Differentiating Glaucomatous from Non-Glaucomatous Optic Nerve Cupping by Optical Coherence Tomography
Preeya K Gupta 1, Sanjay Asrani 1, Sharon F Freedman 1, Mays El-Dairi #1, M Tariq Bhatti*, #1, 2
1 Departments of Ophthalmology Duke University Eye Center and Duke University Medical Center, USA
2 Medicine (Division of Neurology), Duke University Eye Center and Duke University Medical Center, USA
In clinical practice, the differentiation of glaucomatous from non-glaucomatous cupping can be difficult, even for experienced observers. The purpose of this study was to evaluate the role of optical coherence tomography (OCT) in differentiating glaucomatous from non-glaucomatous optic nerve cupping in a cross-sectional pilot study.
Eleven consecutive patients presenting to the Duke Eye Center from September 2007 to July 2008 with non-glaucomatous optic nerve cupping and 12 patients with glaucomatous optic nerve cupping were identified. All patients underwent Stratus® OCT imaging: fast macular map, fast retinal nerve fiber layer (RNFL) 3.4 thickness, and fast optic disc protocols. Automated visual field perimetry was performed on the date of OCT scan in non-glaucomatous cupping patients, and from 0-9 months of scan date in glaucoma patients. Eyes were matched by optic nerve cup-to-disc area ratio; average and mean deviation were calculated for each variable.
For a similar average RNFL, patients with non-glaucomatous optic nerve cupping had lower nasal and temporal RNFL thickness, as well as lower macular thickness and volume compared to patients with glaucomatous optic nerve cupping.
OCT appears to be a useful technology in differentiating glaucomatous from non-glaucomatous optic nerve cupping. The pattern of RNFL loss appears more diffuse in non-glaucomatous optic nerve cupping compared to glaucomatous optic nerve cupping. Future studies with larger sample size and specific neuro-ophthalmic causes of optic nerve cupping may further elucidate the role of OCT in this clinical setting.
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
* Address correspondence to this author at the Departments of Ophthalmology and Medicine (Division of Neurology), 2351 Erwin Road, Duke University Eye Center, DUMC 3802, Durham, NC 27710-3802, USA; Tel: 919.681.9191; Fax: 919.684.0547; E-mail: firstname.lastname@example.org#These authors have contributed equally.