Optic Nerve Disease and Axon Pathophysiology - International Review of Neurobiology - page 1

CHAPTER ONE

Optic Nerve Disease and Axon
Pathophysiology

Alireza Ghaffarieh * , Leonard A. Levin * , †
*Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public
Health, Madison, Wisconsin, USA
† Department of Ophthalmology, McGill University, Montreal, Quebec, Canada

Contents
1. Introduction 2

2. The Anterior Visual Pathways and Disease 2

2.1 Glaucoma 3

2.2 Ischemic optic neuropathy 5

2.3 Optic neuritis 7

3. Axonal Degeneration 8

4. Therapies for Optic Nerve Disease 10

4.1 Somal protection 11

4.2 Axoprotection 12

5. Conclusions 13

Acknowledgments 13

References 13

Abstract
Optic neuropathy is the most common cause of irreversible blindness worldwide.
Although the most common optic neuropathy is glaucoma, there are also many other
optic neuropathies, for example, those associated with multiple sclerosis, giant cell ar-
teritis, ischemia, and many other diseases. In almost all cases, the pathogenesis involves
injury to the retinal ganglion cell axon, with consequent somal and axonal degenera-
tion. This chapter reviews the clinical and pathophysiological properties associated with
three of the most common optic neuropathies, as well as recent findings in understand-
ing axonal degeneration. It concludes with a status report on therapies for optic nerve
disease, including axoprotection, an approach being studied that has the goal of
maintaining axonal integrity and function after injury.