Refractive lens exchange with multifocal intraocular lens implantation
- Autores: Susana Ortí Navarro
- Directores de la Tesis: Robert Montés Micó (dir. tes.)
- Lectura: En la Universitat de València ( España ) en 2010
- Idioma: español
- Tribunal Calificador de la Tesis: Álvaro Pons (presid.), Alejandro Cerviño Expósito (secret.), José Fco Castejón Mochón (voc.), Norberto López Gil (voc.), María Jesus González García (voc.)
- Materias:
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- Resumen
The decrease of the accommodative amplitude starts at age of 10-12 years and ends with the nearly complete loss of accommodative ability al 50-55 years of age. This condition, know as presbyopia, constitutes the most frequent visual impairment in humans as it affects, without exception, all humans who reach a sufficient age.
Presbyopia can be corrected by various optical methods, such as spectacles, contact lenses and surgical procedures. One option is the implantation of multifocal or pseudoaccommodative intraocular lens (IOL). The objective of any multifocal design is to create multiple image points behind the lens, providing good unaided distance and near vision. Current IOL technology is well equipped to meet the visual demands of young patients with refractive errors and older patients with cataracts.
Cataracts are defined as partial or total opacity of the lens, which can occur at any time of life, even in newborns, but the most common is the senile cataract, which usually occurs between 65 and 70 years. Multifocal IOLs have been evaluated in many previous studies after cataract extraction; however,there are few studies that have evaluated its performance after clear lens extraction or refractive lens exchange (RLE).
In addition, under our knowledge, previous reports have not assessed the differences in performance of these lenses evaluating the different degrees of myopia and hyperopia.
In this thesis we have described five studies of visual performance of multifocal IOLs after RLE and after cataract surgery, considering differences into myopic and hyperopic eyes.
The chapters 2, 3 and 4 analyze the efficacy, safety and predictability after RLE in myopic and hyperopic patients who had bilateral implantation of three different IOL designs: - Asymmetric Acri.Twin bifocal diffractive IOLs - Distance- dominant diffractive bifocal IOL - Hybrid diffractive bifocal IOL The results obtained in these studies shown that RLE is effective, safe and predictable for correcting ametropia and presbyopia for both myopic and hyperopic patients. Note that, in general, visual performance at distance was slightly higher in myopic eyes.
The aim of the chapters 5 and 6 was to analyze the differences in refractive and visual results obtained in cataractous eyes with high and low hyperopia and myopia, respectively, after hybrid multifocal IOL implantation. It is shown that the visual acuity and contrast sensitivity for both distance and near, with and without distance correction, were statistically better in eyes with low refractive error compared to those obtained in eyes with high levels of hyperopia and myopia. Chapter 7 presents these conclusions and establish the basis for the future research lines.
