[Current Review: Multifocal Intraocular Lenses and Extended Depth of Focus Intraocular Lenses]

Comparative Analysis of the Visual, Refractive and Aberrometric Outcome with the Use of 2 Intraocular Refractive Segment Multifocal Lenses

To demonstrate the results of ray tracing higher- and lower-order aberrations in pseudophakic eyes with rotationally asymmetrical segment multifocal lenses, total high- and low-order aberrations, measured by root mean square value (RMS), refraction, uncorrected distance and uncorrected near visual acuity (UCDVA and UCNVA), and tear break-up time, were measured at scotopic size in 42 eyes of patients implanted with bifocal refractive Mplus15/Mplus30 IOL with +1.5 dpt near addition (42 eyes of patients implanted with Mplus15)/+3.0 dpt near addition (91 eyes of patients implanted with Mplus30), and 107 eyes of control group. No significant differences were noticed between the examined groups concerning UCDVA, UCNVA, and tear break-up time (p < 0.001). Coma and total high-order aberrations were significantly higher for the Mplus30 lens in comparison to the Mplus15 lens and the control group (Coma, Trefoil p < 0.001, Secondary Astigmatism p = 0.002). The spherical aberrations were significantly higher in the lower-addition lens (p = 0.016) in comparison to the control group and to the higher-addition lens group (p < 0.001). Both intraocular lens models were successful at reaching refractive aim, good distance, and near function with the lower higher-order aberrations for the low-addition lens.

Optical-Quality Analysis and Defocus-Curve Simulations of a Novel Hydrophobic Trifocal Intraocular Lens

Purpose

The optical function of a novel refractive-diffractive trifocal intraocular lens (IOL) was tested in vitro to provide preclinical metrics that predict postoperative performance and may guide patient selection.

Methods

Fundamental optical characteristics of a trifocal hydrophobic-acrylic IOL with a C-loop haptic configuration (AT ELANA 841P, Carl Zeiss Meditec) were assessed using a fully automated optical test device under both monochromatic and polychromatic conditions combined with increased or compensated spherical aberration (SA). The area under the modulation transfer function (MTFa) was calculated across a defocus range from +1D to -3.5D and used to simulate visual acuity (VA). A polychromatic point spread function (PSF) was employed to assess the light distribution and identify photic phenomena.

Results

The highest MTFa values were obtained under monochromatic conditions using an SA-neutral corneal model. Nevertheless, after introducing SA and polychromatic light, the IOL performance remained good. Simulated VA values were 0.00 logMAR for distance, 0.1 logMAR at 100 cm, and progressively improving to 0.05 logMAR at 40 cm from the intermediate point. The light-spread analysis confirmed halos around the PSF center, which is a characteristic of trifocal technology.

Conclusion

AT ELANA 841P demonstrated good optical performance across various distances, independently of spectral and SA conditions, resulting in good simulated VA. Although light spread resembles standard trifocal IOLs, clinical studies are essential to confirm these laboratory results.

The relationship between patient satisfaction and visual and optical outcome after bilateral implantation of an extended depth of focus multifocal intraocular lens

Purpose

To evaluate patient satisfaction after implantation of the Tecnis Symfony multifocal intraocular lens (MIOL).

Methods

120 eyes of 60 subjects with senile cataract were bilaterally implanted with the Tecnis Symfony IOL. Follow-up examination was performed 6 months postoperatively. Main outcome measures included uncorrected and corrected distance and near visual acuity, manifest refraction, and visual quality metrics. According to their subjective symptoms patient were divided in two groups: satisfied and unsatisfied.

Results

Uncorrected intermediate (0.15 ​± ​0.11 vs 0.18 ​± ​0.01, P ​= ​0.04) and near (0.26 ​± ​0.12 vs 0.31 ​± ​0.11, P ​= ​0.04) (UIVA, UNVA) log MAR visual acuity was significantly better, cylindrical error less (0.31 ​± ​0.36 vs 0.67 ​± ​0.29, P ​= ​0.05), axial length (AL) smaller (23.68 ​± ​1.3 vs 24.22 ​± ​1.6, P ​= ​0.05), Strehl ratio higher (0.08 ​± ​0.08 vs 0.05 ​± ​0.04, P ​= ​0.03) and mesopic pupil larger (4.3 ​± ​1.1 vs 3.7 ​± ​1.05, P ​= ​0.01) among satisfied patients.Residual cylinder, Strehl ratio, halos, mesopic pupil diameter and UNVA were significant predictors of patient satisfaction. Uncorrected distance visual acuity, higher order Strehl ratio and pupil diameter were significant predictors of halos. Near visual acuity significantly correlated (P ​= ​0.018, R ​= ​0.22) with axial length.

Conclusions

Uncorrected cylindrical error, poor reading quality, larger pupil and halos seem to be the most disturbing factors for patients implanted with the Tecnis Symfony IOL.

Optical Bench Analysis of 2 Depth of Focus Intraocular Lenses

Background

The aim of the study was to analyze the objective optical properties of 2 enhanced depth of focus (EDoF) intraocular lenses (IOLs) using optical bench analysis.

Methods

This experimental study investigates 2 new EDoF IOLs, the Alcon AcrySof IQ Vivity and the Bausch & Lomb LuxSmart Crystal, on the optical bench, using OptiSpheric IOL PRO2 (Trioptics, Germany) in order to assess the optical quality according to ISO 11979 with ISO-2 Cornea. IOLs (power 22.0 D) were evaluated regarding modulation transfer function (MTF) at 50 lp/mm and Strehl ratio (SR) using a 3.0-mm and a 4.5-mm aperture. In addition, wavefront measurements were obtained using WaveMaster® IOL 2 device (Trioptics, Germany), and USAF targets were analyzed.

Results

Centered: the MTF (mean) at 50 lp/mm (AcrySof IQ Vivity/LuxSmart Crystal) with 3.0 mm aperture was 0.250/0.257 and with 4.5 mm aperture 0.202/0.243. The SR (mean) with 3.0 mm aperture was 0.261/0.355 and with 4.5 mm aperture 0.176/0.206. Decentered by 1 mm: the MTF (mean) at 50 lp/mm (AcrySof IQ Vivity/LuxSmart Crystal) with 3.0 mm aperture was 0.266/0.247 and with 4.5 mm aperture 0.126/0.215. The SR (mean) with 3.0 mm aperture was 0.272/0.234 and with 4.5 mm aperture 0.133/0.183. Tilted by 5 degree: the MTF (mean) at 50 lp/mm (AcrySof IQ Vivity/LuxSmart Crystal) with 3.0 mm aperture was 0.221/0.360 and with 4.5 mm aperture 0.214/0.229. The SR (mean) with 3.0 mm aperture was 0.232/0.428 and with 4.5 mm aperture 0.225/0.229. The simulated visual function using USAF test targets showed corresponding qualitative results. Wavefront measurements proved a complex optical design. Higher order aberrations in the central part of the optics were modulated up to the 10th order to enhance the range of functional vision to near distance, leaving the peripheral parts of the optics aberration free or as aberration correcting.

Conclusion

The diversity of EDOF IOLs, their optics, and their respective impact on the vision quality must be understood in order to select the appropriate IOL in each individual case. This analysis of new, innovative IOL optics based on increased negative spherical aberration may help the ophthalmic surgeon to select the IOL which meets the individual requirements of the patient for best postoperative outcomes. It seems that there is no perfect IOL that is equally suitable for all patients, but the right choice is an individual, customized approach dealing with patients' expectations.