Eyeworld

EW INTERNATIONAL 110 September 2016 the presence of glaucoma comes when there is concordance between structural and functional testing. Also, corroboration of two structural tests or two functional tests increas- es the likelihood that glaucoma is present, he explained. Dr. Weinreb agreed. "Perimetric defects that correspond to structural findings increase the likelihood of glaucoma." Detecting glaucoma in myopic eyes In eyes with moderate or high myo- pia, the optic nerve is often abnor- mal in appearance, and is sometimes tilted with significant sloping of the temporal neuroretinal rim. As a result, "The diagnosis of glaucoma among myopic eyes can be challenging," said Ki Ho Park, MD, Seoul, South Korea. This is an important clinical is- sue, Dr. Park said, because "Existing evidence suggests that individuals with myopia have an increased risk of developing open-angle glaucoma, with the risk being greater for people with high myopia." Dr. Weinreb agreed, pointing out that because the optic nerve is already often abnormal in appear- ance in myopic eyes, "Reference databases are not appropriate for diagnosing RNFL damage in highly myopic eyes." In other words, an ab- normal OCT image may not indicate the presence of glaucoma in myopic eyes. In these eyes, Dr. Park ex- plained, "Confirmed evidence of glaucomatous progression from a well-defined baseline is important for the correct diagnosis of glaucoma in many myopic individuals." EW Editors' note: The physicians have no financial interests related to their comments. Contact information De Moraes: gustavo.demoraes@columbia.edu Garway-Heath: David.Garway-Heath@moorfields.nhs.uk Park: kihopark@snu.ac.kr Weinreb: rweinreb@ucsd.edu by Tony Realini, MD, MPH SAP to detect the earliest signs of deterioration." Given that many visual fields have random abnormal spots owing to the subjective nature of the test, what constitutes an abnormal test in early glaucoma? "When glaucomatous optic neuropathy is suspected, a glaucoma hemifield test criterion of 'outside normal limits' or 'borderline' in a reliable visual field increases the probability that an eye has glauco- ma," Dr. Garway-Heath said. "How- ever, before a visual field can be confirmed as glaucomatous, retinal and non-glaucomatous optic disc conditions should be excluded by a careful examination of the retina and optic disc." "The diagnosis of glaucoma does not always require the de- tection of visual field defects with perimetry," Dr. Weinreb said, and it is possible to diagnose glaucoma before any functional loss. Combining structure and function "How do we best integrate structural and functional assessment in clinical practice?" Dr. De Moraes asked. The best practice is to consider structural and functional assessment jointly. The strongest evidence for available gold standards for glauco- ma diagnosis." To accomplish this, he said, "OCT may be the best currently available digital imaging instrument for detecting and tracking optic nerve structural damage in glauco- ma. RNFL thickness is the most clin- ically helpful parameter of the ones currently available with OCT." There remains a role for optic nerve photography, according to Gustavo De Moraes, MD, New York. "Disc photography is a useful ad- junct for detecting disc hemorrhage and pallor, and also for assessing change compared with future clini- cal examinations," he said. Role of functional assessment Patients universally dislike visual field testing, but its importance in the evaluation and management of glaucoma render perimetry a neces- sary evil. "Functional testing is essential for the evaluation, staging, and monitoring of glaucoma," said David Garway-Heath, MD, Lon- don. Of the many different types of perimetry, "Standard automated perimetry (SAP) is the reference stan- dard for all functional testing. There is only weak evidence for the use of functional measurements other than Global experts provide guidance on identifying this challenging disease T he diagnosis and manage- ment of primary open-an- gle glaucoma (POAG) are challenging in part because we lack unambiguous defi- nitions of its presence and progres- sion. At the recent biennial meeting of the European Glaucoma Society in Prague, a panel of international glaucoma specialists presented the results of a several-month collabo- ration to provide clear guidance on how to definitively diagnose POAG. Consensus process Developing impactful consensus statements on various aspects of glaucoma diagnosis and manage- ment has been a key activity of the World Glaucoma Association (WGA) for more than a decade. Robert N. Weinreb, MD, La Jolla, California, chair of the WGA's consensus initiative, described the process. "Each year or so, we identify a topic in glaucoma for which con- sensus would aid clinicians in the diagnosis and management of the disease. The first consensus initiative took place in 2003 and focused on the diagnosis of POAG. For the tenth consensus initiative, we now return to diagnosis. For this consensus ini- tiative, more than 120 experts from around the globe worked for several months to establish our current state of knowledge on the diagnosis of POAG." After generating a draft con- sensus document, the entire group meets to discuss, revise, and adopt the statements for which group con- sensus is achieved, he explained. Role of structural assessment POAG is an optic neuropathy, and structural assessment of the optic nerve remains a hallmark of the glaucoma care process. "Clinical evaluation and doc- umentation of the optic nerve is essential for the diagnosis and mon- itoring of glaucoma," Dr. Weinreb said. "Detecting progressive glau- comatous retinal nerve fiber layer (RNFL) thinning and neuroretinal rim narrowing are the best currently Reaching consensus on the diagnosis of primary open-angle glaucoma

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