Extending the range of vision using diffractive intraocular lens technology

Optical Bench Evaluation of the Latest Refractive Enhanced Depth of Focus Intraocular Lens

Purpose

Any new intraocular lens (IOL) on the market claims to outperform competitors. We aimed to estimate the modulation transfer function (MTF) for different defocus of a novel refractive enhanced depth of focus (EDoF) IOL and the simulated visual acuity over this range of vision. Further, we analyzed the wavefront pattern produced by this IOL to reveal the function of the IOL's optics.

Methods

For the novel TECNIS® PureSee® (ZEN00V) IOL, through frequency and through focus MTF were recorded on the optical bench (ISO-2 Cornea 0.28 µm, 546 nm). MTFa and the simulated visual acuity were calculated for different defocus. Apertures of 3 mm and 4.5 mm were applied. Higher order aberrations of the IOLs' optics were recorded and analyzed.

Results

PureSee® IOL demonstrated a considerable depth of focus of about 1.7 D at the spectacle plane and a continuous simulated visual acuity over this range of defocus. For the 4.5 mm aperture, near focus depth was reduced, yet far distance MTF was even better. Higher order aberrations revealed increased primary and secondary spherical aberrations.

Conclusion

Optical bench results suggest that the new ZEN00V matches the clinical criteria of an EDoF IOL by an increased range of vision and is far distance dominant for an enlarged pupil. This behaviour seems to be due to subtle power changes in the central optics that produce a complex modification of wavefront.

Optical and clinical simulated performance of a new refractive extended depth of focus intraocular lens

OBJECTIVES

The purpose of this study is to evaluate the optical and expected clinical performance of a new refractive Extended Depth of Focus (EDF) intraocular lens (IOL) designed to maintain a monofocal-like dysphotopsia profile.

METHODS

Simulated visual acuity (sVA) with varying defocus was calculated using the area under the Modulation Transfer Function measured in an average eye model and from computer simulations in eye models with corneal higher-order aberrations. Tolerance to defocus was evaluated using computer simulations of the uncorrected distance sVA under defocus. To evaluate the dysphotopsia profile, halo pictures obtained using an IOL-telescope, as well as simulated images in a realistic eye model under defocus were assessed. The results of the refractive EDF were compared to those of a diffractive EDF of the same platform.

RESULTS

The refractive EDF IOL provides similar range of vision to the diffractive EDF IOL with the same distance, and similar intermediate and near sVA. The refractive EDF IOL provides the same tolerance to hyperopia as the diffractive EDF but more tolerance to myopia. Halo pictures and simulations showed that the refractive EDF provides comparable dysphotopsia profile to the monofocal IOL and better than the diffractive EDF.

CONCLUSIONS

The results of this preclinical study in clinically relevant conditions show that the new refractive EDF IOL is expected to provide similar range of vision to the diffractive IOL of the same platform and higher tolerance to refractive errors. The refractive EDF provides a dysphotopsia profile that is better than the diffractive EDF and comparable to that of the monofocal IOL, also in the presence of residual refractive errors.

Spatio-chromatic vision with multifocal diffractive intraocular lens

BACKGROUND

This study aims to detect alterations in the spatio-chromatic pseudophakic vision produced by multifocal diffractive intraocular lenses (IOLs) and provides a physical interpretation.

METHODS

In vitro characterization of the imaging performance of two diffractive IOLs: AT LISA Tri (Zeiss) and FineVision (PhysIOL) in on-bench model eye illuminated with red (R, 625 nm), green (G, 530 nm) and blue (B, 455 nm) lights. We used the metrics: energy efficiency (EE), area under the modulation transfer function, longitudinal chromatic aberration (LCA), and halo intensity. Through-focus (TF) analysis and calculation of the expected defocus curve under white (W) daylight were included. In vivo visual acuity (VA) of 50 pseudophakics (60 eyes) was assessed under W, R, G, B lights at far and near. Two clinical experiments evaluated LCA and R, G, B TF-EE effects on pseudophakic vision and their relative importance.

RESULTS

Clinical mean VA values under W light agreed with the predicted values at far and near for both IOLs. LCA measurements and R, G, B TF-EE curves were consistent with their lens design based on the 0th and 1st diffraction orders operative for far and near vision, respectively. LCA effects were compensated at near but noticed at far (- 0.75 D under B light). We detected strong asymmetry in visual resolution depending on the object distance and the illuminating wavelength-red predominance at far, blue predominance at near-in consistency with the TF-EE measurements.

CONCLUSIONS

Diffractive multifocal IOL designs produce asymmetries in the spatio-chromatic vision of pseudophakics beyond the alterations strictly due to LCA. VA asymmetry for far/near object distance under R and B illumination is clinically detectable in subjects implanted with IOLs with 0th and 1st diffraction orders for far and near vision, respectively. Such VA asymmetry cannot be explained solely from the influence of defocus, as would be derived from a chromatic difference of power, but mainly from the wavelength dependence of the EE.

Pitfalls of Using NIR-Based Clinical Instruments to Test Eyes Implanted with Diffractive Intraocular Lenses

The strong wavelength dependency of diffractive elements casts reasonable doubts on the reliability of near-infrared- (NIR)-based clinical instruments, such as aberrometers and double-pass systems, for assessing, post-surgery, the visual quality of eyes implanted with diffractive multifocal intraocular lenses (DMIOLs). The results obtained for such patients when using NIR light can be misleading. Ordinary compensation for the refractive error bound to chromatic aberration is not enough because it only considers the best focus shift but does not take into account the distribution of light energy among the foci which strongly depends on the wavelength-dependent energy efficiency of the diffractive orders used in the DMIOL design. In this paper, we consider three commercial DMIOL designs with the far focus falling within the range of (−1, 0, +1)-diffractive orders. We prove theoretically the differences existing in the physical performance of the studied lenses when using either the design wavelength in the visible spectrum or a NIR wavelength (780 to 850 nm). Based on numerical simulation and on-bench experimental results, we show that such differences cannot be neglected and may affect all the foci of a DMIOL, including the far focus.

Comparison of dynamic defocus curve on cataract patients implanting extended depth of focus and monofocal intraocular lens

BACKGROUND

The aim of the study was to compare the dynamic defocus curve on patients post-implantation of the extended depth-of-focus (EDOF) and monofocal intraocular lens (IOL).

METHODS

A total of 62 age-related cataract patients receiving phacoemulsification with implantation of TECNIS Symfony (ZXR00) or monofocal IOLs were enrolled. The binocular static and dynamic defocus curves with corrected distance visual acuity were evaluated at one month postoperatively.

RESULTS

The ZXR00 group achieved significantly better intermediate (P = 0.044) and near (P = 0.017) visual acuity (VA) than the monofocal group. Two groups had similar uncorrected and corrected distance VA (P > 0.05, respectively). The dynamic defocus curve revealed a smoother decline from 0.0 D to - 2.0 D in the ZXR00 group. Defocused dynamic VA in the ZXR00 group was significantly better (P < 0.05) except at 0.0 D (P = 0.724) and - 0.5 D (P = 0.176). The area under the curve (P = 0.002) and corrected dynamic vision accommodation (P = 0.001) derived from the dynamic defocus curves were better in the ZXR00 group. A positive correlation was observed between defocused dynamic and static VA in both groups (P < 0.001). Multiple linear regression analysis indicated that defocused static VA and corrected dynamic vision accommodation were significant influential factors for the defocused dynamic VA from - 1.0 D to - 3.0 D (P < 0.05).

CONCLUSIONS

The EDOF IOL provided similar distance vision, better intermediate and near vision, and a better overall dynamic defocus curve than the monofocal IOL. The dynamic defocus curve may be comprehensively applied to evaluate the all-distance dynamic visual performance post-cataract surgery.

Depth of focus of four novel extended range of vision intraocular lenses

PURPOSE

To assess the depth of focus of four latest non-diffractive extended range of vision IOLs on the optical bench. Such comparison had not been done before.

METHODS

We assessed and compared the through focus modulation transfer function (MTF) of the following novel IOLs with a nominal power of 22 D: Acrysof Vivity, LuxSmart Crystal, RayOne EMV and Tecnis Eyhance. An ISO-2 model eye was applied with apertures of 3 and 4.5 mm with monochromatic light of 546 nm. Measurements were done on OptiSpheric IOL PRO 2 optical bench.

RESULTS

For the aperture of 3 mm, Eyhance and RayOne EMV showed the most pronounced peak in MTF with only little enlarged depth of power. Vivity and LuxSmart showed two peaks of about 1.7 D respectively 1.3 D depth of focus, yet reduced MTF and with maxima differently located. For 4.5 mm, MTF values for Eyhance and particularly for RayOne EMV dropped. For Vivity and LuxSmart, only the peak for the secondary focus decreased.

CONCLUSION

Vivity and LuxSmart showed a larger depth of focus for our measuring conditions than Eyhance and RayOne EMV. Correspondingly, the peak MTF was best for Eyhance and RayOne ERV with small aperture. With the larger aperture, RayOne EMV considerably lost performance.

Effect of Violet Light-Filtering and Manufacturing Improvements in an Extended Depth-of-Focus Intraocular Lens on Visual Performance

Purpose

To assess the experimental visual performance and dysphotopsia characteristics of the new Tecnis Symfony OptiBlue extended-depth-of-focus with violet light-filtering (ZXR00V) intraocular lens (IOL) compared with the colorless Tecnis Symfony (ZXR00) IOL.

Methods

Range of vision was assessed with simulated visual acuity defocus curves, predicted by white light through focus modulation transfer function (MTF) measurements. The clinical visual acuity defocus curve of the ZXR00 IOL was used to validate the predicted range of vision. Image quality was compared by measuring white light MTF at a spatial frequency of 15 cycles per degree (c/deg) for 3 mm and 5 mm pupil diameters with optical powers of 5 D, 20 D, and 34 D using the average corneal eye (ACE) model with the average spherical and chromatic aberration of the cataract population. Effects on dysphotopsias were predicted by measurement and computer simulation of light scatter (straylight parameter) and subsequent determination of retinal veiling luminance (RVL) in vitro. Contrast enhancement under challenging light conditions was calculated based on the effects in RVL.

Results

The simulated visual acuity defocus curves and image quality outcomes were comparable between the ZXR00V and ZXR00 IOLs. The area under the straylight curve for the straylight parameter showed a 19% improvement in halo performance with ZXR00V versus ZXR00. A 12% to 17% reduction in RVL was achieved in favor of ZXR00V over ZXR00, which enhanced contrast vision by 9% to 13% under challenging light conditions.

Conclusion

The violet light-filtering technology and improved manufacturing of ZXR00V delivers a comparable range of vision and tolerance to refractive error to ZXR00 while mitigating dysphotopsias and enhancing contrast vision.

Visualization of Ray Propagation through Extended Depth-of-Focus Intraocular Lenses

Extended depth-of-focus (EDoF) presbyopia-correcting intraocular lens (IOL) models differ in their optical design and performance. In the laboratory, we compared the ray propagation and light intensity profiles of four IOLs: the non-diffractive AcrySof IQ Vivity (Alcon Inc., Fort Worth, TX, USA) and two diffractive models, Symfony ZXR00 (Johnson & Johnson Vision, Jacksonville, FL, USA) and AT Lara 829 MP (Carl Zeiss Meditec, Berlin, Germany). A fourth lens, the monofocal AcrySof IQ SN60WF (Alcon Inc.) acted as the control. We projected a 520 nm laser light through each submerged lens in a bath of fluorescein solution. A camera mounted on a microscope captured the light that emerged from the IOL. We recorded the IOLs' point spread function (PSF) to determine the presence of unwanted visual effects. The ray propagation visualization and light intensity profile of the monofocal control showed one distinct focus, while the AcrySof IQ Vivity demonstrated an extended focus area. We observed two distinct foci with each diffractive IOL. We found a lower level of light spread beyond the PSF center for the AcrySof IQ Vivity compared to the diffractive IOLs. In conclusion, we could confirm the extended range of focus for all the EDoF IOL models. However, the non-diffractive AcrySof IQ Vivity appears to have a smoother transition from a far to an intermediate range. We discuss whether, in clinical use, the higher level of spurious light we found in the diffractive designs may translate into increased dysphotopsia.

Effect of decentration and tilt on four novel extended range of vision intraocular lenses regarding far distance

PURPOSE

To analyze the effect of decentration and tilt on four novel non diffractive extended range of vision intraocular lenses (IOLs).

METHODS

Acrysof Vivity, LuxSmart Crystal, RayOne EMV and Tecnis Eyhance were compared on the optical bench (power of 22 D each). Modulation transfer functions were obtained and Strehl ratio was calculated in an ISO-2 model. Apertures of 3 mm and 4.5 mm were applied. For qualitative assessment, United States Airforce (USAF) chart images were evaluated. Additional to centered IOLs, tilt of 5 degrees and decentration of 1 mm were applied.

RESULTS

RayOne EMV was very robust against misalignment but had considerable deterioration of modulation transfer function (MTF) for large aperture with USAF images seriously blurred. Tilt and decentration decreased the performance of Eyhance significantly but had minor impact on the performance of Vivity and LuxSmart. For 4.5 mm aperture, MTF and Strehl ratio decreased markedly for all IOLs compared to 3 mm aperture size. The best MTF and Strehl ratio was obtained for Eyhance IOL well centered for both sizes of aperture.

CONCLUSION

Tilt and decentration had a major impact on the performance of Eyhance only, which performed best of all IOLs tested when well centered. With large aperture, performance of all IOLs significantly decreased. Manufacturer's different approaches for these novel IOLs to increase depth of focus by increasing spherical aberration lead to a different performance in respect to contrast function and sensitivity to misalignment. Our results apply to the distance vision. Near vision performance will be evaluated in a separate investigation.

Comparison of Bilateral Reading Performance Among Two Presbyopia-Correcting Intraocular Lenses

PURPOSE

To evaluate and compare the performance of a trifocal diffractive intraocular lens (IOL) and a lens combining a bifocal diffractive profile and extended depth of focus (EDOF) profile.

METHODS

This non-randomized, prospective comparative study included 42 patients (84 eyes) undergoing lens surgery with implantation of either the FineVision HP trifocal IOL (PhysIOL) or TECNIS Synergy bifocal EDOF IOL (Johnson and Johnson Surgical Vision). There were 21 patients (42 eyes) in each group. The primary outcome was reading speed at high contrast and luminance. Secondary outcomes were reading speed at lower contrasts and luminances, visual acuity at all distances (distance, intermediate, and near) with and without correction, and quality of vision.

RESULTS

The reading speed at high contrast (100%) and high luminance (100%) was better in the Synergy group (P = .01). This difference between the two IOLs seemed to be preserved at lower contrasts and luminances. There was no statistically significant difference between visual acuities except for monocular uncorrected intermediate visual acuity (P = .046) in favor of the FineVision HP IOL. The mean spherical equivalents in the FineVision HP and Synergy groups were 0.14 ± 0.64 and 0.10 ± 0.33 diopters without significant difference between these means (P = .78). The defocus curve was more dome-shaped for the Synergy IOL. The evaluation of visual symptoms was comparable in both groups. The glare halo (Halometry test; Aston University) was smaller in the FineVision HP group (P = .03).

CONCLUSIONS

The Synergy IOL appears to provide better reading speed and is less sensitive to refractive error. Both lenses provided excellent distance, intermediate, and near vision. [J Refract Surg. 2022;38(7):428-434.].

Comparative Analysis of the Clinical Outcomes of Mix-and-Match Implantation of an Extended Depth-of-Focus and a Diffractive Bifocal Intraocular Lens

OBJECTIVES

To evaluate and compare the clinical outcomes of the extended depth-of-focus intraocular lens (EDOF-IOL) and the diffractive bifocal IOL.

METHODS

Fifty-six eyes of 28 patients underwent cataract surgery with implantation of an EDOF-IOL (TECNIS Symfony, ZXR00) in their dominant eye and a diffractive bifocal IOL (+3.25 D add TECNIS ZLB00) in their nondominant eye. Monocular and binocular uncorrected distance, intermediate and near visual acuity, defocus curves, contrast sensitivity, patient satisfaction score (0-5), and spectacle dependence at near vision were evaluated at 3 months after the surgery.

RESULTS

Postoperative binocular uncorrected distant visual acuity was 0.009±0.031 logMAR, uncorrected intermediate visual acuity was 0.090±0.158 logMAR, and uncorrected near visual acuity was 0.099±0.068 logMAR. The monocular defocus curve demonstrated better performance at intermediate distance in eyes with an EDOF-IOL and better performance at near distance in eyes with a diffractive bifocal IOL. An EDOF-IOL exhibited better outcomes in contrast sensitivity compared with a diffractive bifocal IOL. Three patients (10.7%) required glasses for near vision.

CONCLUSION

Mix-and-match implantation of a diffractive bifocal IOL with an EDOF-IOL provides an excellent range of vision, and high levels of contrast sensitivity and patient satisfaction.

Clinical outcomes with a low add multifocal and an extended depth of focus intraocular lenses both implanted with mini-monovision

OBJECTIVES

To compare the visual acuity, contrast sensitivity (CS), spectacle needs, photic phenomena, and quality of life parameters of patients bilaterally implanted with a low add multifocal (MIOL) or an extended depth of focus (EDOF) intraocular lens (IOL), both with intended mini-monovision.

METHODS

In this prospective, randomized, comparative study, patients were randomized to receive either Tecnis +2.75 D (ZKB00) (MIOL Group, n = 15) or Tecnis Symfony (ZXR00) (EDOF Group, n = 14) for bilateral implantation with mini-monovision (-0.50 D). Binocular logMAR uncorrected visual acuities (UVA), monocular defocus curves, CS with CSV 1000-E, and Pelli-Robson Test (PRT), spectacle needs and quality of life parameters with NEI RQL-42 questionnaire were evaluated at postoperative 1, 3, and 6 months.

RESULTS

Results of MIOL and EDOF Groups at postoperative month 6 are as follows: distance (6 m) UVA -0.03 ± 0.05 and -0.05 ± 0.06 (p = 0.938), intermediate (60 cm) UVA, 0.04 ± 0.08 and -0.03 ± 0.07 (p = 0.046); near (40 cm) UVA, 0.22 ± 0.08 and 0.15 ± 0.07 (p = 0.046); near spectacle needs, 26.7% and 14.3% (p > 0.05), respectively. Better visual acuity was achieved in the EDOF Group between the defocus range of -0.50 and -1.75 D (p < 0.05). No significant difference was found regarding photic phenomena and CS evaluated with CSV 1000-E between the two IOL groups at 6 months after surgery (otherwise there are differences at 1 and 3 months in favor of EDOF). However, EDOF Group performed better in mesopic CS evaluated with PRT (p < 0.05).

CONCLUSIONS

When implanted with mini-monovision better binocular uncorrected visual performance at intermediate and near distances achieved with EDOF than low add MIOL.

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.

Patient Satisfaction and Visual Function Following Implantation of Trifocal or Extended Range of Vision Intraocular Lenses

Purpose

Materials and Methods

Results

Conclusion

Influence of angle alpha on visual quality after implantation of extended depth of focus intraocular lenses

Background

To assess postoperative changes in angle alpha, and to evaluate the postoperative visual quality of patients with different angle alpha values after implantation of extended depth of focus (EDOF) intraocular lenses (IOLs).

Methods

Seventy-nine eyes of 79 patients who had phacoemulsification with EDOF IOLs implantation were enrolled. A cut-off value of 0.3 mm, 0.4 mm, and 0.5 mm in preoperative angle alpha was chosen to divide eyes into groups. Distance, intermediate, and near visual acuities, modulation transfer function (MTF), and aberrations were recorded during a 6-month follow-up. A patient questionnaire was completed.

Results

There were no significant differences in angle alpha postoperatively compared to preoperatively. No significant differences were found in visual acuity and MTF between all groups. With 5 mm pupil diameter, there were significant differences of higher-order aberrations and spherical aberration in ocular aberration and internal aberration between angle alpha<0.4 mm and angle alpha≥0.4 mm. Additionally, significant differences of coma were also added in cut-off value of 0.5 mm. When the value of angle alpha is 0.4 mm or higher, there were significant differences in the score of halos and glare.

Conclusions

Angle alpha did not affect visual acuity, but the value of 0.4 mm or higher in angle alpha affected the visual quality under scotopic conditions and occurrence of halos and glare. For patients with 0.4 mm or higher in angle alpha, the choice to implant a EDOF IOL should be carefully considered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02302-4.

Effect of minimonovision in bilateral implantation of a novel non-diffractive extended depth-of-focus intraocular lens: Defocus curves, visual outcomes, and quality of life

PURPOSE

To evaluate overall patient satisfaction, spectacle independence, visual acuity, and prevalence of optical phenomena following bilateral implantation of a new non-diffractive extended depth-of-focus intraocular lens targeted for minimonovision.

METHODS

Multicenter prospective case series. Postoperative far and near visual acuity at 3 months and patient quality of life by NEI-VFQ-25 questionnaire were assessed. Postoperative evaluation included defocus curves analysis, spectacle independence assessment, and recording of photic phenomena.

RESULTS

The study enrolled 97 eyes of 59 patients that underwent femtosecond-assisted cataract surgery with AcrySof IQ Vivity intraocular lens implantation. Thirty subjects (60 eyes) were eligible for analysis. After 3 months, postoperative achieved binocular uncorrected visual acuity was -0.03  ±  0.06 logarithm of the minimum angle of resolution for distance, 0.06  ±  0.06 logarithm of the minimum angle of resolution for intermediate, and 0.19  ±  0.03 logarithm of the minimum angle of resolution for near. Defocus curve showed a smooth profile with no abrupt decrease of visual acuity. Minimonovision significantly improved visual acuity compared to when minimonovision was neutralized, for values of defocus curves from -1 to -3 D (p < 0.05). Twenty-six (87%) patients reported complete spectacle independence. High levels of satisfaction for distance and near vision resulted at VFQ-25 questionnaire. Only two patients complained of halos (6.7%) and one of them also of glare (3.3%).

CONCLUSIONS

Implantation of this new non-diffractive extended depth-of-focus intraocular lens with minimonovision resulted in satisfying far, intermediate, and near visual acuity with a consistent reduction of spectacle dependence and improvement in patient's quality of life.

Subjective and objective refractions in eyes with extended-depth-of-focus intraocular lenses using echelette optics: clinical and experimental study

PURPOSE

To evaluate differences in subjective and objective refractions in eyes with extended-depth-of-focus intraocular lenses (EDOF IOLs) using echelette optics, and the effect of the light wavelength used during examinations.

METHODS

In the prospective study, subjective and objective refractions of 128 eyes of 64 patients were examined 3 months after implantation of the EDOF IOLs (ZXR00V, Johnson & Johnson Surgival Vision). Objective refractions were measured using an autorefractor with a near-infrared (NIR) light source. Clinical differences in the spherical, cylindrical and spherical equivalent (SE) refractions between the subjective and objective refractions were evaluated. Then, lens powers of monofocal, EDOF and diffractive bifocal IOLs in the use of a 850-nm light source were measured experimentally for using a lensmeter, and the differences from the monofocal IOLs were calculated.

RESULTS

The mean objective refractions were more myopic (p < 0.001) than the subjective refractions; the differences in the spherical, cylindrical and SE refractions were -0.71, -0.26 and -0.84 dioptre, respectively. Experimental investigation resulted that there was the mean difference of 0.83 D with the EDOF from monofocal IOLs at 850 nm, while the difference was -0.20 D with bifocal IOLs.

CONCLUSIONS

The diffractive EDOF IOLs using echelette gratings inherently induced constant differences in the subjective and objective refractions, which arose from the chromatic difference in IOL powers for the visible and NIR lights.

Optical Performance of a Monofocal Intraocular Lens Designed to Extend Depth of Focus

PURPOSE

To test the performance of a new monofocal intraocular lens, intended to extend depth of focus (Tecnis Eyhance, ICB00; Johnson & Johnson Vision, Inc) (ICB-IOL), in comparison to a standard monofocal IOL (Tecnis 1-piece, ZCB00; Johnson & Johnson Vision, Inc) (ZCB-IOL) of the same platform and material.

METHODS

Assessment of the optical performance of the two IOLs was made in vitro using an optical test bench with a model eye. The spherical aberration, modulation transfer function (MTF), and area under the MTF (MTFa) were obtained for pupil sizes ranging from 2 to 5 mm. Through-focus MTFa curves between -3.00 and +1.00 diopters (D) were obtained with three pupil sizes (2, 3, and 4.5 mm). Halo formation was also assessed for both lenses.

RESULTS

The ICB-IOL had slightly worse optical quality at its best focus (ie, lower MTF scores at distance vision) and more negative spherical aberration than the ZCB-IOL for pupils ranging from 2 to 3 mm. The maximum of the through-focus MTFa curve of the ICB-IOL with a 2-mm pupil shifted to a myopic defocus of -0.50 D. For larger pupils (≥ 3.5 mm), there were no differences in spherical aberration, MTF scores, and halo energy between the two lenses.

CONCLUSIONS

The new ICB-IOL is a modified monofocal lens with 0.50 D of additional power in its central 2-mm zone and more negative spherical aberration values, which induce a myopic shift of the maximum of optical quality and could improve intermediate vision. For pupils larger than 3.5 mm, there were no differences between IOLs. The new ICB-IOL design would produce photic phenomena comparable to a standard IOL. [J Refract Surg. 2020;36(9):625-632.].

Visual outcomes and safety of the TECNIS Symfony intraocular lens: results of a pivotal clinical trial

Randomized comparison of the TECNIS Symfony (ZXR00) and the TECNIS 1-piece monofocal (ZCB00) intraocular lenses in cataract surgery demonstrates improved intermediate and near vision with TECNIS Symfony.

To compare the effectiveness and safety of the TECNIS Symfony intraocular lens (IOL; ZXR00) with the TECNIS 1-piece monofocal IOL (ZCB00).

Comparison Between Bilateral Implantation of a Trifocal IOL and Mix-and-Match Implantation of a Bifocal IOL and an Extended Depth of Focus IOL

PURPOSE

To compare the clinical outcomes of mix-and-match implantation of a diffractive extended depth of focus intraocular lens (IOL) (TECNIS Symfony ZXR00; Johnson & Johnson Vision) and a diffractive bifocal IOL (TECNIS ZLB00 +3.25 diopters [D]; Johnson & Johnson Vision) and bilateral implantation of a diffractive trifocal IOL (AcrySof IQ PanOptix; Alcon Laboratories, Inc).

METHODS

This prospective comparative study compares the clinical outcomes of patients with age-related cataract undergoing cataract surgery using the IOLs described. Patients were divided into the mix-and-match group and the trifocal group. Assessment included monocular and binocular uncorrected distance visual acuity (UDVA), intermediate visual acuity (UIVA at 60 cm), and near visual acuity (UNVA at 40 cm), uncorrected defocus curves, contrast sensitivity, and reading speed. Quality of vision was measured with the Visual Function Questionnaire (VFQ-25).

RESULTS

A total of 50 patients (25 in each group) were enrolled. At 6 months postoperatively, outcomes of binocular UDVA, UIVA, and UNVA were similar in both groups. The binocular defocus curve only differed at vergences of -0.50 to -1.00 D (better for the mix-and-match group; P = .032 and .004, respectively) and at -4.00 D (better for the trifocal group; P = .001). Significantly higher reading speeds in the mix-and-match group were measured at 0.7 and 0.5 logMAR (P = .038 and .034, respectively). There were no significant differences between groups for contrast sensitivity and the results of the questionnaire.

CONCLUSIONS

The mix-and-match implantation seemed to be a good option for patients with high demands for distance and intermediate visual acuity, whereas the trifocal IOL appeared to be more suitable for patients with enhanced near vision demands. [J Refract Surg. 2020;36(8):528-535.].

Through-Focus Energy Efficiency and Longitudinal Chromatic Aberration of Three Presbyopia-Correcting Intraocular Lenses

Purpose

To compare the chromatic performance of the Bausch & Lomb Versario 3F trifocal intraocular lens (IOL) with the PhysIOL FineVision MicroF trifocal IOL and the Johnson & Johnson Vision TECNIS Symfony ZXR00 extended range of vision (ERV) IOL.

Methods

The through-focus energy efficiency (TF-EE) was measured in vitro with red (R), green (G), and blue (B) wavelengths and was used to obtain the focus powers and longitudinal chromatic aberrations (LCAs) for each IOL. Other metrics, derived from the RGB TF-EE curves, were assessed for a more complete description of the chromatic performance of the IOLs.

Results

Both of the trifocal IOLs, although not specifically designed to tackle chromatic aberrations, showed acceptable LCA (≤0.50 D) in all foci with more balanced R and B efficiencies of their foci. Despite having the lowest TF-EE value at all foci, the Versario 3F demonstrated the most balanced chromatic performance with the smoothest energy transition among all foci and the smallest chromatic span. The Symfony lens effectively reduced LCA at distance and intermediate foci (≤0.36 D), despite the unbalanced and asymmetric R and B efficiencies at its foci.

Conclusions

To fully describe the chromatic performance of an IOL it is necessary to take into account not only the LCA but also the RGB TF-EE and chromatic span. This comprehensive analysis suggests that, in comparison with the other IOLs under study, the Versario 3F lens might contribute to further mitigating the impact of chromatic aberration.

Translational Relevance

The in vitro bench testing of the optical properties of modern presbyopia-correcting intraocular lenses (more specifically in this work, the polychromatic through-focus energy efficiency and longitudinal chromatic aberration) provides objective and complementary information that helps to interpret the visual quality outcomes of pseudophakic patients obtained in clinics.

Visual performance after bilateral toric extended depth-of-focus IOL exchange targeted for micromonovision

PURPOSE

To evaluate overall patient satisfaction, spectacle independence, binocular visual acuity, rotational stability, prevalence of optical phenomena, and decentration and tilt after bilateral toric extended depth-of-focus intraocular lens (EDOF IOL) implantation targeted for micromonovision.

SETTING

Department of Ophthalmology, Hanusch Hospital, Vienna, Austria.

DESIGN

Prospective case series.

METHODS

The study included 52 eyes of 26 patients with regular corneal astigmatism from 0.75 to 2.60 diopters (D) that were implanted bilaterally with a toric EDOF IOL targeted for micromonovision. Postoperative visual acuity, astigmatism reduction, rotation, tilt, decentration, spectacle independence, patient satisfaction, and photic phenomena were assessed.

RESULTS

For the 52 eyes studied, binocular means expressed in logarithm of the minimum angle resolution for postoperative corrected distance, uncorrected distance, uncorrected intermediate, and uncorrected near visual acuities were -0.10 (±0.12), -0.01 (±0.13), 0.01 (±0.14), and 0.13 (±0.14), respectively. Mean refractive astigmatism reduction was 1.31 ± 0.67 D resulting in a mean refractive cylinder of 0.47 ± 0.46 D at the 3-month visit. Mean postoperative rotation was 3.5 ± 3.5 degrees, at the 3-month time point. Most prevalent dysphotopsia were halos, starburst, and glare affecting 6 (23%), 6 (23%), and 5 (19%) of 26 patients, respectively; 20 (77%) of 26 patients reported spectacle independence, with 19 (95%), 19 (95%), and 14 (70%) of 20 patients questioned being satisfied with distance, intermediate, and near vision, respectively.

CONCLUSIONS

Toric EDOF IOL implantation targeted for micromonovision resulted in reliable reduction of preoperative astigmatism with a high degree of postoperative rotational predictability and centration, enabling functional distance, intermediate, and near vision, which manifested itself in high patient satisfaction.

Comparison of two extended depth of focus intraocular lenses with a monofocal lens: a multi-centre randomised trial

Purpose

The AT LARA 829MP is a next-generation extended depth of focus (EDOF) intraocular lens (IOL) providing continuous vision over a range of distances. The aim of this prospective multi-centre randomised trial was to compare two EDOF IOLs and one monofocal IOL.

Methods

Cataract patients between 50 and 80 years were randomised for bilateral implantation with either the AT LARA 829MP (EDOF), the TECNIS Symfony (EDOF) or the CT ASPHINA 409MP (monofocal). Follow-up was at 1 to 2 weeks, 1 month and 4 to 6 months.

Results

A total of 211 patients were randomised and included in the final analysis. Monocular depth of focus was significantly better for AT LARA 829MP eyes compared with that for TECNIS Symfony at all thresholds (p = 0.024, 0.001 and 0.006, for 0.1, 0.2 and 0.3 logMAR respectively) with no significant difference for binocular depth of focus. LARA eyes had significantly better monocular depth of focus at all levels compared with ASPHINA eyes (all p < 0.0001), while there was no significant difference between Symfony and ASPHINA eyes at 0.1 logMAR and 0.2 logMAR. Both EDOF IOLs were significantly better than the monofocal ASPHINA at all levels for binocular depth of focus (LARA: all p < 0.0001; Symfony: all p = 0.002). Distance visual acuity was similar for all IOLs at 6 months; intermediate and near visual acuity were significantly better for the EDOF IOLs than for the monofocal (p < 0.0001). Refraction improved in all groups relative to baseline. Contrast sensitivity was higher with the CT ASPHINA 409MP but both EDOF lenses had a better spectacle independence rate. At 6 months, all IOLs were well centred with no cases of tilt. No general safety issues were raised for any of the groups.

Conclusion

The two EDOF intraocular lenses investigated provided good visual outcomes with comparable visual acuity at all distances. The AT LARA 829MP provided the widest monocular depth of focus at 0.1 and 0.2 logMAR, with a clear superiority compared with the monofocal IOL. TECNIS Symfony was superior to the monofocal control at 0.3 logMAR. Spectacle independence and patient satisfaction were comparable.

Trial registration

Trial registered on https://clinicaltrials.gov/ under the identification NCT03172351 (date of registration 1 June May 2017).

Lens-based surgical correction of presbyopia. Where are we in 2020?

INTRODUCTION

Presbyopia is the progressive and irreversible loss of accommodation due to aging. It is one of the main causes of loss of quality of life in people from 45 years of age, due to the, often novel, dependence on spectacles. The eagerness to correct it by ophthalmologists impulsed by the desire of millions of people who suffer from it, has become one of the main drivers for the development of intraocular lens (IOL) technology over the last twenty years.

MATERIAL AND METHODS

This review briefly presents the different alternatives that have allowed us to improve the crystalline lens surgical approach of presbyopia; from monofocal lenses and monovision technique, accommodative, refractive, and diffractive multifocal lenses, and finally the most recent extended depth of focus/field lenses known as EDOFs.

RESULTS

Each IOL has its advantages, limitations and disadvantages. Furthermore, there is no single lens that suits the needs of all patients.

CONCLUSIONS

It is necessary to know the variety of lenses available, and to have an in-depth understanding of their optical properties, as well as the impact that these will have later on their clinical performance and on the visual quality of the patients. This should help us to select the best alternative for each of them.

Total Depth of Focus of Five Premium Multifocal Intraocular Lenses

PURPOSE

To compare the in vitro optical performance of five premium multifocal intraocular lenses (IOLs), including a single-valued metric that shows the total range of distances where a multifocal IOL generates an acceptable image quality.

METHODS

Through-focus modulation transfer function (MTF) and the image of a United States Air Force target were obtained for a 3-mm pupil and a wavelength of 546 nm in five multifocal IOLs (Tecnis Symfony [Johnson & Johnson], FineVision Micro F [PhysIOL], Acrysof IQ PanOptix [Novartis], and Artis Symbiose Mid and Plus [Cristalens Industrie] multifocal IOLs). Total depth of focus (TDOF) is computed by adding the vergence intervals where the through-focus MTF at 50 cycles/mm is 0.15 or greater.

RESULTS

Due to their different optical designs (bifocal, trifocal, or extended depth of focus), energy is distributed differently between far, intermediate, and near focus for each multifocal IOL. The light distribution of the Symbiose Mid and Plus multifocal IOLs was similar, concentrating the energy into far focus and the intermediate into near focus, but extending the intermediate focus more (Plus) or less (Mid) toward the near focus. TDOFs were: 1.58 diopters [D] (FineVision); 1.71 D (Tecnis Symfony); 1.73 D (Artis Symbiose Plus); 1.74 D (Artis Symbiose Mid); and 1.90 D (Acrysof IQ PanOptix).

CONCLUSIONS

TDOFs were similar between multifocal IOLs with a maximum difference of 0.32 D and mean value of 1.73 D. The combination of the Symbiose Mid and Plus IOLs can theoretically provide a TDOF of 2.90 D in case one is implanted in one eye and the other in the fellow eye. [J Refract Surg. 2020;36(9):578-584.].

Accuracy of five intraocular lens formulas in eyes with trifocal lens implant

Accuracy of intraocular lens (IOL) calculation formulas SRK/T, Hoffer Q, Holladay 1, Haigis and Barrett Universal II were compared in prediction of postoperative refraction for multifocal and implants using a single optical biometry device. The authors included 88 refractive lens exchange and cataract surgeries, with AcrySof IQ PanOptix implant (Alcon Laboratories, Inc.). All eyes were divided into three groups based on axial length (AL), group 1: <22 mm (14 eyes), group 2: 22-24.5 mm (68 eyes) and group 3: >24.5 mm (6 eyes). The refractive prediction error (RPE) and mean absolute error (MAE) were calculated for 5 different formulas: SRK/T, Hoffer Q, Holladay 1, Haigis and Barrett Universal II. For eyes with the AL between 22 mm and 24.5 mm the greatest percentage of eyes with RPEs within ±0.25 D was 32.4% for Haigis formula, followed by Barrett Universal II, Hoffer Q and Holladay 1 with 29.4%. The percentage of eyes with RPEs within ±0.50 D was 100% only for Barrett Universal II and Holladay 1, 94.1% for SRK/T and 91.2% for Haigis and Hoffer Q. The first and third group with AL <22 and >24.5 mm were too small to have statistical significance due to the reluctancy to use multifocal IOLs on extreme ALs. ANOVA test showed no statistical difference (P=0.166) between the RPEs measured for each formula in this cohort. This study showed no statistical difference between formulas for this trifocal lens implant. There was a tendency for the RPE to be within ±0.25 D for most of the eyes with the Haigis formula, and within ±0.50 D for all the eyes with the Barrett Universal II formula in the group with the AL between 22 and 24.5 mm.

Visual Outcomes and Patient Satisfaction for Trifocal, Extended Depth of Focus and Monofocal Intraocular Lenses

PURPOSE

To assess visual outcomes and patient satisfaction for trifocal and extended depth of focus (EDOF) intraocular lenses (IOLs) compared to monofocal IOLs with and without monovision.

METHODS

Consecutive patients underwent bilateral cataract extraction surgery and implantation of either monofocal IOLs, monofocal IOLs using monovision, EDOF IOLs, or trifocal IOLs. Patients with preoperative biometric data, postoperative refraction, and visual acuity who completed a questionnaire regarding satisfaction and side effects were included. Visual outcome, spectacle independence, patient satisfaction, and subjective photic phenomena were assessed.

RESULTS

Each group comprised 50 patients (100 eyes). The mean postoperative uncorrected distance, intermediate, and near visual acuities (logMAR) were: 0.17 ± 0.14 (Snellen 20/30), not applicable, and not applicable for monofocal; 0.08 ± 0.12 (Snellen 20/24), not applicable, and 0.07 ± 0.12 (Snellen 20/23) for monovision; 0.03 ± 0.08 (Snellen 20/21), 0.08 ± 0.12 (Snellen 20/24), and 0.23 ± 0.17 (Snellen 20/34) for EDOF; 0.07 ± 0.09 (Snellen 20/23), 0.08 ± 0.11 (Snellen 20/24), and 0.02 ± 0.06 (Snellen 20/21) for trifocal. Spectacle independence was reported by 36%, 70%, 74%, and 92% of patients, respectively. Postoperative halos and/or glare were experienced by 2%, 6%, 14%, and 38%, respectively, of which 2%, 0%, 6%, and 10%, respectively, were functionally disturbing. A total of 64%, 72%, 78%, and 76%, respectively, would choose the same IOL again.

CONCLUSIONS

Patient satisfaction rates were high in all groups. Trifocal IOLs were more effective in improving unaided whole range of vision, but were associated with a higher rate of photic phenomena. The EDOF IOL and monovision provided partial spectacle independence with less photic phenomena. [J Refract Surg. 2019;35(7):434-440.].

The Effect of a Spectral Filter on Visual Quality in Patients with an Extended-Depth-Of-Focus Intraocular Lens

PURPOSE

Wavelength dependence of diffractive intraocular lenses (IOLs) was recognized in vitro but not yet assessed in vivo. By examining pseudophakic patients who had extended-depth-of-focus diffractive implants, this spectral effect on their vision was measured clinically and the lens was tested in vitro.

DESIGN

Cross-sectional study with laboratory investigation.

METHODS

Twelve pseudophakic patients (23 eyes) with a Symfony lens (Johnson & Johnson Vision) were measured monocularly under red and white light at far, intermediate, and near distances. Corrected distance visual acuity (CDVA), distance-corrected intermediate visual acuity (DCIVA), and distance corrected near visual acuity (DCNVA) were assessed. Contrast sensitivity was examined at several spatial frequencies. The in vitro lens modulation transfer function was measured under different spectral conditions by using an IOL metrology device.

RESULTS

CDVA was comparable under red and white light. DCIVA and DCNVA were significantly better under white light by 0.06 and 0.09, respectively. Contrast sensitivity was slightly better with a red filter at far distance but was worse at intermediate distance, although differences were significant only at 1 frequency. Near contrast sensitivity was better under polychromatic than red light, which was significant at 3 frequencies. The in vitro analysis confirmed Symfony's wavelength dependence: performance was improved at far distance but was worse at intermediate and near distances.

CONCLUSIONS

Symfony's spectral dependence was observed to affect visual acuity and contrast sensitivity. Although the red filter did not improve distance vision, it caused visual deterioration at near distance. One should take this effect into account when optimizing the reading performance of patients with diffractive IOLs.

Comparison of visual outcomes after bilateral implantation of two intraocular lenses with distinct diffractive optics

Purpose

The aim of this study was to compare the visual outcomes and subjective visual quality between bilateral implantation of an extended depth of focus intraocular lens, J&J Vision Tecnis Symfony^® ZXR00 (Group A) and bilateral implantation of a diffractive trifocal intraocular lens, Alcon Acrysof IQ PanOptix^® TNFT00 (Group B).

Methods

This prospective, nonrandomized, comparative study of consecutive cases assessed 52 eyes of 26 patients operated on by the same surgeon (WTH) and binocularly implanted with multifocal intraocular lenses between May 2016 and July 2018. Binocular visual acuity for far, intermediate and near was tested in all cases. Ophthalmological evaluation included the measurement of binocular uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA) at 40 cm, uncorrected intermediate visual acuity (UIVA) at 70 cm, monocular visual defocus curve and the quality of life (QoL) questionnaire, National Eye Institute Visual Functioning Questionnaire - 25 ( NEI-VFQ 25).

Results

Postoperative UDVA was 0.00 and 0.09 logMAR (P<0.001), UIVA was 0.20 and 0.39 logMAR (P<0.001) and UNVA was 0.16 and -0.01 logMAR (P<0.001) in groups A and B, respectively; postoperative CDVA was -0.05 and 0.06 logMAR (P<0.001) in groups A and B, respectively.

Conclusion

Both groups reported good subjective quality of vision regarding long, intermediate and short distances. Group A had a better performance for binocular UDVA, UIVA at 70 cm and CDVA, while regarding the monocular defocus curve, Group A outperformed Group B for long distances. Furthermore, Group B surpassed it in the short to very short distances, between the range of ≥2.00 D to 5.00 D of vergence. While Group A had a better performance regarding the vergences between 0.00 and 1.00 D (P<0.05) and at the vergence of +2.50 D (P=0.007). Group B outran Group A for UNVA at 40 cm.

Visualization of Light Propagation with Multifocal Intraocular Lenses Using the Ouzo Effect

The number of presbyopia correcting intraocular lenses (IOLs) is increasing and new technologies are constantly emerging with the aim of correcting the loss of accommodation after cataract surgery. Various optical designs have been proposed to implement multifocality or an extended depth of focus (EDOF). Depending on the optical principle of an implanted lens, the visual performance often is deteriorated by superposition of individual image planes and halos of varying intensity. This experimental study presents a concept to visualize the light fields and especially the halos of mono- and multifocal IOLs using the well known alcoholic beverage “ouzo” in order to obtain qualitative data on the imaging characteristics. We conclude that ouzo is a useful, cost effective, and nonpolluting medium for beam visualization and an alternative to fluorescein or milk, which could find an application for educational purposes.

Optimal near and distance stereoacuity after binocular implantation of extended range of vision intraocular lenses

PURPOSE

To evaluate stereopsis and visual quality after bilateral implantation of extended range of vision intraocular lenses (ERV IOLs).

SETTING

R.P. Centre for Ophthalmic Sciences, AIIMS, New Delhi, India.

DESIGN

Prospective interventional study.

METHODS

Patients underwent phacoemulsification with bilateral implantation of ERV IOLs. The primary outcome measures were stereopsis (distance and near Randot) and visual quality (ray-tracing aberrometry). The secondary outcome measures were visual acuity and patient satisfaction. Follow-up was performed on day 1 and at 1, 3, 6, and 12 months postoperatively.

RESULTS

The study comprised 50 patients (100 eyes). The mean age of the patients was 58.9 years ± 8.9 (SD). At 1 year, the mean distance stereopsis was 103.6 ± 49.1 seconds of arc (arcsec) and near stereopsis was 21.1 ± 2.3 arcsec. Perfect near stereopsis of 20 arcsec was present in 80% of cases, and 82% had good distance stereopsis of 100 arcsec or better. Stereopsis correlated well with the patient satisfaction score (P < .001) and average internal modulation transfer function (MTF) (P < .015). The mean Strehl ratio was 0.029 ± 0.021, MTF was 0.24 ± 0.08, total higher-order aberrations were 0.62 ± 0.41 μm, and coma was 0.25 ± 0.18 μm. The mean binocular uncorrected decimal visual acuities were 0.98 ± 0.07 (distance), 0.82 ± 0.09 (intermediate) and 0.64 ± 0.08 (near). The mean patient satisfaction score was 9.08 ± 1.1, and no case required IOL explantation because of visually disturbing phenomena or patient dissatisfaction.

CONCLUSION

Excellent stereoacuity was observed after bilateral implantation of ERV IOLs, which correlated well with patient satisfaction and quality of vision.

Longitudinal Chromatic Aberration and Polychromatic Image Quality Metrics of Intraocular Lenses

PURPOSE

To measure longitudinal chromatic aberration (LCA) of various intraocular lenses (IOLs) and to assess LCA effects on polychromatic image quality with a focus on multifocal IOL designs.

METHODS

The LCA values of four multifocal IOL models (three diffractive models: AT LARA 829MP and AT LISA 809M [both from Carl Zeiss Meditec AG, Jena, Germany] and Restor SN6AD1 [Alcon Laboratories, Inc., Fort Worth, TX] and one refractive model [Mini Well Ready; SIFI Medtech, Sant'Antonio, Italy]) were compared with that of their monofocal counterparts. Optical properties were assessed using an optical bench device with spectral filters. LCA was calculated as a difference of a lens power at 480 and 644 nm. The optical quality was evaluated objectively by means of modulation transfer function metrics.

RESULTS

At far, LCA of an aphakic model eye (1.04 diopters [D]) increased with the AT Lisa, Restor, and Mini Well IOLs to 1.40, 1.91, and 1.27 D, respectively, but decreased to 0.78 D with the AT Lara IOL. The AT Lisa and Restor IOLs showed comparable results with their monofocal platforms. A near-focus LCA decreased only in the diffractive IOLs. At far, the polychromatic modulation transfer function was reduced in all IOLs, but LCA effects were attenuated at near.

CONCLUSIONS

Multifocal IOLs and their monofocal counterparts show similar material dispersion. Multifocal diffractive IOLs proved effective in reducing LCA, but the efficiency of the LCA correction differed depending on the optical design. LCA adversely affects the polychromatic image quality. [J Refract Surg. 2018;34(12):832-838.].

Impact of light conditions on reading ability following multifocal pseudophakic corrections

Purpose

To examine the impact of light intensity and temperature on reading performance following bilateral pseudophakic multifocal presbyopic correction.

Patients and methods

This is a prospective clinic-based trial conducted at the Department of Ophthalmology in the University Hospital of Alexandroupolis, Greece. Three groups of patients were formed (G1: patients with bilateral bifocal implantation, G2: patients with bilateral trifocal implantation, and control group: patients with bilateral pseudophakic monofocal implantation). Reading ability was quantified with the Greek version of MNREAD chart with minimal reading speed at 80 words/min for the following light intensities (25, 50, and 75 Foot-Candles [FC]) and temperatures (3,000, 4,000, and 6,000 K). Preferred light conditions for reading were assessed, as well. ClinicalTrials.gov Identifier: NCT03226561.

Results

Control group demonstrated significantly lower reading ability at all light combinations with maximal ability at 75 FC and 6,000 K (0.58±0.18 logMAR). Bifocal group presented a light-dependent reading ability that ranged from 0.45±0.08 logMAR (25 FC and 3,000 K) to 0.40±0.11 logMAR (75 FC and 4,000 or 6,000 K). Trifocal participants presented the best reading ability that was light intensity-independent; however, their performance was reduced at 6,000 K. G1 and G2 preferred primarily intermediate light temperature, while control participants preferred cold light temperature.

Conclusion

Multifocal pseudophakic corrections improve reading ability; however, they present variable efficacy according to the light conditions.

Monocular Clinical Outcomes and Range of Near Vision following Cataract Surgery with Implantation of an Extended Depth of Focus Intraocular Lens

Importance

A full range of near and intermediate vision has not been clinically evaluated for the Symfony extended depth of focus intraocular lens (EDOF IOL).

Background

To evaluate the monocular range of near visual acuity with an EDOF IOL.

Design

Retrospective case series.

Participants

Consecutive patients of a single surgeon from January 2017 through March 2018.

Methods

Phacoemulsification with implantation of an EDOF IOL.

Main Outcome Measures

Uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), distance-corrected near visual acuity (DCNVA), range of DCNVA, and optimal near focal length.

Results

Seventy-six eyes of 48 patients (34 or 71% female, mean age: 68 years) were included with a mean follow-up of 68 days. Mean values were as follows: logarithm of the minimum angle of resolution (logMAR) UDVA 0.02 ± 0.09, logMAR UNVA 0.12 ± 0.09 at a mean distance of 51 cm, logMAR CDVA -0.05 ± 0.07, logMAR DCNVA 0.08 ± 0.07 at a mean distance of 51 cm, and a spherical equivalent of -0.16 diopters ±0.35. Percentage of eyes achieving DCNVA of 20/30 were 84% at 36 cm, 92% at 41 cm, 99% at 51 cm, 93% at 61 cm, and 74% at 71 cm. DCNVA of 20/40 or better was achieved in nearly 100% of eyes over a range of 35 cm.

Conclusions and Relevance

The Symfony EDOF IOL achieved excellent distance visual acuity while providing a 35 cm range of near visual acuity at levels useful for many tasks in nearly all patients.

Visual acuity of pseudophakic patients predicted from in-vitro measurements of intraocular lenses with different design

The optical quality of a set of IOLs (modeling set: one monofocal and two bifocals) was assessed through focus by the area under the modulation transfer function (MTFa) metric and related to the visual acuity (VA) defocus curves of pseudophakic patients implanted with said IOLs. A non-linear relationship between the MTFa and clinical VA was obtained with an asymptotic limit found to be the best VA achievable by the patients. Two mathematical fitting functions between clinical VA and MTFa were derived with high correlation coefficients (R²≥0.85). They were applied to the MTFa obtained from a different set of IOLs with advanced designs (trial set: one extended range of vision -ERV-, one trifocal ERV and one trifocal apodized) to predict VA versus defocus of patients implanted with these IOLs. Differences between the calculated VA and the clinical VA for both fitting models were within the standard deviation of the clinical measurements in the range of -3.00 D to 0.00 D defocus, thus proving the suitability of the MTFa metric to predict clinical VA performance of new IOL designs.

Presbyopia: Effectiveness of correction strategies

Presbyopia is a global problem affecting over a billion people worldwide. The prevalence of unmanaged presbyopia is as high as 50% of those over 50 years of age in developing world populations, due to a lack of awareness and accessibility to affordable treatment, and is even as high as 34% in developed countries. Definitions of presbyopia are inconsistent and varied, so we propose a redefinition that states "presbyopia occurs when the physiologically normal age-related reduction in the eye's focusing range reaches a point, when optimally corrected for distance vision, that the clarity of vision at near is insufficient to satisfy an individual's requirements". Strategies for correcting presbyopia include separate optical devices located in front of the visual system (reading glasses) or a change in the direction of gaze to view through optical zones of different optical powers (bifocal, trifocal or progressive addition spectacle lenses), monovision (with contact lenses, intraocular lenses, laser refractive surgery and corneal collagen shrinkage), simultaneous images (with contact lenses, intraocular lenses and corneal inlays), pinhole depth of focus expansion (with intraocular lenses, corneal inlays and pharmaceuticals), crystalline lens softening (with lasers or pharmaceuticals) or restored dynamics (with 'accommodating' intraocular lenses, scleral expansion techniques and ciliary muscle electrostimulation); these strategies may be applied differently to the two eyes to optimise the range of clear focus for an individual's task requirements and minimise adverse visual effects. However, none fully overcome presbyopia in all patients. While the restoration of natural accommodation or an equivalent remains elusive, guidance is given on presbyopic correction evaluation techniques.

Rotational stability and visual performance 3 months after bilateral implantation of a new toric extended range of vision intraocular lens

Purpose

To evaluate the clinical outcomes after implantation of Symfony^® toric extended range of vision (ERV) intraocular lenses (IOLs) in subjects with preoperative corneal astigmatism.

Setting

Ifocus Øyeklinikk, Haugesund, Norway.

Design

Prospective non-comparative study.

Patients and methods

The study population consisted of 30 patients, with preoperative corneal astigmatism between 0.88 and 3.29 D, undergoing bilateral cataract removal or refractive lens exchange with implantation of Tecnis Symfony toric ERV IOLs. Main outcome measures were visual acuity, refraction, IOL axis rotational stability, patient and surgeon satisfaction, photic phenomena, and quality of life at 3 months.

Results

Postoperatively, mean binocular uncorrected distance, intermediate, and near visual acuities (logMAR) were −0.05±0.11, −0.03±0.08, and 0.09±0.10, respectively. A significant reduction in manifest cylinder (P<0.001) and spherical equivalent (P=0.001) was found after 3 months. Monocular and binocular corrected distance visual acuity also improved significantly with surgery (P<0.001). In terms of binocular uncorrected intermediate and near visual acuity, a total of 96% and 82% of patients achieved 0.1 logMAR (Snellen: 20/25) or better, respectively. Toric IOL axis showed a median rotation of 2.0 degrees (range 0.0–16.0 degrees) from the end of surgery to 3 months. The median patient satisfaction scores for distance, intermediate, and near vision were 9.0, 9.0, and 8.0, respectively. Fifty percent of patients reported complete spectacle independence and most patients (89%) were not bothered by any photic phenomena.

Conclusion

Bilateral implantation of the Symfony toric ERV IOL appeared to be safe and achieved good visual performance and high satisfaction.

Visual outcomes of patients bilaterally implanted with the extended range of vision intraocular lens: A prospective study

Purpose:

The aim of this study was to analyze the objective and subjective visual outcomes of patients bilaterally implanted with the extended range of vision intraocular lens (EROV IOL), the Tecnis Symfony.

Methods:

This was a prospective interventional case series conducted at a tertiary eye care hospital in South India. The study included patients with bilateral implantation of EROV IOLs. The uncorrected and corrected visual acuity for distance, intermediate, and near vision was recorded at 6 weeks and 6 months’ postoperative visit. A subjective questionnaire was administered to assess spectacle independence, photic phenomenon, and overall satisfaction. All data were recorded using Microsoft Excel worksheet. The analyses were performed using SPSS for windows software.

Results:

Our study included fifty patients with bilateral implantation of EROV IOLs. The mean age was 59.84 ± 11.68 years. The mean uncorrected binocular distance, intermediate, and near visual acuity (in standard decimal equivalent) was 0.89,0.99 and 0.99 respectively, at 6 months’ postoperative visit. Ninety-six percent of the patients did not require spectacles for distance and 98% of the patients were free from spectacles for intermediate and near vision. 94% of our patients perceived no or minimal photic phenomena such as glare and halos. The mean subjective patient satisfaction score (out of 10) for distance, intermediate, and near was 9, 10, and 9, respectively.

Conclusion:

The EROV IOLs demonstrated high levels of spectacle independence for distance, intermediate, and near vision. The incidence of photic phenomena observed was minimal with a high level of patient satisfaction.

Extended depth of focus intraocular lens: Chromatic performance

We describe a first-and-second-diffractive-order intraocular lens ((1^st,2^nd)DIOL) within the class of hybrid refractive-diffractive designs for intraocular lenses (IOLs) and analyse its properties of focus extension and compensation of longitudinal chromatic aberration (LCA), particularly for lenses with low addition. Power, energy efficiency and their wavelength dependence are extended from monofocal IOL and conventional bifocal zeroth-and-first-diffractive-order IOL ((0^th,1^st)DIOL) to (1^st,2^nd)DIOL of low addition. Compensation of LCA is experimentally assessed in optical bench through the through-focus energy efficiency of three Tecnis IOLs with red, green and blue illuminations: ZA9003 (monofocal), ZKB00 (bifocal (0^th,1^st)DIOL with + 2.75 D add) and Symfony ZXR00. We prove Tecnis Symfony ZXR00 IOL can be considered an example of (1^st,2^nd)DIOL design of low addition, with LCA compensation in both the distance and intermediate foci, whereas the bifocal (0^th,1^st)DIOL does not compensate in the distance focus. However, the energy efficiency of (1^st,2^nd)DIOL for wavelengths other than the design wavelength is markedly more asymmetric.

Optical bench performance of a novel trifocal intraocular lens compared with a multifocal intraocular lens

Purpose

The purpose of this study is to compare the optical characteristics of the novel PanOptix presbyopia-correcting trifocal intraocular lens (IOL) and the multifocal ReSTOR +3.0 D IOL, through in vitro bench investigations.

Methods

The optical characteristics of AcrySof^® IQ PanOptix™ (PanOptix) and AcrySof^® IQ ReSTOR +3.0 D (ReSTOR +3.0 D) IOLs were evaluated by through-focus Badal images, simulated headlight images, and modulation transfer function (MTF) measurements which determine resolution, photic phenomena, and image quality. Through-focus Badal images of an Early Treatment of Diabetic Retinopathy Study chart were recorded at both photopic and mesopic pupil sizes. Simulated headlight images were taken on an MTF bench with a 50-μm pinhole target and a 5.0 mm pupil at the distance focus of the IOL. MTF curves were measured with a 3.0 mm pupil, and spatial frequencies equivalent to 20/40 and 20/20 visual acuities were recorded to illustrate the through-focus MTF curves. Far-, intermediate-, and near-focus MTF values were obtained.

Results

Bench Badal image testing and MTF measurements showed that PanOptix has a near focus at a distance of 42 cm and an additional intermediate focus at a distance of about 60 cm. The near focus for ReSTOR +3.0 D is at 45 cm. PanOptix and ReSTOR +3.0 D have comparable photopic distances and near MTF values. Additionally, PanOptix provided a substantial continuous range of vision from distance to intermediate and to near compared with ReSTOR +3.0 D. The halo propensity for PanOptix was slightly higher than that for ReSTOR +3.0 D.

Conclusion

Laboratory-based in vitro simulations showed that PanOptix trifocal IOL has comparable resolution and image quality performance in distance and near foci compared with ReSTOR +3.0 D IOL. PanOptix showed better resolution and image quality performance at the intermediate focus than ReSTOR +3.0 D IOL.