Morphological Features and Important Parameters of Large Optic Discs for Diagnosing Glaucoma

Abstract

PurposeTo compare the optic disc parameters of glaucomatous eyes to those of non-glaucomatous eyes with large discs.MethodsWe studied 225 consecutive eyes with large optic discs (>2.82 mm2): 91 eyes with glaucoma and 134 eyes without glaucoma. An eye was diagnosed with glaucoma when visual field defects were detected by the Humphrey Field Analyzer. All of the Heidelberg Retina Tomograph II (HRT II) parameters were compared between the non-glaucomatous and glaucomatous eyes. A logistic regression analysis of the HRT II parameters was used to establish a new formula for diagnosing glaucoma, and the sensitivity and specificity of the Moorfields Regression Analysis (MRA) was compared to the findings made by our analyses.ResultsThe mean disc area was 3.44±0.50 mm2 in the non-glaucomatous group and 3.40±0.52 mm2 in the glaucoma group. The cup area, cup volume, cup-to-disc area ratio, linear cup/disc ratio, mean cup depth, and the maximum cup depth were significantly larger in glaucomatous eyes than in the non-glaucomatous eyes. The rim area, rim volume, cup shape measurement, mean retinal nerve fiber layer (RNFL) thickness, and RFNL cross-sectional area were significantly smaller in glaucomatous eyes than in non-glaucomatous eyes. The cup-to-disc area ratio, the height variation contour (HVC), and the RNFL cross-sectional area were important parameters for diagnosing the early stage glaucoma, and the cup-to-disc area ratio and cup volume were useful for diagnosing advanced stage glaucoma in eyes with a large optic disc. The new formula had higher sensitivity and specificity for diagnosing glaucoma than MRA.ConclusionsThe cup-to-disc area ratio, HVC, RNFL cross-sectional area, and cup volume were important parameters for diagnosing glaucoma in eyes with a large optic disc. The important disc parameters to diagnose glaucoma depend on the stage of glaucoma in patients with large discs.

Neuroretinal rim in non-glaucomatous large optic nerve heads: a comparison of confocal scanning laser tomography and spectral domain optical coherence tomography

“…Chauhan et al 20 demonstrated a decline of global mean BMO-MRW and RNFLT with age at a rate of −1.34 and −0.21 μm/year for BMO area ranging from 1.05 to 3.40 mm2. In a recent study by Vianna et al , healthy controls had a significant reduction of BMO-MRW (mean: −1.92 μm/year, p<0.01) and RNFLT (mean: −0.44 μm/year, p=0.01) 27.…”

“…This study contributes to the current effort to compare margin-based rim area measurements from CSLT with BMO-based measurements from SD-OCT by analysing a group of non-glaucomatous eyes with very large optic discs, so-called macrodiscs (disc size >2.45 mm2 in CSLT). The aim of this study was to create a reference base to large ONHs in SD-OCT diagnostics of the ONH and to correlate CSLT with SD-OCT measurements.…”

Bruch’s membrane opening-based optical coherence tomography of the optic nerve head: a useful diagnostic tool to detect glaucoma in macrodiscs

“…Reason for this includes, that patients with large optic discs present physiologically a large irregular excavation of the optic nerve head. [1][2][3] Morphometric analysis of the optic nerve head (ONH) and visual field testing represent the major keystones in diagnosis, treatment planning and follow-up of glaucoma patients.…”

Determinants of maximum cup depth in non-glaucoma and primary open-angle glaucoma subjects: a population-based study

“…A histological study has reported that the micro-vascular bed of the disc is an integral part of the retina-optic nerve vascular system [42]. A clinical study reported that the MCD was significantly larger in glaucomatous eyes compared to non-glaucomatous eyes [43]. Considering that CRAE is a part of the retina-optic nerve vascular system, the association between deeper MCD and narrower CRAE in the population suggests a relationship between altered optic nerve head (ONH) blood flow and movement of the lamina region.…”