Case study: Options of refractive surgery

Refractive eye surgery helps to improve uncorrected vision by overcoming myopia, hyperopia, astigmatism and the near vision loss suffered through presbyopia, thereby reducing dependency on glasses or contact lenses. As such, it is considered as a procedure that improves visual function. Methods mainly include reshaping the cornea or inserting an implant within the eye.

Surgical techniques advancing from radial keratotomy (RK), photorefractive keratectomy (PRK), laser sub-epithelial keratomileusis (Lasek) to laser-assisted in situ keratomileusis (Lasik) has led to the widespread acceptance of laser treatments over the past 25 years. The most commonly performed type of refractive surgery now is Lasik with impressive benefits of a quick procedure, a speedy visual recovery and minimal discomfort, where a highly sophisticated femtosecond laser is used create a flap from the corneal surface followed by the ablation of a thin layer of underlying tissue with an excimer laser. Removal of stromal tissue in the centre of the cornea corrects myopia through flattening of the surface while in hyperopia, the ablation is applied in the mid-periphery of the stroma steepening the cornea, resulting in the refractive error moving towards emmetropia.