According to the research monitored
on case series study, it was discovered that bright light therapy had the
ability to suppress melatonin secretion and improve depressive symptoms (Willis,
& Turner, 2007). In this study, the intensity of 1000 – 1500 lux was used.
Within two weeks, there were improvement in bradykianaesia and rigidity was
observed in most patients. Tremor was not affected by LD treatment. However,
agitation, dyskinaesia and psychiatric side effects were reduced. Elevated
mood, improved sleep, decreased seborrhea, reduced impotence and increased
appetite were observed. Light therapy also granted reduce drug intake.
Another study discovered other
different benefits of phototherapy on Parkinson’s disease. In this study (Jang,
& Han, 2014), low intensity laser was administered. It is found that
phototherapy increased the speed of adenosine triphosphate (ATP) production
which in turn may slow down the progression of neurodegeneration. The biggest
limitation of the study was that the sample size was not based on human
subjects. Therefore, there may be some variable effects on human.
There was very little improvement in
motor symptoms due to phototherapy (Paus, et al., 2007). On the other hand, bright
light therapy improved the depressive symptoms which can be effective as
serotonin reuptake inhibitors while there is no distinctive effect on
sleepiness. The study concluded that it was a safe, easy to use and inexpensive
non-pharmacological treatment option which significantly improves tremor and
most noncardinal features of PD. For depression, more severely affected
patients showed a greater response.
On the contrary, Pigeon (2010)
highlighted the undesirable side effects of phototherapy which are insomnia,
hypomania, agitation, visual blurring, eye strain and headaches. In addition,
patients who are at risk for eye-related problems should be advised to seek an
advice from an eye care specialist before the treatment took place. Another
study researched on pretreatment with near-infrared light showed that the
treatment can reduce neurotoxin from drug treatment for Parkinson’s disease and
negate the effect of decreasing the ATP production by drugs taken (Ying,
Liang, Whelan, Eells, & Wong-Riley, 2008). This study suggested that
phototherapy could be considered as preventive treatment.
In conclusion, light therapy can
reduce drug intake and eliminate some side effects of drug take as well.