Visual quality after monovision correction by laser in situ keratomileusis in presbyopic patients

Abstract

Monovision correction by LASIK improved functional near vision in presbyopic patients. Although visual acuity was good for far vision, contrast sensitivity and stereoacuity diminished significantly.

Prise en charge de patients hypermétropes presbytes par chirurgie cornéenne de type presbylasik centré

“…L'approche cornéenne est séduisante car elle présente un minimum de risques, particulièrement en comparaison à la chirurgie endoculaire (risque d'endophtalmie aiguë sur un oeil parfaitement voyant). Il existe à ce jour plusieurs techniques de chirurgie cornéenne proposées aux patients presbytes : la monovision ou « bascule », les inlays intracornéens, l'intracor (intrastromal femtosecond treatment) et le presbylasik [2][3][4][5][6][7][8][9][10][11][12][13][14]. Ce dernier se divise en deux techniques capables de réaliser « une cornée multifocale » par chirurgie réfractive cornéenne.…”

Designing multifocal corneal models to correct presbyopia by laser ablation

“…To design the aspheric model, we looked for an aspheric corneal surface, characterized by a curvature radius (R c ) and asphericity (Q c ) of 6.5 mm in diameter. 19 This area is joined to the original cornea of the LiouBrennan model by a transition surface of 9.5 mm in diameter.…”

“…Corneal ablation by laser has become a steadily more common treatment for presbyopic patients. [7][8][9][10][11][12][13][14][15][16][17][18][19] Currently, clinics offer mainly two techniques for presbyopia treatment: monovision and multifocal corneal ablation. In monovision, one eye is corrected for distance (normally the dominant eye) while the other eye is corrected for near vision (the nondominant eye).…”

“…In monovision, one eye is corrected for distance (normally the dominant eye) while the other eye is corrected for near vision (the nondominant eye). [15][16][17][18][19] Some authors recommend, furthermore, that asphericity of the corrected cornea be incremented for near vision (hyperprolate cornea) to increase spherical aberration and thereby provide greater depth of field. 20 Despite the degree of satisfaction of patients subjected to monovision correction by LASIK (between 88 and 98%), [15][16][17] studies demonstrate a reduction in the contrast-sensitivity function, a loss of visual-discrimination capacity, and a clear worsening of stereoacuity, among other functions.…”

“…20 Despite the degree of satisfaction of patients subjected to monovision correction by LASIK (between 88 and 98%), [15][16][17] studies demonstrate a reduction in the contrast-sensitivity function, a loss of visual-discrimination capacity, and a clear worsening of stereoacuity, among other functions. 18,19 In multifocal ablations, the aim is to achieve a multifocal cornea able to correct any visual defect for distance while simultaneously reducing spectacle dependency for near vision. There are two main patterns of multifocal ablations.…”