Eyeworld

vative-free options. Jean Philippe Nordmann, M.D., University of Paris, addressed the clinical chal- lenge of deciding when to initiate IOP-lowering therapy for patients with early glaucoma. The decision should be based on a global assess- ment of risk factors for the develop- ment and progression of functional vision loss. He advised measuring IOP on at least three occasions be- fore initiating therapy. The goal of therapy should be a minimum of 20- 30% IOP reduction from baseline. Prostaglandin analogues are the most common first-line drugs, but beta-blockers still have a role as pri- mary therapy when prostaglandin side effects or cost are factors. Dr. Kahook discussed the clini- cal implications of chronic preserva- tive exposure in glaucoma patients. He pointed out that the most com- monly used preservative in oph- thalmic formulations is benzalkonium chloride (BAK). BAK is a strong detergent that disrupts the cell walls of bacteria in the drug bottle but also disrupts cell walls of ocular surface cells. Switching from a BAK-preserved treatment to a pre- servative- free treatment is associ- ated with a uniform improvement in the signs and symptoms of ocular surface disease. Norbert Pfeiffer, M.D., Univer- sity of Mainz, Germany, presented the safety and efficacy of tafluprost, which he described as "the first and only preservative-free prostaglandin analogue." Like other drugs in this class, tafluprost has high affinity and selectivity for the FP receptor, where it is a potent agonist. In Phase II testing, preservative-free tafluprost lowered IOP by a mean of 33% from untreated baseline. Tafluprost's side effect profile is also consistent with the class, the most common side ef- fect being hyperemia. Because BAK enhances ocular penetration of drugs, a trial was conducted compar- ing BAK-preserved and preservative- free tafluprost and found equivalent IOP-lowering effects. Editors' note: Dr. Kahook has financial interests with Alcon. Dr. Pfeiffer has financial interests with MSD (Merck, Whitehouse Station, N.J.) and Alcon. The glaucoma debates: Hot topics Physicians spent this session debat- ing some of the hot topics surround- ing glaucoma treatment. Dr. Fechtner advocated that patients who fail an initial trabeculectomy can successfully undergo repeat tra- beculectomy if they are selected carefully. The most important con- sideration is a thorough understand- ing of why the first surgery failed. "You can't select the next procedure wisely if you don't know why the first procedure failed," he said. Exu- berant wound healing, for instance, can be more aggressively modulated the second time around. Trabeculec- tomy, including repeat trabeculec- tomy, remains a simple and effective procedure that has stood the test of time and can be successful. In contrast, Richard Parrish, M.D., University of Miami, lobbied for tube shunt surgery as the appro- priate second procedure following trabeculectomy failure. Citing strong evidence including a meta-analysis and a randomized clinical trial, he said that tube shunt surgery was at least as good as trabeculectomy in eyes at risk for trabeculectomy fail- ure. The Trabeculectomy Versus Tube Study demonstrated higher success rates with tube shunt surgery compared to trabeculectomy in eyes with prior surgery, he said. David Greenfield, M.D., Uni- versity of Miami, felt that patients with pre-perimetric glaucoma re- quire treatment with IOP-lowering therapy. He pointed out that selec- tive tests of structure and function, such as blue-yellow perimetry and spectral-domain OCT, will often re- veal defects not evident on standard automated perimetry. While he does choose to observe some patients without treatment, he prefers to in- dividualize treatment decisions based on risk assessment and life ex- pectancy. Anders Heijl, M.D., Lund Uni- versity, suggested that most patients with pre-perimetric glaucoma fare better without treatment. The goal of treatment, he pointed out, is not to lower IOP or prevent clinically unimportant small field defects, but rather to preserve quality of life. The psychological influence of being di- agnosed with glaucoma negatively impacts quality of life more than glaucoma does, he said. "There is no rush to make the diagnosis of glau- coma," he said. "There is plenty of margin between clear cut visual field defects and loss of quality of life." A variety of sessions were offered throughout the day on Friday, July 1, as part of WGA Surgery Day Other highlights included an eye- opening session on new ideas in medical treatment, an interesting session that reconsidered some of the myths and misconceptions in glaucoma, and a symposium on dis- covering a fixed PGA combination without BAK (sponsored by Alcon). WGA Surgery Day: Decision-making and laser trabeculoplasty Very little is known about rates of glaucoma surgery around the world, especially in developing countries where glaucoma is most prevalent. Kaweh Mansouri, M.D., University of California, San Diego, discussed the limited data available for assess- ing the global epidemiology of glau- coma surgery. He proposed a new parameter: The Glaucoma Surgical Rate (GSR) is the total number of surgeries performed in a country in a year's time per 1 million people. Data was collected by survey from 37 countries representing 1.6 billion people. The GSR in these countries ranged from single digits in low-in- come, high-prevalence, developing countries to over 1,000 in Portugal. He suggested that more robust char- acterization of the GSR worldwide will help guide the allocation of glaucoma resources to regions where they are most needed. Laser trabeculoplasty (LTP): First line-therapy? Fotis Topouzis, M.D., Aristotle University of Thessaloniki, Greece, suggested that in the ab- sence of clinical trials comparing laser trabeculoplasty to modern medications, there is inadequate evi- dence to support the use of LTP as primary therapy. However, there are CAUTION: Federal law restricts this device to sale by or on the order of a physician. INDICATION: The EX-PRESS ® Glaucoma Filtration Device is intended to reduce intraocular pressure in glaucoma patients where medical and conventional surgical treatments have failed. CLINICAL STUDY INFORMATION: A clinical study was performed with the EX-PRESS ® Glaucoma Filtration Device versions R-30 and R-50. The study was a prospective, open-label multi-center study of 113 open angle glaucoma patients with a follow-up period of one year. Results indicated an 80.4% overall success for the per-protocol cohort (R-30 and R-50, n=58) at one year, where overall success was defined as an IOP reduction greater than 20% from baseline with or without medications. Results indicated a 75.9% overall success for the per-protocol cohort (R-30 and R-50, n=58) at one year, where overall success was defined as an IOP of less than 21 mmHg with or without medications. The mean IOP reduction at one year was 33.8%. The percentage reduction from baseline was greater than 28% for the R-30 version and greater than 40% for the R-50 version. The overall average number of glaucoma medications dropped significantly from 1.55 pre-operative to 0.52 medications at one-year postoperative. The clinical study was not designed to compare between the various versions of the EX-PRESS ® Glaucoma Filtration Device. The selection of the appropri- ate version is according to the doctor's discretion. The most commonly reported adverse events included the need for further filtering surgery, device explantation, bleb revision and iris touch. Reasons for device explantation included flat anterior chamber with hypotony, device exposure from erosion, and poor efficacy. Other adverse events such as, but not limited to, corneal and retinal complications, uveitis, and significant reduction in visual acuity, may occur as well. CONTRAINDICATIONS: The use of this device is contraindicated if one or more of the following conditions exist: Presence of ocular disease such as uveitis, ocular infection, severe dry eye, severe blephari- tis; pre-existing ocular or systemic pathol- ogy that, in the opinion of the surgeon, is likely to cause postoperative complica- tions following implantation of the device or patients diagnosed with angle closure glaucoma. WARNINGS/PRECAUTIONS: The surgeon should be familiar with the instructions for use. The integrity of the package should be examined prior to use and the device should not be used if the package is damaged and sterility is compromised. This device is for single use only. MRI of the head is permitted, however not recommended, in the first two weeks post implantation. ATTENTION: Reference the Directions for Use labeling for a complete listing of indications, warnings and precautions. © 2011 Novartis AG 7/11 EXP10587JAD 1 7/12/11 2:04 PM continued on page 62 August 2011 World Glaucoma Congress

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