Biomedical Engineering Reference
In-Depth Information
(
A
)
(
B
)
Figure 2.17
Angioma (
A
) before and (
B
) after treatment with pulsed dye laser (7 mm, 10 J/cm
2
, 1.5 ms, 40 ms spray and 30 ms delay with cryogen spray).
an increase in Demodex mites (36). It is hypothesized that these
mites may play a role in the infl ammation of rosacea. Studies
have demonstrated thermal destruction of these mites after IPL
therapy, which may contribute to the therapeutic effects of IPL
(37). Telangiectasia represents the later phase of vascularization
and probably results from a reduction in mechanical integrity of
the upper dermal connective tissue, allowing a passive dilatation
of capillaries. Infl ammation and associated angiogenesis may
contribute to the telangiectasia. Interestingly, facial temperature
is higher in rosacea and this has been associated with a differ-
ence in the nature and behavior of skin bacteria, particularly
coagulase-negative staphylococci (38). Therefore, the elimina-
tion of excessive blood vessels may not only decrease the ery-
thematous appearance of rosacea but also modify the bacterial
fl ora further decreasing the cutaneous erythema. Erythema usu-
ally recurs within six months of laser treatment most likely due
to a resurgence in Demodex population and/or associated
infl ammation. We advise our patients to plan on having at least
two treatments a year to maximize control of their rosacea.
Aminolevulinic acid-photodynamic therapy (ALA-PDT) has
also been applied successfully to resistant rosacea regions (39).
only 50% had less papulopustular lesions after an average
of 2.4 treatments with parameters of the PDL previously
described above (45). However, even in this “negative” paper,
two of the 10 treated patients had excellent results when evalu-
ated fi ve years after treatment.
Intense Pulsed Light
The IPL has been found to be effective in treating rosacea. As
described previously, this light source has the advantage of rela-
tively quick vessel elimination without signifi cant purpura or
crusting. Scanning Doppler evaluation demonstrated a 30%
decrease in blood fl ow after fi ve IPL treatments (46). In addi-
tion, a 21% decrease in erythema intensity as well as a 29%
decrease in the actual size of the cheek with telangiectasia was
noted in this study of four patients. A larger study of 60 patients
were treated with the IPL with pulse durations of 4.3-6.5 ms
and energy density of 25-35 J/cm
2
(47). A mean clearance of
77.8% was achieved and maintained for a follow-up period
averaging 51.6 months. An additional study of 32 consecutive
patients treated with an average of 3.6 IPL treatments similar to
the above-mentioned parameters showed that 83% of patients
had reduced redness, 75% experienced reduced fl ushing, and
64% noted fewer acne breakouts (48). We treat the entire facial
area affected by the erythematous rosacea. Short pulses appear
to be most effective. We typically use a 550 or 560 nm cutoff
fi lter with a double pulse of 2.4 and 4.0 ms with a 10-ms delay
and an energy density of 26 J/cm
2
with the Quantum SR, and
3.0 ms and 3.0 ms at 18 J/cm
2
with the Lumenis One, or
34 J/cm
2
and 10 ms with the Palomar MaxG device. Patients are
retreated every 3 to 4 weeks until clear. We have found
that most patients clear in two or three treatments (Fig. 2.18).
A certain percentage of patients (20%) do not respond to the
IPL and need to be treated with the PDL. Most of our patients
need to return for re-treatment once or twice a year. We have
also found the large spot KTP laser to be useful in rosacea.
Pulsed Dye Laser
Rosacea-associated telangiectasia and erythema respond well to
treatment with the PDL (40-42). We have reported good-to-
excellent results in 24 of 27 patients (89%). In addition to the
cosmetic improvement resulting from elimination of the vas-
cular component of this disorder, PDL treatment also appears
to alter the pathophysiology of this condition because a decrease
in papule and pustule activity occurs in up to 59% of patients.
After PDL treatment, patients who responded to treatment
with elimination of the vascular component required less or
no topical or systemic antibiotic therapy to maintain disease
resolution (43). The effi cacy of the fi rst-generation PDL was
reproduced in a study of a 6-ms PDL at 595 nm with fl uence
between 7 and 9 J/cm
2
and cryogen spray cooling (44). Here,
two of 12 patients had over 75% improvement with one treat-
ment. Another two had 50-75% improvement; fi ve had 25-50%
improvement. These parameters did not produce signifi cant
purpura.
In assessing the overall success and potential risk of each
laser used in the treatment of facial telangiectasia with rosacea,
we believe that the PDL provides effective and relatively risk-
free results. In addition, one study of 10 patients showed that
poikiloderma of civatte
Poikiloderma was originally described by Civatte and repre-
sents a sun-induced dilation of blood vessels, sometimes
accompanied by hyperpigmentation. The condition is best
treated by IPL, large spot KTP laser, or extended pulse PDLs.
Multiple sessions are necessary, and some cases are resistant to
treatment. Interestingly, even in cases where both melanin and
telangiectasia appear to be in excess, treatment of the ectatic
