Contrast sensitivity in patients with aspheric profiles in light-adjustable intraocular lenses

Investigative Ophthalmology & Visual Science
Eloy A. Villegas; Lucia Hervella; José Caballero; Matthew Haller; Antonio Benito; Jose María Marín; Pablo Artal

Purpose: To assess contrast sensitivity (CS) both with and without the presence of glare, in patients implanted bilaterally with light-adjustable intraocular lenses (LALs).Patients were treated to have one eye set to emmetropia and the contralateral with induced negative spherical aberration (SA) to increase the depth of focus.
Methods: Twenty cataract patients were implanted bilaterally with LALs (Calhoun Vision, Pasadena, USA). Two weeks after surgery, the implanted lenses were irradiated with appropriate spatial light intensity profiles to correct for defocus and astigmatism in both eyes and to induce a pre-defined amount of negative SA in the non-dominant eye. After the adjustment procedures, two photo-lockin treatments were performed to ensure the LALs were fixed. Refraction and ocular SA were measured during the entire adjustment process using an adaptive optics instrument (AOneye, Voptica SL, Spain). Visual acuity (VA) and CS were measured both monocularly (each eye separately) and binocularly with and without a glare source surrounding the gratings patch.
Results: In the eyes treated with aspheric treatments, the final negative SA ranged between -0.05 and -0.23 microns (for a 4-mm pupil diameter). Mean values of binocular uncorrected decimal VA was around 1.00 at far and intermediate (60 cm) distances and ranged between 1.00 and 0.80 at 40 cm depending on the particular SA. As expected, uncorrected monocular contrast sensitivity was better in the emmetropic eyes than in aspheric eyes at all spatial frequency.Binocular summation improved the CS with respect to the monocular case with emmetropic eyes. Glare had not a measurable impact in the binocular CS.
Conclusions: Patients implanted with LALs bilaterally with induced asphericity in one eye showed normal binocular contrast sensitivity. There were not significant differences between the binocular contrast sensitivity measured with and without glare.