Anterior Chamber Characteristics of Keratoconus Assessed by Rotating Scheimpflug Imaging

Illés Kovács MD, PhD, Kata Miháltz MDa, János Németh MD, DSca and Zoltán Z. Nagy MD, DSca

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From Semmelweis University Budapest, Faculty of Medicine, Department of Ophthalmology, Budapest, Hungary.

More Than 30 years Distinguished Service for the Eye Care Industry

Irving Arons

Irving Arons is a leading and highly experienced commentator on ophthalmic technology and industry issues.

Retired after more than 30 years of consulting in the ophthalmic and medical laser industries. Eleven years as managing director of Spectrum Consulting, including publishing Executive Laser Briefing; twenty-five years at Arthur D. Little, as manager of the Ophthalmic and Medical Laser Consulting Group.

Currently publishes :

Only retired people know that retired people never really retire. People in the Industry who retire automatically become, by popular demand - teachers in the field, role models, mentors, commentators, opinion leaders. Retirement becomes one of discovery - new found time, new found freedoms, new social networking, and new current affairs to review, with a renewed independence.
 
Retirement allows the sharing of the three gifts - of life, love and laughter, given to you at birth even more now with the rest of the world - with these gifts being special due to them never diminishing in size the more you share them.

Remember, back in the day the industry's past and present seniors. They have been determined to extend themselves in pro bono efforts benefiting their fellow colleagues in the field, and they have made our community a better place to live.

It is never too late to seek a newer world.

The company prepares for immediate commercial launch throughout Europe and Asia

Waltham, MA, April 20, 2010 — Avedro, Inc. today announced its Vedera™ System for performing the Keraflex® procedure has received the European Union's CE Mark. The CE Mark certifies the Vedera has met the EU's health and safety standards and opens the door to commercialization across the European Economic Community and in other countries recognizing the CE Mark.

"I am pleased by how quickly Avedro has been able to transform its Thermo-biomechanics platform technology into a commercially available ophthalmic device. Avedro has been conducting clinical trials to treat myopia and keratoconus with the Keraflex procedure and is extremely pleased with the results. CE Mark certification is an important milestone for the company, and also represents a vital new offering to ophthalmic patients and their physicians," said David Muller, PhD, President and CEO of Avedro.

The Keraflex procedure is a non-invasive, incision-less ophthalmic procedure for flattening the cornea. Because Keraflex thermally remodels the cornea without the removal of any tissue, the procedure offers the unique ability to induce refractive change without weakening the cornea's biomechanical integrity, as happens with LASIK and other refractive correction procedures.

Keraflex KXL, Corneal Flattening and Corneal Stabilization

In its European clinical trials for the correction of myopia and the treatment of keratoconus, a progressive disease of the cornea, Avedro has investigated a two-step procedure whereby Keraflex provides corneal flattening to achieve refractive correction and concomitant collagen crosslinking stabilizes the cornea.

"The Keraflex procedure, by thermally altering the tension of collagen fibers, induces a corneal flattening and achieves a more prolate cornea. This confers refractive correction, and, for the keratoconic cornea, smoothing of the irregular cornea, thereby improving visual acuity. The synergistic use of corneal collagen crosslinking improves the stability of the induced refractive effect while also working to halt disease progression," explains Prof. John Marshall, PhD, Institute of Ophthalmology, University College, London.

The company plans to immediately begin commercialization of the Keraflex procedure throughout Europe and Asia, and looks forward to training and collaborating with its ophthalmic surgeon partners.

Avedro, a privately held medical device company based in Waltham, MA, is developing the science of Thermo-biomechanics for therapeutic medical applications. Keraflex® KXL is the first technology Avedro has developed from its Thermo-biomechanics platform. Avedro recently announced it has signed a definitive agreement with Peschke Meditrade GmbH to acquire the rights to its US-based Phase III studies of corneal collagen crosslinking for the treatment of progressive keratoconus and post LASIK ectasia. The company looks forward to closing the follow-up phase of the studies and completing the necessary steps to introduce crosslinking to the US market. For more information, visit www.avedro.com

"Since these trials were initiated, over 300 subjects were treated with corneal collagen crosslinking. Avedro now looks forward to closing the follow-up phase of the study and completing the necessary steps to introduce this exciting technology into the US," said David Muller, PhD, President and CEO of Avedro.

Corneal crosslinking combines the application of riboflavin with ultraviolet-A light. Together, these increase corneal strength and stability by inducing new crosslinks between or within collagen fibers. In multiple international clinical trials, crosslinking has been shown to halt the progression of keratoconus and ectasia and to enhance the biomechanical stability of the cornea. Crosslinking is now approved for use Internationally outside the US. "Collagen crosslinking has been accepted as an important advance in the treatment of keratoconus by surgeons around the world. I am very excited that the experienced team at Avedro is taking over the US clinical trials initiated by my company and completing this important work," comments Rudi Peschke, CEO of Peschke Meditrade GmbH.

I can't even begin to tell you how much this International Organization helped us when we first found out that my son has KC.

We went the route of trying different kinds of contacts, but he felt pain in his eyes when he used them and he gave up on them. He has glasses now which corrects one eye. The other eye has just a clear lens since it can not be corrected.

In one month he will be 19, and this year he is doing a year's service for the country before enlisting in the IDF (Israel Defence Force). The year's service includes working with the youth movement in small villages, plus working with autistic children. He has grown up a lot these last few months, learning how to budget money with a small group of volunteers who all live together in a common house. They buy their food, use the money for travelling and whatever else they need. It's a good lesson for life in general.

As for the army, he got a low profile because of his Kerataconus which means he can't be in a combat unit. So who says Kerataconus is all negative? (don't tell him I said that). He has been accepted into an officer's training unit after his year's service is over, and hopefully he'll acquire skills there that he can use after his service. Both his sister and brother are officers in the army too. So is his Dad. That's what happens when a country is so tiny. Everyone helps out.

And I've learned all sorts of healing methods from Reiki, Rising Star, Matrix Energetics, Reconnective Healing. I have used them all on my son (in vain!). I'm still waiting for him to say: hey! I can see in both eyes!

I did help him when he had the flu. So I guess I can't complain...

Location: San Francisco 2009 AAO, Moscone Center, Room: South 238.

Presenting Author: Ricardo Gomes dos Reis MD.

Purpose: Evaluate the vision-related quality of life in keratoconus patients treated with riboflavin and ultraviolet radiation for Corneal Collagen Cross-linking (CXL).

Methods: The National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25) was applied in twenty-one patients with progressive keratoconus treated by CXL. The questionnaire was applied before and after the procedure, with ranges of 3, 6 and 12 months.

Results: The NEI-VFQ-25 composite score increased 5,3 points after 3 months (P<0,05); 4,2 points after 6 months (P<0,05) and 5,4 points after 12 months (P<0,05).

Conclusion: The vision-related quality of life had a general improvement after cross-linking treatment.

 Location: San Francisco 2009 AAO, Moscone Center, Room: South 238

Presenting Author: Ricardo Lamy MD.

Co-Authors: Adalmir M Dantas MD, Haroldo V Moraes Jr MD, Mariana G Pecego MD, Camila F Netto MD, Ricardo Gomes dos Reis MD, Bruno P Procopio Da Silva, MD, Lorena Vianna.

Purpose: Assess the effects of corneal collagen crosslinking (CXL) on visual acuity and contrast sensitivity.

Methods: Sixty two eyes of 31 patients were enrolled. One eye was treated and the fellow served as control. Pelli-Robson contrast sensitivity test (PR) and best corrected visual acuity (BCVA) were compared preoperatively and 40, 90, 180 and 365 days after cross-linking.

Results: In the treated group, BCVA (logMAR) improved (P<0,05) after 40 days (-0,08); 90 days (-0,14); 180 days (-016); 365 days (-0,18) and PR decreased -0,13 points (P=0,34) after 40 days and increased +1,23, +1,81 and +2,35 points after respectively 90, 180 and 365 days (P<0,05).

Conclusion: CXL was efficacious in improving visual acuity and contrast sensitivity.

Purpose: To investigate the change in biomechanical properties of the cornea induced by high-dose hydrocortisone.

Methods: The influence of hydrocortisone was investigated in 12 fresh porcine corneas incubated in culture medium of 2.5 μM of hydrocortisone for 7 days. Twelve additional porcine corneas incubated in culture medium without hydrocortisone for the same time served as the control group. Strips of cornea were cut and the stress–strain relationship was measured in a biomaterial tester. Young’s modulus was calculated.

Results: After incubation, the thickness of the cornea was 11206130 μm in the control group and 1320690 μm in the hydrocortisone group. The hydrocortisonetreated corneas were 18% thicker compared to the control corneas. However, the difference in the biomechanical stress value at 10% strain was significantly larger. In the control group, the stress value measured 122640
kPa, and in the hydrocortisone group, it measured 77619 kPa (P=.003), representing a reduction of the corneal stiffness by 37% due to hydrocortisone treatment. Young’s modulus was reduced by 42.8% from 2.9061.10 MPa in the control group to 1.6660.49 in the hydrocortisone group.

Conclusions: Hydrocortisone is a modulating factor of the biomechanical properties of the cornea. The significance of the cortisol status of the patient and its influence on the biomechanical stability of the cornea should be considered in the development of keratectasia in keratoconus or after refractive surgery.

 [J Refract Surg. 2009;xx:xxx-xxx.] doi:10.3928/1081597X-2009 

In the Line of Sight: News in the Pentacam Software

During the ASCRS in Chicago Oculus has presented two unique software features of the Pentacam:

• Belin/Ambrosio Enhanced Ectasia Screening, developed by Prof. Michael Belin, MD, Albany/New York and Renato Ambrosio, MD, Rio de Janeiro/Brazil,

• 3D lens densitometry with the Pentacam Nucleus Staging called “PNS”, developed by Donald Nixon, MD, Ontario/Canada.
  

“The goal of the Belin/Ambrosio Enhanced Ectasia Display is, to combine elevation based mapping and pachymetry corneal evaluation in an all inclusive display”, says Prof. Michael Belin one of the clinical investigators.

A new method is used to fit the sphere to the cornea called the enhanced BFS. It offers two main advantages:

• A cone in an early stage of Ectasia or Keratoconus is more pronounced

• A elevation map of normal eyes (eg. an astigmatism) looks same with the common BFS and the enhanced BFS. Only irregularities like early Ectasia are more pronounced. 

The pachymetry progression analysis is already included in the Pentacam software and well known. Together with the enhanced BFS it completes this display. “We found that Keratoconus patients have thinner corneas and faster and more abrupt increase of corneal thickness progression than normal corneas. These findings were in agreement with previous reports in the literature pioneered by Mandell and Polse. Interestingly, these new parameters are effective in detecting abnormalities in the majority of eyes with normal anterior curvature maps in patients with keratoconus in the contra-lateral eye. Thus, these parameters increase our sensitivity to detect Ectasia and its susceptibility. However, the enhanced display has increased our specificity to detect not ecstatic cases with inferior steepening” says Dr. Renato Ambrosio the second clinical investigator.

More than 800 eyes were examined in Rio de Janeiro/Brazil, Ankara/Turkey and Albany/USA to define the borderline numbers.

The investigation and interpretation of the display is intuitive:

• If the corneal thickness progression shows an average index higher 1.1 the increase of thickness progression is clinically significant and the red curve is not parallel to the black broken lines but steeper and...

• If the difference map between the BFS and the enhanced BFS elevation map shows a red center it is clinically significant as well.

 Screen Display

The evaluation of the crystalline lens conditions in terms of opacifications is clinical routine. There are lens opacification systems like the LOCS grading but it still subjective and open to interpretation. Another question is: what are the most efficient Phaco settings.

The Pentacam measures the lens density in an objective, reproducible and accurate. “The new software measures a 3D template volume and optical density to generate a nuclear cataract grade”, says Dr. Donald Nixon the clinical investigator of this project. More than 300 patients were included into the clinical studies in Ontario/Canada which were done with the AMO Signature Phaco System linked to the Pentacam Nucleus grading system. The results are very promising, because:

• Significant less EPT and BSS was used with Pentacam guided settings

• The needle time significantly less in grade 4-5 cataracts.

These results were confirmed and presented during the ASCRS in Chicago by T.M.Rabsilber, MD member of the refractive group leaded by Prof. G.U. Auffarth, MD at the University of Heidelberg, and Prof. Ekkehard Fabian, MD, AugenCentrum Rosenheim.

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