The use of Conductive Keratoplasty as a possible solution for ectasia after LASIK or for keratoconus that occurs naturally is relatively new with no long term follow-up. It is not FDA approved for this indication.

I wrote Dr. David Hardten of Minnesota Eye Consultants in Minneapolis, MN for an explanation of the procedure. One of our members plans to have this procedure and has also had intacs inserted by Dr. Hardten.

Dr. Hardten : " The general concept is that in keratoconus as well as ectasia after LASIK, there is an area of the cornea that bulges out asymmetrically. Intacs as you know have been used to essentially stent this area to pull it backwards again. Conductive keratoplasty is a device that is now FDA approved to treat hyperopia in normal eyes and works by contracting the cornea with radiofrequency energy that essentially creates heat in the cornea to shrink it. If it is used asymmetrically to heat/shrink the cornea over areas that are ectatic or bulge forward, then it can be used to shrink the cornea backwards. If used over the ectatic areas, then it pulls this area back more than other areas and has the potential to be titrated to make the cornea more round. The main issues are the asymmetric response and how to control this, the fact that the cornea may continue to change over time in keratoconus and possibly LASIK induced ectasia (which is usually probably keratoconus that was unable to be detected with the preoperative testing), as well as the variability in response from patient to patient. Unlike Intacs, though, Conductive Keratoplasty has some titratability associated with it - i.e. if you don't get enough initially, and need more later, you can add extra spots later on."

Additional information:

Posted on the http://www.kcenter.org website is a thread about a keratoconus patient who had intacs followed by CK.

http://messages.kcenter.org/2/OpenTopic?a=tpc&s=072090354&f=7710989142&m=6223085086

More information about intacs: http://www.getintacs.com/index.html

CK website: http://www.refractec.com/

I will respectfully disagree with Dave Hardten on this particular topic, though in general I think he's one of the more credible sources and best surgeons around today.

I do not think that there is any very good role for either Intacs or CK in post-LASIK ectasia. The role of Intacs in primary keratoconus is dubious at best, and has not to my knowledge been proposed by any ethical surgeon in the context of post-surgical ectasia. CK is in my opinion not a very good procedure for anything save perhaps the +1.00 presbyopic hyperope, and would be a terrible idea in the ectasia-post-LASIK patient.

Ectasia describes uncontrolled progressive corneal thinning and shape change, typically steepening over the thin areas. The uncontrolled shape change invariably produces undesirable optical consequences. Ectasia can arise in the absence of surgery (keratoconus, pellucid marginal degeneration, keratoglobus, etc.) or as a result of laser treatment removing enough tissue to compromise the biomechanical integrity of the remaining stroma.

Our profession needs to develop better means to stabilize structurally compromised tissue. In my mind, this means developing methods to (a) stimulate growth of new corneal collagen where needed; (b) stimulate overall hypertrophy of stroma leading to increased thickening and improved mechanical stabiity; or (c) onlay donor tissue to reinforce thin, weak areas.

Intacs has never been suggested to stop ectasia even in the keratoconus patient, but is portrayed as as a poor man's substitute to any of the above. Intacs' manufacturer, Keravision, has been in and out of bankruptcy over the past few years and is still a procedure in search of a good indication. In over 11 years of doing LASIK I have referred one patient with mild keratoconus for consideration of Intacs, and that patient has (wisely, in my opinion) chosen to defer any surgery at all.

I cannot say too many nice things about CK. Remember "LTK" (laser thermokeratoplasty) and how it tanked? Remember plain old thermo-keratoplasty ("TK," or burning the cornea with a hot wire to effect local shrinkage)? CK (formerly called RFTK or "radio-frequency thermo-keratoplasty") does exactly the same thing, without laser accuracy.

To me, even the mere proposal of further damaging corneal collagen in an eye with ectatsia from any cause is grounds for demanding that the proponent stay after class and write "I will not do anything to damage the cornea" 1,000 times on the blackboard before being allowed to leave class.

Currently, in my opinion the best method to treat clinically and optically significant ectasia is corneal transplantation. This of course has its own risks and inherent costs. Our profession would do much to earn respect in the eyes of the public if PKP (penetrating keratoplasty) surgery weren't so darn expensive. Particularly as in the era of laser refractive surgery, we are seeing health insurance carriers flatly deny coverage for such care to people that have had any laser corrective surgery previously.

David A. Wallace, M.D.
Medical Director
LA Sight
11600 Wilshire Blvd., Suite 200
Los Angeles CA 90025
310 828-2020
www.LA-Sight.com

Dr. Wallace,
First - I want to thank you for your developement of a very important piece of technology that doctors throughout the world use in the care of their patients - the Tonopen. The Tonopen is an amazing achievement - and I appreciate it on a daily basis!!
However - I have to respectfully disagree with your comments on the management of ectasia.
First - I do want to agree that at this time the evidence is still shakey on the use of CK for ectasia patients. I agree that Dr. Hardten is a well-respected and excellent clinician and I highly respect his opinions. However, I am not aware of all of his data and the data of other CK surgeons on the success of treating ectasia with Intacs. Hopefully we will be pleasently surprised - but only time will tell.
On the other hand - I have to completely disagree with your suggestion that the best option for a patient with ectasia ia a corneal transplant. In my opinion - corneal transplants are the option of last resort, since corneal transplants are not without significant risk.

1. Ectasia patients can often be fit with cotnact lenses to manage their visual situation. Although some patients can be fit with standard toric or RGP lenses - there are so many other contact lens stratgies available for patients that may at first seem to fail contacts. The key is to have the ectasia patient work with an experienced contact lens fitter.

2. Patients who are contact lens intolerant must be carefully examined for dry eyes - which is a common occurrence after LASIK and seems even more common in ectasia patients (perhaps because of their corneal irregularity). Treatment of their dry eyes with punctal plugs and restasis may improve their uncorrected vision and may also help with their ability to successfully wear contact lenses.

3. Although Intacs is by no means a panacea - Brian Boxler Wachler, MD, Ioannis Pallikaris, MD and many other excellent surgeons have provided reports in peer-reviewed journals of successful treatments with Intacs for patients with ectasia following LASIK (as well as for keratoconus). Intacs can help stabalize the cornea and reduce the amount of astigmatism. As well, Intacs can improve the ability to tolerate contact lenses.
In my experience - I have helped 2 patients with Ectasia following LASIK receive Intacs - and both are now wearing spectacles following the Intacs procedure with improved best-corrected visual acuity.

4. Corneal transplants have risks that include graft rejection, glaucoma, and blindnesss. Since many patients after corneal transplants still need to wear contact lenses - it seems that agressive contact lens fitting for patients with ectasia is a far better option than a corneal transplant. As well - Intacs is a far-less invasive procedure than a corneal transplant and has a much lower risk of serious sight-threatening complications. If both contacts and Intacs proved unsuccessful - then corneal transplantation would be the next option - unless other procedures become available.

Since you practice in Southern California -I urge you to contact your nearby colleague (Brian Boxler Wachler, MD - who is also in Los Angeles) and allow him to share his Intacs experience with you. Obviously your other suggestions of developing methods to cause thickenning or strengthening of the cornea are valid - but will not be available in the near future.

Best regards

Bill Trattler, MD
Miami, FL


P.S. I noticed on your website that in the LASIK section you have a corneal topography in the left margin. It looks like the toography of OS has inferior steepening. Was this a patient that succesfully had LASIK? If so - was there preoperative inferior steepening or is that just ny imagination (the topo size is very small on the screen).



References:
Kymionis GD, Siganos CS, Kounis G, Astyrakakis N, Kalyvianaki MI, Pallikaris IG. Management of post-LASIK corneal ectasia with Itacs inserts: one-year results. Arch Ophthalmol. 2003 Mar;121(3):322-6.


Boxer Wachler BS, Christie JP, Chandra NS, Chou B, Korn T, Nepomuceno Intacs for keratoconus. Ophthalmology. 2003 May;110(5):1031-40. Erratum in: Ophthalmology. 2003 Aug;110(8):1475.

Thanks for your comments, Bill. It's been way too long since we exchanged postings on kera-net! Forgive me if I implied that corneal transplantation is the best or the only option for treatment of ectasia; that is clearly not my belief, nor is it true. I agree with the points you make.

I wanted to point out that ectasia occurs as a consequence of progressive, uncontrolled thinning of corneal tissue. The best and most logical method to treat this in my opinion is to support the tissue where it is thin and/or weak, by any method that will add tissue, lead to tissue hypertrophy, or tissue replacement with thicker (and hopefully healthier) tissue.

I do know and have spoken with Dr. Boxer-Wachler about Intacs for keratoconus. Intacs for ectasia is a slightly different situation, in my mind. The argument that curved sections of plastic placed in the paracentral cornea can buttress and somehow stabilize thin areas of central cornea is a tenuous one. I'm just as interested in methods to avoid and treat ectasia as we all are, but I want the treatments to make sense. I have read the articles you referenced.

The other point I wanted to make is that I think it's a bad idea to treat ectasia by CK, as the CK process (like all thermal corneal surgery) damages and shrinks additional areas of corneal tissue. Even though, in highly selected cases, it may "work" in the short run, I still don't like it.

Regards and Happy Holidays!

David A. Wallace, M.D.
Medical Director
LA Sight
11600 Wilshire Blvd., Suite 200
Los Angeles CA 90025
310 828-2020
www.LA-Sight.com

http://www.eyeworld.org/jan04/0104p51.html

Study: CK and Intacs show promise for treatment of ectasia, keratoconus

I thought this was a good, honest article in EyeWorld about Dr. Hardten's work. We have a member in the Ectasia Support Group who is a patient of Dr. Hardten. He has had intacs and CK and is very pleased with the results. Hopefully, these results will remain stable. We have a lot to learn. Thank you Dr. Trattler and Dr. Wallace for contributing to this thread.

[This message was edited by Gail Keziah on Thu January 22 2004 at 07:01 PM.]