Phakic intraocular lenses.

The main objective of refractive surgery is improving the patient’s quality of life by decreasing their dependence on spectacles and contact lenses. In the majority of cases, we, refractive surgeons, are dealing with young healthy individuals with excellent quality of vision; they are seeking no less than excellent uncorrected visual acuity with at least the same quality of vision postoperatively. Hence, any complication after refractive surgery has a dramatic impact on the patient’s quality of life. With the introduction of excimer lasers in refractive surgery, more than 25 years ago, the predictability and safety of refractive procedures improved to unprecedented levels compared to contemporary procedures such as radial keratotomy and keratomileusis. Over the last 2 decades, excimer laser keratorefractive procedures have become the standard of care to correct a wide range of refractive errors with generally excellent outcomes. There were a number of developments over time including a better understanding of the effect of ablation and flap creation on corneal biomechanics, and the development aberrometers to measure the induction of high order aberrations after laser vision correction. Limitations of excimer laser ablation and in rare cases, the detrimental effects on corneal stability and/or quality of vision were also evaluated by aberrometry and from studies of corneal biomechanics. In the late eighties and early nineties, the concept of phakic IOL was revisited with new lens materials, contemporary microsurgical techniques, modern viscoelastics and advanced imaging devices. Subsequently, phakic IOLs passed through many stages of development and innovation to achieve the state-of-the art designs that are available today. Currently, there are 3 available phakic IOL designs, classified according to the position of the lens inside the eye; angle supported, iris-fixated and posterior chamber phakic lenses. Angle supported phakic IOLs were the first to be introduced by Jose Barraquer, modern designs were introduced and improved by Georges Beikoff, before they were withdrawn from the market due to late endothelial decompensation. The most recent angle supported lens is the AcrySof Cachet (Alcon Laboratories, Inc., Fort Worth, TX). The AcrySof Cachet is a single piece foldable hydrophobic lens, that can be implanted in the anterior chamber through a 2.6 mm clear corneal incision. It is designed to achieve predictable positioning in the anterior chamber, stable vaulting and low compression forces on the irido-corneal angle. The iris fixated lenses were first introduced by Jan Worst in 1984, the earlier design was a biconcave PMMA lens, that