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Reporting from Hawaiian Eye 2016, January 16–22, Wailea, Hawaii EW MEETING REPORTER 98 Sponsored by that these are predictive, Dr. Wiggs said, adding that she and others are in the process of such a study. A prospective study could help reveal clinically useful screening or diagnostic tests. Therapies directed toward modulating vascular tone could potentially be useful, she said. Dr. Wiggs suggested that it's important to carefully monitor the central 10 degrees in patients with systemic risk factors and to encour- age patients to include green, leafy vegetables in their diets. Editors' note: Dr. Wiggs has received research support from the National Eye Institute. Normal-tension glaucoma workup One problem when handling normal-tension glaucoma (NTG) and its workup is there is no consensus on what exactly should be done each time, said Annette Giangiacomo, MD, Atlanta. Her presentation focused on what to consider when working up a patient for NTG. NTG is a chronic optic neu- ropathy associated with cupping and visual field loss characteristic of glaucoma, she said. It represents about 20–50% of patients with chronic open-angle glaucoma, but this percentage may be even higher. NTG is a diagnosis of exclusion, Dr. These observations suggest that there's a different set of risk factors that influence loss of vision in the central region, she said. If there is a separate set of risk factors, should these patients be treated differently? There are several ways to examine this question. In terms of systemic risk factors, these patients are more likely to have systemic hypotension, mi- graines, Raynaud's phenomenon, and sleep apnea, Dr. Wiggs said. "An underlying theme uniting these sys- temic risk factors is vascular tone." Patients with loss of vision in the paracentral region also have environmental and genetic factors to consider as well. Positive envi- ronmental factors include dietary nitrate, plus increased smoking and increased BMI have a small impact. There are also 3 genes influencing paracentral scotoma, and these 3 genes influence NOS3, a major regulator of nitric oxide production. How significant are the risk factors? Dr. Wiggs said the systemic ones are the ones with the highest influence, followed by genetic and then envi- ronmental influences. It's important to remember that these are complex diseases defined by a set of risk factors, she said. A single factor is not sufficient to develop disease, but testing them in combination may be helpful. There needs to be some sort of prospective study to show for about 4 weeks, and measuring the IOP in both eyes again at the same time of day. Then, the physi- cian calculates the therapeutic effect by subtracting the IOP change in the untreated eye from the IOP change in the treated eye. Does the one eye trial work? Dr. Fechtner said that it does not and is not an efficient measurement. "Abandon one eye trials," he said. These trials assume several things, Dr. Fechtner said. First, there is the assumption that spontaneous IOP variation is symmetric. Stud- ies have proven this to be untrue, with fluctuations of around 15–20% between eyes. The one eye trial also assumes that the diurnal curve is reproduc- ible over time, and Dr. Fechtner said studies have shown that diurnal IOP patterns are not repeatable in the short term in healthy individuals. These trials assume that medica- tion has no crossover effect, which is untrue. Both eyes would need to respond similarly to the same medi- cations for these trials to work. "You can't tell what the left eye is going to do from what the right eye did," Dr. Fechtner said. The last point was that patients use their drops as prescribed, which has tended to be untrue. The litera- ture on compliance and adherence is voluminous, he said, and the best thing to do for medical therapy is to take the patient out of the equation. If you do a one eye trial, it should be because only 1 eye needs treatment, Dr. Fechtner concluded. Editors' note: Dr. Fechtner has no related financial interests. Risk factors for loss of central visual field in glaucoma Janey Wiggs, MD, Boston, discussed some of the risk factors for loss of central visual field in glaucoma. This group of patients is a subgroup within glaucoma whose visual field defects form in the paracentral region instead of in the peripheral region, she said. These patients with paracentral scotoma have a greater risk of losing visual acuity, having difficulty reading, and having diffi- culty driving, Dr. Wiggs said. February 2016 View videos from Hawaiian Eye 2016: EWrePlay.org Sheri Rowen, MD, discusses the role of Cassini imaging in evaluating astigmatism prior to cataract surgery.

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