Optic Nerve Compliance Study

Chronic glaucoma is one of the leading causes of blindness and visual loss in the developed world. It is a condition where long term exposure to high eye pressures (intra-ocular pressure) damages the nerve fibres in the eye. This damage can be seen by examiners as changes in the optic nerve. The exact mechanism of how the high intra-ocular pressure causes nerve damage is unknown. Both physiological and mechanical mechanisms are thought to play a role. Previous authors have reported structural changes in the connective tissue of optic nerves of eyes with glaucoma. Structural changes in the optic nerve head which affect the mechanical compliance of the nerve may be significant in the cause of glaucomatous nerve damage. This study aims to assess the compliance of the optic disc in subjects with and without glaucoma. We would test compliance by imaging the optic discs of participants before and during a brief (less than two minutes) increase in intra-ocular pressure. We would aim to repeat the tests on the same subjects 3 years later to see how compliance changed. We would also seek to correlate other important parameters such as corneal thickness and visual field changes with our findings