Comparative characteristic of visual functions and aberrometry data in patients with spherical, aspheric and accommodative IOL designs

    Purpose. To compare the results of surgery in patients with age-related cataracts after phacoemulsification with implantation of different types of IOL: spherical (SN60AT), aspherical (Micro AY) and accommodative (Crystalens HD), to determine functional relations between quantitative and qualitative characteristics of visual function and wavefront.

    Methods. There were participated in the study 49 patients (89 eyes) with age-related cataracts: 17 patients (29 eyes) had phacoemulsification and were implanted with accommodative IOLs Crystalens HD (Bausch & Lomb), 15 patients (30 eyes) were implanted with a spherical IOL SN60AT (Alcon), another 17 patients (30 eyes) were implanted with aspherical IOL Micro AY (PhysIOL).

    Before surgery, all patients had ophthalmologic examinations including refractometry, measurement of visual acuity, pneumotonometry, biometry, biomicroscopy, ophthalmoscopy. Postoperative examinations were performed at 1, 14, 30 days, after 3 and 6 months. Besides the studies listed above, there were also included contrast sensitivity test, aberrometry and measurement of focus depth.

    Results. Distance visual acuity (VA) was comparable in all groups of patients. The highest rates of near and intermediate VA were obtained in patients with accommodative IOL (Crystalens HD). Differences in mesopic and photopic contrast sensitivity were only found between groups with aspheric and accommodative IOLs with higher rates in the group with aspheric IOLs. There was a statistically significant (p<0.05) differences in depth of focus in all three groups: 2.31±0.74D (accommodative IOL), 1.85±0.74D (mono-focal spherical IOL) and (1.45±0.72D (mono-focal aspheric IOL). It was revealed that the total spherical aberration (SA) and coma are factors which increase the depth of focus and a positively influence on VA at near and intermediate distances. Statistically significant (p<0.05) difference in point spread function has been found between the groups with aspheric (0.29±0.06) and accommodative (0.26±0.1) IOLs only.

    Conclusions. The results of the present study allow to conclude that the quality of the eye optics is higher after implantation of aspheric IOL than in eyes implanted with a spherical IOL. The total spherical aberrations increase the depth of focus and positively influence both on near and intermediate VA. Accommodative Crystalens HD IOL provides a better near and the intermediate VA and a larger depth of focus compared with monofocal IOLs.

    Keywords: phacoemulsification, intraocular lens, spherical aberration, depth of focus, spatial contrast sensitivity, accommodative IOL.