Effect of high-order aberrations and scattered light on visual quality in pseudophakic eyes with aspheric monofocal IOLs

Abstract

Background High order aberrations and scattered light may be the main influencing factors of visual quality after phacoemulsification combined the aspherical IOL implantation.However, the study on objectively assessing the impact of them is little. Objective This study was to assess the impact of high order aberrations and scattered light on visual quality after phacoemulsification combined the aspherical IOL implantation. Methods A series cases-observational study was performed.Sixty-seven eyes of 53 patients who finished phacoemulsification and aspherical IOL implantation for at least 3 months in Tianjin Eye Hospital from February to August 2014 were enrolled.The root mean square (RMS) of total aberrations and high order aberrations was measured under the 4 mm pupil diameter with i-Trace aberrometer, including general high order aberrations, spherical aberrations, coma, and trefoil of entire eye, cornea and internal optics.The correlations between ocular aberrations and corneal or internal optic aberrations were analyzed.Objective scatter index (OSI) and objective visual quality parameters were measured, including MTF cut off frequency (MTF cut off), strehl ratio (SR) and OQAS values (100%OV, 20%OV, 9%OV) with OQASⅡ, and the correlations between the objective visual quality parameters and OSI, ocular aberrations, corneal aberrations or internal optic aberrations were analyzed.In addition, the correlations between OSI and ocular, corneal or internal optic aberrations were evaluated.Writen informed censent was obtained from each patient before entering the study. Results Ocular aberrations were significantly positively correlated with corneal or internal optic aberrations (r=0.255-0.586, all at P<0.05; r=0.582-0.907, all at P<0.01), and the associations between internal optic and ocular aberrations was stronger than those between corneal and ocular aberrations.The objective visual quality parameters were negatively correlated with ocular, corneal and internal optic aberrations (r=-0.247- -0.675, all at P<0.05; r=-0.245- -0.497, all at P<0.05; r=-0.246- -0.513, all at P<0.05)as well as with OSI(r=-0.620--0.781, all at P<0.01). Most of the associations between internal optic aberrations and objective visual quality parameters were stronger than those of corneal aberrations.Furthermore, ocular, corneal and optical aberrations were all positively correlated with OSI (r=0.396-0.727, all at P<0.01; r=0.320-0.522, all at P<0.05; r=0.319-0.598, all at P<0.01). Conclusions High order aberrations and scattered light seem to interact with objective visual quality in aspherical IOL implanted eyes, and the correlation between internal optic aberrations and ocular aberrations tends to be stronger than that of corneal aberrations. Key words: Cataract; Aspherical intraocular lens; Aberration; Scattered light; Visual quality