Excimer laser ablation to create a multifocal cornea is not only possible but represents a safe and effective method for treating presbyopia, according to research.
Bogotá, Colombia-Excimer laser ablation to create a multifocal cornea not only is possible but represents a safe and effective method for treating presbyopia, said Gustavo Tamayo, MD.
Dr. Tamayo discussed his experience with a wavefront-guided multifocal procedure (CustomVue with the VISX IR excimer laser, Abbott Medical Optics) for the treatment of myopia and presbyopia. The presbyLASIK ablation corrects the myopic refractive error and creates a peripheral multifocal area for near vision.
Data from 97 eyes with a mean follow-up of 40 months showed mean distance uncorrected visual acuity (UCVA) was 20/20, all patients gained at least 1 line in near UCVA compared with their preoperative level, and near visual acuity remained good with distance correction. There were no patients who lost lines of distance or near best-corrected visual acuity, and 96% of patients achieved complete freedom from glasses.
Dr. Tamayo explained that multifocality can be defined both as a topographic feature, i.e., the production of multiple different powers in the cornea resulting in multiple focal points, and as a wavefront term based on the appearance of new negative spherical aberration or a decrease in positive spherical aberration. Topography maps and wavefront maps from several patients demonstrate that it is possible to create a multifocal cornea with excimer laser ablation.
Review of the topography maps also explains why patients with a multifocal cornea can experience problems with halos and glare at night as do patients with a multifocal IOL. In addition, the presbyLASIK procedure is associated with decreased contrast sensitivity visual acuity, although this generally returns to normal levels within 3 to 6 months, Dr. Tamayo said.
Gustavo Tamayo, MD
Dr. Tamayo is a consultant to Abbott Medical Optics.