Posterior Capsule Opacification

Posterior capsule opacification (PCO, secondary cataract) has been well-known since extracapsular techniques (extracapsular cataract extraction [ECCE]) were introduced into cataract surgery (Fig 1). Indeed, PCO was noted by Ridley in his first intraocular lens (IOL) implantations. PCO usually causes impairment of visual acuity by direct blockage of the visual axis. Also, indirect complications secondary to mechanical forces resulting from cell proliferation may occur (e.g., striae or folds of the posterior capsule, traction-induced IOL decentration). Clinically, visual symptoms may vary widely, though they usually are proportionate to the amount of PCO. Nonetheless, many patients who have relatively severe PCO, as documented by slit-lamp examination, have few or no complaints; these patients therefore do not require treatment. Other patients may complain vigorously about even minimal haze, requiring secondary capsulotomy. As we enter the new millennium, it is worthwhile to recognize that the incidence of PCO is decreasing rapidly. PCO was the most common remaining complication of ECCE (including phacoemulsification) and posterior chamber intraocular lens (PCIOL) implantation. It occurred at an incidence of between 30% and 50% through the 1980s and early 1990s,