Retinal fibrosis in diabetic retinopathy

• Retinal fibrosis is usually a late stage occurrence associated with PDR.
• Activated Müller cells, the glial cells of the retina, facilitate retinal fibrosis.
• Interactions of various growth factors promote retinal fibrosis.
• The effect of PRP and anti-VEGF therapy may contribute to retinal fibrosis.

In response to injury, reparative processes are triggered to restore the damaged tissue; however, such processes are not always successful in rebuilding the original state. The formation of fibrous connective tissue is known as fibrosis, a hallmark of the reparative process. For fibrosis to be successful, delicately balanced cellular events involving cell proliferation, cell migration, and extracellular matrix (ECM) remodeling must occur in a highly orchestrated manner. While successful repair may result in a fibrous scar, this often restores structural stability and functionality to the injured tissue. However, depending on the functionality of the injured tissue, a fibrotic scar can have a devastating effect. For example, in the retina, fibrotic scarring may compromise vision and ultimately lead to blindness. In this review, we discuss some of the retinal fibrotic complications and highlight mechanisms underlying the development of retinal fibrosis in diabetic retinopathy.