Wrinkle reduction

Abstract

Wrinkles are cosmetically removed from a superficial area of mammalian skin tissue having an epidermal layer, a basal layer, and a dermal layer, by irradiating the dermal layer through the basal layer, the irradiation being selected to be absorbed by a chromophore in the dermal layer such that collagen present in the dermal layer is heated, while the basal layer remains intact so as to substantially inhibit contact of the dermal layer with ambient air.

Description

[0001] This is a Continuation In Part of U.S. patent application Ser. No. 08 / 919,472 Filed on Aug. 28, 1997.BACKGROUND TO THE INVENTION[0002] The present invention relates to a method of reducing wrinkles from a superficial area of mammalian skin tissue, and apparatus therefor.[0003] The application of laser technology in healthcare is well known, and the use of lasers in medical applications has been studied extensively since the early 1960's. In recent years an increasing interest has been shown in cosmetic applications. Two such cosmetic applications are skin resurfacing and wrinkle removal; in this field lasers can be used as an alternative to surgical facelifts.[0004] There is a distinct difference between wrinkle removal and skin resurfacing. Skin resurfacing is where laser energy vaporizes thin layers of the epidermis without breaking through the basal layer into the dermis. This is essentially a superficial process primarily used to give the skin a "fresher" appearance. Howe...

AI Technical Summary

Benefits of technology

[0013] It is therefore the primary object of the present invention to provide a technique for removing wrinkles from a superficial area of mammalian skin tissue without causing secondary burns and other problems associated with traditional wrinkle removal.

[0016] The irradiation of the dermal layer in the method according to the invention is tailored to shrink the skin tissue without damage to the dermis (in other words, without causing second degree burns) because the barrier provided by the basal layer remains intact. This is achieved by selecting the required radiation wavelength to match the characteristic absorbtion wavelength of the chromophore whilst being absorbed to an insignificant degree in the epidermis and basal layer. The energy delivered per pulse is also tailored to ensure that ablation does not occur of the target structure, but rather that energy absorbed in the target provides sufficient heating that heat energy diffusing outwards from the target heats the surrounding tissues to a degree sufficient to thermally induce shrinkage of the surrounding tissue and also stimulate the production of new tissue components such as elastin and collagen.

[0020] The method according to the invention is non-invasive and non-ablative and can readily be performed by non-medical personnel. The total energy delivered per pulse is sufficient to effect the required physical change in the tissue surrounding the target chromophore without causing ablation of the target or other skin components through which the radiation passes.

Problems solved by technology

However, wrinkle removal as a more aggressive technique where tissue is removed layer by layer, invading the dermis and effectively inducing a second degree burn.

During aging, the collagen changes its structure impacting negatively on the cosmetic appearance of the skin.

Also, the incidence of side effects is significant, the most common being hyperpigmentation occurring in 30-40% of cases.

A delayed hypopigmentation, which can occur up to a year after the procedure was performed, has recently emerged as a complication of aggressive laser resurfacing.

This second stage of the procedure is primitive; the skin weeps, scabs form and redness of the skin appears for many weeks.

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