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March 2012 Ph.D. The event that initiates the damage cascade is likely elevated IOP in many patients, said Jeffrey Goldberg, M.D. This leads to im- paired axonal transport, which in turn leads to axonal damage and ul- timately to death of retinal ganglion cells (RGC). "There is no RGC regen- eration after optic nerve head in- jury," Dr. Goldberg said. "They don't regrow back to the brain." He pointed out that neuroprotection should be thought of as two distinct but equally important goals: pro- moting survival of RGCs and their regeneration once lost. Ciliary neu- rotrophic factor (CNTF) may promote both survival and regenera- tion, and an intravitreal implant eluting a steady dose of 20 ng/day of CNTF is currently being evaluated in a Phase I trial in human glaucoma, Dr. Goldberg reported. Will we see a neuroprotective agent available in clinical practice any time soon? Robert N. Weinreb, M.D., was not optimistic. "The failure of the me- mantine glaucoma neuroprotection trial to achieve its primary endpoint put a significant damper on enthusi- asm for developing a neuroprotec- tive agent for glaucoma," he said. The FDA, he said, has signaled its de- sire for a structural rather than func- tional endpoint for neuroprotection clinical trials, partly because there is no subjective component to func- tional assessment as there is with vi- sual field testing. More problematic is the FDA's suggestion that this structural endpoint should have high correlation with visual func- tion. This is a bar that we may not be able to clear, said Dr. Weinreb, as structure and function have a non- linear relationship and both are needed for comprehensive evalua- tion of the status of the optic nerve in glaucoma. Visual function symposium The recent Low-Pressure Glaucoma Treatment Study demonstrated that patients treated with brimonidine were less likely than those treated with timolol to experience visual field progression over a 3-4 year fol- low-up period. Gustavo de Moraes, M.D., evaluated risk factors for pro- gression in a subset of study patients who had undergone at least 5 visual fields during the study period. In a multivariate analysis, the factors as- sociated with visual field progression included randomization to timolol, older age, use of systemic antihyper- tensive therapy, lower mean ocular perfusion pressure, and greater fluc- tuation of ocular perfusion pressure. "These are all autoregulatory fac- tors," Dr. de Moraes pointed out, saying that autoregulatory impair- ment has long been suspected as a contributing factor to the low-ten- sion glaucoma disease process. In a separate study, Anjali Bhorade, M.D., said "patients with glaucoma report increased driving difficulty and more frequent driving cessation than people without glau- coma." Further, glaucoma patients have a 6.6-fold higher risk of motor vehicle crashes than those without EW MEETING REPORTER 135 glaucoma. She presented the results of a study comparing the driving skills of patients with and without glaucoma using a standardized and validated on-road driving test on a 14-mile loop through both business and residential areas of St. Louis. "Fifty percent of glaucoma patients versus only 21% of control patients received a marginal pass or fail grade on the driving test," she said. Among the glaucoma patients, those continued on page 137