Designing multifocal corneal models to correct presbyopia by laser ablation

Abstract

Abstract. Two multifocal corneal models and an aspheric model designed to correct presbyopia by corneal photoablation were evaluated. The design of each model was optimized to achieve the best visual quality possible for both near and distance vision. In addition, we evaluated the effect of myosis and pupil decentration on visual quality. The corrected model with the central zone for near vision provides better results since it requires less ablated corneal surface area, permits higher addition values, presents stabler visual quality with pupil-size variations and lower high-order aberrations.

Current management of presbyopia

“…According to the authors, the corrected model with the central zone for near vision provides better results because it requires less ablated corneal surface area, permits higher addition values, presents more stable visual quality with pupil-size variations and lower high-order aberrations 33. Very recently, a new proprietary ablation pattern (Supracor, Bausch and Lomb/Technolas, Munich, Germany) was applied using a profile that steepens the center of the cornea to create hyperprolate shape resulting about 2 D near addition with controlled higher order aberrations (HOA) 34. Ninety-six percent of the patients were satisfied with this procedure at 6 months 34…”

Vignetting and Field of View with the KAMRA Corneal Inlay

“…Physiological accommodation is well known to decrease over time and to end-up in presbyopia, a condition where accommodation is no longer sufficient for focusing on objects at near distance. It has been a dream for ophthalmic surgeons for a very long time to recover accommodation in progressed age, and many attempts have been made to develop active or passive lens implants (such as accommodating lenses) [ 1 – 6 ], refractive or diffractive multifocal lenses [ 7 ], customized photorefractive keratectomy (PRK) or Laser in situ keratomileusis (LASIK) ablations using the excimer laser generating sectorial or zonal near focus region in the cornea [ 8 – 11 ], or changing the global shape of the cornea to a hyperprolate surface [ 8 , 12 ].…”