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Ophthalmology Times Conference Brief, American Academy of Ophthalmology, 2010 Joint Meeting  October 16-19, 2010  Chicago, IL
Ophthalmology Times
In This Issue
Streptococcal isolates more common in endophthalmitis after injection
Anti-VEGF therapy use may be suboptimal
OCT has value in compressive optic neuropathy
Radiotherapy standard of care for optic nerve sheath meningioma
Femtosecond improves predictability of effective lens position
Study shows benefit of laser capsulotomy
Laser lens fragmentation reduces ultrasound energy use
Femtosecond system under development for in situ IOL customization
Drs. Jervey, Rice honored by AAO
Bascom Palmer earns top honors
OWL panel to focus on dynamics of change
 
ANTI-VEGF AGENTS

Streptococcal isolates more common in endophthalmitis after injection

Chicago—Streptococcal isolates are seen more often in cases of endophthalmitis following intravitreal injection of anti-vascular endothelial growth factor (VEGF) drugs. Spread of oropharyngeal droplets may be responsible for this finding, said Colin McCannel, MD, Jules Stein Eye Institute, UCLA School of Medicine, Los Angeles.

The rate of endophthalmitis after injection of intravitreal anti-VEGF drugs is low, but Dr. McCannel wants to lower it even more. To that end, he analyzed the findings from cases of endophthalmitis. He conducted a meta-analysis of the topic and determined that Streptococcus organisms comprised 30.8% of organisms in cases of endophthalmitis, which was three to four times higher after injections compared with after surgery in operating rooms in the United States.

“An important finding is that Streptococcus isolates are found among the normal conjunctival flora in similar populations,” he said. “These isolates are virulent and are on oropharyngeal droplets.”

Droplet contamination can occur while talking when facing the sterile field and not wearing a face mask. Dr. McCannel suggested that oropharyngeal droplet transmission can be decreased by wearing a mask or by minimizing talking, coughing, and sneezing while administering intravitreal injections.


NEOVASCULAR AMD

Anti-VEGF therapy use may be suboptimal

Chicago—Anti-vascular endothelial growth factor (VEGF) medications ranibizumab and bevacizumab (Lucentis and Avastin, respectively, from Genentech) are administered to treat neovascular age-related macular degeneration (AMD), but their use in clinical practice has been unclear.

Lesley Curtis, PhD, associate professor, Duke University School of Medicine and Duke Clinical Research Institute, Durham, NC, investigated the use of these agents in 414, 535 Medicare recipients and reported the treatment patterns.

“We know that monthly injections of anti-VEGF treatments for 2 years provide optimal outcomes, and less frequent injections result in worse visual acuity,” Dr. Curtis said. “We also know that bevacizumab injections are a fraction of the cost of ranibizumab. We do not know how these drugs are used in clinical practice.”

The highlights of the study findings were as follows. The use of anti-VEGF medications increased from 2005 to 2008; in 2005, 49% of recipients were treated with an anti-VEGF drug and in 2008 that number increased to 77% among Medicare patients with AMD. However, interestingly, less than 20% of patients received more than six injections during the first treatment year and treatment in 60% of patients was discontinued within 12 months of initiation of treatment. Almost 25% of patients switched treatments during the first treatment year.

Dr. Curtis said that future studies are needed to determine why the use of anti-VEGF medications was suboptimal and why they were discontinued prematurely. In addition, there is a need to assess the association between treatment patterns and visual acuity outcomes.


NEURO-OPHTHALMOLOGY

OCT has value in compressive optic neuropathy

Chicago—Optical coherence tomography (OCT) can be used to provide patients who have undergone surgery for compressive optic neuropathy with an honest assessment of their visual potential, said Randy Kardon, MD, PhD.

He discussed patients who had undergone surgery but did not have visual acuity improvement in eyes in which the visual acuity was severely affected. In these patients, the tumor causes conduction block of the nerve fiber that, if relieved, may allow the nerve to function again, and there is nerve demyelination with chronic compression that may return to normal over time. There also is axon loss that will not return to normal, said Dr. Kardon, director of neuro-ophthalmology services, Ophthalmology and Visual Sciences, University of Iowa, Iowa City.

Dr. Kardon discussed the possibility of predicting visual acuity postoperatively based on the ocular structures. Using a graph, he showed how the visual field loss is related to the ganglion nerve fiber bundle.

“There is a fairly predictable relationship,” he said.

When decompression surgery is performed, for example, in a patient with a normal nerve fiber layer thickness and abnormal threshold sensitivity, the normal nerve fiber layer is a good sign that the function can return toward normal, Dr. Kardon said. However, because of the variability of the nerve fiber layer, he also is looking at the ganglion cell layer thickness at the fovea to determine the number of neurons that remain.

“There is a strong relationship between the ganglion cells, their axons, and visual loss,” he said. “This relationship between structure and function is not strong enough to predict precisely the outcome of decompression surgery.

“If there is a normal thickness of the nerve fiber layer and the ganglion cells, it is strong enough to provide patients with hope for vision improvement, but it is not strong enough to take away that hope,” he added. “I use OCT as a tool to give hope to patients that they may have visual improvement. If there is no hope, I suggest another decompression surgery.”


ORBITAL TUMOR

Radiotherapy standard of care for optic nerve sheath meningioma

Chicago—In patients with a progressive optic nerve sheath meningioma, fractionated stereotactic radiotherapy is the standard of care and prevents further vision loss, according to Peter Savino, MD.

Optic nerve sheath meningiomas are rare and represent about 2% of all orbital tumors. The tumor occurs more frequently in women. The tumor is characterized by progressive visual loss, optic atrophy, and optochoroidal or optociliary shunt vessels seen on magnetic resonance imaging, said Dr. Savino, Shiley Eye Institute, University of California, San Diego.

“There are only several options, the first of which is observation,” Dr. Savino said. “However, almost all patients with an optic nerve sheath meningioma will go on to lose vision. A previous popular option was surgery, but it is no longer performed routinely. Radiotherapy was later considered to be a viable treatment option.”

Initially, standard radiation was used to treat these patients, but because of the associated complications, the visual outcomes were actually better for patients who had only been observed. When fractioned stereotactic radiotherapy began to be used, a large study that compared the results of standard radiation with those of fractioned stereotactic radiotherapy indicated that the results were better because of the limited treatment field and the decreased rate of complications.

“I first observe to determine if the patient is progressing,” Dr. Savino said. “If that is the case, I treat with fractioned stereotactic radiotherapy.”


CAPSULOTOMY CREATION

Femtosecond improves predictability of effective lens position

Chicago—The ability of a proprietary femtosecond laser system (LenSx, Alcon Laboratories) to create a perfectly centered, sized, and circular capsulotomy has been shown in a clinical study to translate into reduced variability in effective lens position, said Roger F. Steinert, MD. He is the Irving H. Leopold Professor and chairman, Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine.

Having previously established in a comparative study that the femtosecond laser system offers much higher accuracy for creating a capsulotomy of intended size relative to a manual technique, Dr. Steinert and co-workers undertook a prospective study to determine the effect of capsulotomy method on effective lens position. The procedures were performed in Budapest, Hungary. There were 25 eyes in the laser capsulotomy group and 21 that underwent manual capsulorhexis. Intended size was 4.5 mm in both groups.

Effective lens position and anterior chamber-to-axial length ratio were determined at 1 month using data collected with an optical biometer (LenStar, Haag-Streit).

The results showed mean effective lens position was not significantly different between the two groups. However, the standard deviation was less in the femtosecond laser group versus manual controls both for effective lens position and the ratio of anterior chamber depth-to-axial length, and the differences in standard deviations were highly statistically significant.

“The increased predictability in effective lens position achieved using this femtosecond laser system should lead to more predictable visual outcomes,” Dr. Steinert said. “The next step in our series of investigations will be to determine the actual refractive predictability.”


IOL POSITION, ACCURACY

Study shows benefit of laser capsulotomy

Chicago—Results of a fellow eye comparative study show the benefit of an investigational femtosecond laser-assisted cataract surgery system (OptiMedica) for significantly improving the reproducibility of capsulotomy size and shape compared with manual capsulorhexis performed by experienced surgeons, said Stephen S. Lane, MD, adjunct clinical professor of ophthalmology, University of Minnesota, Minneapolis.

Dr. Lane reported the findings from a study that enrolled 29 patients who had one eye randomly assigned to laser capsulotomy and one eye to the manual technique. After the capsulotomy was created, the excised discs were stained with trypan blue and subjected to image analysis to determine the diameter and shape in terms of circularity. In addition, centration of the laser capsulotomy relative to the dilated pupil center was measured using a still frame captured from a high-resolution, near-infrared video that is part of the femtosecond laser.

Statistically significant differences were achieved favoring the laser capsulotomy group over the manual controls in analyses of mean deviation from intended capsulotomy size (27 ± 25 µm versus 339 ± 248 µm) and capsulotomy shape (0.942 ± –0.040 versus 0.765 ± 0.148, where 1 = a perfect circle). The laser-created capsulotomies also demonstrated excellent centration, with the average root square decentration from the dilated pupil center being 86 ± 51 µm.

“These findings have potential implications with respect to the ability of this system to maximize effective lens position and IOL power prediction accuracy and thereby, hopefully, provide better vision outcomes that will lead to happier patients,” Dr. Lane said.


PHACOEMULSIFICATION

Laser lens fragmentation reduces ultrasound energy use

Chicago—Use of a proprietary femtosecond laser system (LensAR) for lens fragmentation significantly reduces the amount of ultrasound energy needed for phacoemulsification, said Harvey Uy, MD, director of research, Asian Eye Institute, Makati City, Philippines.

The femtosecond laser system used in this study is commercially available and approved for use to create the anterior capsulotomy in cataract surgery. Dr. Uy presented the results of a prospective, open-label study that evaluated three pattern cut algorithms (sphere, cube, and pie) in a total of 153 eyes and compared the results for the preferred algorithm against a control group of 39 eyes that underwent cataract surgery without laser lens fragmentation. The primary outcome measure was cumulative dissipated energy (CDE) recorded by the phacoemulsification machine (Infiniti Vision System, Alcon Laboratories) at the end of the procedure.

The results showed the choice of treatment algorithm for lens fragmentation impacted the way the nucleus could be disassembled and removed and favored the pie pattern. Overall, using the laser for lens fragmentation in a pie-cutting pattern reduced CDE by about one-third compared with the control group (12.56 versus 18.84; p < 0.001). For eyes with cataract grades 1 and 2, CDE was reduced by more than 90% using the laser while there was a 64% reduction in CDE among eyes with grade 3 cataracts and a 21% reduction in the grade 4 cataract group.

“Data we have collected since this study and after further refinement of the treatment algorithm shows that we achieved a 30% reduction in CDE for grade 4 cataracts using the laser for lens fragmentation,” Dr. Uy said. “The reduction in ultrasound energy used during the surgery should result in less inflammatory response and preservation of endothelial cells.”


REFRACTIVE INDEX

Femtosecond system under development for in situ IOL customization

Chicago—Findings from initial experiments indicate the feasibility of using focused femtosecond laser pulses for in situ creation of customized IOLs, said Josef Bille, PhD.

The prototype system used in the research Dr. Bille described was developed by Heidelberg Engineering and would have the capability of performing in situ modification of refractive index to adjust IOL dioptric power, toricity, and asphericity. Dr. Bille is director, Institute for Applied Physics, University of Heidelberg, Germany.

The components of the novel experimental system include an infrared femtosecond laser, a newly developed 2-photon microscope for in vivo imaging of the eye, and an HRA2 scanner. The femtosecond laser is used to modify the refractive index of plastic materials in a technique known as Refractive Index Shaping (RIS). To increase the amount of power change that can be achieved, a phase wrapping technique is employed. The 2-photon microscope allows visualization of the refractive index change.

Bench testing was performed using hydrophobic acrylic IOLs formulated with different levels of ultraviolet light absorbers and yellow dye (provided by Aaren Scientific) and demonstrated success of the RIS technique. Dr. Bille noted that using a 500-mW laser, an inscribing speed of 120 mm/sec and higher could be achieved with a 0.8 μm resolution of the inscribing pattern. He said the system could be used for customization with any IOL material, and with its micron level of resolution, to do very precise modifications in power and wavefront patterns.

“The motivation for this novel method of in situ modification of customized IOLs derives from market data showing about 10% of all cataract surgeries result in residual refractive errors of more than 1 D,” Dr. Bille said. “These data indicate that a method for in situ refinement of IOL optical properties would be invaluable.”


HUMANITARIAN SERVICE

Drs. Jervey, Rice honored by AAO

Chicago—Edward D. Jervey, MD, and Robert A. Rice, MD, were honored with the American Academy of Ophthalmology (AAO) Outstanding Humanitarian Service Award. The two ophthalmologists were recognized for their participation in charitable activities, indigent care, community service, and humanitarian activities in providing services to the poor and needy populations around the world.

“Dr. Jervey and Dr. Rice have made important contributions toward the lives of those who do not have access to quality health care,” said Randy Johnston, MD, president of the AAO. “The academy is proud to honor them for their hard work and dedication to preventing blindness worldwide.”

For Dr. Jervey, the majority of his humanitarian work has been in Haiti, where he established an eye-care program in a rural setting. He has worked with Partners in Health to provide glasses and exams as well as vision-saving surgery.

In 2000, Dr. Jervey established an eye clinic in the Cange community 40 miles northwest of Port-au-Prince, and he also started a joint venture with the ophthalmic residency program in Port-au-Prince. More than 1,500 patient visits and an average of 30 surgeries are performed each month by an on-site Haitian ophthalmologist. Residents from Port-au-Prince staff five outlying eye clinics. One million people in the central plateau of Haiti now have access to quality eye care.

Dr. Rice’s devotion to humanitarian service over the past 22 years includes care of the indigent, the homeless, and the medically underserved in South Texas and Mexico.

In 1992, Dr. Rice established I Care San Antonio (ICSA), a non-profit organization dedicated to providing free eye care to the needy. Dr. Rice is the medical director and leading volunteer-clinician for ICSA, which, to date has cared for more than 18,000 patients, providing free eye exams and treatment worth more $3.3 million.

In 1995, Dr. Rice established outreach mobile eye clinics along the Mexico-U.S. border in Piedras Negras, Nuevo Laredo, and Ciudad Acuna. In 2005, he organized a program to provide free eye care to displaced residents from Hurricane Katrina. He also coordinated with Luxottica’s Gift of Sight Foundation to provide more than 3,000 pairs of glasses to patients at no cost, according to the AAO.


BEST PROGRAMS 2010

Bascom Palmer earns top honors

Chicago—The Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, was honored for excellence in three areas of ophthalmic achievement in Ophthalmology Times’ 2010 Best Programs Awards.

The institution was ranked first in the categories of Best Clinical Care, Best Residency, and Best Overall programs. The results were tabulated from the magazine’s annual poll of chairmen and residency directors from the Association of University Professors of Ophthalmology and all Ophthalmology Times e-mail subscribers.

Eduardo C. Alfonso, MD, chairman, Department of Ophthalmology; director, Bascom Palmer Eye Institute; and holder of the Kathleen and Stanley J. Glaser Chair in Ophthalmology, as well as Steven J. Gedde, MD, professor of ophthalmology, Bascom Palmer Eye Institute, accepted the honor. The award was presented Sunday evening during Bascom Palmer Eye Institute’s reception at The Ritz-Carlton.


AFTER-HOURS


OWL panel to focus on dynamics of change

Chicago—Ophthalmic Women Leaders (OWL) will hold a networking reception and meeting Monday, Oct. 18, from 5 to 7 p.m. at Hyatt McCormick Place in the Regency Ballroom.

The organization’s signature Monday evening event will be followed by a special program, “Managing Change—Before It’s Managing You,” a panel discussion focused on the challenges and opportunities of experiencing change.

“Many companies and individuals are challenged with how to maintain a growth position during this rapidly changing health-care environment,” said Pamela Gleeson, president of OWL and chief financial officer of Santen Inc. “We brought together a panel of experts to discuss how they have been able to navigate change and continually provide value to their companies, colleagues, and or practices while advancing their careers.

“We’ll also discuss how OWL has redefined our strategies and programs with an increased focus on educational, career, and leadership programs to better address the professional development needs of our members within this changing environment,” Gleeson added.

Discussion panelists include Adrienne Graves, former chief executive officer of Santen Inc.; Giulia Newton, director of global marketing for Abbott Medical Optics; and Laurie Brown, administrator for the practice of Drs. Fine, Hoffman & Packer in Eugene, OR. The program moderator will be OWL Board Member Heather Ready, national sales director at USGI Medical.

Open to everyone, the event is free for OWL members and $20 for non-members.

To register for the OWL program, go to the OWL Web site (owlsite.org/event-calendar).

DISCLAIMER:
This information has been independently developed and provided by the editors of Ophthalmology Times. The sponsor does not endorse and is not responsible for the accuracy of the content or for practices or standards of non-sponsor sources. These articles may discuss regimens that have not been approved by the FDA. For full prescribing information including indications, contraindications, warnings, precautions, and adverse experiences please see the appropriate manufacturer's product circular.


 
 

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