Excimer laser photorefractive keratectomy: the correction of myopia and astigmatism - nonsystematic review
Conseil d'Evaluation des Technologies de la Sante du Quebec
Record ID 31998008418
The aim of this technology brief is to discuss the most widespread application of the excimer laser in ophthalmology - photorefractive keratectomy for the correction of myopia and myopic astigmatism. It describes this new technique and the main steps involved in this treatment, and reviews the current knowledge regarding its effectiveness, reliability and safety, and patient satisfaction.
Authors' results and conclusions:
Since 1988, hundreds of thousands of people worldwide have undergone photorefractive keratectomy, and this number can be expected to grow steadily, given that a quarter of the world's population is myopic. This technology has thus undergone very rapid diffusion, even if this type of excimer laser refractive surgery is still, in several respects, at the experimental stage. Different countries have or are considering adopting regulations requiring that excimer lasers be approved before they can be marketed, such approval being or to be based on the assessment of experimental prototypes.
This assessment of photorefractive keratectomy indicates that it can successfully correct myopia and astigmatism and that a very large percentage of patients say they are very satisfied with the procedure. However, a significant proportion also experience adverse effects, such as night glare. Many patients, especially among those who are highly myopic, will not achieve the desired correction, and some will even experience a decrease in best corrected visual acuity. Lastly, recent studies suggest that damage can be caused to the deep corneal layers, and it is still not known if it can eventually lead to visual problems.
The authors conclude that excimer laser photorefractive keratectomy does not constitute a medical necessity. It is an irreversible process associated with certain risks and is usually performed for mainly aesthetic reasons. Anyone considering excimer laser surgery to correct myopia or astigmatism should compare it with glasses or contact lenses, for these alternatives are extremely effective and are not associated with the complications observed with photorefractive keratectomy.
The authors consider excimer laser photorefractive keratectomy for the treatment of myopia and astigmatism to be an innovative technology, that is, as technology that has passed the experimental stage and whose efficacy has been established, but about which there are some important questions that are still unanswered. Specifically, for patients with higher degrees of myopia (about -6.00 diopters or more), knowledge is less complete than for patients with lower degrees of myopia.
English language abstract:
An English language summary is available
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Conseil d'Evaluation des Technologies de la Sante du Quebec (CETS)