Notes on the Filters and the orders of the filters
Well, this all stems from the concept of layering the energy delivered by successive passes
in a way that is unlikely to result in any harm. The filters are low cut off filters. This means that each filter cuts out wavelengths below the number but allows through wavelengths above the filter number all the way up to 1200nm
First Pass - usually 590nm filter Starting Fluence c. 22J/cm2
OR the 560 nm filter
(OR occasionally 515nm filter).
Second Pass - usually the 615nm filter Starting Fluence c. 24J/cm2
Third Pass - usually the 695nm filter Starting Fluence c. 26J/cm2
I start with the "wider" filter first (lowest number) because that may be all that you can deliver if the skin has had enough when the first pass is done. There is no problem delivering two or one pass rather than the customary three passes, if having finished the pass, you and the patient feel that the patient's skin has absorbed more than sufficient energy. Each time you advance to another pass, you are increasing the energy but decreasing the delivered wavelength bandwidth.
Therefore, if you do a typical treatment 590/615/695nm at 22/24/26J/cm2 then:-
The first pass delivers all wavelengths from 590 up to 1200nm at 22J/cm2.
The second pass misses out 590-614nm but delivers 615-1200nm at 24 J/cm2.
More energy (24 J/cm2) to drive the light towards deeper structures but missing out some of the wavelengths likely to harm the epidermis
The third pass misses out 590-694nm but delivers 695-1200nm at 26 J/cm2.
More energy (26 J/cm2) to drive the light towards deeper structures but missing out some of the wavelengths likely to harm the epidermis
Why not go in the other direction?
If the skin will tolerate all three passes then it probably doesn't matter that much what order you perform the passes. The reason I don't go in the other direction is that as we are often increasing the doses of energy as we are doing the passes and when you are doing this, you don't yet know that the skin will tolerate it and you may have to stop after pass one or two. I'd rather see the effect of the first filter setting and then choose whether to add a "safer" i.e. narrower bandwidth dose of energy on top than to heat up the skin first with the third and second passes (if we were going in reverse) only to top them off with the widest filter at increased fluence. I wonder whether that is the increasing fluence value together with the increasing filter wavelength number that implies that the 2nd and 3rd pass are more likely to be injurious to the skin. It is the relative effects of filter vs fluence that is the tricky concept here. More power yes, but a narrower, safer blend of wavelengths as the fluence and filter numbers rise.
(I hope that this is making sense). I don't know what would be an appropriate logical analogy - if anyone can think of one it would be good to know of one. Doing the filters in reverse now would feel like sanding down wood with the coarsest sandpaper last. This may not be a good analogy I accept this but over the years and 20,000 treatment shots later, what was initially counter-intuitive seems more obvious now.
Others will adapt and follow their own paths and create their own protocols and this is by no means a bad thing - the comparative results will yield a greater understanding of how best to treat rosacea using the Lumenis One.
I hope that the above is helpful.
Peter
Dr Peter Crouch
22nd June, 2009
visits to this page since 22nd June, 2009
Important Note:-
This protocol is not intended to replace clinical judgement* and the author accepts no responsibility for any damage caused by other practitioners adopting these treatment protocols in place of their own clinical judgement. Physicians must assess each patient's suitability based on their medical history, skin type, severity of rosacea and co-morbidity. This expert medical protocol remains the copyright of the author and The Burghley Park Clinic and permission must be obtained from the author before reproduction of this material in full or in part in written, electronic or other form.