How long after a CO2 laser treatment should I wait before starting a series of non-ablative fractional laser treatments?

In general, its 4-6 weeks but you really should check with your treating provider as there are certain issues like delayed healing that may be a factor in delaying further treatments. 

I recommend following up with your Doctor about the recommended timeline for fractional laser treatments after Co2. Keep in mind, it will take several weeks for the Co2 laser results to settle. Acne scars need a combination approach with lasers, microneedling/prp, Cosmelan subcision and fillers. I recommend getting a formal evaluation with a cosmetic dermatologist. Best, Dr. Emer

Thank you for your question. You state  for your acne scars, after you underwent CO2 laser treatment you became aware the treatment was about 50% effective in improving acne scars, so you want to know when to follow-up the treatment with a 1540nm laser, and how long after initial treatment can you do that.
I can share with you the principles that are relevant with this type of question. A little background: I’m a Board-certified cosmetic surgeon and Fellowship-trained oculofacial plastic and reconstructive surgeon. I have been in practice in Manhattan and Long Island for over 20 years. I have been using lasers since the early to mid 90s including the original CO2 ablative lasers, and it’s a time in laser treatment when we have so many options. When you have these many options, you also understand there’s clearly no single best approach to any particular problem.
Acne scars are one of the most challenging problems to treat. You have to think about someone who can manage you from all aspects, and not just treat you with the laser. The reason is most people who have acne scars have a combination of scars, from rolling scars, boxcar scars, ice pick scars, atrophic scars, to facial fat atrophy.
Before you start with any laser, what I do is look at the foundation of what gives a person smooth looking skin. People think it’s all about trying to smooth out the top layer, but when you think about skin, you get a structure that’s about 2 millimeters in thickness in the face. You also have to think about volume below the skin.
When you ask a question like this, I hope you’ve also had a discussion with the physician about strategies. When I evaluate a patient with acne scars, I take photos with direct light, and I take photos with backlight. Backlighting shows me areas which cast a significant shadow. Often I find the most significant shadows are cast because of volume loss.  What I often do for a younger person is Structural Volumizing, which is placing a long lasting filler like Juvederm Ultra Plus and Juvederm Voluma at the cheek level, on the bone which results in a restoration of volume so acne scars look smoother. A lot of patients who come in who have experienced facial aging on top of acne scars really appreciate that significant change, probably more than anybody. The point is understanding you have to work from the inside, then outward.
We also combine other treatments to improve the skin’s ability to respond, so I sometimes combine this with platelet-rich plasma (PRP) injection, or microneedling with platelet-rich plasma. I try to minimize more aggressive ablative procedures, so before doing them we get the skin healthy and full, so you may end up needing more conservative treatment.
There’s a basic principle in wound healing where after you have an injury including the controlled injury of laser resurfacing, there is a proliferative phase of generating collagen that lasts about a month. Based on that concept, it might be safe for you to do a non-ablative procedure such as this particular laser to try to stimulate collagen. I would caution you that there’s also a wound remodeling phase. I would lean more on the conservative before trying to stimulate the skin to generate more collagen because you can only generate so much. Often, people are frustrated because they get a laser, and another laser, and another to the point where they have come to me, and their skin after so many different laser treatments looks really thin. We then do tissue rehab where we’re using platelet-rich plasma derived from your blood, sometimes combined with Acellular matrix to help stimulate the fat cells and give the skin some substance before treating it with another laser. Interestingly, the world is coming full circle with a lot of the luminaries who were the biggest proponents for laser are now advocating PRP as well as microneedling.
I think you have to think through this process and have a realistic understanding of outcome. People generally want to see significant improvement. Often, acne scar patients get very frustrated because they don’t necessarily see improvement, they only see where there’s still loss. It’s very important to have a good relationship with your doctor, and have clarity with what the outcomes will be, and the timing. We have a lot of tools, but you have to know when to use them, and when to hold back and wait. Ultimately, it’s my goal to do what is most effective, with the least amount of downtime, and have a sense of what makes the most impact. Unfortunately, you have to accept there’s no perfect solution for acne scars. There are ways to treat and improve appearance, but some things cannot be completely reversed. I hope that was helpful, I wish you the best of luck and thank you for your question.

It sounds as though you desire to be aggressive in your therapy. There are many factors to consider, not only the devices used or time separating treatments. I have the equipment you describe and use them nearly everyday.  It's excellent equipment with which I or another skilled practitioner can accomplish much with.
I frequently utilize both devices during the same session. However, post Co2, I'd generally give at least 6 weeks to let a good portion of healing from the Co2 treatment occur. 
If your a skin type 1 to 3, you're likely reasonably safe to receive a treatment after a few weeks, provided your practitioner is fully informed of your prior therapies. In other words, it may be possible, but I'd wait for at least 80% of the Co2 results and error on the side of reasonable caution.  
The Palamar Icon 1540 on its' own likely won't get you to where you hope to be as fast as a combination therapy will. A combination therapy will deliver superior results. However, the delivery of a combination therapy won't help as much if performed incorrectly. 
For example; using the 1540 followed by microneedling and PRP simply applied topically (surface of skin) will have no where near the result as also properly injecting the PRP under the scar. 
When properly performed in a manner that the PRP hydro-dissects and breaks up the underlying scar tissue, conventional subcision is not required. This method better promotes normal tissue regeneration absent scar reformation.
If you have not already done so, first get your acne under control. First identify and address the root cause of your acne. If you have not, you will simply be going in circles with flares and costly repairs.
     Warmly,
Arbella Sarkis, MD

Thanks for your question.  You really should ask the physician doing the treatments.  Each doctor will have their own protocol.  If you were our patient, we would encourage you to wait.  It can take 6 months to see the full results from any resurfacing treatment.  You are trying to remodel your skin from the bottom up.  It just takes time.  You probably need to wait a minimum of 4-6 weeks for your skin to heal.  We would recommend waiting at least 3 months.  Best of luck.

After CO2 laser treatment to the usual depth (upper to mid dermis) for acne scarring, the subsequent healing process lasts at least 6 weeks or more, depending on adjunctive measures and your skin type. Therefore I would advise waiting at least this long before beginning secondary fractional treatments. Good luck!

To answer your question 4-6 weeks depending on the setting of the CO2 laser- energy coverage, your skin type and your skin condition. IF you are thinking of non ablative for acne scarring or even rejuvenation you are actually taking a few steps back from fractional CO2. 
Acne scar revision is a sub-specialised field. For the best results, one should target the acne scar type with ideal treatments and not just one device. The web reference below will take you to a resource to help you understand acne scar revision at a specialist level. I embedded all the videos in one page to help.

For example deep ice pick scars, and narrow box car scars can be treated with TCA CROSS peels, mixed scars, rolling, and atrophic scars treated with fractional devices such as Fraxel, fractional lasers, PRP and INFINI radiofrequency. Atrophic scars (depressions) can be treated with either fat grafts, or with HA dermal fillers. Tethered and anchored scars are best treated with surgical techniques such as subcision. Other surgical techniques that we use include punch elevation, surgical elevation, punch excision and traditional excision of focal scars.

The majority of patients will have a collection of different scar types, and hence a tailored treatment METHOD will be best. Careful examination, especially under angled lighting with scar mapping will give you an understanding of what are the best options for your scars. In the majority of patients its finding the correct combination that give you best results, and everyone is unique! All the best,

Dr Davin Lim. Acne scar dermatologist specialist. Brisbane, Australia.