Visual Simulationapplication to monofocal intraocular lens analysis

Resumen

PURPOSE: Compare two monofocal intraocular lenses (IOLs) with different designs. METHOD: An adaptive optics visual simulator (crx1, Imagine Eyes, France) was used to simulate the aberration pattern of two IOLs, a spherical monofocal IOL (AcrySof SN60AT IOL, Alcon Laboratories, USA) and an aspheric monofocal IOL (AcrySof IQ SN60WF IOL Alcon Laboratories, USA). The Visual Acuity (VA) was measured at high- mediumand low- contrast when each IOL was centered, decentered and tilted different degrees. Depth-of-focus of both lenses was evaluated when each IOL was centered. The Modulation Transfer Function (MTF) and the Point Spread Function (PSF) were computed for all conditions. All measures were taken for 5 mm pupil diameter. RESULTS: There were no statistical significant differences in VA between both IOLs for centered and decentered 0.2 mm positions (P > 0.05). For these positions, both lenses showed good VA (about 20/20) at high contrast. But at 50% and 10% of contrast VA values were worse (up to 20/40). At 0.4 mm of decentering and both tilts, the SN60AT IOL has better VA values than SN60WF IOL showing statistically significant differences (P<0.05). The values of depth-of-focus were 0.25 and 0.75 dioptres (D) for aspheric and spherical IOLs, respectively. MTFs and PSFs decrease when both IOLs were decentered and tilted. The spherical IOL shows worse PSFs than aspheric IOL in centered position. CONCLUSION: It seems that spherical design is more robust and provides more depth of focus than the aspheric model. Although, aspheric model induces better optical quality in centered position.