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MANAGING OPEN ANGLE GLAUCOMA





               Clinical Recommendation for OCT and the macula:
                  •   Macular damage and accompanying central visual field loss is common in early glaucoma, but easily
                     overlooked: it is prudent to obtain good quality RNFL and macular OCT scans for all suspects identified
                     through clinical exam.

               PERIMETRY
               Although structural (retinal ganglion cell) damage is what defines glaucoma, functional (visual field) loss is
               what impacts an individual, and preventing vision loss is ultimately the reason why glaucoma treatment should
               be initiated. This makes reliable automated visual field (AVF) assessment essential at baseline and regularly
               during follow-up. Despite its many limitations, white-on-white standard automated perimetry (SAP) remains
               the gold standard.  Primarily due to its extended testing time, inter-test variability, and the impact of cataract
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               on its reliability, the initial promise of short-wavelength automated perimetry (SWAP, blue-on-yellow) has not
               been realized.  Frequency doubling technology (FDT) perimetry may detect glaucomatous VF loss prior to
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               SAP, and can be positioned in screening at-risk suspects who are followed with SAP post-diagnosis. 264
               The Swedish Interactive Threshold Algorithm (SITA) strategies available on the Humphrey Field Analyzer
               (HFA) significantly reduce the time required for threshold SAP with little if any loss of sensitivity.  Conven-
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               tional wisdom has been to screen (pre-diagnosis) with SITA-Fast and follow (post-diagnosis) with SITA-Stan-
               dard; although SITA-Standard is a more precise testing algorithm, the precision of SITA-Fast appears to allow
               effective and efficient detection of change through the glaucoma continuum.  Given that Guided Progression
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               Analysis cannot currently integrate SITA-Fast and -Standard strategies, it may be pragmatic to ensure that
               the same strategy is used for as long as possible. Figure 12 reviews the single field analysis for a 24-2 SITA-
               Standard for a patient with glaucoma.


















































               CANADIAN JOURNAL of OPTOMETRY    |    REVUE CANADIENNE D’OPTOMÉTRIE    VOL. 79  SUPPLEMENT 1, 2017  35
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