Eyeworld

MAR 2012

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

Issue link: https://digital.eyeworld.org/i/78716

Contents of this Issue

Navigation

Page 134 of 167

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

Articles in this issue

Archives of this issue

view archives of Eyeworld - MAR 2012