Laser Surgery - Use of Cosmetic Laser Surgery as Eye and skin surgery

The term Laser Surgery implies Light Amplification by Stimulated Emission of Radiation. These are optical devices producing electromagnetic energy with their special properties viz. light output is monochromatic for each type of laser, light is coherent (complete alignment of all the waves produced and emitted) and light is highly climated (no divergence during travel - essentially directed beam without loss of intensity).

Since its first use in 1960, lot of research has been done in this field. Not only newer lasers are being produced, but usefulness and disadvantages of each laser are also being studied extensively in different parts of the word.

A laser device has the following components:

1. Active medium-Ruby rod (solid), CO2 (gas), liquid (fluorescent dyes).

2. Power supply-for energizing the active medium electrical, chemical, radio frequency or mechanical.

3. Optical resonator-or tube surrounding the active medium. It has a totally reflecting mirror at one end and partially transmitting one for the laser beam. In the continuous-wave laser, shuttered pulses for certain therapeutic modalities are used like the shuttering device in a camera. Action of the laser beam on the skin depends upon the following factors:

• Optical properties of the skin-water content, melanin, haemoglobin (red cell mass) and the presence of other colours.
• Wavelength, power density (watts per sq. cm) and energy fluence (irradiance multiplied by time of exposure expressed as joules per sq. cm) of the laser.
• Length and type of exposure.

Penetration, absorption of the laser beam by different tissues (red cells, black melanin, Fibroblasts etc.) and tissue scatter depend upon these three factors and hence the ultimate destruction of the desired diseased tissues and the saving of healthy surrounding tissues (to avoid scarring) are calculated in treatment.

It is believed that long exposures produce no specific destruction and short exposures produce specific localised damage to desired tissues. Tissue scatter and thermal relation are the other factors to be taken into consideration while planning laser therapy.

At the present junction, six laser systems are in use. Only No. 2, 4, 6 are used in dermatology. Their different properties are briefly tabulated laser systems

1. Argon Laser

2. Carbon dioxide Laser-for warts, Keloids, lymphangiomas etc.

3. Ruby Laser

4. Helium-Neon Laser-for acne vulgaris

5. Neo-Dymium YAG Laser

6. Tunable Dye Laser with fluorescent dyes (esp. rhodamine 6 G)-for haemangioma and moles