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Physician education a prominent theme at the World Ophthalmology Congress
Leading ophthalmologists stressed the importance of education to combat the “intolerable disparity” in vision care between wealthy and poor nations.
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SAO PAULO, Brazil — Physician education is vital to saving vision throughout the developing world, leading ophthalmologists from around the world said here at the World Ophthalmology Congress.
Speaking at the opening session of the meeting, Congress President Rubens Belfort Jr., MD, PhD, sounded the theme of physician education. He said “education, education, education” is needed to foster the advancement of modern medicine.
“We want more than just the advance of ophthalmology,” Dr. Belfort said. “We want modern medicine advancing everywhere.”
Gottfried Naumann, MD, president of the International Council of Ophthalmology, echoed the theme, calling for better global educational efforts to combat the “intolerable disparity” in vision care between rich and poor countries.
By gathering ophthalmologists from many countries at one international venue, Dr. Naumann said, the meeting underscores the global disparities in access to quality care. One reason for highlighting those discrepancies, he said, is to spark physicians’ interest in “creating a world without avoidable blindness.”
During the opening session of the six-day WOC, heads of the world’s foremost ophthalmology associations took their places on the stage alongside local dignitaries. They wore the traditional garb of the opening academic procession: long, black robes with green or yellow sashes.
After introductory speeches, Dr. Naumann presented the Gonin Medal on behalf of the ICO to Alfred Sommer, MD. He also presented the International Duke-Elder Medal to Bradley Straatsma, MD, and the Jules Francois Golden Medal to Bruce Spivey, MD. Mark Tso, MD, presented the Ophthalmic Pathology Award to Thaddeus Dryja, MD.
On behalf of the Academia Ophthalmologica Internationalis, Koichi Shimizu, MD, presented the Bernardo Streiff Gold Medal to Dr. Naumann.
A number of awards were presented on behalf of the Pan-American Association of Ophthalmology: The A. Edward Maumenee Medal for Distinguished Services to Juan Verdaguer, MD; the Gradle Medal for Good Teaching to Miguel Burnier, MD; and the Benjamin F. Boyd Humanitarian Award to Tim R.G. Sear, MBA, former chairman, president and chief executive officer of Alcon. The Boyd award was presented by Dr. Boyd’s son, Samuel Boyd, MD.
On behalf of the Brazilian Council of Ophthalmology, the association’s president, Harley Biccas, MD, presented Ruth Cardoso, PhD, with a medal for her work with the group called Communitas, which seeks to combat poverty and social isolation in Brazil.
Meeting organizers announced that the WOC, formerly held every 4 years, will now be held biennially, with the next one planned for Hong Kong in 2008.
The meeting drew 12,000 ophthalmologists from 117 countries to São Paulo, according to organizers. Regional and international subspecialty associations are represented, as are supranational organizations, such as the ICO, and numerous nongovernmental organizations.
Below are additional highlights from the WOC, as first published on the OSN SuperSite. Look for in-depth coverage from the conference in upcoming issues.
Glaucoma
Electronic glaucoma risk calculator an adjunct to experience
An electronic calculator designed to predict conversion from ocular hypertension to glaucoma can serve as an additional tool to guide a physician’s treatment decision, according to the research team that developed it. The calculator was first made available last year in a manual device similar to a slide rule.
Robert N. Weinreb, MD, and Felipe Medeiros, MD, both from the Hamilton Glaucoma Centre at the University of California, San Diego, described the new electronic version of the risk calculator at a press briefing sponsored by Pfizer Ophthalmics.
The risk calculator concept is based on the outcomes of the National Eye Institute’s Ocular Hypertension Treatment Study and further validated by data from a subset of patients in another study, Dr. Weinreb said.
The electronic version introduced here is easier to use than its slide rule predecessor, Dr. Medeiros said. He said physicians can calculate a single numerical score based on six factors (age, IOP, central corneal thickness, vertical cup-to-disc ratio, pattern standard deviation on perimetry and presence or absence of diabetes). The “score” tallied by the calculator indicates the potential risk that a patient with ocular hypertension will convert to glaucoma in the next 5 years.
Knowing patients’ risk levels will allow the physician to focus on the patients who are at greatest risk, Dr. Weinreb said.
As more data from larger studies are released, Dr. Weinreb said, he hopes the risk factor may be able to be calculated out to 10 or 15 years.
“The risk calculator should be an adjunct to, not a replacement for, clinical experience and judgment of the physician,” Dr. Medeiros said. Physicians should also consider a patient’s overall health status, life expectancy and commitment to treatment.
Pfizer Ophthalmics is providing copies of the electronic risk calculator to interested physicians.
Device may improve success, consistency of trabeculectomy
A cylindrical, biodegradable collagen implant may increase the rate of success of filtration surgery, according to investigators.
“Bleb formation and structure is almost random and is subject to a patient’s genetic makeup,” said Robert Ritch, MD. The OculusGen Collagen Matrix implant is the first application of bioengineering to glaucoma, he said.
The implant creates a “planned bleb structure” that represents “a new era in bleb control and structure,” he said at a sponsored symposium introducing the new device.
Another physician presented results of a small pilot study of 12 patients implanted with the device. Henry Shen-Lih Chen, MD, described 12 patients who underwent trabeculectomy with the OculusGen for the treatment of refractory glaucoma. The patients’ mean preop IOP was 45.67 mm Hg, and patients were taking an average 2.07 glaucoma medications.
In the surgical procedure, the OculusGen is placed on top of the scleral flap at the limbus, Dr. Chen said. The conjunctival wound is then closed with a continuous suture, he added.
At the 6-month follow-up visit, mean postop IOP was 16.11 mm Hg for all eyes; glaucoma medication use had dropped to 0.33 per patient on average. No significant intraoperative complications were noted, although transient shallow anterior chamber, hyphema and hypotony occurred postoperatively in one patient, Dr. Chen said.
“The preliminary results of this study indicate that OculusGen implantation in trabeculectomy represents a new, safe, simple and effective therapeutic approach for treating refractory glaucoma,” Dr. Chen said. “Normalization of subconjunctival wound healing by tissue engineering is applied to traditional filtering surgery, bringing a novel approach to anti-scarring.”
Dr. Chen said a longer follow-up period and a larger-scale study of the device is needed.
Titratable Gold Micro-Shunt implanted in first human eyes
An adjustable glaucoma drainage shunt has been implanted in three human eyes, according to its developer. The device, the DeepLight Gold Micro-Shunt from Solx, has been in development for several years, and these are the first human implantations, said Gabriel Simon, MD, PhD.
In an interview with Ocular Surgery News, Dr. Simon said he had implanted the first three human patients with a redesigned version of the titratable device within the past 2 weeks.
According to Dr. Simon, these cases constitute the first “artificial trabeculectomies.”
The shunt is inserted into the anterior chamber and the suprachoroidal space through a 2-mm incision. The device is 40 µm thick and contains 12 “windows,” which can be opened or closed with a titanium-sapphire laser also developed by Solx as part of the DeepLight system.
Dr. Simon said that, after implantation of the shunt, IOP was reduced by 10 mm Hg in all three eyes, with a resultant flow rate of 8 mL per minute. When he opened a third window in the shunts using the laser, an additional drop of 3 mm Hg occurred in all three eyes, Dr. Simon said.
All three eyes ended up with IOPs of 14 mm Hg, Dr. Simon said.
“This device duplicates the action of a prostaglandin in a device,” he said.
The DeepLight Gold Micro-Shunt is expected to be launched in about 5 months, first in Europe, followed by Canada and the United States, according to Doug Adams, chief executive officer of Solx.
Link seen between corneal elasticity and glaucomatous damage
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Image: Mullin DW, OSN |
The physiology of the cornea, not only its anatomy, appears to be strongly correlated with glaucomatous damage, according to a study presented here.
Nathan Congdon, MD, presented a paper that examined physiologic factors such as corneal bioelasticity as predictors of glaucomatous damage.
“Parameters besides the thickness of the cornea, related to deformability or the physiologic state of the cornea, may also be related to glaucoma risk,” Dr. Congdon said.
The study by Dr. Congdon and colleagues at Johns Hopkins University was named one of the “Best National Papers” here at the meeting.
Clinical studies have confirmed a relationship between corneal thickness and glaucomatous damage, but the nature of the relationship is not yet clear, Dr. Congdon said.
“We know that measured IOP varies with central corneal thickness for all modalities,” he said. “Yet this relationship has not been quantified and may or may not be linear.”
Because the significance of central corneal thickness is still not entirely clear, Dr. Congdon said it is “important to look at the physiology and not just the anatomy.”
Among the physiologic factors to be considered are hydration, connective tissue composition and bioelasticity, he said.
Dr. Congdon and associates conducted a retrospective review of the charts of one or two eligible eyes of 230 participants, 85% of whom were glaucoma patients or suspects. From the patients’ charts they recorded age, race, gender, diagnosis, number of years since diagnosis, baseline and current IOP, and cup-to-disc ratio. They also recorded visual field data including mean defect, pattern standard deviation, visual field progression and hemifield test.
Hysteresis was then measured in these subjects using the noncontact Ocular Response Analyzer from Reichert. Dr. Congdon and colleagues found that low corneal bioelasticity, also known as hysteresis, was associated with the presence of visual field progression, while central corneal thickness was not.
Dr. Congdon acknowledged that the study was not able to establish causality and was limited by the fact that much of the data were attained retrospectively. However, he said, it is “one of the first studies to suggest the link between corneal deformability and glaucoma damage.”
Gradle lecture: Glaucoma specialists must be ‘soothsayers’
Glaucoma specialists must act as “soothsayers” for their patients, accurately assessing their needs with evidenced-based medicine, according to a physician honored here.
“Soothsayers predict the future, usually based on specific knowledge. That’s what we need to be as we manage glaucoma,” said H. Dunbar Hoskins Jr., MD, delivering the Pan-American Association of Ophthalmology Gradle Medal lecture.
“We need to be able to give answers to four questions. Does the patient have glaucoma? Does the patient need treatment? Does the patient need more treatment? Does the patient need surgery?” Dr. Hoskins told the audience.
“If we can answer those questions, if we can predict the future for that patient, then we know exactly what we need to do for that patient,” he said.
A definition of glaucoma is paramount for predicting the progression of the disease, Dr. Hoskins said. He quoted the definition from the online encyclopedia Wikipedia.
“Glaucoma is a group of diseases of the optic nerve involving loss of retinal ganglion cells in a characteristic pattern of optic neuropathy … Raised IOP is a significant risk factor for developing glaucoma,” Dr. Hoskins quoted from the dictionary.
“Not only is IOP a significant risk factor for developing glaucoma,” he commented, “it’s the only risk factor we know how to treat.”
The challenge of combating glaucoma on a global scale cannot be ignored, Dr. Hoskins said. The World Health Organization has said that of 37 million blind people in the world, 12% are blind because of glaucoma – “a disease that, when managed properly, will not result in blindness,” Dr. Hoskins said.
In developing countries, management of glaucoma presents great challenges. “The cost of treatment often exceeds the annual wages of the patients’ families,” he said
Dr. Hoskins discussed the role of evidence-based medicine in managing glaucoma. Historically, he said, treatment decisions were based on a physician’s experience, which forms the physician’s opinion of what an individual patient needs at a given time. In the future, he predicted, treatment decisions will increasingly be based on evidence-based medicine.
“As we listen to the experts to make our opinions about how to manage care, we must examine their sources of data, their information, and understand that it is trustworthy and credible,” Dr. Hoskins said. But expert opinion is the lowest level of evidence-based medicine, he said.
Dr. Hoskins said the American Academy of Ophthalmology’s Preferred Practice Patterns series is an attempt to help physicians evaluate existing evidence. But recommendations in that series for management of glaucoma are not “supported very strongly by anything much more than a consensus of experts,” he said.
In short, the clinician still needs to be a soothsayer to determine treatment options for each patient the physician sees, Dr. Hoskins said.
“What we really want are devices that will consistently give us reproducible measurements and predict the future of treatment,” he said.
Cornea
Penetrating keratoplasty with femtosecond laser is ‘promising’
Penetrating keratoplasty using a femtosecond laser has yielded “promising results” in a handful of human clinical cases performed to date, according to a presenter here.
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Image: Mullin DW, OSN |
Francis W. Price Jr., MD, told attendees at an IntraLase-sponsored symposium that initial results of what he termed “advanced PK” with the IntraLase FS 60 kHz femtosecond laser have been encouraging.
The laser allows donor and recipient tissue to be “easily harvested,” even when the tissue is edematous, Dr. Price said.
To date, 16 advanced PK procedures have been performed by five surgeons, Dr. Price said. Along with Dr. Price, William W. Culbertson, MD; Sonia H. Yoo, MD; Eduardo C. Alfonso, MD; and Roger F. Steinert, MD, have performed the procedure with the IntraLase.
In the laser PK technique, first an outer vertical cut is performed, followed by a horizontal doughnut-shaped lamellar stromal dissection, followed by an inner vertical cut, Dr. Price said.
Advanced PK “combines the versatility of IntraLase wound construction and the more secure vertical wound healing in LASIK with the clarity of full thickness PKP,” he said. “Early results for a shaped PK procedure are promising.”
Dr. Price said he believes the versatile IntraLase technology will enable surgeons to devise new applications for the laser, including deep lamellar dissection, pocket creation for corneal inlays and astigmatic keratotomy.
“This is an exciting time in corneal surgery, with new ideas and new capabilities,” Dr. Price said.
IntraLase introduced the 60 kHz version of its femtosecond laser here during the conference.
Dry eye patients at greatest risk for corneal graft failure
Patients with severe dry eye are at high risk for rejection of grafts used in ocular surface reconstruction surgeries, according to José Alvaro P. Gomes, MD. He said preoperative preventive measures should be taken to improve management of these patients, including maximizing aqueous tear function with punctual plugs or other therapies.
“Patients with severe dry eye, who have no production of tear film, do very badly,” Dr. Gomes said.
Dr. Gomes said other conditions aside from dry eye can also promote rejection, such as inflammation, immunologic rejection and stem cell exhaustion.
To anticipate complications and improve outcomes, surgeons should learn to pinpoint the exact type of graft failure, as well as when, how and why it occurs, he said.
The earliest stage of failure, known as acute failure, occurs within 1 month of the reconstruction procedure, Dr. Gomes said. Acute failure is often caused by inflammation or infection, he said.
The next stage, classified as early failure, occurs within the first year – typically 2 to 4 months after the transplantation – and is often caused by immunologic rejection. Chronic inflammation is also a problem at this early stage, according to Dr. Gomes.
The final category, late failure, refers to graft failures after 1 year. These are typically known as stem cell exhaustion, referring to the “loss of ability of stem cells to maintain turnover of the corneal epithelial cells,” or a late immunologic rejection, Dr. Gomes said.
Dr. Gomes said research has shown that dry eye and Stevens-Johnson syndrome are the most important diagnostic indicators for graft rejection across the board. Patients with these conditions should be carefully monitored preoperatively and postoperatively to address lid abnormalities and promote normal tear function, he said.
Patients with Stevens-Johnson syndrome or dry eye are considered even more at risk than patients who have sustained ocular injuries, Dr. Gomes noted.
Retina
Short interfering RNA drug shows early promise in retinal disease studies
A new type of drug technology has shown promising early results for the treatment of both age-related macular degeneration and diabetic macular edema, according to Alexander Brucker, MD. He spoke about phase 1 and phase 2 trials of Cand5, Acuity Pharmaceuticals’ short interfering RNA therapy that targets vascular endothelial growth factor. Phase 1 safety studies are complete, and phase 2 trials are ongoing, he said.
An important finding of the phase 1 safety trial of the drug for AMD, Dr. Brucker said, was that no evidence of short interfering RNA circulating in the circulating blood was found. He added that mean visual acuity was stable at 6 weeks, and there was “very high stability over a period of 12 weeks.”
“We have a very powerful anti-VEGF molecule,” Dr. Brucker said. “It appears to have no systemic exposure and no significant ocular side effects.”
In a phase 2 trial in 129 patients with choroidal neovascularization, subjects are being injected every 6 weeks with one of three doses of Cand5. A primary outcome of the phase 2 trial will be best corrected visual acuity, Dr. Brucker said. The last patient in that trial will receive the final injection during the first quarter of this year.
“We’re going to have results and data on the efficacy of this drug probably by the summertime of this year,” he said.
In addition to the AMD trial, Cand5 is under investigation as a potential treatment for diabetic macular edema as well, Dr. Brucker said.
“If we can inhibit messenger RNA inside the cell from releasing the VEGF into the vitreous, we can then perhaps decrease this vascular permeability molecule and vascular endothelial growth factor and decrease neovascularization and leakage,” he said.
In the phase 2 diabetic macular edema trial, patients are being treated every 4 weeks, Dr. Brucker said. Based on the rapid rate of enrollment in the trial, he expects the recruitment for the study will be completed “by the end of April or May, rather than in the third quarter” of 2006, Dr. Brucker said.
Dr. Brucker said Acuity plans to begin phase 3 trials for each indication some time in the first half of 2007.
Protein kinase inhibitor reduced vision loss in diabetic retinopathy, study says
In patients with moderate to severe nonproliferative diabetic retinopathy, orally administered ruboxistaurin reduced the occurrence of moderate vision loss by 40%, said one researcher.
Aniz Girach, MD, and colleagues at the Lilly Research Lab in the United Kingdom randomly assigned 685 patients in a study to receive either ruboxistaurin or placebo. Ruboxistaurin is a protein kinase C beta inhibitor that targets a “key underlying process that causes diabetic microvascular damage,” according to Lilly materials.
The primary endpoint of the study was a sustained moderate (three lines) visual acuity loss for the last 6 months of the 3-year study. Patients with “moderately severe to very severe” nonproliferative diabetic retinopathy, a best corrected visual acuity score of 45 letters on the ETDRS chart and no prior photocoagulation in the study eye were included in the study, Dr. Girach said.
Of 340 patients taking placebo, 9.1% experienced a sustained moderate vision loss. Of 345 patients taking ruboxistaurin, 5.5% had a sustained moderate vision loss, Dr. Girach said.
The researchers said 28 patients taking ruboxistaurin gained 15 letters compared with 14 patients taking placebo (P = .027); 38 patients taking ruboxistaurin lost 15 letters compared with 57 taking placebo (P = .44), Dr. Girach said. No major differences were seen between the two groups in discontinuation or demographic information.
Other physicians involved in the study include Alexander J. Brucker, MD; Lloyd P. Aiello, MD; Louis Vignati, MD; Matthew Sheetz, MD; Matthew D. Davis, MD; and Roy C. Milton, MD, Dr. Girach said.
Pending regulatory approvals, Eli Lilly & Co. plans to market ruboxistaurin under the brand name Arxxant.
Gravity linked to diurnal fluctuation in macular edema, researcher says
Gravity and hydrostatic pressure appear to play a role in diurnal variation in the severity of diabetic macular edema, according to a retina specialist.
“Our study supports the hypothesis that gravity and hydrostatic pressure play a major role in determining time-related shifts in clinically significant macular edema,” said Francesco Bandello, MD.
He and colleagues examined diurnal fluctuations of macular thickness in 10 diabetic patients with an average macular thickness of 574 µm.
During the course of the day, patients tested when standing upright demonstrated a 20% decrease in mean foveal thickness compared to their foveal thickness in a recumbent position, Dr. Bandello said.
He said systemic factors, including fluctuations in blood pressure and body temperature, were ruled out as possible causes of diurnal changes.
One explanation for the change, he noted, could be the physical shift of a patient from the sleeping recumbent position to the awake upright position.
“The high hydrostatic pressure in the recumbent position may increase [the fluid] … to the tissue of the visual compartment,” Dr. Bandello said.
Artificial vision chip for retinal pathologies
Japanese investigators are planning a second clinical trial this spring to evaluate a retinal prosthesis for artificial vision, according to a presenter here.
Yasuo Tano, MD, said the prosthesis, known as the suprachoroidal transretinal stimulation system (STS), has shown promising results in two patients with retinitis pigmentosa who volunteered for the first trial.
With the STS, a chip with nine electrodes is introduced into a scleral pocket, and suprachoroidal transretinal stimulation is applied.
“The electrical current was comparable with what had been reported previously in [studies of other] retinal prostheses,” Dr. Tano said.
He anticipates that patients will achieve reading vision and enhanced visual navigation in the second trial because the STS allows increased numbers of electrode arrays.
Retinal prostheses represent the latest milestone in a long line of macular surgery advances, Dr. Tano said.
“Many impossible dreams have already come true,” he said. “Macular surgery will endlessly evolve for the benefit of better surgical outcomes.”
Cataract
Educating doctors, staff, patients regarding phaco is key
With the incidence of global cataract blindness on the rise, speakers here emphasized that surgeon and staff training in phacoemulsification, as well as patient education, may be important factors in reducing the backlog of blindness.
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Abhay Vasavada, MD, FRCS, said the ideal approach for implementing advanced cataract surgery in developing parts of the world is to teach phaco techniques in those countries.
“Phaco is a safer surgery, with superior clinical outcomes [than manual small-incision surgery or extracapsular cataract extraction],” Dr. Vasavada said. “It is important to accept this to achieve sustainable, quality eye care.”
Dr. Vasavada said that, thanks to aid from nongovernmental organizations, local governments and the ophthalmic industry, cost is not the primary impediment to lowering the incidence of cataract blindness.
“The real issue is training,” Dr. Vasavada said. “What we need are more paramedics. We need to train more paramedics.”
Inadequate training in phaco in medical schools is also common, he said.
Yehia Salah Mostafa, MD, agreed that phaco is the best surgical method to teach to surgeons in developing countries because it is faster than other options and a “perfect fit” for the situation.
“We really need to transfer knowledge to best serve our patients,” Dr. Mostafa said. “Training doctors is more important than just doing surgery.”
Looking at the global cataract blindness problem from the standpoint of supply and demand, Emanuel Rosen, FRCOphth, said in the end “it is a political problem.”
Mr. Rosen said that, in the United Kingdom, after the general public was educated about cataract surgery and its benefits, the public put pressure on the government to increase the number of cataract surgeons and surgeries it would finance.
In many developing countries, he said, the biggest problem is the ratio of ophthalmologists to general population. As an example, Mr. Rosen pointed out that there are as many ophthalmologists in San Francisco as there are in all of Africa.
High myopia an additional challenge in cataract cases
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Patients with high myopia undergoing cataract surgery have a heightened risk of retinal complications, and surgeons should pay greater attention to IOL power calculation and anesthesia choice in these patients, suggested one surgeon speaking here.
When compared with the general population, people with high myopia are four times more likely to develop cataract, said Carlos E. Leita Arieta, MD. Intraoperatively, there is a higher risk of retinal complications such as detachment and hemorrhage in patients with myopia who are undergoing cataract surgery, he said.
Dr. Leita Arieta told meeting attendees to conduct a detailed preoperative examination of the retina in highly myopic patients.
The surgeon may also have difficulty estimating the IOL power needed in these patients, Dr. Leita Arieta said. He suggested using recognized methods such as the later Holladay and SRK/T formulas and careful biometry. Even using those formulas, the surgeon should not overpromise to these patients, he said.
Dr. Leita Arieta said he prefers to use parabulbar or peribulbar anesthesia in patients with high myopia as it offers good protection and good safety. Finally, intraoperatively, he recommends slow-motion phacoemulsification, as this technique provides improved safety in highly myopic patients.
Imaging makes complicated cataract cases ‘almost routine’
Anterior segment imaging technologies can help reduce the risk of complications in challenging cataract surgery cases, such as intumescent cataracts, according to a speaker here.
Virgílio Centurion, MD, said anterior segment imaging has turned once-daunting conditions into “almost routine” surgical cases. He described his experience with the Oculus Pentacam imaging system at a symposium of the Latin American Society of Cataract and Refractive Surgeons held during the WOC.
“In difficult and challenging cases, we want the surgery to become more predictable,” Dr. Centurion said.
To help accomplish this, he said, the Pentacam employs a rotating Scheimpflug camera to create three-dimensional views of the anterior segment.
He said new imaging technology makes it possible to distinguish between a cataract that is intumescent and one that is merely white. The Pentacam images reveal the depth of the anterior chamber as well as the thickness of the crystalline lens, both factors that can help determine if the cataract is intumescent, he said.
“The most important thing is to have a diagnosis that is certain,” Dr. Centurion said. With this, the surgeon can create a protocol tailored specifically to the pathology at hand.
For intumescent cataracts, Dr. Centurion said, his surgical approach includes dyeing the capsule, applying a dispersive viscoelastic, and aspirating the cataract immediately upon needling the capsule.
He said the Pentacam gives surgeons a correct diagnosis, enabling them to adopt “a strategy suited to avoid problems with the capsulotomy.”
New chopper uses ultrasound to divide nucleus
A new chopper helps divide the cataract nucleus into fine pieces “as if it were cutting a bar of chocolate with a hot knife,” according to the device’s developer.
Luis Escaf, MD, presented his experience with the device, which he called the Ultrachoper. The Ultrachoper has been registered with the U.S. Patent Office, but it is not yet commercially available, he said.
The Ultrachoper attaches directly to a phacoemulsifier and cuts and divides the nucleus using high-frequency ultrasound energy, Dr. Escaf said. The power can be adjusted according to the degree of hardness of the nucleus, he said.
The device can be used in conjunction with conventional ultrasound or with the AquaLase cataract liquefaction system from Alcon.
Dr. Escaf said that 60% to 70% of cataracts in his native Colombia are grade 3 or 4 and that the Ultrachoper has helped him divide even the hardest cataracts into as many as eight to 10 pieces with an easy, clean cutting motion.
“This new development will have very interesting repercussions [for cataract surgeons],” he said.
Refractive
Refractive surgery can be a lifelong experience for patients
Refractive surgeons should consider the lifelong implications of what they do for patients, said George O. Waring III, MD, FACS, FRCOphth. He said looking at a patient’s refractive surgery experience as a single event may be a false assumption. There is a possibility that the patient will return to the same refractive surgeon for additional surgery.
“A refractive surgeon is more than a LASIK surgeon,” Dr. Waring said. “A LASIK surgeon is not a refractive surgeon.”
To illustrate his point, Dr. Waring traced the refractive surgical history throughout a hypothetical patient’s life.
In childhood, due to rapid changes in refractive error, the eye is changing too fast for surgery, Dr. Waring said. In adolescence, the patient may be motivated to undergo refractive surgery because, socially, that is the most important decade to be spectacle free, he said. So in his teens this hypothetical patient might opt for either LASIK or epi-LASIK to achieve spectacle independence for his minor refractive error.
As this patient reaches his 20s, he experiences a marked increase in high myopia, which is treated, again by the same surgeon, with a phakic refractive lens. Then while the patient is still in his 20s, he experiences a high residual error and unacceptable glare, so he receives his first wavefront-guided LASIK re-treatment.
In his 30s, this same patient undergoes progression of myopia, so he returns to undergo a second re-treatment.
As the patient ages into his 40s he starts to experience increasing presbyopia, so he undergoes another re-treatment for monovision, perhaps receiving a presbyopic corneal inlay.
In his 50s the presbyopia of the patient exceeds the reach of monovision, so he undergoes refractive lens exchange with an accommodating multifocal IOL.
Finally, in his 60s, the patient develops Fuchs’ dystrophy and undergoes a corneal procedure that does not adjust his refraction, such as a posterior lamellar graft.
While this is just one example of the lifelong possibilities for interaction between a surgeon and his patient, Dr. Waring said his demonstration was meant to show the different refractive surgeries that are “appropriate throughout life for the patient who wants [them].”
Cross-linking therapy a promising treatment for keratectasia
A therapy that uses ultraviolet light and riboflavin to create cross-linking of corneal collagen may be a promising treatment for keratectasia, a preliminary study has shown.
Maria Regina Chalita, MD, reported results from a prospective analysis of the treatment in seven patients who had developed corneal ectasia following LASIK surgery. Prior to the treatment, each patient had progression of ectasia documented by at least two corneal topography maps, she said.
Dr. Chalita said the procedure begins with proparacaine topical anesthesia, followed by mechanical epithelial debridement, and then instillation of a riboflavin solution 5 minutes before UV light irradiation using UV-emitting goggles. Patients then wear a bandage contact lens for 4 days after the treatment.
At the 3-month follow-up point, uncorrected visual acuity had improved in the seven patients and best corrected visual acuity remained the same, Dr. Chalita said.
“Most patients reported better [visual] quality than before surgery,” she said.
“We expected to see a lot of change in corneal topography, but we didn’t,” she continued. “There were no reported adverse effects and no patients lost lines [of visual acuity]. No regression was observed at the 3-month follow up.”
Dr. Chalita concluded that corneal cross-linking with riboflavin and UV light seems to be a safe procedure, but longer-term follow up with a larger patient cohort is needed.
Industry news
Macugen launched in Latin America
A treatment for age-related macular degeneration already marketed in the United States and Europe is now available in Latin America, company officials announced here.
Pfizer Ophthalmics formally launched Macugen (pegaptanib sodium injection, Pfizer/OSI Pharmaceuticals) in Latin America during the meeting, a press release from the company said.
Macugen, which works by fighting vascular endothelial growth factor, is indicated for treatment of the wet form of AMD. Macugen was approved for marketing in the United States in December 2004 and by the European Union in February.
According to Pfizer, Macugen has also been approved in Argentina, Brazil, Canada, Peru, Pakistan and the Philippines and has filed for approval applications in 15 other countries. An OSI Pharmaceuticals press release noted that Mexico, Australia and Switzerland are among those 15 countries.
Alcon launches DisCoVisc in Brazil
Alcon introduced its latest ophthalmic viscosurgical device to the Brazilian market here at the meeting, company officials said.
DisCoVisc (sodium chondroitin sulfate 4%, sodium hyaluronate 1.65%, Alcon) is intended for use during all stages of anterior segment surgery, according to a press release. The company calls the product a viscous dispersive, meaning it marries properties of cohesive and dispersive viscoelastic agents that are currently on the market.
DisCoVisc acts as a cohesive in that it maintains the shape of the anterior chamber during phacoemulsification and is easy to remove, according to Alcon. At the same time, the dispersive quality allows the product to stay in the eye and protect the endothelium, the company said.
New dry eye treatment available in Brazil
A new medication for the treatment of moderate to severe dry eye syndrome is now available in Brazil, according to the manufacturer.
Liposic gel (carbomer 2 mg/g plus sorbitol) is available by prescription, said Alessandro Guimaraes, supervisor of sales and marketing for Bausch & Lomb Brazil. The gel’s dosing regimen will depend on the severity of the patient’s dry eye and will be at the discretion of the physician.
Contact lens line launched
CIBA Vision has introduced its O2Optix contact lens line to the Brazilian market, the company announced.
Company officials said the lenses – made of a silicone hydrogel material called lotrafilcon B – are the company’s most “breathable” line. Users can wear them for up to 6 nights of extended wear.
The lenses have a “uniquely curved base that facilitates the eye’s adaptation, and biocompatible plasma surface,” according to company information. The lens’ biocompatibility makes it more resistant to deposits, the company said.
The lens is 33% water and blue-tinted for visibility. The material has a Dk/t of 138. CIBA officials noted that 125 Dk/t is the minimum required for extended wear lenses.
CIBA said the lenses are “ideal” for people who spend most of the day in front of the computer or who want or need to wear their contact lenses for long periods of time.
Visante OCT now available in Brazil
Carl Zeiss Meditec Inc. introduced Visante OCT to the Brazilian market here at the meeting, according to company officials.
The device is designed for non-cataract anterior segment imaging throughout a range of applications, including glaucoma, retina and refractive procedures. The Visante OCT offers high-resolution ocular coherence tomography imaging of structures such as the cornea, iris, angle and lens, company officials said.
The Visante does not require anesthesia or a water bath, and can be used for diverse procedures including corneal imaging, full-thickness pachymetry, measuring flaps and measuring residual stromal bed thickness after LASIK, according to the company.
Tecnis multifocal launched in Latin America
A new diffractive multifocal IOL is now available in Latin America, according to the lens’s manufacturer.
The Tecnis multifocal IOL, from Advanced Medical Optics, was introduced to the Latin American market here at the meeting, company officials said.
The IOL is for patients with presbyopia who undergo clear lens extraction. The Tecnis multifocal is not yet approved by the U.S. Food and Drug Administration, but was granted the CE Mark in 2004.
As cataract patients increasingly demand both near and far vision improvements, the diffractive multifocal design and sharp optics provide “excellent results for presbyopia,” company officials said. The aspheric profile compensates for spherical aberration, improves contrast sensitivity and is said to give patients better night driving vision, AMO officials said.