What laser was applied on my hands? Confused...Help!

Here's the short answer:

1.  Photofacials are performed with an IPL, aka Intense Pulsed Light.  You didn't mention which IPL they used, so I can't comment on the quality of it.  These don't usually completely eliminate all brown spots in one treatment, for various reasons ... read more below.

2.  IPL stands for intense pulsed light.  Basically a light bulb with different filters that narrow the light to go after specific targets, like the brown spots on your hand ... read more below.

3.  Lasers will remove wrinkles, since they ablate the surface of the skin.  Spider veins can be treated with either lasers or IPL.  More confused?  Read on.

4.  Age spots and fine veins can be treated with either the laser or IPL.  Wrinkles can be treated with laser. This looks suspiciously like question #3.

Here's the long answer:

There are basically two types of light-based treatments available for a variety of skin concerns:  the laser, and the IPL (intense pulsed light).  Many people interchange the two, but they are quite different.  The basic effect of light affecting a target, destroying it, and the body removing it, still lies true for both types of light-based devices. 

Light comes in different wavelengths, some of which cannot be seen by the human eye.  You may have seen sunlight broken down into different colors with a prism (or water, as in a rainbow); these colors represent different wavelength of light.  There are also infrared light and ultraviolet light, and a myriad of other wavelengths that we cannot see that are used in lasers and IPL's.  The lasers or filters in IPL's utilize these wavelengths of light to go after different targets that are responsive to them.

Different targets (referred to as chromophores) respond to different wavelengths of light.  The targets that we want to destroy include hemoglobin in blood vessels; pigment in brown spots, hair or tattoos; propiones acnes bacteria and sebaceous glands in acne; water; or collagen.  Destruction or modification of these targets depends on many factors, including their size, depth, and other targets that may compete with them in the vicinity.  The more specific the wavelength, the better it will hone in on that target and ignore other things in its way.  Targets that have basically no pigment (like gray or blond hair) have nothing to go after, so hair removal of this color hair is virtually impossible at this time.

Light affects the target by being absorbed by the target and destroying it.  Then the body goes in and removes it. Darker or larger objects absorb heat better, and are destroyed more readily.  Think of walking out in the sun in a black T-shirt versus a white T-shirt; you'll get hotter faster and stay hotter longer with the black T-shirt.  This is how the skin and other surrounding tissues are spared when the light is used.

Lasers are a single color and a single wavelength (think of laser pointers).  They go after one target that responds to that wavelength.  So a laser that removes hair won't necessarily work as well for vein removal, because the pigments respond to different wavelenghts.  Lasers are more focused and tend to ignore other tissues that don't respond to that wavelength, somewhat like a heat-seeking missile.  Depending on the wavelength, lasers are safe in most skin types.  Lasers that target water (erbium, CO2) are resurfacing lasers, and they ablate / vaporize the water under the surface of the skin, thereby removing the skin above that layer.  This will remove not only wrinkles but also superficial pigment in the skin that is vaporized. 

Intense pulsed light is a light bulb connected to a computer that tells it how often and how long to flash to destroy the target.  A filter is applied to the bulb to focus the light to a specific wavelength to go after a specific target.  The filters, however, have a broader span of wavelengths, instead of a single wavelength as in a laser.  So, if there is surrounding tissue that is similar enough to the target, there is a risk the light will go after that as well or instead of the intended target.  Intense pulsed light is best on what I call "Snow Whites," meaning fair-skinned people with dark hair (in the case of hair removal).  For example, if you recently got a tan on your hands before you went in for this treatment (i.e., if you're not religious about applying SPF everyday before you drive), then had the IPL try to treat the brown spots, it could have gone after the melanin instead of the brown spots.  The clinician should  determine your Fitzpatrick score (how you respond to sun) to see what treatment and settings to perform on you.  IPL's generally are safe to use up to Fitzpatrick scores of 4 (as dark as Asian or Middle-Eastern people).

Intense pulsed light is most likely the device that was used on your hand, if the term "photofacial" was used.  The filter they used was specifically used for the pigment in your brown spots.  Depending on the machine and the filter, some of the brown spots would have been better affected than the others. 

Things to look for in your next "spa laser center" (or better yet, a medical spa):

1.  Before and after pictures of treatments performed at that location (not stock photographs from the laser company).  Ask for in-between pictures if available, so you know what kind of healing process and appearance to expect. Ask if these results are typical or just their best patients.  Also ask them how many treatments it took to achieve the results shown in the picture.

2.  Ask about the experience and the frequency with which they perform this treatment.  Many states prohibit the use of light-based treatments by people other than medical professionals (physicians, nurses, P.A.'s, medical assistants).  The specialty of the physician is irrelevant, since none of us get this type of training during residency.   I personally perform all of my treatments, and I attend continuing education on them almost every month.  Ask to see the credentials of the one performing the treatment on you.

3.  Ask if they have ever burned anyone with the machine.  If so, how did they treat it; what was the outcome?

4.  Really read your consent form.  It is a legal document you are signing.  Ask questions if you need to, and never feel pressured to do anything without understanding it.

Best of luck.

Updated July 2, 2008:

This is the answer to the follow-up questions:

The Starlux IPL is a decent IPL.  All IPL's are basically light bulbs hooked up to a computer that tells it how often and how fast to pulse the light.  There are different terms, such as Broadband Light, Variable Pulsed Light, and Intense Pulsed Light.  They all refer to the same thing, and the terms are basically a sales gimmick that many companies use to differentiate themselves in the market.  As I mentioned before, different filters are attached to this light bulb to narrow the wavelength of light to treat certain conditions.  Although this narrowed width of light will treat that specific target, it may also overlap some to treat other conditions.  However, the filter used for telangiectasias (spider veins) narrows the spectrum down to a different band of light that is used for lentigos (brown spots) or hair.  So this means a different filter needs to be changed out for those specific treatments, which means a different treatment, more time, and more cost (because they will charge for a different treatment).  There is usually a different filter (and, hence, wavelength) to address collagen (also known as Skin Tightening) that could also be applied to the skin to help the collagen develop.  This filter works best on sagging areas such as the double chin or jowls and basically aligns the collagen so everything tightens up.  The Cutera Titan has the name-recognition for this, but many companies have this filter available for their IPL's.  I seriously doubt the treatment you received would do all treatments simultaneously,  but you should really check your "before" pictures to see what has truly improved.  You look at your hands everyday, and it is difficult to discern what has really changed compared to what your mind remembers from previously.   You will need multiple treatments to address pigments at different depths.  If the IPL is not powerful enough, or if the settings were not properly chosen, you will not notice a significant change, even after several treatments. 

The Fraxel is the first of the fractionated lasers that came out that creates smaller cylinders of light that go into the skin and vaporize just those areas.  This leaves intact tissue around these areas, which is why it would not work as well for brown spots.  As I mentioned previously, lasers and IPL's are two different animals.  Many companies have fractionated lasers that perform as well as, if not better than, the original Fraxel.  The wavelength of light that is in the Fraxel is different from the Erbium or CO2 laser that I discussed before.   The basic principle behind fractionated beams is removal of small amounts of tissue, sparing the surrounding tissue.  The areas that are removed heal, and become filled with collagen, and the surrounding tissue grows closer, creating a tightening effect.  If you live in a cold climate, then you would understand the analogy with aerating your lawn, so water and nutrients can work their way down into the dirt.  It sound like this "spa laser center" does not carry the Fraxel or other lasers.

It's hard to imagine spider veins on the hands and arms, since they are usually more evident on your face (cheeks and around the nose) and legs than the upper extremities.  Sclerotherapy is what is usually performed to reduce the appearance of spider veins.  However, I doubt that is what your concern truly is; I would guess it is more the increased appearance of veins in the hands and arms.  If that is the case, I would also recommend long-acting dermal fillers that activate collagen production under the surface of the skin. Those options should have been addressed during your consultation. If not, you may consider getting a second opinion.