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CRSToday Europe News — March 2007
Cataract Scheme an Expensive Overreaction
The independent sector treatment center (ISTC) scheme for the National Health System (NHS) cataract services was an expensive overreaction regarding the need to increase rates of cataract surgery, said senior doctors in a letter to the British Medical Journal.
Many ophthalmology departments had improved cataract surgery pathways before the ISTC program was proposed, wrote consultant ophthalmic surgeon, Simon Kelly, in the letter, signed by the president and vice president of the Royal College of Ophthalmologists and the chair of the British Medical Association's (BMA) Ophthalmic group committee.
Had the Department of Health followed the advice of clinicians, the royal colleges, and the BMA when the cataract and other ISTC schemes were proposed, improved access to cataract surgery would have been realized with much less expenditure, without adverse effects on surgical training, and without destabilizing NHS eye departments, according to the letter.
An alternative direction was taken, authors said. Despite the paucity of clinical outcome data and the lack of evidence of cost-effectiveness of phase 1 of the ISTC program, further investment in cataract surgical facilities continues into phase 2.
"Meanwhile, for long-term stability of the service, the best option for the public is to support local NHS units, which brought down cataract waiting times, which patients need to call on in an emergency or for chronic eye disease, and which train the next generation of surgeons while meeting waiting time targets," the authors continued.
A constructive partnership of clinicians, managers, and commissioners is a surer way to achieve sustained improvements in access and quality of care, rather than centrally imposed initiatives and diktat, such as cataract ISTCs, they concluded.
AMO Acquired Wavefront-Guided Diagnostic Company
Advanced Medical Optics Inc., (Santa Ana, California) announced the acquisition of the refractive wavefront diagnostic systems, WaveFront Sciences, Inc., (Albuquerque, New Mexico) for $20 million. Earlier this year, AMO also announced its intent to acquire IntraLase Corp. (Irvine, California).
WaveFront Sciences, Inc., designed and manufactured the industry's highest resolution Shack-Hartmann–based aberrometer, according to Steve Schallhorn, MD, who recently retired as Director of Refractive Surgery for the US Navy.
"There is no question this acquisition is valuable for the AMO, as most vision scientists feel like the WaveFront Sciences Hartmann-Shack aberrometer is the finest available. It is very robust and has a greater dynamic range that can capture more most highly aberroted eyes," said Dr. Schallhorn in an interview with Cataract and Refractive Surgery Today Europe.
Combining the technologies of AMO, IntraLase and WaveFront Sciences is consistent with AMO's strategy to offer the safest, most effective wavefront-guided refractive surgery, said Leonard Borrmann, AMO Corporate Vice President, Research and Development, in a telephone interview with CRST Europe.
"With the acquisition, the AMO will secure proprietary technologies and research and development expertise in wavefront sensing and laser optics to further strengthen the Advanced CustomVue [Advanced Medical Optics, Inc.] laser vision correction technology, and accelerate the introduction of next-generation diagnostics that build on our WaveScan Wavefront systems," said AMO chairman and CEO Jim Mazzo, in a company news release.
The WaveFront Sciences acquisition included a $14 million cash payment at closing and an agreement to make a total of $6 million in future cash payments, which are contingent on achievement of certain milestones over the next 3 years.
"I have worked with WaveFront Sciences for many years, and believe that the AMO has acquired a real jewel. This really solidifies that AMO is a leader in aberrometry and makes the statement that they want to remain the dominant player in laser vision correction," said Dr. Schallhorn.
Bausch & Lomb Formed Alliance with AcuFocus
Bausch & Lomb (Rochester, New York) made an undisclosed equity investment, with a secured option to purchase AcuFocus, Inc. (Irvine, California), a privately owned company that is developing corneal inlay technology for the treatment of presbyopia.
"We are truly excited to collaborate with AcuFocus on the development and delivery of their leading-edge corneal inlay technology," said Henry Tung, MD, Corporate Vice President and Head of Global Surgical Strategy for Bausch & Lomb, in an email to CRST Europe. "We believe this pioneering technology has the potential to significantly enhance the alternatives available to the large population of presbyopic patients.
"There has been a significant amount of interest in AcuFocus corneal inlay technology for the treatment of presbyopia. This has been particularly evident among surgeons outside of the United States, where the technology could be available as early as 2008," Dr. Tung added.
The ACI 7000 (AcuFocus, Inc.) corneal inlay is implanted in the cornea under a LASIK flap and increases depth of field and near vision. Recent studies have demonstrated that the ACI 7000 improves near vision in emmetropic patients, as well as previous LASIK patients.
"Current surgical presbyopic solutions involve compromises that can negatively affect the quality of vision for many patients. The ACI 7000 corneal inlay is designed to remove those compromises through a safe and simple procedure," said Daniel S. Durrie, MD, principal investigator, in a company news release. "Moreover, preclinical studies performed outside the United States show excellent early results and high patient satisfaction."
Alcon's AcrySof Restor Received FDA Approval
Alcon Laboratories Inc., (Fort Worth, Texas) was granted US Food and Drug Administration (FDA)-approval of the AcrySof Restor apodized diffractive aspheric IOL for the visual correction of aphakia following cataract surgery in adult patients with and without presbyopia. The AcrySof Restor IOL is the only FDA-approved presbyopia-correcting IOL that incorporates aspheric optics into its design. Alcon will begin a phased commercial launch of this lens in the United States after necessary consignment quantities are established, with full distribution expected by the middle of 2007.
Study Examined Incision and Wavefront Error
A study published in the Journal of Cataract and Refractive Surgery examined the effect of cataract surgery through 3.2-mm superior incisions on corneal aberrations with two types of aspherical monofocal IOLs. The study found that the incisions induced consistent and significant changes in several corneal Zernike terms (ie, vertical astigmatism, trefoil, and tetrafoil), which resulted in a significant increase in overall corneal root-mean-square (RSM) wavefront error.
Corneal topography of 43 eyes were split into two groups, with Tecnis Z9000 silicone IOL (Advanced Medical Optics, Inc.) implanted in 22 eyes. The AcrySof IQ SN60WF (Alcon Laboratories, Inc.) was implanted in the remaining 21 eyes in a similar fashion. Corneal aberrations were estimated using custom-developed algorithms for 10- and 5-mm pupils.
Susana Marcos, PhD, and colleagues from the Instituto de Optica Daza de Valdes, found that RMS wavefront error did not change in the AcrySof IQ group, but increased significantly in the Tecnis group with both 10- and 5-mm pupil diameters. Vertical astigmatism, vertical trefoil and tetrafoil also changed in both pupil diameters. Mean vertical astigmatism increased by 2.47 µm ±1.49 (SD) and 1.74 ±1.44 µm in the Tecnis and AcrySof IQ group, respectively. Vertical trefoil increased by 1.81 ±1.19 µm and 1.20 ±1.34 µm, respectively. Tetrafoil increased by -1.10 ±0.78 µm and -0.89 ±0.68 µm, respectively.
These results may be used to improve predictions of optical performance with new IOL designs using computer eye models and identify the potentially different impact of incision strategies in cataract surgery, researchers wrote.
OVD Substances Impacted Endothelial Cell Count
Choosing a dispersive hyaluronate ophthalmic viscoelastic device (OVD) during phacoemulsification may allow for protection of endothelial cells, while suppressing the formation of free radicals, according to a study published in the Acta Ophthalmologica Scandinavica.
In a prospective, single-masked, randomized study, 60 eyes were assigned to three groups of 20 patients each, according to what OVD was used: Celoftal (Alcon Laboratories, Inc.), Vitrax (Advanced Medical Optics, Inc.), or Healon (Advanced Medical Optics, Inc.). The corneal response to surgery was evaluated by measuring endothelial cell loss, the variation in mean cell area of endothelial cells (CV), the frequency of hexagonal cells, and central corneal thickness.
Allan Storr-Paulsen, MD, and colleagues from the Frederiksberg University Hospital, Denmark, found that postoperatively all three groups had a significantly decreased cell count, but the decrease was less in the Vitrax group (n=6.97%) than in the Celoftal (n=18.03%) and Healon (n=18.46%) groups. No changes in CV or corneal thickness were observed, and an increase in visual acuity was equal among the groups.
Because viscoelastics facilitate cataract surgery and protect the corneal endothelium during the procedure, choosing a dispersive hyaluronate OVD during phaco may allow for protection of the CV. This may be the reason for the superior protective effect of Vitrax, compared with Celoftal and Healon, researchers concluded.
NEWS FROM ESCRS
Light Adjustable IOL Had High Predictability
A new light adjustable IOL (Calhoun Light Adjustable Lens; Calhoun Vision, Inc., Pasadena, California) that corrects refractive error was shown to provide precise and noninvasive postoperative adjustment of IOL power. This lens should only be introduced in one eye, and a standard aspheric IOL should be used in the other, said José L. Guell, MD, during a presentation at the 11th ESCRS Winter Refractive Surgery Annual Meeting.1 This lens also showed high predictability and stability for myopic and hyperopic corrections.
The Calhoun Light Adjustable Lens was implanted in four patients from Barcelona. Although implanted like a standard IOL, the light-sensitive surface of the lens was protected with a light filter. After implantation, all patients experienced an improved UCVA, and approximately 90% of the eyes were within 0.25 D of intended correction.
The lens is recommended for Conformiteé-Europeénne (CE) Mark approval, and will hopefully receive approval in 2 months to 3 months, said Dr. Guell. US FDA trials are scheduled for this year. Furthermore, the researchers are also working on a multifocal light adjustable lens to create multifocus.
LaserAce Shown to Restore Natural Dynamic
Accommodative Function
Biometric analysis may be an effective method of analyzing biomechanical mechanisms for accommodative function, according to Annmarie Hipsley, MD.1 The LaserAce (AceVision Group, United States) is a binocular wavefront device that works to restore biomechanics of accommodative visual function.
Dr. Hipsley presented data from 10 presbyopic patients, aged 42 years to 66 years, at the 11th ESCRS Winter Refractive Surgery Annual Meeting. All patients were treated with LaserAce to restore their accommodative function; mean follow-up was 6.5 months. According to Dr. Hipsley, the mean intraocular pressure decreased by 3.5 mm Hg, and the mean accommodative range was 2.00 D. After 1 year, 10 of 10 patients reached J3 or better.
Dr. Hipsley and colleagues concluded that the LaserAce procedure may indeed restore the natural dynamic accommodative function. This, she said, may depend on the corneal power in each patient.
Clinical Trial Examined New Laser
Ziemer Ophthalmics' (Port, Switzerland) newest femtosecond laser, the Femto LDV (Leonardi Da Vinci; formerly known as the Da Vinci) was shown to produce precise LASIK flap cuts, predictable thicknesses, and smooth stromal beds, according to the first prospective clinical study.1
Presented at the 11th ESCRS Refractive Winter Surgery Annual Meeting by Bojan Pajic, MD, and colleagues, the Femto LDV produced highly predictable quality for corneal resectioning, he said. Twenty eyes were involved in the evaluation, which included topography, wavefront measurement, confocal corneal laser-scanning microscopy, and corneal optical coherence tomography. Dr. Pajic reported that the mean flap thickness was 141 µm, and the intended flap thickness was 140 µm in all cases. Standard deviation was 8.5 µm. The Femto LDV produced smooth surfaces, with no tissue bridges, and was approximately as fast as a mechanical keratome, he said. Additionally, visual acuity was shown to restore significantly faster in eyes treated with femtosecond laser versus mechanical keratome, he said.
Surgeons Recommended Relifting Versus Recutting Flap
Relifting a LASIK flap is safer than recutting a flap to perform enhancement procedures, according to a presentation made by José L. Guell, MD, at the 11th ESCRS Winter Refractive Surgery Annual Meeting.1 The thickness and quality of the original flap determine which method to use.
When performing the procedure Dr. Guell recommended keeping the cornea dry, because water can change the ablation rate, which may result in undercorrection, he said. Pachymetry should routinely be performed to ensure accurate results, he added.
A survey conducted between 1998 and 2002, showed that attitudes for lifting versus cutting the flap have changed dramatically over the years. Previously, almost 20% of surgeons cut new flaps, whereas that number has now dropped to less than 1%.
Vikentia Katsanevaki, MD, also addressed recutting versus relifting, and said that she does not believe there is any flap that cannot be lifted. She did caution, however, that to avoid diffuse lamellar keratitis and inflammation, it is important not to traumatize the epithelium. Dr. Katsanevaki recommended using a blunt instrument to put slight pressure on the cornea. This recognizes the edge of the primary flap. She reported using this method consistently and only considers recutting a flap if there are obvious problems (eg, scarring, inflammation). Recutting a flap can create significant problems, is not as safe, and could jeopardize the ability to perform an enhancement, she said.
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