The many faces of glaucomatous optic neuropathy

Abstract

Background: Glaucoma manifests mostly in the elderly, who frequently have other ocular changes that frustrate clear visualisation of the optic nerve head or nerve fibre layer. In the past, a large or asymmetric cup/disc ratio has been used to indicate the possibility of glaucoma. In this paper, I will argue that cup/disc ratios alone have poor sensitivity to glaucoma, and a more sophisticated approach is needed to make the earliest diagnosis.

Methods: This paper reviews the literature and describes the changes that occur at the optic nerve head and in the peripapillary region as a consequence of glaucomatous optic neuropathy (GON).

Results: The concept of ‘risk factors’ is developed to help screen for glaucoma. Glaucoma suspects require a full clinical investigation (visual field, IOP, assessment of anterior chamber, disc features and nerve fibres) and need to be monitored annually. For future reference, they should have their disc features recorded by instrumental methods or with photography at an early age. As no single sign provides the perfect diagnostic marker for the disease, clinicians need to examine for a group of signs before making the diagnosis. A clinical logic is developed in this paper to enhance the detection of glaucoma.

Conclusion: Adoption of a protocol similar to that detailed in this paper will enhance the early and reliable detection of glaucoma.

Key words:

• cup/disc ratio
• glaucoma
• neuroretinal rim
• optic disc haemorrhage
• retinal nerve fibre layer