In conclusion, the treatment modality described may be a new approach to the treatment of wrinkles.

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Irradiation by the haemoglobin-specific short-pulsed 585 nm laser induced a fivefold increase in procollagen production rate compared with a biologically comparable fluence delivered in a broadband spectrum. An additional treatment after 2 weeks further increased the effect of the short-pulsed 585 nm laser to 148% of the control. Vascular-specific light/tissue interactions seem to play a key role in stimulating skin collagen production.

Lasers have been established as effective treatment for hair removal, with possible long-term suppression of hair growth in treated areas. The purpose of this study was to assess long-term hair regrowth after treatment with the ruby laser. Volunteers recruited into the 1997-99 study were divided between three treatment groups, each having left and right treatment sides. Two treatments were given on both sides at monthly intervals. A third treatment was given randomly to one side. Hair counts of the experimental sites were made at monthly intervals for 1 year. The three patient groups were: top lip (25), axillae (25) and legs (19). Long-term hair reduction was achieved in all patients. A single treatment reduced hair counts by up to 75. Three treatments had an impact for 2 additional months, but not long term. Unexpected spontaneous hair reduction was found 5 months following treatment and lasted 2 months. This ruby laser produced a persistent two-thirds reduction in hair count over 8 months of follow-up. Extension of the follow-up to 12 months did not show significant regrowth. Existing experimental data, together with the results of this study, suggest that hair shaft damage is the key feature in achieving damage to the hair-producing mechanism. The correlation of treatment success and anagen growth phase is less likely.

The current annual global market for domestic intense pulse light (IPL) hair removal has been estimated at US $1 billion and continues to grow. The five key technological parameters to consider in cutaneous photo-therapy are wavelength, energy density, pulse duration, spot size and spatial distribution. Uneven energy distribution in the treatment area can result in over or under treatment of the treated area, thus causing dissatisfaction or harmful results. This study investigates a method of measuring and analysing spatial distribution of a number of commercially available home-use IPL systems as there is no quantitative method to conduct and compare spatial distribution at the present. Using a CCD camera and a phosphorescent screen to extend the pulse duration, averaged time frames were analysed using Matlab mathematic software. 3D graphical images of the data are presented to show the spatial profile of five commercially available IPL systems. Numerical analysis of the data was completed by two methods, arithmetical mean roughness and path difference.

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Flexor tendon injuries are a common problem requiring sutured repair followed by early postoperative mobilisation. Results are better if active rather than passive flexion is allowed, however active movement increases the incidence of dehiscence. This has prompted examination of thermal bonding as a strategy for strengthening tendon repairs. Three experiments are described, using method and experimental design similar to those previously described. The strength of thermal bonds created between sections of bovine Achilles tendon at a range of temperatures and times was measured. Bonds were created by heating compressed sections in a water bath. Bond strength was measured on a tensiometer as load (N) and stress (N/mm2 and N m kg-1) then calculated using measured cross-sectional area, weight and length. Results were in broad agreement with those previously described, showing peak bond strength in samples heated to 62 degrees C for 8 min (median 17.11 N/cm2, SD 2.13). The effects of cooling to 0 degree C for 10 min immediately after bonding was to increase median bond strength when compared with non-cooled samples bonded under similar conditions (non-cooled, 9.11 N/cm2, SD 3.11; cooled, 11.96 N/cm2, SD 2.93). Statistical analysis using a quadratic regression model showed a close correlation between experimental data and curves modelled to best fit the data. Peak values for thermal bonds created using the methods described approached and in some cases exceeded that reported for the epitendinous element of modified Kessler tendon repairs in human digital flexor tendons. If such bonds could be created in vivo, thermal bonding may have a role in augmenting the strength of tendon repairs. The methods described are impractical for a non-laboratory environment. A laser would seem the most attractive alternative source of heat energy.