4 months ago I underwent CK (conductive keratoplasty) to finally correct residual hyperopic astigmatism resulting from conventional lasik and enhancements 7 years ago.
For lasik survivors who were myopic and over-corrected or primary h-lasik pateints like me who ended up with less than acceptable results on the hyperopic side, CK is proving by far to be the least invasive and best choice to resolve refractive errors up to +2 for either sphere or cylinder. I was about +1.25, -1.25 x 15 in both eyes and now have less than +0.5 cylinder with most of the very annoying low light glare and degraded clarity almost gone. Finally getting a solid 20/20 uncorrected is incredible.

CK is fast and virutally painless, with very quick recovery and no risks whatsoever to flaps or making dry eye issues worse. An RF probe is placed at typically 8 spots around the periphery of the cornea that causes the collagen to shrink, pulling down the edges making the cornea less flat. The spots can be moved towards the center a bit closer in the cylinder plane to correct astigmatism.

It is commonly misunderstood that CK effects are only temporary and not permanent. That's probably because it is used mostly for monovision to fix presbyopes with 20/20 distance vision. Advancing presbyopia over time makes additional CK treatments necessary to compensate. But, getting CK to fix hyperopic refractive errors for distance vision IS permanent. While there is a little bit of regression, the correction stabilizes at 2 or 3 months.

I couldn't be more pleased with the results. If you want more info, find a CK specialist in your area. They are usually found at Opthamology clinics and eye surgery centers that do everything, not just lasik. No this is not a commercial for CK. I am a real person who underwent the procedure and offer this information completely on my own volition.

I am delighted to hear of your excellent outcome with CK, however you are incorrect on one important point. The effects of CK on the cornea are temporary. They regress at a rate of about 0.25 - 0.35 diopters per year. This was affirmed during the clinical trials and holds true today. You may want to read http://www.usaeyes.org/lasik/faq/lasik-nearvision-ck.htm and visit the FDA website at http://www.fda.gov/cdrh/mda/docs/p010018.html

Conductive Keratoplasty is a temporary correction. It may take a long time for it to regress, but eventually the cornea returns to its state before CK.

Glenn Hagele
http://USAEyes.org
Lasik Patient Advocacy & Surgeon Certification

I am not a doctor.

As Glenn has said, CK slowly regresses. I read it regresses at 1/4 diopter per 3 years. Its great to give an emerging presbyope a bit of myopia to keep him out of readers for another 5 years but the CK regresses and the presbyopia becomes too severe. Most hyperopes get lasik because its permanent. CK can be repeated but only once I believe or itll damage your cornea. Dont worry, ive done some reading on epithelial thinning/thickening that can address both myopia(up to -1.5 I heard) and hyperopia(up to -3 I heard)

There appears to still be quite a bit of misinformation lingering out there about CK. The main article you quote is dated 2002 and is no longer accurate. The other is merely a followup study on CK used for monovision presbyopes. It is true that when the FDA first approved CK for hyperopia in 2002, the effects studied in the clinical trials appeared to be less stable and more temporary. CK got the "temporary effect" label then and folks like you and Ace have not updated yourselves. The FDA approved it for presbyopia treatment in 2004 for which the vast majority of CK treatments are performed. The "temporary effect" label seems to have stuck for most since presbyopia is progressive and the need to regain good near vision with the non-dominant eye will continue as a CK patient ages, so they will likely need several retreatments to "stay even". But such is not the case for using CK to treat distance vision for hyperopes with or without astigmatism.

The procedure has undergone significant refinement since 2002. Imporved technique and the use of better probes in applying CK is now showing much more stable corrections that do not regress as you suggest. Where you got the idea that the effects of CK will definitely revert all the way back to the original scripts over time is simply outdated and presumptive at best. Here is a more updated overview of where CK is today:
http://www.allaboutvision.com/visionsurgery/ck_ltk_eye_surgery.htm (March 2006)

Other recently published resources describe the effect of CK as "irreversible" and "permanent":
http://www.steen-hall.com/ckfaq.html#link1
http://www.sightfirstclinics.com/ck.html#permanent
http://www.furlongvision.com/CK_faqs.html

The collagen is permanently reformed by the RF and is not tissue that gets replaced to a pre-treated shape over time any more than striae disappear if left untreated on the corneal surface.

Experienced CK surgeons are now using this procedure as a very effective remedy for post lasik corrections including astigmatism, something the 2002 and 2004 studies had not contemplated nor anticipated.

Clearly CK is changing and improving as more data and histories are studied. But it is a rather new procedure to be sure. Only time will tell how truly permanent its effects really are for the majority of CK patients, excluding the issue of presbyopia.
Everything my doctors are telling me indicate its effects are much more permanent than temporary.

Obviously reasonable people can disagree, however the effects of the procedure have not changed since its inception, the real long-term regression experienced by patients who have had the procedure, the fact that the company itself states Conductive Keratoplasty is a temporary correction, and the comments by the surgeons who developed it indicates to me that my research is not flawed. Your citations are nice articles about CK, but they are not peer-reviewed studies or a part of an FDA approved clinical trial. CK correction is long-term, but is not permament.

I respect and appreciate your observations Glenn, but it appears Refractec, the inventor of CK, has not updated their webite beyond stating any conclusions derived from the clinical trials that formed the basis of their FDA acceptance for hyperopia correction in 2002 and presbyopia in 2004. That is old data. They also still list LTK as a viable option for refractive farsighted correction, but its well known LTK is no longer used and the company that invented it went out of business in 2002.

However the website does say that some CK patients will retain some or all of their hyperopic correction longterm, so obviously the healing characteristics of the collagen subjected to the thermal effects of RF for indiviual patients does vary, just as corneal tissue subjected to the laser does for h-lasik.

Since Refractec aleady has FDA acceptance, more clinical trials to establish its safety are no longer needed. As you suggest Glenn, the industry does need to see more peer review and scientifically complied results for CK over time. I presume the company is collecting ongoing patient histories from the doctors and clinics who bought the techology to better establish the long term efficacy of hyperopia and astigmatic correction using CK. They already know and it has been well established that presbyopia correction is ever-changing as the patient's need for increasing near vision power offsets the correction achieved by CK over time. For that procedure, the effects will always be "temporary", at least until presbyopia levels off in most patients around age 70. It would be helpful if they would publish more current data as it comes in to better clarify the efficacy of CK for distance vision correction procedures.

As a long time patient and student of refractive correction technologies, I have observed that as a new procedure is introduced and clinical trials proceed, many "off-label" procedures are performed. My own h-lasik was done before FDA approval was granted. As more patients are treated and healing response data is shared, the results get better and better. Early h-lasik was well known to cause much more regression than myopic lasik. Too many surgeons undercorrected patients as a result and h-lasik was even called a flawed procedure by many. I can recall reading the opinions of respected doctors who were convinced that h-lasik would regress at a steady rate over time and in many cases, all the way back to the original script. Most lasik docs would not do h-lasik over +3 since results were not as good or predictable. Many still don't. But since those early days, nomograms and the lasers themselves have improved, along with the applied surgical technique and as a result, h-lasik longterm outcomes have greatly improved.

Had those who predicted h-lasik regression was as severe as first believed were correct, my original +5 correction would not have stopped regressing at +1 as it did after about 2 years. 100 seconds under the laser torched a ton of corneal tissue, but regression does stop as the healing process ends and the residual refractive error does stabilize.

I see CK following a similar pattern. The smaller the amount of correction, the less regression should occur. In the end, Time will tell us the truth.

You may have a point. Thanks for the links! They say its permanent but they also say it regresses over time. Perhaps the improved CK regresses much less, if at all. I wonder why people still get lasik for hyperopia when CK is much better and safer? I know if I were in their shoes and I had gotten H-lasik when I could have had much better, safer results with CK I would be really upset. Could CK just be repeated if there was any regression and how many times? I heard it can only be repeated once. How much hyperopia and astigmastim can be corrected? When will CK be addressed for myopia? I would be interested!