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PURPOSE. To determine whether beta and gamma peripapillary atrophy (PPA) areas measured with optical coherence tomography (OCT) enhances glaucoma diagnosis in myopic subjects.METHODS. We included 55 myopic glaucoma patients and 74 myopic nonglaucomatous controls. Beta-PPA comprised the area external to the clinical disc margin, with absence of retinal pigment epithelium and presence of Bruch's membrane. Gamma-PPA comprised the area external to the disc margin, with absence of both RPE and Bruch's membrane. OCT scans colocalized to fundus photographs were used to measure PPA, choroidal thickness, border tissue of Elschnig configuration, optic disc area, and optic disc ovality. 2 , respectively). However, the distributions of both beta-and gamma-PPA in the two groups overlapped widely. The areas under the receiver operating characteristic curve of beta-and gamma-PPA areas were 0.60 and 0.59, respectively. Larger beta-PPA area was associated with larger disc area, thinner choroidal thickness, longer axial length, less oblique border tissue configuration, older age, and greater disc ovality. Larger gamma-PPA area was associated with greater disc ovality, more oblique border tissue configuration, and longer axial length. RESULTS.CONCLUSIONS. Subclassifying PPA with OCT into beta and gamma zones reveals association with different covariates, but does not enhance the diagnostic performance for glaucoma in a population of predominantly Caucasians myopic subjects.

The reproducibilities of BMO-MRW, BMO area measurements and FoBMO angle were excellent in both healthy subjects and patients with glaucoma. Bruch's membrane opening minimum rim width (BMO-MRW) reproducibility is comparable to that of RNFLT measurements.

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Objective: We determined the differential aging effects of the inner six layers of the macula in contrast to the minimum neuroretinal rim width (MRW) and peripapillary retinal nerve fibre layer (RNFL) thickness.

Retinal ganglion cell (RGC) loss is the hallmark of optic neuropathies, including glaucoma, where damage to RGC axons occurs at the level of the optic nerve head. In experimental glaucoma, damage is assessed at the axon level (in the retinal nerve fibre layer and optic nerve head) or at the soma level (in the retina). In clinical glaucoma where measurements are generally limited to non-invasive techniques, structural measurements of the retinal nerve fibre layer and optic nerve head, or functional measurements with perimetry provide surrogate estimates of RGC integrity. These surrogate measurements, while clinically useful, are several levels removed from estimating actual RGC loss. Advances in imaging, labelling techniques, and transgenic medicine are making enormous strides in experimental glaucoma, providing knowledge on the pathophysiology of glaucoma, its progression and testing new therapeutic avenues. Advances are also being made in functional imaging of RGCs. Future efforts will now be directed towards translating these advances to clinical care.

Purpose of review A process is ongoing to produce a definition of glaucomatous optic neuropathy (GON) using quantitative, objective data from structural and functional tests. At present, a common practice is to define GON by subjective features said to be ‘characteristic’ as judged by those experienced in glaucoma care. Recent findings An objective definition would standardize the comparison of clinical research results across studies, without precluding simultaneous use of idiosyncratic definitions in the same reports. To achieve this goal, expert opinion was solicited to reach optimal agreement on one or more consensus, GON definitions. An interactive period of online discussion by 176 international experts led to 110 responses in an online survey that narrowed possible definitional structures into testable criteria. Summary Two approaches to validation of one or more sets of criteria for definite and possible GON are ongoing. The general principles include definition for each eye individually, inclusion of a borderline category, no intraocular pressure criterion, and both structural and functional defects in appropriate physical locations. Each validation approach uses clinician diagnosis as a standard against which objective criteria are compared, with the initial approach using a three-level categorical scale, and the second approach using 0--100 scaling.

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