alexa Cluster Analysis of Glaucoma Patients Using the Retinal
ISSN: 2155-9570

Journal of Clinical & Experimental Ophthalmology
Open Access

Like us on:
OMICS International organises 3000+ Global Conferenceseries Events every year across USA, Europe & Asia with support from 1000 more scientific Societies and Publishes 700+ Open Access Journals which contains over 50000 eminent personalities, reputed scientists as editorial board members.

Open Access Journals gaining more Readers and Citations

700 Journals and 15,000,000 Readers Each Journal is getting 25,000+ Readers

This Readership is 10 times more when compared to other Subscription Journals (Source: Google Analytics)

Research Article

Cluster Analysis of Glaucoma Patients Using the Retinal Nerve Fiber Layer Thickness of the Optic Nerve and DTI Parameters of the Optic Radiation

Georg Michelson1,4,5, Simone Wärntges1,5*, Tobias Engelhorn2, Ahmed El Rafei3,4, Joachim Hornegger3,4, and Arnd Doerfler2
1Department of Ophthalmology, Germany
2Department of Neuroradiology, Germany
3Department of Computer Science - Pattern Recognition Lab, Germany
4Erlangen Graduate School in Advanced Optical Technologies (SAOT), Germany
5Interdisciplinary Center of Ophthalmologic Preventive Medicine and Imaging (IZPI), University Erlangen-Nuremberg, Erlangen, Germany
Corresponding Author : Simone Waerntges, MD
University of Erlangen-Nuremberg, Department of Ophthalmology
Interdisciplinary Center of Ophthalmologic
Preventive Medicine and Imaging (IZPI)
Schwabachanlage 6, D-91054 Erlangen, Germany
Tel: +49 (9131) 853-4272
Fax: +49 (9131) 853-4271
E-mail: [email protected]
Received September 09, 2011; Accepted November 05, 2011; Published November 15, 2011
Citation: Michelson G, Wärntges S, Engelhorn T, Rafei AE, Hornegger J, et al. (2011) Cluster Analysis of Glaucoma Patients Using the Retinal Nerve Fiber Layer Thickness of the Optic Nerve and DTI Parameters of the Optic Radiation. J Clinic Experiment Ophthalmol S4:001. doi: 10.4172/2155-9570.S4-001
Copyright: © 2011 Michelson G, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Related article at
DownloadPubmed DownloadScholar Google


Background: In glaucoma the optic radiation may be affected by ascending degeneration and/or ageing. This study classified groups of patients who are distinguishable related to their age, retinal nerve fiber layer thickness (RNFL), axonal integrity (measured by fractional anisotropy and mean diffusivity) and demyelination (measured by radial diffusivity) of the optic radiations. The goal was to separate glaucoma-induced damage of the optic radiations from impairment caused by the ageing effect.

Design: Prospective comparative observational study. Participants: Fourty-five patients diagnosed with glaucoma of different entities and 17 patients with vital papilla (mean age 57.5 ± 13.8 years).

Methods: Multimodal MRI including diffusion tensor imaging (DTI) of the optic radiations and measurement of the RNFL thickness by Spectralis Optical Coherence Tomography. Hierarchical cluster analysis selected the optimal number of patient groups. Data were corrected for age. The t-test and a multiple linear regression model were applied.

Main Outcome Measures: Fractional anisotropy, and mean, axial, and radial diffusivity.

Results: Four clusters, two middle-aged and two older groups with different RNFL thickness each but same age, were classified. Multiple linear regression analysis showed a significant effect of the RNFL thickness on fractional anisotropy, mean diffusivity, and radial diffusivity of the optic radiations in the older patients having the stronger RNFL reduction (p = 0.019, 0.021, and 0.010, respectively). The slope of the radial diffusivity versus RNFL was different between the two older groups (p = 0.025).

Conclusions: In middle-aged glaucoma patients with reduced RNFL we found no change in the optic radiation. An ascending degeneration to the optic radiation was not verifiable. In contrast, in older glaucoma patients with reduced RNFL the axonal integrity/ demyelination of the optic radiation was impaired. The impairment was significantly associated with loss of RNFL and ageing.

Share This Page

Additional Info

Loading Please wait..
Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version