When the word 'Laser' is used, it evokes immages from films like 'Star Wars' or television series like 'Star Treck'. Powerful laser beams used to shoot down and destroy enemy spacecraft. The reality about Lasers is that they are a very important component in many of the technologies that today we take for granted. Technologies like CD players, DVDs and Laser printers all use lasers. Lasers have many uses and they are increasingly being used in medicine to deliver better health outcomes. 

What are Lasers?
The word L.A.S.E.R. is an acronym which stands for Light Amplification due to  Stimulated Emission of Radiation. Lasers were developed in the 1940s by scientists studying the properties of light. The details of the physics behind lasers is beyond the scope of this discussion. Essentially laser beams are a highly specialised form of light that contain a single colour. Different lasers contain different colours. There are blue lasers, red lasers, green lasers and yellow lasers. 

How do Lasers work on the skin?
Lasers have been found to have many useful properties that can be used in clinical work:

• Lasers can pass through the surface layers of the skin without damaging them. This allows the treatment of blood vessels and pigmentation within the skin and under the skin. 
• Different lasers penetrate the skin to different depths. This property allows targeting of different layers within the skin.
• Lasers passing throught the skin are absorbed by blood vessels or pigmentation and converted to heat. This property allows the selective destruction of blood vessels and pigmentation.

The most important aspect of laser treatments to the skin is that, if the treatment goes according to plan, there will be no visible mark left after healing is complete.

How do lasers work on capillaries?

• The laser goes through the superficial layers of the skin without damaging them.
• The laser light is absorbed by the blood in the capillaries
• The laser light is converted to heat
• The temperature of the blood rises sharply and internally burns the capillary

How do lasers work on pigmentation?

• The laser goes through the superficial layers of the skin without damaging them.
• The laser light is absorbed by the dark colour of the particles of pigmentation 
• The laser light is converted to heat
• The temperature of the particles of pigmentation rises sharply and burns them 
• The burned pigmentation will either work its way to the surface of the skin and be shed or it will be absorbed in the deeper layers of the skin

How do lasers work on hairs?

• The laser goes through the superficial layers of the skin without damaging them.
• The laser light is absorbed by the dark colour within the hair shaft 
• The laser light is converted to heat
• The temperature of the hairs rises sharply and burns them 
• The burned hair will either be shed or it will be absorbed in the deeper layers of the skin

How do resurfacing lasers work?

• Resurfacing lasers are totally different types of lasers designed to peel or remove superficial layers of the skin without damaging the deeper layers.
• Resurfacing lasers are absorbed by the water within the cells 
• The laser light is converted to heat
• The temperature in the cells rises sharply and burns them 
• The burned cells evaporate and leave a raw area of skin which heals within a few days.

Are lasers safe?
Medical lasers are very safe

Advantages of laser therapy

• Laser therapy aims to give patients better cosmetic results
• Healing following laser therapy is usually rapid 
• Lasers give patients freedom from their capillaries, pigmentation and hairs for prolonged periods of time
• Resurfacing lasers reduce wrinkles
• The effects of lasers may be permanent

Disadvantages of laser therapy

• The results of laser therapy can not be completely predicted
• Results can not be guaranteed
• Laser therapy results in skin damage in a small number of patients  

Lesions of the skin that can be treated by laser

These red spots are called haemangiomas. Laser therapy is very sucessful.

Freckles can be treated by laser, however, new freckles will develop with the passage of time and sun exposure. Laser treatment of freckles require regular treatments once or twice per year.

Spider veins and capillaries of the face are treated very successfully.

'Poikiloderma of civatte' the name given to this red condition of the neck. Requires regular treatments with laser once or twice per year.

'Caffe au lait spots' the name given to this light brown discolouration of the skin. Requires regular treatments with laser once or twice per year. 

These blue to black spots commonly found on patients lips can be treated very successfully.