Dyer et al., "The path to open-angle glaucoma gene discovery: Endophenotypic status of intraocular pressure, cup-to-disc ratio
, and central corneal thickness," Investigative Ophthalmology & Visual Science, vol.
Eye pressures taken were 13 mmHg OD and 11 mmHg OS and a cup-to-disc ratio
of less than 0.1 bilaterally (OU) as shown in Figures 1 and 2.
OCT can be used to analyze and measure not only the peripapillary RNFL thickness [3-5] but also topographic parameters of the ONH, including the disc area, neuroretinal rim area, and the cup-to-disc ratio
Optic disc parameters on optical coherence tomography in patients with nonglaucomatous retinal nerve fiber layer damage Mean Standard deviation Minimum Maximum Average RNFL thickness ([micro]m) 79.7 20.3 52 117 Rim area ([mm.sup.2]) 1.5 0.4 1.1 2.1 Disc area ([mm.sup.2]) 1.8 0.2 1.5 2.1 Average C/D 0.4 0.2 0.1 0.6 Vertical C/D 0.4 0.2 0.1 0.6 Cup volume ([mm.suyp.3]) 0.1 0.1 0 0.2 C/D: Cup-to-disc ratio
, RNFL: Retinal nerve fiber layer Table 2.
The relationship between cup-to-disc ratio
and estimated number of retinal ganglion cells.
Objective: To evaluate the correlation between Central Corneal Thickness (CCT) and Visual Field (VF) defect parameters like Mean Deviation (MD) and Pattern Standard Deviation (PSD), Cup-to-Disc Ratio
(CDR) and Retinal Nerve Fibre Layer Thickness (RNFL-T) in Primary Open-Angle Glaucoma (POAG) patients.
Peto, "Measurement of optical cup-to-disc ratio
in fundus images for glaucoma screening," in Proceedings of the 2015
Tirado et al., "Automatic cup-to-disc ratio
estimation using active contours and color clustering in fundus images for glaucoma diagnosis," in ICIAR 2012: Image Analysis and Recognition, vol.
The automatic glaucoma detection technique processes this 2-D fundus image and identifies the Cup-to-Disc ratio
. The image processing techniques such as image acquisition, future extraction, image enhancement, region segmentation and image classification are used to screen the glaucoma.
(1) The unaffected eye often has a 'disc-at-risk' appearance with a small cup-to-disc ratio
. (12) The pathogenesis of NAION is highly complex and is likely to be associated with small vessel disease involving the short posterior ciliary arteries with resultant hypoperfusion and infarction.
Results: Nonmydriatic camera was noted to have a sensitivity of 88.3% (159/180 images) and 100% in detecting diabetic retinopathy and abnormal cup-to-disc ratio
An increase in the cup-to-disc ratio
of the optic nerve head in combination with a decrease of the mean deviation in visual field testing was defined as glaucoma progression.