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Can Cross-Linking (CXL) treat Terrien’s Marginal Degeneration (TMD)?

What is Terrien’s Marginal Degeneration?

Surprisingly little is known about what causes Terrien’s marginal degeneration (TMD). We do know that: it’s rare, three in every four people affected are men; its onset is usually in people’s third-to-fifth decade of life, and both eyes are affected most of the time.

We know more about the pathology: the disease is characterized by thinning of the margin (edges) of the cornea where it meets the white part of the eye (the sclera). The thinning usually starts in the top part of the margin, it usually progresses and involves the whole circumference of the corneal periphery. The disease typically results in the growth of new blood vessels – neovascularization – plus scarring and lipid deposits (usually seen as fine, yellowish punctate stromal opacities) at the margin. As the degeneration progresses, it usually leads to increasing against-the-rule or oblique astigmatism. The cornea can become severely weakened, spontaneous ruptures of Descemet’s Membrane can occur and result in interlamellar fluid or corneal cysts. Although spontaneous perforation is rare, even minor trauma can perforate the cornea. The question is: how can TMD be treated?

Until recently, there wasn’t much that could be done, other than trying to manage the patients’ astigmatism with spectacles or rigid gas-permeable lenses and careful monitoring of corneal thinning. But if the cornea becomes so thin that perforation is imminent, then corneal transplantation is then the logical next step – although given the fact that the disease is peripheral in nature, and the corneal transplants have to extend to the periphery of the cornea… successful treatment can be extremely hard to achieve.

However, there is another approach that might help.

Can Terrien’s Marginal Degeneration be cross-linked?

Corneal cross-linking (CXL) can successfully treat corneal ectasias (thinning diseases) like keratoconus, post-LASIK ectasia and corneal melting. Cross-linking the proteins (mostly collagen) in the corneal stroma is thought to not only strengthen the cornea, but also render it more resistant to enzymatic digestion. If CXL can stop corneal melting (a hallmark of TMD), could it also stop TMD from progressing?

Yes. We have successfully treated several patients with TMD using CXL, applied to the area of maximal corneal thinning, and by using a sponge to cover and protect the corneal limbus from UV-illumination. We have found that CXL using the gold-standard Dresden Protocol not only improves these patients’ corneal shape, visual acuity and quality, but also reversing the corneal thinning that occurred in the melted, peripheral ectatic areas of these patients’ corneas.

The best explanation for these results is that CXL increases the resistance of the corneal stroma to enzymatic digestion. Under normal conditions, there is homeostasis – a fine balance – between corneal collagen synthesis and breakdown. It appears that CXL, by making collagen breakdown harder to occur, shifts the balance towards synthesis, which would explain the improvements in these patients’ corneal thickness seen to date. Successful treatment with CXL has the additional benefit of avoiding the need for keratoplasty – helping preserve scarce corneal tissue, and sparing the patient from the risks and demanding post-procedural eyedrop regimen that’s an integral part of corneal transplantation procedures.

These results also imply another use of CXL in TMD: prophylaxis. Unlike keratoconus in adults, which starts and stops progressing, and where CXL is only indicated for use once progression is observed, TMD tends to continue to progress inexorably. CXL performed early in the disease course of TMD could help arrest the progression of the disease early, preserving vision and perhaps sparing people from needing to use rigid gas permeable lenses or some of the later-stage manifestations of the disease.

 

This OCT image shows a thinning of the cornea at the periphery (the edges) of the cornea)

This corneal topography map shows that the patient’s TMD has resulted in significant corneal asymmetry and therefore astigmatism.

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Augeninstitut ELZA
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mike
09:02 04 Jan 23
Overall as a 50 year old, who wanted to continue to avoid wearing glasses and/or contact lenses, my goal was 100%... achieved with ELZA and Dr. Hafezi. I greatly appreciated the overall approach by Dr. Hafezi and his friendly and competent team in reviewing my vision at the start and following a comprehensive eye exam- the explanations of my options. For me I chose PRK in one eye for a monovision solution to correct short sightedness which was becoming more prevalent in night driving and sports such as skiing and cycling. PRK heals slowly but the outcome is worth the wait- and the cost- you use your eyes every waking moment- and for me I cannot see any reason not to pursue better vision with the ELZA team! A great quality of life enhancement!read more
Zuzana Fecko
Zuzana Fecko
21:48 31 Oct 22
Thank you so much, Dr. Torres and prof. Hafezi. 26 years I was only “dreaming” about the eye surgery due to possible... complications. I was worried ..Thank you for encouraging me to make a decision and thank you for your professionalism, explanations and great work!I wish you all the best, lots of success and only happy patients!read more
Serena Fazio
Serena Fazio
11:15 06 Mar 22
I have been to the ELZA clinic to have surgery for my miopy, as my eyes were rejecting the contacts and I was tired of... wearing glasses. From the first preliminary visit, to the actual surgery and post-surgery care Dr. Hafezi and all his collaborators have been extremely professional, considerate and helpful. All the steps of the (very short!) surgery were thoroughly explained to me in order to be as calm as possible, together with the medication plan and precautions to be aware of so that my eyes could heal in the best way possible. By following their exact instructions, the healing process has been very successful and smooth, and after about one week I was able to see perfectly. I absolutely recommend this team and their expertise!read more
Robin A
Robin A
11:43 16 Feb 22
Top experts and professional team. Highly recommended
Thunder Shiviah
Thunder Shiviah
14:05 23 Nov 21
After some research on local options I decided to go with ELZA since it stood out as the best. The operation and the... post-operation recovery went extremely smooth (something I was worried about with PRK). Now my vision is much better than I had hoped and I have no side effects such as dry eye or night vision problems. Thank you!read more
Thomas S.
Thomas S.
09:37 07 Jul 21
My left eye had to be operated on because of a cataract. As I had an Artiflex lens implanted a few years ago, it had to... be removed first before a modern lens could be implanted to correct the cataract. Prof. Hafezi treated me in an very competent and friendly manner. I am very happy with the result.read more
Selma A. Rahim
Selma A. Rahim
19:45 02 Jul 21
Dr. Hafezi.. the KING OF CXL🤴
Gianluca Ricci
Gianluca Ricci
12:46 10 Apr 21
Great team and service!
rehaneyecare
rehaneyecare
05:36 08 Apr 21
Excellent surgeon
Steven H.A
Steven H.A
16:13 11 Jan 21
Prof. F. Hafezi s expertise is enormous and he has a very pleasant and calm nature which gives the patient... security.Thank youread more
Online Commande
Online Commande
09:19 05 Dec 20
Totally creepy, very arrogant Prof.He just want your money.It may explain, why this Prof. is not in the center of the... city of Zürich and why he has been thrown away from University of Geneva.read more
Elena Churilova
Elena Churilova
10:06 17 Nov 20
At the moment, 3 months have passed since the moment I made laser vision correction in this clinic. and I can say that... I am happy that I chose this particular clinic and Prof. F. Hafezi. The entire staff of the clinic is very friendly, treats patients with sympathy and patience if they are nervous before surgery (my big gratitude to Aida Alili for all support and patience). The doctor Hafezi and other doctors of the clinic are very professional and ready to explain to you as many times as you need. I can only recommend!read more
Michele Aggiato
Michele Aggiato
18:17 10 Jan 20
The day I had Prof Hafezi checking my keratoconus I knew I was finally in the right place after years of searching for... a good ophthalmologist. Prof Hafezi recommended a surgery due to a drastic degeneration of my cornea. The surgery was performed by himself with the assistance of Dr Rodriguez, one more collaborator of Prof Hafezi’s team who got my full trust.read more
Ashley Faulkes
Ashley Faulkes
15:30 21 Mar 16
Professor Hafezi and the team at the ELZA Institute have done an amazing job of creating a first class eye clinic, with... cutting edge technology and support. I went there for a dry eye issue and other issues with my prescription, and they were easily able to help me and put me on the road to better vision! High recommend them to anyone in the Zurich/Aargau area.read more
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