Immune mechanisms in inflammatory and degenerative eye disease

• Inflammatory responses in the eye are modulated by its immune-regulatory environment.
• Distinct immunopathological processes drive uveitis and age-related degenerative diseases.
• Uveitis and age-related degenerative eye disease may share autoimmune underpinnings.
• Uveitis mechanisms may shed light on inflammatory processes in degenerative eye disease.
• Age-related macular degeneration may illuminate general mechanisms of para-inflammation.

It has recently been recognized that pathology of age-associated degenerative eye diseases such as adult macular degeneration (AMD), glaucoma and diabetic retinopathy, have strong immunological underpinnings. Attempts have been made to extrapolate to age-related degenerative disease insights from inflammatory processes associated with non-infectious uveitis, but these have not yet been sufficiently informative. Here we review recent findings on the immune processes underlying uveitis and those that have been shown to contribute to AMD, discussing in this context parallels and differences between overt inflammation and para-inflammation in the eye. We propose that mechanisms associated with ocular immune privilege, in combination with paucity of age-related antigen(s) within the target tissue, dampen what could otherwise be overt inflammation and result in the para-inflammation that characterizes age-associated neurodegenerative disease.