Rigid gas-permeable contact lens fitting in LASIK patients for the correction of multifocal corneas

Abstract

Contact lenses with large diameters, in combination with selection of the back optic zone radius 0.2 mm peripheral of the refractive ablation zone, facilitate contact lens fitting to restore best-corrected visual acuity in LASIK patients with multifocal corneas.

Comparison of Axial and Tangential Topographic Algorithms for Contact Lens Fitting After LASIK

“…Our chosen CVK reference points are measuring corneal curvatures approximately 0.2 mm or 0.7 mm peripheral to the topographic optic zone on tangential or axial displays, respectively. These data correlate well with those of Eggink et al, 10 who used tangential maps to find the curvature 0.2 mm outside the "refractive ablation zone" for GP fitting after LASIK. They also fit lenses with a large back optic zone diameter (range, 8.3-8.5 mm) with good success.…”

“…myopic keratorefractive surgery. Eggink et al 10 used tangential maps to fit eight eyes after LASIK. They recommended selecting a point 0.2 mm outside of the "refractive ablation zone," as measured by a tangential display.…”

“…They are also fitted with limited success in eyes with decentered ablations because a reverse-geometry lens will center on the decentered flat zone and will be decentered from the line of sight. 10 Therefore, most reports in the literature and most practitioners use traditional prolate posterior profile contact lens designs after LASIK rather than reverse-geometry lenses. 4,9,10 These traditional GP lenses have posterior lens curves that progressively flatten in the periphery.…”

“…10 Therefore, most reports in the literature and most practitioners use traditional prolate posterior profile contact lens designs after LASIK rather than reverse-geometry lenses. 4,9,10 These traditional GP lenses have posterior lens curves that progressively flatten in the periphery. In many cases, these lenses are sufficient for most post-LASIK corneas.…”

Adaptação de lentes de contato após cirurgia refrativa

“…Além das complicações acima citadas, têm-se também córneas multifocais e flutuação da visão (2)(3)(4) . Em estudo feito por Astin e col. (5)(6) , as lentes de contato levaram a uma melhora da acuidade visual, e em casos de moderado astigmatismo irregular houve significante melhora em relação ao uso de óculos.…”