Truths about Keratoconus and Cross Linking

I am amazed when docs claim that they have invented a procedure even though it existed for years before. For example a surgeon claiming they invented cornea cross linking even though it was being performed in Europe for many years.

What gets me peeved is that some doctors use unproven technology and convince patients its the best. Snake oil sellers are an amusement till patients are harmed. So i decided to list some truths about keratoconous eye disease and cornea collagen cross linking.

The 10 Golden Truths about Cornea Cross Linking By Rajesh Khanna, MD a Keratoconus specialist.

  1. Keratoconus is a sight threatening disease.It involves thinning and bulging of the cornea.
  2. Recent data suggests it may be more prevalent than 1 in 2000
  3. Cornea Collagen Cross Linking (CXL) is proven and effective to halt the progression of progressive keratoconus eye disease.
  4. CXL may used to stabilize post lasik ectasia.
  5. Epithelium off Cornea cross linking is more effective than epi on cross linking.
  6. Conventional cornea cross linking – 3 mw for 30 minutes is the gold standard.
  7. Conventional  cross linking is more effective than accelerated cross linking (18 mw or 30 mw). No other power setting is better.
  8. No studies have shown epi on cross linking to be more effective than conventional api off cross linking.
  9. FDA has only approved Avedro KXL system/Photrexa for treatment of progressive keratoconus. No other system nor riboflavin compound has passed that litmus test.
  10. Avedro KXL/ Photrexa which treats at 3mw is currently safer and more effective than currently available api on choices in Los Angeles

I would invite comments by optometrists, ophthalmologists and peers especially keratoeonus experts.

Avedro KXL system in the hands of an experienced Keratoconus surgeon following FDA protocols would be safer than an unproven experimental api on technology.We therefore offer Avedro cornea collagen cross linking with FDA approved protocol.

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Keratoconus treatment and FDA approvals

We have been receiving a lot of questions from patients via social media and telephone calls. People out there are confused regarding the safety and efficacy of the various advertised treatment methods for keratoconus.  A quick recap of the currently available interventions to help people suffering from keratoconus eye disease. We have Intacs, Cornea cross linking, DALK and Corneal transplant. Talk and corneal transplant are surgical techniques and and are not in purview of FDA. Lets confine our discussion today than to Intacs and cross linking of cornea for keratoconus eye disease.

Intacs for Keratoconus are FDA approved

Yes Intacs are the only intracorneal ring implants approved by FDA. Others like Ferras rings are not approved and cannot be sold in USA. DrKhanna is one of the participants an Institutional Review Board monitoring by Integrview.  This ongoing oversight ensures the results are safe.

Is Corneal Cross linking FDA approved?

There are three types of Corneal cross linking available in USA today.

  1. FDA approved : There is one and only one FDA approved – KXL device and riboflavin called Photrexa manufactured by Avedro. This means that Avedro did a clinical study to demonstrate the safety and efficacy of their  formulation with their unique device. Data was submitted to FDA. Federal Drug and Administration studied the repots. They asked questions and requested more data. Once this was reviewed  FDA approved the Avedro method.
  2. Clinical studies : There are clinical studies being performed by different groups like the AECOS and CXL study groups. Fda has not given the green light on them.
  3. God Given: These are devices which doctors cannot explain how they arrived in their  offices or surgery rooms. The data from these unexplained devices is not being submitted to FDA nor even peer review. No one knows what drugs are being used.

Which one should you use?

FDA ensures the safety of our eyes. They review the statistical data to keep us safe. Therefore when comparing different treatments it is easier for us to know which is safer.

Since there is only one FDA approved cross linking choose AVEDRO cornea cross linking.

Learn more about treatment modalities for keratoconus.

Pupil Tracking in Cornea cross linking for Keratoconus.

We have been talking about the advantages of epithelium off cross linking. This from of cross linking has shown to work in numerous studies across the world.

But are all delivery methods the same? Certain machines hope the patient keeps looking at the UV light.  Have you tried staring at something for 30 minutes. As a kid you may have played the stare off game. Its tough to do it especially in Los Angeles with the dry weather.

The solution in this fight against keratoconus is to involve a pupil tracker. In the above video you will see it in action. If the eye moves away form the light the UV delivery and the timer will stop. You  can set how much movement you are willing to allow.

This increase the safety. One can definitely know that 30 minutes were delivered. It can avoid a situation where a fidgity patients moves and receives  only 20 minutes of the radiation. Increasing safety also relaxes the patients. Most of people requiring this intervention against Keratoconus eye disease are teenagers. Pupil tracking rocks.

Line of Demarcation after cornea cross cross linking

Epithelium off Cornea collagen  cross linking is not voodoo. We realize that early in new technology lot of unfounded claims like api on cxl being Better than epi off might be made. It behooves us clinicians to present proof to peers.

There is a symbiosis between diagnostic technology and treatments. We will take help of Carl Zeiss Ocular coherence tomography to demonstrate the effectiveness of api off cxl.

Here is a High Density picture of a keratoconus cornea before any treatment. Yes it is early keratoconus in a young girl. This is the best time to intervene to treat Keratoconus. Look how uniform the picture is. The top layer of epithelium can be clearly seen. We remove this layer with laser or as Professor Theo Seiler recommends with ethyl alcohol.

HD OCT Cornea in Keratoconus

Epithelium prevents riboflavin from entering the stroma and hinders the UV absorption. Look at the picture below. You can clearly see a haze which ends around 80 % depth as a line of demarcation.

Line of Demarcation after cross linking

The same line of demarcation after cornea cross linking is better highlighted in they colored OCT of the Cornea.

Color line of Demarcation cross linking

If you are suffering from Keratoconus Call 805-283-6520 to see if cross linking of cornea is the best option for you.

 

Is Corneal Cross Linking experimental?

or Does it really work?

We pose this question as  many medical Insurances deny patients reimbursement for cornea cross linking to treat keratoconus.     Many parents also pose this question as their own optometrists were unaware of the benefits of cross linking the cornea.

We are going to turn to Australia for a peer review objective answer to this question. Our Australian colleagues performed a study which has been vetted by our peers. The Australian keratoconus experts selected 100 eyes with progressive keratoconus eye disease. They divided them into 2 groups. One would receive Conventional cornea cross linking while the other would have no intervention ( like your insurance company would want). They measured various data like vision, cornea thickness, and curvature of the cornea at various intervals over a period of 3 years.

Are you ready for the results? Can you guess what they showed?

Yes Conventional cross linking with UVA applied on riboflavin soaked eyes was able to prevent steepening  of the cornea. It preserved vision both uncorrected and best corrected. It also improved the shape and vision in many instances. We are so convinced by the results we would not be bale to repeat it here in the United States. For we would not condemn any kid with keratoconus to be in the control group. The benefits are so obvious. Like society eradicated  Polio it is time to wipe away keratoconus eye disease.

Feel Free to print the abstract from the respected Journal Ophthalmology which is attached as an image to show your doubting doc, illogical insurance rep or obstinate optometrist.

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Autobahn of Cornea cross linking to treat Keratoconus

BMW on the autobahn is a hair rising experience. Now our German friends want to bring that concept to cxl or corneal cross linking. You may have heard of accelerated cornea cross linking? This is cxl with 10 minutes of UV radiation treatment, In the newest version they propose treatment of only 5 minutes utilizing 18 mw/cm2 of UV radiation.

This would of great benefit to patients. The amount of time they have to stare at the blue light would decrease. Exposure of the cornea to the elements  would be less.

We would like to quote the results of the study here ” The mean follow-up time was 21.7 ± 7.2 months (range, 12-34 months). No statistically significant changes were found in the mean corrected distance visual acuity, corneal astigmatism, Kmean, Kflat, Ksteep, corneal pachymetry (at the apex and at the thinnest point), and corneal densitometry at follow-up. A significant reduction of Kmax, index of surface variance, index of vertical asymmetry, and Km of the posterior corneal surface (Km(B)) was observed (Kmax: P = 0.018; index of surface variance: P = 0.016; index of vertical asymmetry: P = 0.038; Km(B): P = 0.008). No complications were reported during the postoperative follow-up period in this study.”

Our question for the authors are. 1) How deep was the demarcation line?

2) was any comparison made to conventional cross linking?

Other papers or followup studies should be address the questions.

Dr.Khanna is a Keratoconus Expert. These informative blog posts are for information purposes. They should not replace a careful discussion with you Keratoconus Eye surgeon.

Conventional cross linking is still King Kong – say surgeons from Hong Kong

Keratoconus eye disease is no laughing matter. It afflicts teens and can destroy careers. We need to accelerate our fight against this vicious disease. At the same time we have to study scientifically the newer protocols. Accelerated cross linking speeds the treatment by decreasing the time of exposure of UV light. This has recently been studied in pediatric keratoconus.

This landmark study from Hong Kong By Surgeons of Royal college is a landmark one. It shows that accelerated cornea cross linking slows the progress of the bulging eye disease. it is the first one to document that only conventional cornea cross linking with its deep demarcation line can actually flatten the cornea. In essence it means that the 30 min api off intervention can halt the progression as well as reverse some of the effects.

The deeper the demarcation line the more the cornea flattening .

Keratoconus Experts in Los Angles thank the authors to bring new meaningful data for mutual benefit.