The glaucomas are a collection of progressive optic neuropathies that can lead to irreversible damage to retinal ganglion cells (RGC) and their axons and eventual loss of vision if inadequately treated. In the early stages the disease is largely asymptomatic and it is estimated that only half of glaucoma patients are aware that they have the disease. Clinically, glaucoma patients show characteristic optic nerve head (ONH) and retinal nerve fiber layer (RNFL) changes. These include thinning of the neuroretinal rim, increased cup-to-disk ratio, peripapillary atrophy and attenuated RNFL (Figure 1). Visual field deficits, especially in the periphery, are also a hallmark of glaucoma presentation. The clinical utility of imaging devices is growing as the technology rapidly evolves. Instruments are faster, resolution is increasing, computational algorithms are more refined and normative databases are expanding to include a wider range of patients. A current trend in glaucoma clinical care is the development of metrics that combine information from multiple testing modalities.13, 14, 15 Pathologic changes noted in glaucoma include ONH, RNFL and macular (ganglion cell-inner plexiform layer) deficits as well as atrophy of the lateral geniculate nucleus (LGN) and visual cortex. A potential biomarker for glaucoma involves imaging apoptosis of RGCs. Glaucoma is a disease with multifactorial mechanisms. Advances in diagnostic instrumentation and out understanding of the pathology of the disease will benefit patients. An individualized treatment approach will result in improved patient outcomes.
