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SFO report addresses vascular pathologies
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PARIS — Vascular ocular pathologies were the topic of the French Society of Ophthalmology’s Rapport, an annual publication and one of the oldest traditions of the SFO that gathers major contributions from leading specialists in a chosen field.
“Ocular circulation is involved in the mechanisms of many vascular disorders, mainly ischemic conditions affecting the optic nerve and the retinal circulation,” said Constantin Pournaras, MD, coordinator of the report.
Angiogenesis is a physiological mechanism in situations such as menstruation and cicatrization but becomes pathological in other conditions such as cancer and several ocular diseases, Francine Behar-Cohen, MD, said.
In other words, neovascularization is a pathological abnormal development of vessels, which is a characteristic of conditions such as diabetic retinopathy, age-related macular degeneration and anterior ischemic optic neuropathy.
The symposium where the report was presented focused on the pathophysiological mechanisms of the neovascularization of these conditions and on treatment applications.
“We discussed the major systemic diseases affecting the retinal and choroidal circulation and the most recent developments in the etiology, diagnosis and treatment of each one of them,” Dr. Pournaras said.
The most recent and promising treatments, currently, are those applied in the vitreous cavity. Different molecules, such as anti-VEGF agents, are demonstrating to be effective in interfering with the mechanisms that lead to new vessel formation, and the majority of diseases can be improved if the application of the treatment comes from the vitreous side.
“Neovascular formations are sensitive to any drug which comes directly into contact with the exterior part of the vessels. Unfortunately, the systemic approach has proven to be not as effective as we thought initially,” Dr. Pournaras said.
These items appeared originally as daily coverage from the meeting on OSNSuperSite.com. Look for more in-depth coverage of these and other topics in upcoming issues of Ocular Surgery News.
Bag-in-the-lens IOL effective in pediatric cataract patients
Bag-in-the-lens IOL implantation can treat congenital or traumatic cataract in pediatric patients, according to the results of a study carried out between 1999 and 2007 by Marie-José Tassignon, MD.
The bag-in-the-lens IOL features a unique design, with two round haptics surrounding the optic, and a consequently unique technique of implantation, in which, after anterior rhexis and posterior rhexis of identical sizes are made with the help of a precalibrated ring, both the anterior and posterior capsule are positioned inside a fine groove that lays between the haptics. The lens has proven over the years to be stable and to create a good barrier against cell migration, thus preventing posterior capsule opacification, Dr. Tassignon said.
She presented the results of a study on pediatric patients that included 54 eyes of 37 children between 2 months and 14 years. Nineteen cataracts were bilateral. Patients were divided into groups according to age: 0 to 1 year, 1 to 6 years and 6 to 15 years.
“Results are not uniform, due to the difficulty of measuring refraction in children less than 3 years of age,” Dr. Tassignon said.
During follow-up, there were no cases of secondary cataract.
“The technique doesn’t allow epithelial cells to migrate into the capsule, which is sealed and within the lens haptic,” she said.
Best results were obtained in 22 children (35 eyes) older than 6 years in whom visual acuity improved from 20/100 to 20/25. If cataract was bilateral, visual acuity approached 20/20. Mean postoperative spherical equivalent was –0.5 D. Worst results, with a final visual acuity of less than 20/40, were obtained in five eyes due to persistent primary hyperplastic vitreous (one eye), amblyopia in cases of unilateral cataract (three eyes) or acid burn (one eye).
No cases of capsule rupture occurred because this particular lens creates a good equilibrium of forces within the capsule, Dr. Tassignon said.
Dr. Tassignon said she strongly recommends the use of this technique in pediatric patients. In cases of unilateral cataract it allows, depending on age, fast recovery or prevention of amblyopia. Vision is excellent, and enough accommodation is retained to allow most children to read without spectacles.
Oral mucous membrane epithelial sheet transplant successful
Surgeons have successfully performed an autologous transplantation of oral mucous membrane epithelial sheet in corneas with severe damage, a speaker said.
Carole Burillon, MD, presented first results of phase 1 and 2 trials of the procedure for restoring corneal stem cells in patients with bilateral stem cell deficit from corneal burns and Stevens-Johnson syndrome.
The autologous epithelial oral mucosal stem cell transplantation was first performed on seven patients in October.
“The seven patients showed improvement of the principle criteria, which were reduction of keratitic precipitates, suppression of ulcer and regression of corneal neovascularization,” Dr. Burillon said.
The only patient who had an adverse reaction was suffering from Lyell’s syndrome, according to Dr. Burillon.
Based on those results, Dr. Burillon and colleagues were able to enroll five more patients in February.
In European experience, phakic IOLs a story of hope and disappointment
With 20 years experience implanting phakic IOLs in Europe, phakic IOLs have “a long history of short-term success and long-term failure,” French Society of Ophthalmology president and OSN Europe/Asia-Pacific Edition Editorial Board member Joseph Colin, MD, said. And while early results with a new phakic IOL are encouraging, a great amount of caution is necessary.
During a joint symposium with the French Society of Ophthalmology and the American Academy of Ophthalmology, Dr. Colin reviewed the up-and-down history of the European experience with phakic IOLs and the recent problems with endothelial cell loss encountered with angle-supported phakic lenses.
 Joseph Colin |
As was well-publicized in the media, angle-supported phakic IOL manufacturers IOLTech/Carl Zeiss Meditec and Corneal, in cooperation with the French Agency for the Sanitary Safety of Health Products (AFSSAPS), withdrew the Vivarte and NewLife phakic IOLs in January 2007 and the Icare lens in March 2007, Dr. Colin said.
“A study retrospectively carried out at several centers in France confirmed the high incidence of the complication 2 to 3 years after implantation for the NewLife phakic IOLs,” Dr. Colin said. “Among 2,324 implants, 27 were removed due to significant endothelial cell loss.”
A similar although smaller risk was found with the GBR/Vivarte phakic IOL, with 15 explantations out of 4,033 cases, he said.
After the retrospective reviews, AFSSAPS recommended all anterior chamber phakic IOLs undergo a mandatory evaluation of the endothelial cell count every 6 months after implantation. Currently, if a decrease of more than 30% of endothelial cells or density of less than 1,500 cells/mm² is observed, explantation is recommended, he said.
Despite these problems, phakic IOLs are in popularity, and there is good reason to continue to search for a workable solution with these lenses. Dr. Colin said they are a good choice in cases in which laser refractive surgery is not indicated, such as thin corneas, and phakic IOLs preserve accommodation and are easily removed in most cases.
Researchers have also learned a number of criteria to avoid complications in angle-supported lenses, he said. Among those are an anterior chamber depth of more than 3 mm, a corneal diameter greater than 11 mm and an IOL power of less than 20 D.
Dr. Colin said he has been encouraged by results of a multicenter European phase 3 study of the Alcon AcrySof phakic IOL. At the 2-year follow-up, the researchers found minimal effects on endothelial cell loss. All eyes maintained best corrected visual acuity, there was no reported chronic inflammation or raised IOP, and there were few adverse events. The lens also showed a high rate of predictability and stable refraction over the 2-year time period, he said.
Despite the positive results, given the recent history of angle-supported phakic IOLs, Dr. Colin urged caution until longer-term results are known.
While researchers have found that many complications resulted from improper IOL sizing, which is now limited by new imaging technology, Dr. Colin said, “Current models must not be used until the results of retrospective studies provide more reliable information on the safety of these implants.”
UV collagen cross-linking shows encouraging results in French study
UV corneal collagen cross-linking is showing encouraging results in patients with keratoconus and post-LASIK ectasia, according to the results of a study conducted at two centers in France.
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Images: Mullin D, OSN |
David Touboul, MD, and Pierre R. Fournié, MD, respectively under the direction of Joseph Colin, MD, in Bordeaux, and François Malecaze, MD, in Toulouse, discussed favorable experimental results with cross-linking, which they think could change outcomes for many keratoconus patients.
“To date, there is no device that can measure the changes in corneal stiffness in vivo, but laboratory ex vivo studies have largely demonstrated that the treatment indeed produces a cross-linking of collagen fibers that leads to increased corneal rigidity and re-structuring,” Dr. Fournié said.
What is seen clinically is a halting of keratoconus progression in most patients, he said.
“Results are not uniform,” Dr. Touboul said. “The individual response to the treatment is quite variable, for reasons that are still unknown; however, in most patients, keratoconus progression is halted or at least slowed down, and visual acuity increases quite a few lines.”
Both physicians pointed out that it is still early to draw definitive conclusions, and although UV cross-linking so far has been shown to cause no complications apart from transient haze in some cases, they recommended caution. The treatment should be administered only in cases of proven keratoconus progression, and patients with corneal thickness that is 400 µm or less should not be candidates for the procedure because riboflavin, and consequently UV light penetration, in these thin corneas would cause severe damage to the epithelium.
“Hopefully, we will be able to produce new molecules that will allow us to safely use the procedure also in thinner corneas,” Dr. Touboul said.
No limitations seem to be necessary in terms of age, but early stages of keratoconus appear to respond better, he said.
While the IROC system was initially used in both centers, Dr. Touboul said that best results were obtained with the new CBM X Linker, which may be more user-friendly and more precise.
Accurate antiseptic measures were recommended, as well as the application of a therapeutic contact lens and the use of topical antibiotic and corticosteroid therapy after the treatment.
“In spite of the cornea being disepithelialized and remaining exposed for 1 hour, we had no case of infection,” Dr. Touboul said.
Antimetabolites successfully treat corneal neoplasia in study
Mitomycin-C and 5-fluorouracil either reduced or resolved corneal neoplasia in a recent case series, according to a speaker.
“Antimetabolites, in selected cases, may be a therapeutic option for the treatment of conjunctival or corneal neoplasia,” Mirsad Ibisevic, MD, said.
Dr. Ibisevic presented results from a series of 11 interventional cases performed between April 2005 and June 2007. Six cases were treated with 5-FU 1% and five were treated with MMC 0.04%. Of those treated with 5-FU, three tumors regressed without recurrence, two tumors decreased but required surgery and one enlarged. In the five MMC cases, two tumors regressed without recurrence, two tumors decreased but required surgery and one decreased without surgery.
“In seven cases, we didn’t notice any recurrence from 4 to 16 months after antimetabolite treatment with or without surgery,” Dr. Ibisevic said.
Femtosecond laser, iris-recognition wavefront-guided ablation may optimize LASIK
The benefits of performing LASIK with a femtosecond laser flap and a combined iris-recognition wavefront-guided ablation were demonstrated in a retrospective series of 1,200 eyes, half of which were treated with conventional LASIK.
“In this series, we compared the different techniques, and we found there was definitely a benefit in the quality of vision and safety,” Michael Assouline, MD, said.
Quality of vision was greatly improved in the femtosecond laser wavefront-guided ablation group because of a significant amount of astigmatism correction, he said.
“About 70% of the patients had no astigmatism after the procedure, compared with the 30% to 40% with conventional LASIK,” he said. “This was the first statistically significant clear-cut benefit in our study.”
The difference in accuracy of spherical correction was not significant, while the wavefront-guided method demonstrated superiority in terms of higher-order aberrations.
Another aim of the study was to assess whether the wavefront-guided method produced the same results with or without dilation.
“The answer was yes. In other words, wavefront analysis performed preoperatively without dilation doesn’t preclude having all the benefits of the technique,” Dr. Assouline said.
The last parameter that was tested was contrast sensitivity, which was statistically significantly better in the wavefront group.
“In our opinion, the increased accuracy in the delivery of the laser ablation profile and increased quality of vision are largely due to the fact that iris recognition allows for compensation of the cyclotorsion of the eye during laser ablation,” he noted.
In his opinion, the femtosecond laser dissection of the flap also played a role in improving the results of the treatment.
“We get much fewer complications than with a microkeratome: There was no flap displacement, no decentration and only one buttonhole, due to decalibration of the femtolaser, but the patient was treated 1 month later without problems. We had one case of DLK, which is a very low rate in a series of more than 500 eyes,” Dr. Assouline said.
He attributed this low rate of diffuse lamellar keratitis to the fact that, along with the femtosecond laser technology, he also used disposable equipment, which reduced the risk of infection or inflammation related to the sterilization process.
Screening campaign assesses AMD prevalence in France
A national screening campaign was launched in 2007 to evaluate the prevalence of AMD in France and to provide the French population with more information about the disease and its principal risk factors.
“Detecting AMD at its early stages gives better opportunities for treatment and preservation of vision. We are convinced that by increasing people’s awareness, the devastating social and individual consequences of AMD on vision and life can be reduced,” Valérie Le Tien, MD, said.
In several towns, people older than 50 years were invited to free macula screening by fundus photography and non-mydriatic retinography in May and June 2007. Local teams of ophthalmologists were provided with the same classification of signs for age-related maculopathies (large drusen and alterations of the retinal pigment epithelium) and AMD (macular hemorrhages, exudates, retinal pigment epithelium detachment, serous retinal detachment, geographic atrophy). The presence of other cases of AMD in the family, smoking habits, weight and height of each patient were also assessed.
A total of 3,432 people were screened. Of those, 71% were normal. Early forms of AMD were found in 17.7% of the participants, and in 3.6% of the people, more advanced stages of AMD were found.
“The prevalence of AMD that we found through this campaign is in line with the data found in literature,” Dr. Le Tien said. “Fundus photography with the aid of non-mydriatic retinography is an effective first step in the diagnosis of potential forms of age-related maculopathies. It allows to rapidly select the patients who need further investigation in specialized centers.”
New IOL respects the individual anatomy of the capsular bag
 Philippe Sourdille |
The Quatrix Evolutif implant from Croma has unique capabilities for adapting to capsular bags of different diameter, without causing deformations with consequent ovalization, capsular folds, imprecise refraction, unnatural expansions of the capsular bag diameter beyond the limits of the ciliary ring and consequent loss of pseudoaccommodation capabilities.
“We have demonstrated by in vivo high-frequency ultrasound imaging that size and position of the crystalline lens and capsular bag vary between individuals,” OSN Europe/Asia- Pacific Edition Editorial Board Member Philippe Sourdille, MD, said during a symposium.
Crystalline lens diameter has been shown to vary between approximately 8 mm and 10 mm.
“This variability has practical consequences on the design and sizing of intraocular lenses, which can perform well only if the individual anatomy of the eye is respected,” he said.
Another important factor, which is often overlooked, is the relationship between the crystalline lens diameter and the ciliary ring. In 80% of the cases, crystalline lens diameter appears to be equal to or less than the diameter of the ciliary ring.
“Respecting this natural balance when an IOL is implanted is critical to the preservation of pseudoaccommodative movements, but our observations have shown that in the majority of cases IOL implantation increases the capsular bag diameter and more when loop haptic lenses rather than angle piece lenses are used. In most cases, the relation between capsular bag and ciliary ring diameter is completely reversed,” Dr. Sourdille said.
The Quatrix Evolutif implant, he said, has been designed to address this need of true customized sizing.
As previous studies have demonstrated, the diameter of the capsular bag is correlated with corneal power and axial length. In a myopic eye, which has a greater axial length and a lower refractive power, a larger diameter IOL will be required, while a progressive decrease of IOL diameter will be calculated in relation with the increase in lens power and decrease in axial length.
“This customized, progressive variation enhances the performance of the implant tremendously and never causes the capsular bag to reverse the natural anatomical relationship with the ciliary ring,” Dr. Sourdille said.
Presby-LASIK outperforms multifocal IOLs, study shows
Both multifocal IOLs and presby-LASIK are viable solutions for presbyopia correction, but the latter has a greater range of visual acuity at different distances, according to a study.
“Presbyopic LASIK using the Gaussian ablation type, which means a +1.7 D, 3-mm optical zone, slightly decentered 1 mm inferiorly and nasally, is able to provide an acceptable level of distance vision, on average 20/25 to 20/20 and up to 20/18 in some cases, along with an acceptable or even very good level of near and intermediate vision,” Dr. Assouline said.
In comparison, multifocal IOLs have shown less satisfactory visual performance.
“They are, in fact, bifocal, and intermediate vision is generally poor,” he said.
Defocus curves show that, on average, visual acuity is 20/25 for a defocus of –1.5 D with presbyopic LASIK and 20/50 to 20/30 with multifocal IOLs.
“Defocusing is the best way of comparing multifocal techniques. It clearly demonstrates for the so-called multifocal IOLs that they have bimodal curves with a peak at 0 D for distance vision and a second peak at around –2.50 D, while the defocus curve for presby-LASIK is a continuous curve that has its highest point at 0 D with a slow decrease toward –3 D. This leaves 80% of vision at –0.5 D and 60% at –3 D, which is good enough for intermediate and near vision respectively,” Dr. Assouline said.
In the study, special emphasis was placed on assessing the optical nature of multifocality in presbyopic LASIK patients. A number of tests, based on corneal topography and aberrometry, were performed. “The total power map of the cornea shows an average addition zone, which is taking about 25% of the area of the entrance pupil in the patient and has a +3.8 D average power at the vertex. This shows that the patient sees with part of his entrance pupil for near and with the rest, which is about 75%, at distance,” he said.
Presbyopic LASIK is performed only in the nondominant eye, which allows the fellow eye, either non-operated when emmetropic or operated with hyperopic LASIK, to have adequate distance vision.
“This gives us truly satisfied patients,” Dr. Assouline said.
Aberrometry was performed with the Bausch & Lomb Zyoptix Zywave system.
“We were able to demonstrate that most of the defocusing effect created with the presbyopic LASIK technique was, in fact, negative spherical aberration and coma,” he said. “Having this [higher-order aberration] introduced in the optical system of the patient does not affect emmetropia for most of the entrance pupil but only in the central part of it. This means that the patient has a composite image, made of a near image and a distance image both of them being quite clear.”
Anti-VEGF therapy on the rise, fully reimbursable in France
Age-related macular degeneration is increasingly treated by anti-VEGF therapy in France, where health authorities provide full reimbursement for what international multicenter trials and evidence-based medicine showed to be the best standard of care.
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In an interview, Gabriel Coscas, MD, told Ocular Surgery News that a large investment has been made by the government to offer AMD patients the best medication currently available, namely Lucentis (ranibizumab, Genentech), despite the high costs involved.
“We have done the same for other ocular diseases, like cataract, and nobody would discuss the high cost of treating a patient for cancer,” Dr. Coscas said. “So I don’t see why anyone should be surprised at the amount of money that is spent on a drug that treats a severe and, unfortunately, increasing emergency like AMD. Verteporfin [photodynamic therapy], which didn’t have results as good as those of the anti-VEGF therapy, was not less expensive than ranibizumab.”
He also said no predetermined limits, but regular monitoring of the effects of the treatment, should decide the number and frequency of anti-VEGF injections.
“Patients must be followed closely and regularly examined using all the currently available technological equipment. This again requires investing money and time, but there is no other way doctors, politicians and a civilized society can deal with a condition that threatens the vision, functionality and quality of living of so many people,” Dr. Coscas said.
Reimbursement is provided to patients for this standard of care in whatever specialized center, public or private, they are referred to.
Because of these provisions, the use of off-label drugs such as Avastin (bevacizumab, Genentech) is not an issue in France, he said.
“Bevacizumab has proven effective in small studies and seems to have no particular side effects, but there is no reason why we should offer to our patients a drug that has not been properly tested in international, multicenter, randomized clinical trials and that is not available in the dosage that is required for intraocular use, rather than another one that has undergone the regular process of validation. Particularly since it doesn’t make any difference in terms of individual or institutional costs,” Dr. Coscas said.
DNA bank set up for research on AMD in France
A large DNA bank of patients with AMD is being set up in France to study the genetic factors potentially related to the development of the disease.
“AMD is a multifactorial disease, which involves environmental and polygenetic factors, with an extremely large variety of phenotypes. Our classification is based on fluorescein angiography,” Eric Souied, MD, said.
The project involves four centers: the Centre Hospitalier Intercommunal in Créteil, the Centre d’Imagerie et de Laser, the Hôpital de XV-XX in Paris and the CHU Pellegrin in Bordeaux.
Questionnaires, demographic data, blood serum samples and DNA samples were collected, and fluorescein angiography was performed for each of the patients.
So far, 1,229 patients have been included over a period of 20 months. The mean age of the patients was 80 years.
“We are hoping that the research done on the angiography-based phenotype, compared with healthy control eyes, will give us a chance to go a step forward in our research on the genetic component of AMD,” Dr. Souied said.
Optical analysis technology the future of lens-based refractive surgery
The double-pass Optical Quality Analysis System from Visiometrics will soon become the gold standard for analyzing anterior segment-related quality of vision, according to a speaker.
“The Optical Quality Analysis System is the only currently available system that provides all the information that is indispensable for complete and true evaluation of visual function because of its unique capability of measuring the combined effects of both high-order aberrations and the loss of ocular tissue transparency on the quality of retinal image,” Damien Gatinel, MD, said.
All of the information provided by the Optical Quality Analysis System (OQAS) is gathered from the analysis of the point spread function (PSF), which is three-dimensionally represented by the system.
“This representation allows an easier and more accurate analysis and interpretation of the PSF,” Dr. Gatinel said.
The main indices provided by the OQAS are the index of predicted contrast visual acuity at 100%, 50%, 20% and 9% contrast, taking into account the optical characteristics of the eye in terms of optical aberrations and light scattering; the curve of modulation transfer function and the scattering index, he said.
“The OQAS will be able to give precious information to all clinicians involved in the study and treatment of the different pathologies that lead to a reduction of ocular transparency, cataract in the first place,” Dr. Gatinel said. “It will be a predictor of the optical performance of both monofocal and multifocal lenses.
A note from the editors:
To facilitate bringing news to readers rapidly, for OSN SuperSite articles and meeting wrap-up articles, OSN departs from its editorial policy and typically does not send these items out for source corrections.