January’s Ophthalmology
A retrospective, interventional case series by Chong et al. demonstrates a clinical benefit of anti-CD20 (rituximab) in the treatment of severe thyroid-associated ophthalmopathy that is refractory to corticosteroid therapy or orbital decompression.
Thyroid-associated ophthalmopathy affects 30 to 50 percent of patients with Graves’ disease. It is thought that B cells may produce autoantibodies against thyroid-stimulating hormone receptors and insulinlike growth factor-1 receptors. Rituximab depletes B cells by enhancing apoptosis and promoting antibody-dependent cellular toxicity and complement-dependent cellular toxicity. In the six patients studied, four developed dysthyroid optic neuropathy prior to the rituximab treatment. Orbital inflammation and dysthyroid optic neuropathy improved following rituximab treatment in all six patients. No one experienced disease relapse, and proptosis remained stable.
While the authors urge caution due to the uncontrolled nature of the study, they assert these data justify conducting prospective studies to determine whether rituximab is a viable alternative in patients with progressive, corticosteroid-resistant thyroid-associated ophthalmopathy.
Wednesday, January 27, 2010
Refractive surgical practices in persons with human immunodeficiency virus positivity or acquired immune deficiency syndrome
Eyeworld
Investigators here wanted to feel out what refractive practices were currently doing with regard to performing elective surgery on those who had either tested positive for HIV or, who had Acquired Immune Deficiency Syndrome (AIDS). Of the 285 practitioners who responded to an anonymous, web-based survey emailed to members of the International Society of Refractive Surgery, 50.2% said that they were willing to consider those with HIV positive status as candidates, while just 35% said that they would consider performing elective surgery on those with AIDS. Of those who would perform the surgery, 72.7% claimed that they take extra precautions in such cases, such as wearing double layers of gloves, and evacuating the laser plume immediately after surgery. They also said that they would limit any procedures to one eye and would make sure that the surgery was the last on the schedule for the day in such patients.
Investigators here wanted to feel out what refractive practices were currently doing with regard to performing elective surgery on those who had either tested positive for HIV or, who had Acquired Immune Deficiency Syndrome (AIDS). Of the 285 practitioners who responded to an anonymous, web-based survey emailed to members of the International Society of Refractive Surgery, 50.2% said that they were willing to consider those with HIV positive status as candidates, while just 35% said that they would consider performing elective surgery on those with AIDS. Of those who would perform the surgery, 72.7% claimed that they take extra precautions in such cases, such as wearing double layers of gloves, and evacuating the laser plume immediately after surgery. They also said that they would limit any procedures to one eye and would make sure that the surgery was the last on the schedule for the day in such patients.
Femto face-off
Eyeworld
Experts argued the advantages of using competing femtosecond lasers in a face-off of the different technologies Monday. Explaining the basic differences between the currently available lasers, N. Timothy Peters, M.D., Portsmouth, N.H., said that the current IntraLase FS and Femtec systems (Technolas Perfect Vision, St. Louis) use higher-energy, lower-frequency pulses than the Femto LDV laser (Ziemer, Port, Switzerland) and the VisuMax (Carl Zeiss Meditec, Dublin, Calif.) falls somewhere in between.
Dominating market use at 91%, the newest generation of IntraLase is faster with lower energy and tighter spot separation, therefore producing better results than before, said. Daniel Durrie, M.D., Overland Park, Kan. With over 350,000 procedures having been performed using the IntraLase, there is substantial evidence for its safety and efficacy.
Arguing for the VisuMax, Dan Z. Reinstein, M.D., M.A., N.Y., said the technology provides very high flap thickness accuracy and reproducibility, fast treatment outcomes, excellent visual outcomes in combination with the MEL80 (Carl Zeiss Meditec, Dublin, Calif.), while extremely user-friendly for surgeons and affording the patient a more comfortable experience.
The formation of an opaque bubble layer (OBL) within the cornea during flap creation is a common issue with femtosecond laser technology, said Dr. Reinstein, as it can interfere with the ability of eye-tracking systems to function properly. The VisuMax, he said, produces a very thin layer of OBL, which he and colleagues have found dissipates in the time between flap-creation. There is no time wasted in the operating theatre and an average treatment time for bilateral LASIK is 12 minutes with the VisuMax and MEL80.
Speaking about the Ziemer LDV, Richard Foulkes, M.D., Chicago, said the lack of an epithelial edge gap is one advantage the technology has over the IntraLase FS. In addition, Dr. Foulkes said the technology produces no OBL or transient light sensitivity (TLS).
Experts argued the advantages of using competing femtosecond lasers in a face-off of the different technologies Monday. Explaining the basic differences between the currently available lasers, N. Timothy Peters, M.D., Portsmouth, N.H., said that the current IntraLase FS and Femtec systems (Technolas Perfect Vision, St. Louis) use higher-energy, lower-frequency pulses than the Femto LDV laser (Ziemer, Port, Switzerland) and the VisuMax (Carl Zeiss Meditec, Dublin, Calif.) falls somewhere in between.
Dominating market use at 91%, the newest generation of IntraLase is faster with lower energy and tighter spot separation, therefore producing better results than before, said. Daniel Durrie, M.D., Overland Park, Kan. With over 350,000 procedures having been performed using the IntraLase, there is substantial evidence for its safety and efficacy.
Arguing for the VisuMax, Dan Z. Reinstein, M.D., M.A., N.Y., said the technology provides very high flap thickness accuracy and reproducibility, fast treatment outcomes, excellent visual outcomes in combination with the MEL80 (Carl Zeiss Meditec, Dublin, Calif.), while extremely user-friendly for surgeons and affording the patient a more comfortable experience.
The formation of an opaque bubble layer (OBL) within the cornea during flap creation is a common issue with femtosecond laser technology, said Dr. Reinstein, as it can interfere with the ability of eye-tracking systems to function properly. The VisuMax, he said, produces a very thin layer of OBL, which he and colleagues have found dissipates in the time between flap-creation. There is no time wasted in the operating theatre and an average treatment time for bilateral LASIK is 12 minutes with the VisuMax and MEL80.
Speaking about the Ziemer LDV, Richard Foulkes, M.D., Chicago, said the lack of an epithelial edge gap is one advantage the technology has over the IntraLase FS. In addition, Dr. Foulkes said the technology produces no OBL or transient light sensitivity (TLS).
Glaucoma update
Eyeworld
A new refillable and programmable drug delivery system for glaucoma that could also change treatment approaches to many ocular diseases in the future was described. Designed to solve glaucoma patient compliance issues, the device (REPLENISH, Pasadena Calif.), is implanted in the patient’s eye through minimally invasive surgery, and supplies the appropriate amount of drug needed at determined intervals into the anterior chamber, said Mark S Humayun M.D., Ph.D., Los Angeles. The intraocular drug pump, which is made of biocompatible material, can last between five to 10 years and can be refilled while implanted. Pre-clinical trials showed successful transconjunctival refilling every four to six weeks for a period of four to six months. In addition, Dr. Humayun said, switching medications in between refills is possible as the device is able to flush out its reservoir. In the future, the system may also be designed to include two chambers for delivery of two drugs. Concerns with the device include endothelial damage, infection, tube clogging and the amount of drug that remains in the reservoir.
Looking further into the future, Stuart J McKinnon, M.D., Ph.D., Durham, N.C., presented hope for glaucoma specialists trying to reduce intraocular pressure in their patients. Dr. McKinnon described the possibility of neuroprotective treatment for glaucoma. He explored three strategies including blocking the formation or aggregation of amyloid-β, complement activation, and tumor necrosis factor-α signalling, and said they represented considerable promise.
A new refillable and programmable drug delivery system for glaucoma that could also change treatment approaches to many ocular diseases in the future was described. Designed to solve glaucoma patient compliance issues, the device (REPLENISH, Pasadena Calif.), is implanted in the patient’s eye through minimally invasive surgery, and supplies the appropriate amount of drug needed at determined intervals into the anterior chamber, said Mark S Humayun M.D., Ph.D., Los Angeles. The intraocular drug pump, which is made of biocompatible material, can last between five to 10 years and can be refilled while implanted. Pre-clinical trials showed successful transconjunctival refilling every four to six weeks for a period of four to six months. In addition, Dr. Humayun said, switching medications in between refills is possible as the device is able to flush out its reservoir. In the future, the system may also be designed to include two chambers for delivery of two drugs. Concerns with the device include endothelial damage, infection, tube clogging and the amount of drug that remains in the reservoir.
Looking further into the future, Stuart J McKinnon, M.D., Ph.D., Durham, N.C., presented hope for glaucoma specialists trying to reduce intraocular pressure in their patients. Dr. McKinnon described the possibility of neuroprotective treatment for glaucoma. He explored three strategies including blocking the formation or aggregation of amyloid-β, complement activation, and tumor necrosis factor-α signalling, and said they represented considerable promise.
Annual ISRS/AAO survey reflects 15% drop in refractive procedures
Eyeworld
In its ninth year, and its first year completed online, the ISRS/AAO annual survey provided insights into national trends in refractive surgery. Among the findings Richard J. Duffey, M.D., Mobile, Ala., presented included ISRS/AAO members endured about a 15% dip in refractive procedures last year. Most of the losses were seen in LASIK volume, but the drop was not “across the board” for all refractive procedures. In fact, Dr. Duffey said refractive lens exchange procedures and phakic intraocular (IOL) implantations both went up last year, to 8% and 16% of refractive procedures, respectively. The VISX laser system (Abbott Medical Optics, AMO, Santa Ana, Calif.) continues to be the most popular system, but the WaveLight system (Alcon, Fort Worth, Texas) is also gaining in popularity and last year was no different. VISX’s popularity has dropped to 2:1 ratio to WaveLight, Dr. Duffey said. In refractive multifocal IOLs, Crystalens (Bausch & Lomb, Rochester, N.Y.) remains the most popular with ReStor (Alcon) not far behind. In a distant third is the Tecnis Multifocal (AMO), which has essentially replaced the ReZoom among those surveyed, Dr. Duffey said.
In its ninth year, and its first year completed online, the ISRS/AAO annual survey provided insights into national trends in refractive surgery. Among the findings Richard J. Duffey, M.D., Mobile, Ala., presented included ISRS/AAO members endured about a 15% dip in refractive procedures last year. Most of the losses were seen in LASIK volume, but the drop was not “across the board” for all refractive procedures. In fact, Dr. Duffey said refractive lens exchange procedures and phakic intraocular (IOL) implantations both went up last year, to 8% and 16% of refractive procedures, respectively. The VISX laser system (Abbott Medical Optics, AMO, Santa Ana, Calif.) continues to be the most popular system, but the WaveLight system (Alcon, Fort Worth, Texas) is also gaining in popularity and last year was no different. VISX’s popularity has dropped to 2:1 ratio to WaveLight, Dr. Duffey said. In refractive multifocal IOLs, Crystalens (Bausch & Lomb, Rochester, N.Y.) remains the most popular with ReStor (Alcon) not far behind. In a distant third is the Tecnis Multifocal (AMO), which has essentially replaced the ReZoom among those surveyed, Dr. Duffey said.
Cataract surgery closer to femtosecond laser assistance
Eyeworld
At least three different companies are developing a femtosecond laser to be used for cataract surgery. During refractive surgery subspecialty day, physicians presented different models of femtosecond lasers being developed by three different companies for refractive cataract surgery. Zoltan Nagy, M.D., deputy director, Semmelweis University, Budapest, Hungary, updated a presentation he gave earlier this year at the ASCRS annual meeting on a laser system being developed by LenSx Lasers (Aliso Viejo, Calif.). In 200 eyes, the laser successfully liquefied the lens nucleus and created reproducible sized, shaped, and centered capsulotomy. Jonathan H. Talamo, M.D., Waltham, Mass., expanded on the benefits a femtosecond laser brings to cataract surgery when introducing a laser by Optimedica Pascal System (Santa Clara, Calif.). In addition to easing nucleus aspiration and improving capsulotomies, the lasers increase a physician’s control over the capsulorrhexis, astigmatism, and cataract incisions. A third laser is being developed by LensAR Laser System (Winter Park, Fla.), said Louis D. “Skip” Nichamin, M.D., Brookline, Pa. Having been used on 59 eyes in Mexico, Dr. Nichamin reported similar results to what Dr. Nagy reported; chiefly “a more accurate and more repeatable capsular opening with a more regular shape compared to manual capsulorrhexis. The laser-cut capsule is easy to remove at the beginning of cataract surgery.”
At least three different companies are developing a femtosecond laser to be used for cataract surgery. During refractive surgery subspecialty day, physicians presented different models of femtosecond lasers being developed by three different companies for refractive cataract surgery. Zoltan Nagy, M.D., deputy director, Semmelweis University, Budapest, Hungary, updated a presentation he gave earlier this year at the ASCRS annual meeting on a laser system being developed by LenSx Lasers (Aliso Viejo, Calif.). In 200 eyes, the laser successfully liquefied the lens nucleus and created reproducible sized, shaped, and centered capsulotomy. Jonathan H. Talamo, M.D., Waltham, Mass., expanded on the benefits a femtosecond laser brings to cataract surgery when introducing a laser by Optimedica Pascal System (Santa Clara, Calif.). In addition to easing nucleus aspiration and improving capsulotomies, the lasers increase a physician’s control over the capsulorrhexis, astigmatism, and cataract incisions. A third laser is being developed by LensAR Laser System (Winter Park, Fla.), said Louis D. “Skip” Nichamin, M.D., Brookline, Pa. Having been used on 59 eyes in Mexico, Dr. Nichamin reported similar results to what Dr. Nagy reported; chiefly “a more accurate and more repeatable capsular opening with a more regular shape compared to manual capsulorrhexis. The laser-cut capsule is easy to remove at the beginning of cataract surgery.”
The water-drinking test in glaucoma`
January's Eyeworld
The water-drinking test was proposed decades ago as a means to diagnose glaucoma. The premise was straightforward. If glaucoma affects the drainage angle and impairs outflow facility, then the ability of eyes with glaucoma to handle a fluid challenge should be impaired. Following a baseline intraocular pressure (IOP) measurement, the subject quickly consumes one liter of water and undergoes subsequent IOP measurements every 15 minutes for one hour. Normal eyes should be able to handle the fluid challenge by increasing outflow, whereas a glaucomatous eye with impaired outflow would be less able to adapt to the fluid influx and thus should manifest an IOP rise. A rise in IOP of 6 to 8 mmHg or an increase from baseline of 30% or more at any time during the hour was considered a positive test.
New applications for an old test
The water-drinking test was proposed decades ago as a means to diagnose glaucoma. The premise was straightforward. If glaucoma affects the drainage angle and impairs outflow facility, then the ability of eyes with glaucoma to handle a fluid challenge should be impaired. Following a baseline intraocular pressure (IOP) measurement, the subject quickly consumes one liter of water and undergoes subsequent IOP measurements every 15 minutes for one hour. Normal eyes should be able to handle the fluid challenge by increasing outflow, whereas a glaucomatous eye with impaired outflow would be less able to adapt to the fluid influx and thus should manifest an IOP rise. A rise in IOP of 6 to 8 mmHg or an increase from baseline of 30% or more at any time during the hour was considered a positive test.
New applications for an old test
“The eye with worse glaucoma manifested a higher IOP rise than the better eye, and the worse eye also took longer to recover to pre-test IOP baseline than the better eye,” he said. He pointed out that the water-drinking test challenged the eye and revealed relevant data that was not apparent in the unperturbed system. “Intraocular pressure hemostasis was worse in the worse eye.”
“The IOP peaks in the hour following the water-drinking test were higher in the group that had visual field progression compared to the group whose visual fields had remained stable,” he said. This suggests that the water-drinking test can predict which patients with open-angle glaucoma may be at higher risk of progression, he added.
“Peaks and fluctuations in IOP have been identified as important risk factors for glaucoma progression,” she said. “But detecting IOP peaks and fluctuation requires diurnal IOP measurement, which is difficult and expensive.”
“In the morning, mean IOP rose from 14.3 mmHg to a peak of 17.3 mmHg, while in the afternoon, IOP rose from 12.7 mmHg to 16.8 mmHg,
Updates on HSV
january's Eyeworld
Now that Zirgan (ganciclovir ophthalmic gel 0.15%) has been approved by the Food and Drug Administration (FDA) for acute herpetic keratitis, ophthalmologists may wonder how this will fit into their treatment options..“Zirgan is a welcome treatment for dendritic keratitis in the U.S. It’s a five-times-a-day gel drop and is as effective if not more effective than aciclovir. It’s also more comfortable and less toxic than Viroptic(1% trifluridine, GlaxoSmithKline, Middlesex, United Kingdom)...
Now that Zirgan (ganciclovir ophthalmic gel 0.15%) has been approved by the Food and Drug Administration (FDA) for acute herpetic keratitis, ophthalmologists may wonder how this will fit into their treatment options..“Zirgan is a welcome treatment for dendritic keratitis in the U.S. It’s a five-times-a-day gel drop and is as effective if not more effective than aciclovir. It’s also more comfortable and less toxic than Viroptic(1% trifluridine, GlaxoSmithKline, Middlesex, United Kingdom)...
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