Fibrotic modifications of the lens epithelium

Maintaining lens integrity is a lifetime ambition of the lens. However, if this integrity is breached through an altered ocular environment or physical disruption, such as cataract surgery, then fibrotic modifications to the lens can occur that are ultimately detrimental to vision. Fibrotic changes involve hyperproliferation, transdifferentiation from an epithelial to a myofibroblast phenotype, matrix deposition and matrix contraction. Fibrotic conditions of the lens include anterior subcapsular cataract and posterior capsule opacification, which affect millions. In this chapter we will discuss the regulatory mechanisms that facilitate fibrotic events, which will involve the intimate relationship between growth factors (especially transforming growth factor beta-TGF-β), signal transduction pathways and the extracellular matrix.