So that, required effect is to have a phase delay shift,
following a later sleep-wake times.
Phototherapy treatment is given as evening bright light
therapy prior to bedtime and dim light after wake time.
Adverse Effects
Retinopathy is absolutely inadvisable for bright light
therapy.
Therefore, in order to avoid ocular damage, prior to the
therapy, eye examination of the patient should be done.
Retinopathy is absolutely inadvisable for bright light
therapy.
Therefore, in order to avoid ocular damage, prior to the
therapy, eye examination of the patient should be done.
Light Sources
White light boxes,
light visors,
dawn stimulators
coloured light boxes
are some commercially available devices used in this therapy.
Anyhow, the light source should provide adequate filtering of
ultraviolet and infra-red light, to avoid ocular damages.
The illuminanceof the phototherapy light source can be kept
constant, unlike the variable natural light sources.
White light boxes,
light visors,
dawn stimulators
coloured light boxes
are some commercially available devices used in this therapy.
Anyhow, the light source should provide adequate filtering of
ultraviolet and infra-red light, to avoid ocular damages.
The illuminanceof the phototherapy light source can be kept
constant, unlike the variable natural light sources.
Photodynamic Therapy
Photodynamic therapy is also a form of phototherapy,
where light is administrated after giving a
photosensitising drug to the patient. Though this drug is
non toxic to the normal cells, it is toxic to the malignant
and diseased cells.
Photodynamic therapy is also a form of phototherapy,
where light is administrated after giving a
photosensitising drug to the patient. Though this drug is
non toxic to the normal cells, it is toxic to the malignant
and diseased cells.
Cont.
By absorbing the energy of the light, photosensitizing
agent reaches to its excited state.
Then the excited molecule reacts with oxygen and forms
reactive oxygen species.
The latter causes damage to the malignant and diseased
cells.
So it is important to not to expose the unaffected areas
of the body.
Hence, target phototherapy or photodynamic therapy is
used as a treatment option for breast cancers,
oesophageal carcinoma, bronchial lung carcinoma etc.
By absorbing the energy of the light, photosensitizing
agent reaches to its excited state.
Then the excited molecule reacts with oxygen and forms
reactive oxygen species.
The latter causes damage to the malignant and diseased
cells.
So it is important to not to expose the unaffected areas
of the body.
Hence, target phototherapy or photodynamic therapy is
used as a treatment option for breast cancers,
oesophageal carcinoma, bronchial lung carcinoma etc.
References
1] Grossweiner, Leonard I., Linda Ramball. Jones, James B. Grossweiner, and B. H. Gerald. Rogers. The
Science of Phototherapy: An Introduction. Dordrecht: Springer, 2005. Print.
2] The Nobel Prize in Physiology or Medicine 1903." The Nobel Prize in Physiology or Medicine 1903.N.p.,
n.d. Web. 25 Jan. 2016
3] Robert Murray, Victor Rodwell, David Bender, Kathleen M. Botham, P. Anthony Weil, Peter J.
Kennelly. Harper's Illustrated Biochemistry. 28th Edition ed. N.p.: Mcgraw-hill, Jun 2, 2009. Print.
4] Stokowski, Laura A. "Fundamentals of Phototherapy for Neonatal Jaundice."Advances in Neonatal
Care 11 (2011): n. pag. Web.
5] "Phototherapy of Neonatal Jaundice."The Science of Phototherapy: An Introduction (n.d.): 329-35.
Web.
6] Kumar, ParveenJ., and Michael L. Clark. Kumar & Clark's Clinical Medicine. 9th ed. Edinburgh:
Saunders Elsevier, 2009. Print.
7] DograS, KanwarAJ. Narrow band UVB phototherapy in dermatology. Indian J DermatolVenereol
Leprol2004;70:205-9
8] Gelder, Michael G., LópezIborJuan José, and Nancy C. Andreasen. New Oxford Textbook of
Psychiatry.Oxford: Oxford UP, 2000. Print.
1] Grossweiner, Leonard I., Linda Ramball. Jones, James B. Grossweiner, and B. H. Gerald. Rogers. The
Science of Phototherapy: An Introduction. Dordrecht: Springer, 2005. Print.
2] The Nobel Prize in Physiology or Medicine 1903." The Nobel Prize in Physiology or Medicine 1903.N.p.,
n.d. Web. 25 Jan. 2016
3] Robert Murray, Victor Rodwell, David Bender, Kathleen M. Botham, P. Anthony Weil, Peter J.
Kennelly. Harper's Illustrated Biochemistry. 28th Edition ed. N.p.: Mcgraw-hill, Jun 2, 2009. Print.
4] Stokowski, Laura A. "Fundamentals of Phototherapy for Neonatal Jaundice."Advances in Neonatal
Care 11 (2011): n. pag. Web.
5] "Phototherapy of Neonatal Jaundice."The Science of Phototherapy: An Introduction (n.d.): 329-35.
Web.
6] Kumar, ParveenJ., and Michael L. Clark. Kumar & Clark's Clinical Medicine. 9th ed. Edinburgh:
Saunders Elsevier, 2009. Print.
7] DograS, KanwarAJ. Narrow band UVB phototherapy in dermatology. Indian J DermatolVenereol
Leprol2004;70:205-9
8] Gelder, Michael G., LópezIborJuan José, and Nancy C. Andreasen. New Oxford Textbook of
Psychiatry.Oxford: Oxford UP, 2000. Print.
Thank You!
Download
Download Slideshow Get the original presentation fileQuick Actions
Statistics
- Views 53,435
- Slides 56
- Favorites 97
- Age 3371 days
Related Slideshows
36
Clinical approach Dyspnoea A simple and practical approach.pptx
ShajahanPS
23 views
238
Cancer Awareness therapy for public by Dr Kanhu Charan Patro
kanhucpatro
23 views
41
Prof Satyadas Memorial oration Kozhikode.pptx
ShajahanPS
18 views
26
Viral Conjunctivitis and it;s managment.pptx
ZaidAzhar
33 views
30
Essential Thrombocythemia 15 Years of Experience at the Hematology Department, Algies, Algeria.pdf
sbelakehal
29 views
10
Hypertension sign symptoms cmdt style with regime
androiddabest
30 views