Corneal regeneration after photorefractive keratectomy: a review / Regeneración de la córnea tras queratectomía fotorreactiva: revisión bibliográfica

Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain (AU)

La queratectomía fotorrefractiva (PRK) remodela el estroma de la córnea para compensar los errores refractivos. La eliminación del epitelio y la ablación del estroma provoca la alteración de los nervios corneales y la liberación de diversos péptidos de la lágrima, epitelio, estroma y nervios. Innumerables citoquinas, factores de crecimiento y metaloproteasas de la matriz participan en el proceso de regeneración y cicatrización corneal. Su equilibrio determinará si la re-epitelización y la remodelación del estroma son adecuados. El objetivo final es el logro de la transparencia corneal para restablecer la función de la córnea, así como la calidad visual adecuada. Por tanto, la respuesta de regeneración y cicatrización corneal es esencial para el éxito de la cirugía refractiva. Nuestro objetivo es aportar una visión general sobre el modo en que se desarrolla dicho proceso tras la PRK. Revisaremos también la influencia de la aplicación intraoperatoria de mitomicina C, lentes de contacto terapéuticas, y otros fármacos para prevenir el haze y el dolor tras la PRK (AU)

Axial movement of the dual-optic accommodating intraocular lens for the correction of the presbyopia: optical performance and clinical outcomes / Movimiento axial de las lentes intraoculares acomodativas de doble óptica para la corrección de la presbicia: rendimiento óptico y resultados clínicos

Presbyopia occurs in the aging eye due to changes in the ciliary muscle, zonular fibers, crystalline lens, and an increased lens sclerosis. As a consequence, the capacity of accommodation decreases, which hampers to focus near objects. With the aim of restoring near vision, different devices that produce multiple focuses have been developed and introduced. However, these devices are still unable to restore accommodation. In order to achieve that goal, dual-optic accommodating Intraocular Lenses have been designed, whose anterior optic displaces axially to increase ocular power, and focus near objects. Although dual-optic accommodating IOLs are relatively new, their outcomes are promising, as they provide large amplitudes of accommodation and a greater IOL displacement than single-optic accommodating IOLs. The outcomes show comfortable near vision, higher patients’ satisfaction rates, and minimal postoperative complications like Posterior Capsular Opacification and Anterior Capsular Opacification, due to their design and material (AU)

La presbicia se produce en el ojo envejecido debido a los cambios en el músculo ciliar, las fibras zonulares y el cristalino, y al incremento de la esclerosis del mismo. Como consecuencia, disminuye la capacidad de acomodación, lo que dificulta el enfoque de los objetos cercanos. Con el fin de restaurar la visión de cerca, se han desarrollado e introducido diferentes dispositivos que producen múltiples focos. Sin embargo, dichos dispositivos no son aún capaces de restaurar la acomodación. A fin de lograr este objetivo, se han diseñado las lentes intraoculares acomodativas de doble óptica, cuya óptica anterior se desplaza axialmente para incrementar la potencia ocular, y enfocar los objetos cercanos. Aunque estas LIOs acomodativas son relativamente nuevas, sus resultados son prometedores, ya que aportan grandes amplitudes de acomodación y un mayor desplazamiento de la LIO que las LIO acomodativas de óptica simple. Los resultados muestran una visión de cerca cómoda, unos índices elevados de satisfacción del paciente y unas mínimas complicaciones postoperatorias, tales como la opacificación capsular posterior y posterior, debido a su diseño y material (AU)

Corneal Regeneration After Photorefractive Keratectomy: A Review.

Photorefractive keratectomy (PRK) remodels corneal stroma to compensate refractive errors. The removal of epithelium and the ablation of stroma provoke the disruption of corneal nerves and a release of several peptides from tears, epithelium, stroma and nerves. A myriad of cytokines, growth factors, and matrix metalloproteases participate in the process of corneal wound healing. Their balance will determine if reepithelization and stromal remodeling are appropriate. The final aim is to achieve corneal transparency for restoring corneal function, and a proper visual quality. Therefore, wound-healing response is critical for a successful refractive surgery. Our goal is to provide an overview into how corneal wounding develops following PRK. We will also review the influence of intraoperative application of mitomycin C, bandage contact lenses, anti-inflammatory and other drugs in preventing corneal haze and post-PRK pain.

Axial movement of the dual-optic accommodating intraocular lens for the correction of the presbyopia: optical performance and clinical outcomes.

Presbyopia occurs in the aging eye due to changes in the ciliary muscle, zonular fibers, crystalline lens, and an increased lens sclerosis. As a consequence, the capacity of accommodation decreases, which hampers to focus near objects. With the aim of restoring near vision, different devices that produce multiple focuses have been developed and introduced. However, these devices are still unable to restore accommodation. In order to achieve that goal, dual-optic accommodating Intraocular Lenses have been designed, whose anterior optic displaces axially to increase ocular power, and focus near objects. Although dual-optic accommodating IOLs are relatively new, their outcomes are promising, as they provide large amplitudes of accommodation and a greater IOL displacement than single-optic accommodating IOLs. The outcomes show comfortable near vision, higher patients' satisfaction rates, and minimal postoperative complications like Posterior Capsular Opacification and Anterior Capsular Opacification, due to their design and material.