Fractional CO₂ Laser Versus Intense Pulsed Light in Treating Striae Distensae

Abstract

Context:

Striae distensae are linear atrophic dermal scars covered with flat atrophic epidermis. They may cause disfigurement, especially in females. Many factors may cause striae distensae such as steroids, obesity, and pregnancy. Although there is no standard treatment for striae; many topical applications, peeling, and light and laser systems have been tried.

Aims:

To evaluate and compare the efficacy of fractional CO₂ laser with intense pulse light in treating striae distensae.

Subjects and Methods:

Forty patients with striae distensae were recruited. Twenty of them were treated by fractional CO₂ laser and 20 were treated with intense pulse light. Length and width of the largest striae were measured pre- and post-treatment. Patient satisfaction was also evaluated and graded. Patients were photographed after each treatment session and photos were examined by a blinded physician who had no knowledge about the cases.

Results:

Both groups showed significant improvement after treatments (P < 0.05). Patients treated with fractional CO₂ laser showed significant improvement after the fifth session compared with those treated with ten sessions of intense pulsed light (P < 0.05) in all parameters except in the length of striae (P > 0.05).

Conclusions:

The current study has provided supportive evidence to the effectiveness of both fractional CO₂ laser and intense pulse light as treatments for striae distensae. Fractional CO₂ laser was found to be more effective in the treatment of striae distensae compared with intense pulse light.

What was known?

Striae distensae have no standard line of treatment in spite of many different treatment modalities.

Introduction

Striae distensae, also termed stretch marks, are linear atrophic dermal scars covered with flat atrophic epidermis.[1,2] They were clinically described hundreds of years ago and the first histological description appeared in the medical literature in 1889.[3]

Striae distensae are caused by many physiological conditions such as adolescent growth spurts and pregnancy. They may also be caused by various pathological conditions such as obesity, Cushing's or Marfan's syndromes, and long-term systemic or topical steroid use.[1,4,5] Genetic predisposition assumption has been supported by many evidences such as the occurrence of striae in twins and the association between striae and hereditary diseases of connective tissue as Marfan syndrome.[6,7] Moreover, there is a decreased expression of collagen and fibronectin in striae distensae tissue.[8]

Although striae distensae do not cause any significant medical problems, they can be of great concern regarding their psychological implications, especially for females because of the disfigurement they cause. The exact pathogenesis of striae is still controversial. However, it may be due to changes in the components of extracellular matrix including fibrillin, elastin, and collagen.[9] In the early stages of striae, there are sequential changes in elastolysis and mast cell degeneration. Elastic fibers are the primary target affected in striae, then the pathology extends to the other dermal components.[10] It has been proposed that a striatoxin damages the tissues in a toxic way which leads to striations.[11] Furthermore, striae distensae are diagnosed clinically by their appearance as atrophied lines which are erythematous in early lesions and skin colored or hypopigmented in old lesions. Investigations are not needed except if there is an internal cause such as Cushing's syndrome.[3]

Up till now, there is no standard treatment modality for striae distensae. Several treatment modalities have been tried. Topical tretinoin (0.1%) has been used with an improvement that may persist for almost a year after discontinuation of therapy.[12] Ash et al. have found that combinations of 20% glycolic acid and 0.05% tretinoin or 20% glycolic acid and 10% L-ascorbic acid can improve the appearance of striae distensae. These applications have been supposed to improve the epidermal and dermal thickness to approach that of the adjacent normal skin.[13] Various other topical treatments (Centella asiatica, hyaluronic acid, trichloroacetic acid peels, and oils)[14] and disk micro-needle therapy system[15] have been used for treatment.

In the last two decades, various types of light and laser systems have been used for the treatment of striae distensae with inconsistent findings. Intense pulsed light (IPL) was used to treat striae distensae with good results.[16] A previous study has demonstrated that IPL replaces dermal elastosis with neo-collagen.[17]

Of the various modalities used to treat striae distensae, lasers have recently become the most widely used alternative.[16] The 585-nm flashlamp-pumped pulsed-dye laser was used to treat early immature striae distensae with good results. It acts through dilatation of the blood vessels and increase in collagen deposition in early stages of striae.[18,19,20] Although the 308-nm XeCl laser failed to improve skin atrophy in striae distensae, its action resulted solely from the improvement of pigmentation.[21] The 1064-nm long-pulse neodymium-doped yttrium aluminum garnet laser was used to treat immature striae distensae with satisfactory results through remodeling of elastic and collagen fibers.[22]

Recently, fractional photothermolysis has been introduced as a newer, nonablative resurfacing laser technique. Ultimately, the necrotic debris is expelled and neo-collagenesis occurs.[23] Fractional photothermolysis has been approved for the treatment of many skin conditions such as wrinkles, postacne scars, postburn scars, and other conditions needing skin resurfacing.[23] It has been found that fractional CO₂ laser improved texture and appearance of the mature, white striae distensae in skin Types I–IV in a Brazilian study on 15 females with old striae distensae.[24] Other recent studies showed satisfactory improvement in striae distensae after fractional CO₂ thermolysis.[25] Kim et al. treated six females with striae alba using 1550-nm fractional photothermolysis laser. They evaluated the results by serial photographs, erythema index and melanin index tracking, skin elasticity, histologic examination, and the patients’ subjective satisfaction scores. They concluded that fractional photothermolysis can reduce SD by stimulating new collagen and elastic fiber synthesis.[26]

In the current study, we have evaluated and compared the efficacy of fractional CO₂ laser and IPL in the treatment of striae distensae of variable causes in female patients.

Subjects and Methods

Forty female patients with striae distensae visiting the dermatology out-patient clinic at the Dermatology, Venereology and Andrology Department at Qina Faculty of Medicine, South Valley University, Egypt, were enrolled in this study. Patients were randomly divided into two groups. Each group included 20 patients. The study took place in the period from April 2011 to April 2013. Exclusion criteria included current pregnancy, steroid, retinoids or immunosuppressive drugs intake, history of keloid tendency, and history of striae treatment in the last 6 months. The protocol and informed consent were approved by our local Institutional Review Board. The study was designed as a prospective, case comparison study.

Treatment

A topical anesthetic cream was applied under occlusion for 60 min on the striae and washed off, then dried before treatment. The first 20 patients were treated with fractional 10.6 μm CO₂ laser using (fractional CO₂ ATL 250, advanced technology laser, China) at 40 mJ energy, pulse width 4 ms, and scanning area 10 mm × 10 mm. All the patients received monthly treatment for five sessions. The total treatment duration was 5 months for each patient. The other 20 patients were treated with IPL (GP Flash 1, CACI International, USA). Every patient was treated twice monthly for 5 months. Each patient received 10 treatments by the end of the treatment duration. We used the hand piece of skin rejuvenation treatment with band width 590 nm. The starting dose was 20 J/cm² increased by 1 J/cm²/session to reach the maximum dose of 30 J/cm².

Patients’ evaluation

Width and length of the largest striae were measured and photographs were taken (using high resolution digital identical camera settings “Sony, Tokyo, Japan”) in each patient before the beginning of treatment and 4 weeks after the last session of treatment. Patient satisfaction was rated into either none or less satisfied = 0 or satisfied = 1. Clinical improvement was evaluated by a study-blinded physician by measuring the length and width of the largest striae and comparing photographs before and 1 month after the last treatment. The criteria for photographs evaluation were as follow: (1= ≤50% improvement and 2= >50% improvement).

Statistical analysis

Data were analyzed using SPSS version 17 software (USA). Descriptive statistics: Mean, standard deviation, and percentages were calculated. Test of significances: Chi-square test was used to compare the difference in the distribution of frequencies among different groups. Mann–Whitney U-test was calculated to test the mean differences in continuous variables between groups for the un-paired data, while Wilcoxon signed rank test was used for the paired data (before vs. after treatment). A significant P value was considered when it is <0.05.

Results

Forty patients were enrolled in the study. All the patients completed the treatment sessions. Patient ages ranged from 23 to 48 with a mean of 31.5 ± 7.2 years [Figure 1]. All the patients were females. The duration of striae ranged from 3 to 12 years with a mean of 8.22 ± 3.4 years. The causes of striae distensae were variable as shown in Figure 2. Side effects were mild in the study groups and included erythema, feeling of heat, pruritus, and one patient only showed marked hyperpigmentation [Table 1].

Figure 1.

Age frequency of the studied sample

Figure 2.

Distribution of the sample according to the stria etiology

Table 1.

Comparative analysis of the studied groups (cases vs. controls)

Width and length of striae

In the first group, the width of the largest striae varied between 5 and 9 mm at the start of study. The mean value of width was reduced from 6.95 to 3.25 1 month after the last treatment with high statistical significance (P < 0.001). The base line length of the largest striae varied from 11 to 16 cm. The mean length was reduced from 13.1 before the treatment to 9.3 as measured 1 month after the treatment with significant improvement (P < 0.001) [Table 2, Figures 3–6].

Table 2.

Change of Length and Width of Stria before and after treatment in each treatment group

Figure 3.

(a) A 31-year-old patient with extensive steroid-induced striae before CO₂ fractional laser treatment. (b) A 31-year-old patient with extensive steroid-induced striae with good improvement after CO₂ fractional laser treatment. The patient developed marked hyperpigmentation

Figure 6.

(a) A 22-year-old patient with obesity-induced striae in the abdomen before CO₂ fractional laser treatment. (b) A 22-year-old patient with obesity-induced striae in the abdomen after CO₂ fractional laser treatment

Figure 4.

(a) A female patient aged 26 years with extensive striae in the thigh before CO₂ fractional laser treatment. (b) A female patient aged 26 years with extensive striae in the thigh showed marked improvement after CO₂ fractional laser treatment

Figure 5.

(a) A 28-year-old patient with marked striae in the legs before CO₂ fractional laser treatment. (b) A 28-year-old patient with marked striae in the legs showed marked improvement after CO₂ fractional laser treatment

The IPL-treated patients’ baseline width of the largest striae varied from 4 to 9 mm [Figures 7 and 8]. The mean value of width was reduced from 7.0 to 4.4 mm 1 month after the last treatment which is statistically significant (P < 0.001). The baseline length of the largest striae varied from 10 to 16 cm. The mean length was reduced from 13.2 before the treatment to 10.3 as measured 1 month after the treatment with significant improvement (P < 0.005) [Table 2].

Figure 7.

(a) A 29-year-old patient with obesity-induced striae before intense pulsed light treatment. (b) A 29-year-old patient with obesity-induced striae showed moderate improvement after intense pulsed light treatment

Figure 8.

(a) A 25-year-old patient with steroid-induced striae before intense pulsed light treatment. (b) A 25 years old patients with steroid-induced striae showed mild improvement after intense pulsed light treatment

By comparing both the treatment modalities, there was a significant difference in the improvement in striae width in those treated with laser than those treated with IPL (P < 0.005). There is no significant difference in the improvement of striae length in both study groups (P > 0.05) [Table 3].

Table 3.

Comparison between the two treatment strategy regarding change of Length and Width of Stria before and after treatment

Patient satisfaction

In the first group; 4 patients (20%) were none or less satisfied with the improvement, while 16 patients (80%) were satisfied with the results. In the second group, 16 patients (80%) were non or less satisfied by the results, while only 4 (20%) patients were satisfied. There is a significant difference between the two study groups regarding patient satisfaction (P < 0.005) [Table 4].

Table 4.

Comparative analysis of the studied groups regarding satisfaction and photo-evaluation

Photographic evaluation

By comparing the photographs before and 1 month after the treatments; 3 patients (20%) in the first group have been evaluated to have ≤50% improvement, while 17 patients (80%) have been evaluated to have improvement more than 50%. In the second group, 12 patients (68%) have been evaluated to have ≤50% improvement, while only 8 patients (32%) have been evaluated to have more than 50% improvement. There was a significant difference in the evaluation of photographs between the two study groups (P < 0.005) [Table 4].

Discussion

Striae distensae is a distressing cosmetic problem that has many causes such as obesity, steroids, and many other causes.[4,5,6,7,8] There are various treatment modalities for striae distensae such as topical tretinoin,[12] topical ascorbic acid,[13] topical glycolic acid,[13] and other topical treatments.[14] Other treatment options include: needling systems,[15] ultrasound, and radiofrequency.[27] The most recent treatment modalities are laser and light therapies.[16,17,28]

In this study, we evaluated and compared the efficacy of both CO₂ fractional laser and IPL in the treatment of striae distensae of various causes in 40 female patients. Half of the patients were treated with fractional laser and the other half were treated with IPL.

In the fractional laser treated group, significant improvements in both length and width of striae, photographic evaluation, and patients’ satisfaction after the treatment have been assessed. The findings of the current study were consistent with previous research carried out to evaluate the efficacy of fractional CO₂ laser on striae distensae. Naein and Soghrati compared the efficacy of fractional CO₂ laser with a combination of 10% glycolic acid and 0.05% tretinoin cream in the treatment of striae alba in females. They treated 92 striae and they divided them into two groups. The first group was treated with five sessions of laser resurfacing every 2–4 weeks. The second group was treated with 10% glycolic acid +0.05% tretinoin cream nightly during the study. They found that fractional laser treatment was significantly more effective than medical treatment.[29]

Lee et al. treated 27 patients with striae distensae using an ablative 10,600-nm CO₂ fractional laser. They treated 27 women with striae distensae in a single session with a CO₂ fractional laser and used deep FX mode with a pulse energy of 10 mJ and a density of 2 (percent coverage of 10%). They found that it could be an effective method in treating striae distensae.[30] Shin et al. evaluated the effect of succinylated atelocollagen and ablative CO₂ fractional laser in the treatment of striae distensae. They concluded that both ablative CO₂ fractional laser and succinylated atelocollagen were effective treatments for striae distensae. They suggested that further studies are needed to prove this efficacy.[31] Cho et al. treated patients with striae alba by using the 10,600-nm CO₂ fractional laser. They found a significant improvement of striae alba after the treatment.[32]

Our results also concur with previous studies that proved the efficacy of fractional photothermolysis by other photothermolysis devices. Katz et al. proved the efficacy of nonablative fractional photothermolysis in the treatment of striae rubra.[33] In addition, Bak et al. used fractional photothermolysis in the treatment of striae distensae in females. They concluded that fractional photothermolysis may be effective in treating striae distensae, without significant side effects. Treatment outcomes were better in patients with white rather than red striae.[34]

de Angelis et al., described the safety and efficacy results of treatment with a fractional nonablative 1540-nm erbium:glass laser in patients with Fitzpatrick skin Types II–IV for both striae rubra and striae alba. They detected positive safety and efficacy results with the fractional nonablative 1540-nm erbium:glass laser for the treatment of stria rubra and striae alba ranging in maturation age from 1 to 40 years in Fitzpatrick skin Types II–IV.[35] Guimarães et al., treated 10 female patients with striae distensae developed after breast augmentation by the use of nonablative fractionated 1550-nm erbium glass laser. They demonstrated excellent patient and plastic surgeon satisfaction after treatment. They supposed that the use of fractional photothermolysis is a good treatment modality for striae rubra.[36]

In the IPL-treated group, we found also a significant improvement in both length and width of striae distensae. Regarding the patient satisfaction and photographic evaluation, there was no significant improvement. These results agree with the previous reports which detected positive effects of IPL on striae distensae. Al-Dhalimi and Abo Nasyria compared two different wavelengths of IPL in the treatment of striae distensae. They treated 20 patients with striae by both wavelengths. Every site was treated with different wavelength every 2 weeks for five sessions. They found that both wavelengths were effective.[37]

Bedewi and Khalafawy used synchrotron infrared microspectroscopy to demonstrate the effect of IPL on dermal fibroblasts in patients with striae distensae. They found that IPL can treat striae through fibroblast stimulation which led to protein expression, especially collagen stimulation. They supposed that IPL is a promising therapeutic modality for striae with minimal side effects.[16]

In our knowledge, no previous work has compared the efficacy of fractional CO₂ laser and IPL in the treatment of striae distensae. By comparing the two treatment modalities, we found a significant difference in all the study parameters except in the length of striae. Striae width showed a significant improvement in the group treated with CO₂ fractional laser than the group treated with IPL in the same duration of treatment as evaluated by measurement, while no significant difference was noticed regarding the length of striae. Photographic evaluation showed a significant improvement in CO₂ fractional laser treated patients than those treated with IPL. Patients treated with CO₂ fractional laser were highly satisfied with their results as compared to those treated with IPL. Moreover, the CO₂ fractional laser treated group was treated only with five treatment sessions, while the IPL-treated group was treated with 10 treatment sessions. Both groups showed minimal side effects.

Conclusion

We concluded that both fractional CO₂ laser and IPL are effective treatment for striae distensae. Fractional CO₂ laser is more effective than IPL in the same duration of treatment and with lesser treatment sessions. Both treatment modalities have little side effects. Larger sized studies are needed to corroborate this efficacy.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

What is new?

Fractional CO₂ Laser is an effective and safe treatment modality for striae distensae.