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

<div><p>Purpose</p><p>To compare the optic disc parameters of glaucomatous eyes to those of non-glaucomatous eyes with large discs.</p><p>Methods</p><p>We 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.</p><p>Results</p><p>The 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.</p><p>Conclusions</p><p>The 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.</p></div

The ROC curves of the logistic regression analyses with the stepwise method in which glaucoma was the outcome variable among all subjects.

<p>The ROC curves of the logistic regression analyses with the stepwise method in which glaucoma was the outcome variable among all subjects.</p

The results of the logistic regression analysis with a stepwise method, in which glaucoma was the outcome variable among all subjects.

<p>The results of the logistic regression analysis with a stepwise method, in which glaucoma was the outcome variable among all subjects.</p

The results of the logistic regression analysis with the stepwise method, in which glaucoma was the outcome variable between the non-glaucomatous group and the early stage glaucoma group.

<p>The results of the logistic regression analysis with the stepwise method, in which glaucoma was the outcome variable between the non-glaucomatous group and the early stage glaucoma group.</p

Demographics of the study subjects.

<p>The data are expressed as the means ± SD.</p><p>N: non-glaucomatous group</p><p>G: glaucomatous group</p><p>EG: early stage glaucoma group (MD <-5dB)</p><p>AG: advanced stage glaucoma group (MD ≥-5dB)</p><p>SE: spherical equivalent</p><p>MD: mean deviation</p><p>PSD: pattern standard deviation</p><p>* Difference between the normal group and all glaucoma cases</p><p>† Difference between the normal group and the early glaucoma group</p><p>‡ Difference between the normal group and the progressive/advanced glaucoma group</p><p>Demographics of the study subjects.</p

The sensitivity and specificity of the MRA (Moorfield’s Regression Analysis) for all subjects (n = 225).

<p>tmp: temporal</p><p>nsl: nasal</p><p>sup: superior</p><p>inf: inferior</p><p>The sensitivity and specificity of the MRA (Moorfield’s Regression Analysis) for all subjects (n = 225).</p

The sensitivity and specificity of the MRA (Moorfield’s Regression Analysis) for the non-glaucomatous group and the early stage glaucoma group (n = 200).

<p>tmp: temporal</p><p>nsl: nasal</p><p>sup: superior</p><p>inf: inferior</p><p>The sensitivity and specificity of the MRA (Moorfield’s Regression Analysis) for the non-glaucomatous group and the early stage glaucoma group (n = 200).</p

Scatter diagrams showing the correlations between the disc area and cup area.

<p>(Left figure) R² = 0.384, cup area = 0.585 x disc area—0.540. (Right figure) R² = 0.515, cup area = 0.825 x disc area—0.974.</p