Science > MultiClear How the MultiClear works? Treatment of Psoriasis by UVB is a common, effective and respected therapy for more than 100 years.[1] Narrow band UVB light (peak 296-313 nm) has been clinically shown to be the most effective regime for psoriasis therapy. [2,3] Typical clearing regimen treatment with full body narrow band fluorescent bulbs (such as TL-01) employs a cumulative dose of 13J/cm2 (range 4 J/cm 2-24 J/cm 2 ) exposing both lesional skin and non involved "normal" skin to UV. In classical full body narrow band UVB therapy clearing is achieved in 80% of treated patients in 4 weeks, 3-4 treatments /week. Fifty percent of the responding patients of patients remain clear after 6 months [4]. It is known that normal skin can be exposed More... Successful Treatment of Localized Leukoderma With the MultiClear to up to 3 MEDs without blistering, while psoriatic skin may be exposed to up 3 times this dose (9 MEDs) without blistering. [5,6] A therapy targeted only to psoriasis plaques sparing the healthy skin may thus employ higher fluences and may shorten time to clearance. Another advantage of targeted phototherapy is the sparing of non psoriatic skin from harmful UV effects. Asawanonda et. al [6] treated psoriasis with an Excimer laser emitting 308nm. Fluences of up to 6 MEDs on psoriasis plaques were well tolerated by all patients. Most patients remained cleared after 2 months of followup. Excimer laser therapy was associated with a few mild side effects such as temporary hyper-pigmentation, blistering- similar to a sunburn, erosions and possible mild local pain during therapy. Diericks presented her work with a non coherent targeted UVB phototherapy system. This system produced high intensity UVB light delivered to the skin through an optic fiber to treat a 16mmX16mm spot. In her study, patients with multiple psoriatic plaques were treated with 1,3,5, or 7X MED once per week for up to 15 weeks. Treatments were well tolerated with only minor adverse effects such as erythema transient hyper pigmentation and occasional blistering. Six out of ten patients responded favorably to the treatment. Improvement was noted after one or two treatments. Plaques were cleared from most anatomical locations including the hands, elbows knees, trunk back and buttocks.
The MultiClear is a novel tunable multiwavelentgh medical device which selectively targets a multitude of skin conditions. It emits high intensity incoherent light which is tunable to a few optimal narrow band emission spectra In the UVA and UVB range. Optimal treatment parameters are selected through a fully computerized built in expert system. This high intensity novel device may expose psoriatic skin to high narrow band fluences totally sparing the non lesional skin. Basic setup provides a spot size as large as 23X23 mm. Computerized controls allows exposures of up to 7 MEDs in both continuous or pulses mode. UVB emission peak at 304-313 nm is optimized to fit best efficacy /erythema treatment ratio. Multicenter study: A multicenter study utilized the MultiClear (Curelight Ltd.) operated with an enhanced plasma lamp mixture. Spectral measurements indicated lack of emission below 294 nm and a significant peak at the maximal efficacy wavelengths of 304 and 313nm. A specially designed light concentrator focuses the light on a liquid fiber allowing a homogenous of 23X23mm effective treatment spot size. An initial study included 10 patients with a variety of plaques sizes. Patients had stable psoriasis and have not used any topical anti psoriatic medications for at least 4 weeks prior to trial. Eighty percent of the patients responded to the treatment with minimal side effects.. In responding patients, 80% Clearance was noted after an average of 6 treatment sessions. Dose range per lesion was 0.15-4 J/cm2. Lengths of a full treatment session/per patient was 5-10 minutes.
Figure 1. MultiClear therapeutic spectrum Figure 2. A. Before therapy; female patients, 55 years olds, stable psoriatic plaque on Rt. Elbow. Psoriatic plaque prior to the first treatment. B. Same plaque 5 months after 5 treatments.
Figure 3. Female patient, 75 years old, stable psoriatic plaque on the back. A. Before therapy. B. After 2 weeks (4 treatments) C. After 5 weeks ( 8 treatments) D. 3 months after last treatment. Figure 4. Female patients, 45 years old, stable psoriatic plaque on the lower back. A/B Before therapy. C. After 3 weeks (5 treatments) C. 4 months after last treatment. Summary: Treatment of plaque psoriasis can be effectively and safely achieved with narrow band UVB light (296-313 nm spectral band). Comparing efficacy to the different UVB spectral peaks has shown the 304nm is more efficacious for plaque psoriasis than any other single UV wavelengths. The MultiClear multiwavelentgh targeted phototherapy system tested in the current study allows high intensity 304, 313 nm optimized UVB therapy over a large 23X23mm spot size., Computer guided MED assessment allows an accurate and fast MED assessment crucial to accurate starting dose selection. Built in expert system suggests dose increases based Modified PASI built in scoring. Treatment doses as high as 7 MEDs are used on psoriatic lesions while totally sparing non involved skin. Our preliminary data shows a response rate of 80% of the patients psoriasis plaques with average clearing after 6 biweekly treatments as compared to usual 30-40 treatments with classical full body UVB systems The MultiClear targeted phototherapy provides major advantages to other available full body or targeted UVB modalities. Accumulated lesional UV doses till clearing are a third than accumulated UV doses till clearing in classical full body systems. (4J/cm 2 vs. 13J/cm 2 ). Most importantly the MultiClear targeted phototherapy totally spares non involved skin from UV - thus providing a superior safety profile. Response is achieved in an average of 6 biweekly treatments (3 weeks) instead of 30-40 treatments in full body light boxes (8-10 weeks of 3-4 treatments/weeks). The faster results achieved with the MultiClear (compared to excimer laser or other non coherent targeted phototherapy systems) may be explained by its optimized 304nm UVB wavelength (308nm or non optimized UVB in other devices). It may be also due to better and easier dosing monitoring through the MultiClear UV assessment based Dosing System (MUDS ).
References: 1. Fischer T. UV-light treatment of psoriasis. Acta Derm Venereol (Stockh) 1976;56:473-9. 2. Parrish JA, Jaenicke KF. Action spectrum for phototherapy of psoriasis. J Invest Dermatol 1981;76:359-62. 3. 313 as action spectrum for psoriasis. Abel EA. Phototherapy. Dermatol Clin 1995;13:841-9. 4. Green C, Lakshmipathi T et al. A comparison of the efficacy and relapse rates of narrowband UVB (TL-01) monotherapy vs. etretinate (re-tl-01) vs. etretinate-puva (re-puva) in the treatment of psoriasis patients. Br J Dermatol 1992 Jul;127(1):5-9 5. Bonis B, Kemeny L et al. 308 nm UVB excimer laser for psoriasis. Lancet 1997 Nov 22;350(9090):1522. 6. Asawanonda P, Anderson RR, Chang Y, Taylor CR. 308-nm excimer laser for the treatment of psoriasis: a dose-response study. Arch Dermatol 2000 May;136(5):619-24.