Treatment Options for Keratoconus
Patients with very mild disease may initially be corrected with glasses or soft contact lenses, however the vast majority of patients need rigid contact lenses for adequate vision correction. There are a variety of types of specialized rigid contact lenses and depending on the contact lens fitters experience or expertise they will describe the one best suited for you. The very latest contact lens for treating keratoconus is the “synergize hybrid contact lens” which is rigid in the middle and soft on the edges. This has the potential to give you the good quality vision of the rigid lens with some of the comforts of the soft lens. We don’t fit contact lenses, but we do work with several excellent optometrists who specialize in fitting lenses for keratoconus in the Los Angeles area and would be happy to refer you to one should you so desire. It is always a good idea to try several different contact lenses and fitters before giving up on them and embarking on surgery.
Many patients find their contact lenses uncomfortable and can only tolerate their contact lenses for a short period of time. The reason this happens is that the cornea steepens and rubs against the lens causing an abrasion and light sensitivity . Another reason is patients with keratoconus often have very dry eye and as the eye dries out there is no lubricating barrier between the lens and the cornea contributing to the patient being uncomfortable. There are now many ways to treat dry eyes to improve contact lens tolerance. This includes the use of artificial tears, treating the lids for lid disease, Restasis– for increasing tear production and the use of punctal plugs to prevent tears from draining down your nasolacrimal ducts and keeping the eye moist.
Sometimes a little scar or nebulous appears on the tip of the cornea that constantly rubs against the lens making it difficult to tolerate contact lenses, this scar can be removed with a blade or with the Excimer laser to return patients to contact lens tolerance – this procedure is called phototherapeutic keratectomy(PTK) or nebulectomy.
A method for flattening the cornea that is too steep and making a patient more contact lens tolerant is the insertion of INTACS into the cornea. This procedure is good for patients who are contact lens intolerant and who want to avoid a corneal transplant and whose K readings are not in excess of 58 Diopters. It is also useful for individuals with keratoconus who want to improve their present vision with or without contact lenses. This technique involves the insertion of two arc like plastic segments into the middle of the cornea to flatten the cornea. This procedure was pioneered 8 years ago in France, and is routinely being done by many cornea specialists in the United States. It is FDA approved under an HDE protocol and many insurances cover all or part of the cost. Our center pioneered the use of the Intralase laser for making the channels to insert the plastic segments this makes it a much safer and simpler technique for the patient compared to the mechanical technique which involves using metal blades, our finding have been confirmed by several other large research groups.
We have now done several hundred of these procedures with the Intralase with excellent results. In many instances we have had to remove INTACS that were too superficially placed elsewhere using the mechanical technique only to get an excellent result when it is inserted with the safer and more accurate Intralase technique.
For a review of the literature on this procedure read this recent article by Dr. Rabinowitz. (=102563)
IT IS VERY IMPORTANT THAT THIS TREATMENT BE DONE ONLY WITH THE EPITHELIUM REMOVED (EPI-“OFF”), this is the only methodology which has been tested in the laboratory and has been shown to be safe for treatment in humans. CLICK HERE TO FIND OUT OTHER REASONS WHY WE DON’T PERFORM OR RECOMMEND THE “EPI-ON” PROCEDURE that is advocated only by a handful of doctors, the vast minority doing this procedure.
The slide below which is an Electronmicograph of the cornea, which has undergone the procedure, clearly demonstrates that the epithelium acts as a barrier to cross-linking. As you can see from this slide in the areas where the epithelium is missing, the stroma is compacted and cross-linking has occurred, while in the areas where there is epithelium (blue layer) the corneal fibers below are widely spaced and no cross linking or compaction has occurred (see slide below).
Clinical Trial to compare the effectiveness of Collagen Crosslinking with or without INTACS to halt the progression of Keratoconus
We are pleased to announce that after studying this technology now for many years we are offering the only Clinical Trial in the United states under an FDA protocol approved by the Western Institutional Review Board (WIRB) which will determine whether it is more efficacious to combine INTACS with collagen cross linking or do cross linking alone to halt the progression of Keratoconus.
Recently the Femtosecond Laser was approved for performing Corneal Transplants (also known as I.E.K or Intralase Enabled Keratoplasty). This is one of the biggest advances in Corneal Surgery in the past 30 years. The result is a quicker procedure, quicker recovery and less astigmatism with better vision. The Keratoconus Center is one of the few centers in the world that now uses this groundbreaking technology.
To learn more about the Femtosecond Laser/I.E.K click here
Sometimes patients who have had a successful transplant with a clear cornea still do not see well and cannot tolerate contact lenses. The reason for this is that they have large amounts of astigmatism following their transplant surgery. This can be corrected with Astigmatic Keratotomy (AK) and followed if necessary by Excimer Laser PRK. In most instances patients then become either contact lens tolerant and can see better with glasses or contact lenses.
DEEP LAMELLAR ANTERIOR KERATOPLASTY (DALK) AND I.E.K.
In DALK the bottom layer of the cornea is spared this results in less chance of rejection. We perform this technique with all of our I.E.K. surgeries to minimize the chance of rejection. It should be remembered however that in some instances the separation of the bottom layers of the cornea and the upper parts might be uneven which would result in poorer visual outcomes. In these instances we will convert the DALK procedure combined with I.E.K. to an I.E.K. only procedure. We encourage our patients to discuss with us in detail the risks and benefits of each procedure and the combined D.A.L.K. and I.E.K. procedure. Of course we always perform the procedure that is safest with the best visual outcome for all of our patients.
PRK FOR ‘EARLY’ KERATOCONUS
Though eye care professionals recommend against Excimer laser PRK in patients with keratoconus because it thins the cornea even further, we are actively researching this area. Our experience has shown that in patients who are over age 40 whose vision is stable and whose corneas are thick enough they get similar results with the Excimer PRK as they would get with glasses. Patients who elect to undergo this treatment will be done under an experimental protocol and need to understand that they are at increased risk of scarring with the potential for needing a corneal transplant.
Patients who are extremely nearsighted more than -10D might benefit from phakic intraocular lenses. Currently there are two type of these lenses approved by the FDA –the Verisyse and the Visian ICL. These are implantable contact lens has been approved by the FDA for up to -20Diopters. We are one of few centers performing a research study on the use of these intraocular lenses in keratoconus eyes, This will be an exciting new opportunity for a select number of patients with keratoconus who could potentially improve their vision without the need for laser surgery.
All the procedures outlined above are routinely done by Dr. Rabinowitz himself who is a cornea specialist and an expert in the treatment of keratoconus.