From Oxidative Stress to Inflammation in the Posterior Ocular Diseases: Diagnosis and Treatment

Abstract

Most irreversible blindness observed with glaucoma and retina-related ocular diseases, including age-related macular degeneration and diabetic retinopathy, have their origin in the posterior segment of the eye, making their physiopathology both complex and interconnected. In addition to the age factor, these diseases share the same mechanism disorder based essentially on oxidative stress. In this context, the imbalance between the production of reactive oxygen species (ROS) mainly by mitochondria and their elimination by protective mechanisms leads to chronic inflammation. Oxidative stress and inflammation share a close pathophysiological process, appearing simultaneously and suggesting a relationship between both mechanisms. The biochemical end point of these two biological alarming systems is the release of different biomarkers that can be used in the diagnosis. Furthermore, oxidative stress, initiating in the vulnerable tissue of the posterior segment, is closely related to mitochondrial dysfunction, apoptosis, autophagy dysfunction, and inflammation, which are involved in each disease progression. In this review, we have analyzed (1) the oxidative stress and inflammatory processes in the back of the eye, (2) the importance of biomarkers, detected in systemic or ocular fluids, for the diagnosis of eye diseases based on recent studies, and (3) the treatment of posterior ocular diseases, based on long-term clinical studies.

Keywords: age-related macular degeneration; diabetic retinopathy; glaucoma; inflammation; oxidative stress; retina diseases.

Figure 1

Scheme of oxidative stress role in posterior ocular diseases. IOP: intraocular pressure; ROS: reactive oxygen species; MT: trabecular meshwork; RGCs: retinal ganglion cells; PR: photoreceptors (cones + rods); RPE: retinal pigment epithelium; AMD: age-related macular degeneration; DR: diabetic retinopathy.