Insights into the Immune System and Glaucoma

Abstract

Glaucoma is a neurodegenerative disease of the optic nerve characterized by progressive loss of
retinal ganglion cells (RGCs), which can lead to irreversible blindness. Numerous factors have
been implicated in the disease, with high intraocular pressure (IOP), coupled with advanced
age, being major risk factors. Other factors include ischemia, generation of reactive oxygen
species, a genetic pre-disposition and neurotrophin deprivation in the retina or optic nerve
(Figure 1).1
The pathogenesis of glaucoma is challenging to understand since it is a multifactorial neurodegenerative disease.2,3 It is even more confounding what causes normal tension
glaucoma (NTG). Despite a normal IOP, patients still suffer optic nerve degeneration. The
immune system is a probable player in both high tension glaucoma (HTG) and normal tension
glaucoma (NTG). Findings from numerous studies support the notion that both the innate and
adaptive immune responses are involved in the pathogenesis of glaucoma.1,3-18 Yet, the precise
mechanisms of immune responses and the specific cell interactions contributing to the disease
process are still not fully understood. Many questions remain about the role of the immune
system in glaucoma (Figure 1)