ABSTRACT
A cataract is an opacity in the lens which impairs vision (Figure 27). It is the major cause of blindness worldwide. Cataract surgery has been in existence for more than 5,000 years, though in an extremely crude manner until very recent times. It is less than 20 years since extracapsular cataract extraction (ECCE) treatment was developed with the insertion of a posterior-chamber, intra-ocular lens, which is now the treatment of choice, at least in the highly-industrialised countries of the world. This approach preserves the intact, posterior capsule of the crystalline lens, whose opacification forms the cataract (the Greek word kaetorakt means waterfall, the Latin word means portcullis or obstruction) vastly reducing the potential for post-operative complications. Posterior capsule opacification (PCO) develops in up to 50% of eyes between two months and five years after the initial ECCE surgery, the major cause of which is the proliferation, migration and metaplasia (change in character of lens, epithelial cells left behind) after the initial surgery which largely removes the lens contents, but not all the cellular material.
