It is now widely recognised that posterior capsule opacification (PCO) results from the proliferation and migration of lens epithelial cells (LECs) across the posterior capsule and is the most common cause of reduced visual acuity following modern cataract surgery.1 2 If strategies to prevent PCO are to be developed in a rational way then it will be necessary to understand the mechanisms underlying this relatively aggressive cell growth. Recently, significant advances have been made in the technologies that are required, on the one hand to study the basic molecular mechanisms of growth in vitro,3-5 and on the other to follow the patterns of cell movements within the capsular bag in vivo.6

The recent in vitro studies based on a human capsular bag model have led to a sea change in our views on the forces driving lens cell growth. Formerly it was held that lens cell growth could not be sustained without the addition of external growth factors and this led to an extensive search to define these exogenous factors (see …