Ray propagation imaging and optical quality evaluation of different intraocular lens models

Clinical Outcomes of a Trifocal Versus an Extended Depth of Field Intraocular Lens in Chinese Patients With Cataract: A Prospective Cohort Study

Purpose: To compare the standard outcomes between the PanOptix and Symfony multifocal intraocular lenses (MIOLs) in Chinese patients. Methods: This prospective observational cohort study enrolled patients with cataracts between April 2021 and December 2021 at Xiamen Eye Center Affiliated to Xiamen University. The patients were grouped in the PanOptix (TIOL group) and Symfony (EDF group) according to the IOLs implanted. Uncorrected distant, corrected distance, binocular uncorrected intermediate, and near visual acuity (UNVA), distance-corrected intermediate and near VA (DCNVA) , defocus curve, spectacle independence, contrast sensitivity (CS), and visual disturbances were evaluated after 3 months. Results: Forty patients (80 eyes) were enrolled in the study (20/group). Three months after the operation, UNVA (0.13 ± 0.16) and DCNVA (0.08 ± 0.08) were better in the TIOL group than in the EDF group (0.22 ± 0.08 and 0.22 ± 0.08, respectively, p=0.003 and p < 0.001, respectively). The TIOL group achieved a better-than-0.15-logMAR VA from +0.5 D to -2.5 D (40 cm). VAs of the TIOL group from -1 D (100 cm) to -4 D (25 cm) were better than in the EDF group (p < 0.05). There were no significant differences in the intermediate and far vision outcomes (p > 0.05). Total near-vision spectacle independence was higher in the TIOL group (80%) than in the EDF group (50%) (p=0.039). Conclusion: Compared with EDF, TIOL leads to better near-vision outcomes without significant differences for intermediate and distant vision outcomes. Trial Registration: ClinicalTrials.gov identifier: ChiCTR2100044558.

Effect of decentration and tilt on the in vitro optical quality of monofocal and trifocal intraocular lenses

PURPOSE

To evaluate and compare the effect of decentration and tilt on the optical quality of monofocal and trifocal intraocular lenses (IOL).

METHODS

Optical quality of a monofocal IOL (AcrySof IQ SN60WF; Alcon Laboratories, Inc., USA) and a trifocal IOL (AcrySof IQ PanOptix; Alcon Laboratories, Inc., USA) was assessed using an in vitro optical bench (OptiSpheric IOL R&D; Trioptics GmbH, Germany). At apertures of 3.0 mm and 4.5 mm, modulation transfer function (MTF) at spatial frequency of 50 lp/mm, MTF curve and the United States Air Force (USAF) resolution test chart of the two IOLs were measured and compared at their focus with different degrees of decentration and tilt. Optical quality at infinity, 60 cm and 40 cm and the through-focus MTF curves were compared when the two IOLs were centered at apertures of 3.0 mm and 4.5 mm. Spectral transmittance of the two IOLs was measured by the UV-visible spectrophotometer (UV 3300 PC; MAPADA, China).

RESULTS

The SN60WF and the PanOptix filtered blue light from 400 to 500 nm. Both IOLs at the far focus and the PanOptix at the intermediate focus showed a decrease in optical quality with increasing decentration and tilt. The PanOptix demonstrated enhanced optical quality compared to the previous gradient at the near focus at a decentration range of 0.3-0.7 mm with a 3.0 mm aperture, and 0.5 mm with a 4.5 mm aperture, whereas other conditions exhibited diminished optical quality with increasing decentration and tilt at the focus of both IOLs. When the two IOLs were centered, the SN60WF had better optical quality at infinity, while the PanOptix had better optical quality at 60 cm and 40 cm defocus. The optical quality of the SN60WF exceeded that of the PanOptix at far focus, with a 3 mm aperture decentration up to 0.7 mm and a 4.5 mm aperture decentration up to 0.3 mm; this observation held true for all tilts, irrespective of aperture size. As both decentration and tilt increased, the optical quality of the SN60WF deteriorated more rapidly than that of the PanOptix at the far focal point.

CONCLUSIONS

The SN60WF showed a decrease in optical quality with increasing decentration and tilt. Optical quality of the PanOptix at the near focus increased in some decentration conditions and decreased in some conditions, while it showed a decrease at the other focuses with increasing decentration. While tilt only had a negative effect on optical quality. When both IOLs were centered, the PanOptix provided a wider range of vision, while the SN60WF provided better far distance vision. At the far focus, the SN60WF has better resistance to tilt than the PanOptix, but the optical quality degrades more quickly when decentered and tilted.

Analysis of the optical performance of intraocular lenses using profilometric measurements

PURPOSE

The aim of this study was to develop a methodology, based on profilometer measurements to assess the optical behaviour of Intraocular Lenses (IOls). The "Modulation Transfer Function through-object" (MTF through-object) based on vergence object displacement was calculated for different pupil sizes and pseudophakic eyes. Tilt and decentration were also analysed in a realistic cornea eye model.

METHODS

For comparison between the different IOLs, an optical quality criterion based on a minimum value the MTF through-object and the recognition of simulated vision optotypes was introduced. Five IOLs were used in this study: Tecnis Eyhance, Mini Well, Tecnis Symfony, Tecnis Synergy and RayOne EMV.

RESULTS

The technique was validated with previous methodologies. A general narrowing of the through-object MTF curve compared to the through-focus MTF curve was shown, resulting in greater distances between near and intermediate points and less depth of field around the far peak. The comparison between the IOLs showed that variations in corneal aberrations, pupil size and decentration caused relevant changes in IOL performance. A decrease of the SA produced a hypermetropic shift of the far focus between + 0.3 D and + 0.4 D. Most of IOLs worsen the optical quality as pupil size increased, even the MTF through-object shape changed. Decentration was an important factor in IOL implantation, causing a significant change in MTF through-object shape in most of IOLs.

CONCLUSIONS

This study highlights the need to evaluate pre-operative patients for corneal aberrations and pupillary size to have the best optical success after cataract surgery in multifocal or extended depth of focus IOLs.

KEY MESSAGES

What is known MTF(Modulation Transfer Function) through-focus curves (calculated in image space by moving the detector plane) can be obtained from optical bench assembly or from commercial devices. Recently, some studies proposed to characterize the lens surface design based on the profilometric measurements What is new A novel methodology based on profilometer measurements to assess the optical behaviour of Intraocular Lenses (IOls) was shown. The "Modulation Transfer Function through-object" based on vergence object displacement was introduced in order to analyse five premium IOLs. MTF through-object curve is more appropriate for studying clinical behaviour, as it provides further near and intermediate points distances and lower depth of focus around far peak compare to MTF through-focus curves. The optical behaviour of the five IOLs can vary considerably depending on the eye model and pupil size. The effect of tilt and decentration on the MTF through-object the IOLs was analysed.

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.

Outcomes after bilateral implantation of AcrySof IQ PanOptix trifocal intraocular lens: a prospective interventional study

Background

Implantation of multifocal intraocular lenses (IOLs) is becoming increasingly popular for the treatment of visual demands at various distances in patients undergoing phacoemulsification cataract surgery. We aimed to assess the visual performance and rates of photic phenomena, posterior capsule opacification (PCO), and spectacle independence in patients with bilateral implantation of the AcrySof® IQ PanOptix® multifocal IOL model TFNT00 at one and six months postoperatively.

Methods

This prospective interventional cohort study included adult patients who underwent uneventful phacoemulsification cataract surgery with bilateral implantation of AcrySof® IQ PanOptix® IOL. Uncorrected and corrected visual acuities at far, intermediate, and near distances were measured preoperatively and at the one- and six-month postoperative follow-up examinations. The rates of photic phenomena, postoperative need for near and distance spectacles, and PCO were also recorded.

Results

We included 164 eyes of 82 patients with a male-to-female ratio of 38 (46.3%) to 44 (53.7%) and a mean (standard deviation [SD]) age of 52.37 (7.62) years. There were statistically significant improvements in the visual acuities of both eyes across all distances at the one- and six-month follow-up examinations compared to the preoperative values (all P < 0.001), except for corrected near visual acuity in the right eye (P > 0.05) at six-month. We also detected significant postoperative improvements in visual acuities of both eyes across all distances at the six-month follow-up compared to values at the one-month follow-up (all P < 0.05), except for corrected near visual acuity in the right eye (P > 0.05). The photic phenomenon was reported by 12 (14.6%) of the 82 patients at the six-month postoperative follow-up. Five (6.1%) and eight (9.8%) of the 82 patients reported using spectacles for distance and near, respectively. Additionally, PCO developed in 19 (11.6%) of the 164 included eyes, although it was not clinically significant at six months.

Conclusions

The AcrySof® IQ PanOptix® IOL model TFNT00 is recommended for use, given its excellent performance in all ranges of vision, a high rate of spectacle independence, and a good safety profile. Future comparative studies with longer follow-up periods are warranted to verify superiority of its performance over that of other available multifocal IOLs.

Comparison of postoperative visual performance between trifocal intraocular lens and monofocal intraocular lens

OBJECTIVES

To compare the subjective and objective visual quality more comprehensively after surgery of the commonly used multifocal intraocular lenses (IOL) and monolocal IOL implants through long-term systematic clinical observation, providing reference and basis for clinical application.

METHODS

Non-randomized controlled trial. A total of 91 (138 eyes) patients between June 2020 and December 2020 were implanted trifocal IOL or monofocal IOL after phacoemulsification in a tertiary class hospital in Wuhan. Monocular testing 3 months after surgery included best-spectacles corrected and uncorrected visual at distant, intermediate, and near vision; spherical equivalent (SE); defocus curve; modulation transfer function (MTF); dysfunctional lens index (DLI); Strehl ratio (SR); mesopic contrast sensitivity function; quality-of-life, spectacles independence, visual disturbance, and surgical satisfaction surveys 3 months post-surgery.

RESULTS

There was statistically better uncorrected vision acuity with trifocal IOLs in all range, while monofocal IOL had statistically better mesopic contrast sensitivity at specific spatial frequencies and statistically worse defocus curves, spectacles independence, and surgical satisfaction. The trifocal IOL performed better in subjective quality of vision and life and spectacles independence questionnaires, and the objective quality of vision had no statistical significance.

CONCLUSION

Compared to monofocal IOL, trifocal IOL could provide a full range of clear vision for the majority of patients with simple cataracts, improve the rate of spectacles independence and patient satisfaction. And the objective quality of vision did not show any difference.

Enhanced Depth of Focus Intraocular Lenses: Through Focus Evaluation of Wavefront-Shaping versus Diffractive Optics

Introduction

A new class of nondiffractive, wavefront-shaping Enhanced-Depth-of-Focus (EDoF) IOLs has been introduced very recently to cope with photic phenomena known from diffractive EDoF IOLs. We investigated the through focus modulation transfer function (MTF) of two wavefront-shaping EDoF IOLs compared to an established diffractive EDoF IOL on the optical bench. Such comparison on the optical bench had not been performed before and is of high clinical importance for the cataract surgeon.

Material and Methods

Tecnis Symfony (diffractive) and the wavefront-shaping Acrysof IQ Vivity and LuxSmart Crystal IOLs (22 D each) were assessed by the OptiSpheric IOL PRO 2 imaging test bench with an ISO-2 cornea and a wavelength of 546 nm. Apertures of 3 mm and 4.5 mm were applied.

Results

For all three IOLs, two peaks showed up in the through focus MTF curves representing the primary and secondary focus. For Symfony, these peaks were most distinct. Power difference between far and intermediate focus was 1.25 D (Symfony), 1.75 D (Vivity), and 1.5 D (LuxSmart) with an aperture of 3 mm. With an aperture of 4.5 mm, only for LuxSmart, power difference diminished slightly to about 1 D, and only the MTF in the intermediate focus decreased for all lenses.

Conclusion

For all three IOLs, we could confirm a considerable depth of focus that was most extended for Vivity. Both new wavefront-shaping IOLs had lower values of peak MTF but a markedly more continuous through focus behavior compared to the diffractive EDoF IOL.

Complementary system vs conventional trifocal intraocular lens: comparison of optical quality metrics and unwanted light distribution

PURPOSE

To evaluate the ARTIS Symbiose complementary intraocular lens (IOL) system, consisting of the MID and PLUS models, in comparison with a conventional trifocal IOL (AcrySof IQ PanOptix).

SETTING

The David J. Apple Center for Vision Research, Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany.

DESIGN

Laboratory investigation.

METHODS

Modulation and phase transfer functions were obtained in polychromatic light using an optical bench setup. Simulated visual acuity (VA) values were derived from optical quality metrics weighted by neural contrast sensitivity. United States Air Force (USAF) chart images were acquired and processed. Furthermore, the light distribution beyond the center of a polychromatic point spread function was assessed.

RESULTS

The peak simulated VA values of ARTIS Symbiose MID were at 0 diopters (D) of defocus (-0.02 logMAR) and at -1.5 D (0.00 logMAR); of ARTIS Symbiose PLUS, they were at 0 D of defocus (-0.01 logMAR) and at -2.5 D (0.01 logMAR). AcrySof IQ PanOptix demonstrated 3 peaks: at 0 D of defocus (-0.02 logMAR), at -1.75 D (0.03 logMAR), and at -2.5 D (0.02 logMAR). The summation of USAF chart images in the simulated binocular IOL system produced a slightly better image quality at -1.0 D and -1.5 D than AcrySof IQ PanOptix. The IOLs yielded comparable light spread across the studied range except for a localized intensity spike of the ARTIS Symbiose IOLs.

CONCLUSIONS

The complementary IOL system may yield better monocular intermediate VA compared with the conventional trifocal IOL. However, the effect of binocular summation in terms of VA and the perception of photic phenomena still needs to be investigated.

Advanced Optical Wavefront Technologies to Improve Patient Quality of Vision and Meet Clinical Requests

Adaptive optics (AO) is employed for the continuous measurement and correction of ocular aberrations. Human eye refractive errors (lower-order aberrations such as myopia and astigmatism) are corrected with contact lenses and excimer laser surgery. Under twilight vision conditions, when the pupil of the human eye dilates to 5-7 mm in diameter, higher-order aberrations affect the visual acuity. The combined use of wavefront (WF) technology and AO systems allows the pre-operative evaluation of refractive surgical procedures to compensate for the higher-order optical aberrations of the human eye, guiding the surgeon in choosing the procedure parameters. Here, we report a brief history of AO, starting from the description of the Shack-Hartmann method, which allowed the first in vivo measurement of the eye's wave aberration, the wavefront sensing technologies (WSTs), and their principles. Then, the limitations of the ocular wavefront ascribed to the IOL polymeric materials and design, as well as future perspectives on improving patient vision quality and meeting clinical requests, are described.

The Rostock Method for Qualitative and Quantitative Evaluation of Intraocular Lenses

BACKGROUND

For quantitative and qualitative evaluation of the imaging properties of IOLs, axial cross-sectional images can be obtained from the 3-dimensional light distribution by means of an optical bench, as is known from light sheet recordings in fluorescein baths. This paper presents a new image-processing algorithm to enhance the quality of generated axial cross-sectional images, and the two methods are then compared.

MATERIAL AND METHODS

The 3-dimensional point spread function of a diffractive trifocal IOL (AT LISA tri 839MP, Carl Zeiss Meditec AG, Jena, Germany) was recorded on an optical bench developed in Rostock for different pupil diameters. A specially adapted image processing algorithm was then applied to the measurements, allowing through-focus curves to be generated. In addition, cross-sectional images of the IOLs studied were acquired using the light sheet method in a fluorescein bath.

RESULTS

The study clearly shows the superiority of the newly developed method over the light sheet method in terms of image quality. In addition to the individual focal points, fine focal structures as well as halos can be made visible in the cross-sectional images obtained using the new method. In the generated through-focus curves, 3 intensity peaks can be identified, which represent the near, intermediate and far focus of the tested MIOL and cannot be represented by light sheet methods.

CONCLUSION

The interaction of the optical bench with the developed image processing algorithm allows a more detailed understanding of the image formation and false light phenomena of IOLs, which was restricted by the technical limitations of the existing light sheet method. In addition, other quantities such as the through-focus curve can be derived quantitatively.

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.

Presbyopia correction after previous Intracor treatment: Combined implantation of a small-aperture and a non-diffractive extended-depth-of-focus lens

PURPOSE

We present the case of implantation of two different Extended depth of focus intraocular lenses (EDoF IOLs) in a patient with a history of unilateral intrastromal femtosecond laser treatment for presbyopia correction (Intracor).

OBSERVATIONS

The patient reported decreasing visual acuity at near distance and increasing spectacle dependence. Ten years earlier, he had Intracor treatment for presbyopia correction in his left eye. Corrected distance visual acuity (CDVA) was 0.08 logMAR for the right eye and 0.16 logMAR for the left eye. Apart from dysfunctional lens syndrome, the examination results were unremarkable. Phacoemulsification and subsequent IOL implantation was performed in both eyes. The left eye was implanted with an IC-8 (AcuFocus, Irvine, CA, USA), whereas the fellow eye was implanted with an AcrySof IQ Vivity IOL (Alcon, Fort Worth, TX, USA). Postoperatively, CDVA improved to 0.02 and 0.04 logMAR for the right and left eye. Uncorrected intermediate visual acuity (UIVA) was 0.24 logMAR for the right eye and -0.04 logMAR for the left eye, binocular UIVA was -0.04 logMAR. The patient reported a low level of photic phenomena and spectacle independence for far and intermediate distance.

CONCLUSIONS AND IMPORTANCE

Combined implantation of a non-diffractive and a small-aperture EDoF lens after previous unilateral Intracor treatment could successfully improve visual acuity at far and intermediate distance.

Clinical Outcomes of a New Hybrid Monofocal IOL With Extended Depth of Focus

PURPOSE

To evaluate a new extended depth of focus intraocular lens (IOL), the xact Mono-EDOF ME4 (Santen Pharmaceuticals), Conformitè Europëenne-marked as a monofocal IOL, which has four diffractive rings intended to enhance intermediate vision.

METHODS

Results are reported for 47 IOLs implanted in 28 patients who underwent cataract surgery and implantation of the xact Mono-EDOF ME4 IOL in one (9 patients) or both (19 patients) eyes. Postoperative follow-up examinations included visual acuity testing (monocular and binocular; uncorrected distance visual acuity [UDVA], corrected distance visual acuity [CDVA], uncorrected intermediate visual acuity [UIVA], distance-corrected intermediate visual acuity [DCIVA]), defocus curve and contrast sensitivity testing, and dysphotopsia evaluation.

RESULTS

Follow-up at 6 months postoperatively revealed a monocular UDVA of 0.08 ± 0.15 logMAR, binocular UDVA of -0.02 ± 0.09 logMAR, monocular CDVA of -0.07 ± 0.08 logMAR, binocular CDVA of -0.09 ± 0.09 logMAR, monocular UIVA (70 cm) of 0.18 ± 0.16 logMAR, binocular UIVA (70 cm) of 0.09 ± 0.12 logMAR, monocular DCIVA (70 cm) of 0.25 ± 0.14 logMAR, and binocular DCIVA (70 cm) of 0.13 ± 0.11 logMAR. Defocus curve testing demonstrated a functional defocus of 1.25 diopters at 0.20 logMAR for monocular and 1.50 diopters at 0.20 logMAR for binocular testing. The contrast sensitivity corresponded to the age-appropriate normal values. Patients reported low levels of halo and glare.

CONCLUSIONS

The xact Mono-EDOF ME4 IOL showed good functional results for far and intermediate distance visual acuity while inducing a low level of photic phenomena. [J Refract Surg. 2021;37(9):601-608.].

Visualization of Forward Light Scatter in Opacified Intraocular Lenses and Straylight Assessment

Background: Qualitative visualization of forward light scatter and quantitative straylight measurement of intraocular lenses (IOLs). Methods: We analyzed two calcified IOL-explants, the Euromaxx ALI313Y (Argonoptics GmbH) and the LS-312 MF30 (Oculentis BV), one IOL with artificially induced glistenings (PC-60AD, Hoya), and one control (CT Asphina 409MP, Carl Zeiss Meditec AG) free of any opacification. Analysis included light microscopy, qualitative light scatter visualization using ray propagation imaging technique, and quantitative straylight measurement using C-Quant (Oculus). Results: More light scattering effect—visible as increased light intensity outside the IOL’s main focus—was evident in all opacified IOLs than the control. The highest straylight levels were observed in the Euromaxx (289.71 deg²/sr), which showed extensive granular deposits throughout its optic, followed by the MF30 (78.58 deg²/sr), which only showed opacification in its center. The glistenings-IOL demonstrated numerous microvacuoles within the optic and had straylight levels of 22.6 deg²/sr, while the control showed the lowest straylight levels (1.7 deg²/sr). Conclusions: Ray propagation imaging technique allowed qualitative assessment of off-axis veils of light that result from increased forward light scattering. Straylight was increased in all opacified lenses compared to the clear control lens. The IOL opacifications are significant sources of glare.

Comparison of the Visual Outcomes of an Extended Depth-of-Focus Lens and a Trifocal Lens

Purpose

To compare the visual performance of the AcrySof IQ PanOptix trifocal intraocular lens and the TECNIS Symfony extended depth-of-focus lens at near and distance visual ranges.

Methods

A total of 146 patients (221 eyes) who underwent phacoemulsification and cataract extraction and received either a PanOptix or Symfony lens from January 2019 to July 2020 were included in the study (83 PanOptix non-toric, 30 PanOptix toric, 70 Symfony non-toric, and 38 Symfony toric). Uncorrected distance (UDVA), uncorrected near (UNVA), and corrected distance (CDVA) visual acuity were assessed at one-day, one-month, and three-months postoperatively. Averages of UDVA, UNVA, and CDVA were taken to evaluate which lens was superior at near and distance visual ranges. Secondary outcome measures including glare, halo, dryness, and problems with night vision were documented at each postoperative visit.

Results

At one month postoperatively, the average UNVA was 0.16 ± 0.14 logMAR in the PanOptix group and 0.21 ± 0.14 logMAR in the Symfony group (P=0.007); the average UDVA for the PanOptix group was 0.09 ± 0.13 logMAR compared to the Symfony group at 0.10 ± 0.14 logMAR (P=0.67); and the average CDVA was 0.02 ± 0.05 logMAR in the PanOptix group and 0.00 ± 0.04 logMAR in the Symfony group (P=0.11). At three months postoperatively, there were no statistically significant differences in UNVA, UDVA, or CDVA between the two groups (P=0.18, 0.79, 0.68 respectively). There was no statistically significant difference in secondary outcome measures at one- and three-months (P=0.49, 0.10 respectively).

Conclusion

The AcrySof IQ PanOptix trifocal intraocular lens appears to afford better UNVA compared to the TECNIS Symfony extended depth-of-focus intraocular lens at one-month postoperatively, though this difference was not seen at three months postoperatively. There is no statistically significant difference in UDVA and CDVA between the two groups at postoperative day one, one-month, and three-months.

Laboratory analysis and ray visualization of diffractive optics with enhanced intermediate vision

BACKGROUND

To assess the optical behavior of a new diffractive intraocular lens (IOL) and compare its performance to that of an established extended-depth-of-focus (EDOF) IOL.

METHODS

This study assessed the Proming EDOF Multifocal AM2UX [Eyebright Medical Technology (Beijing) Co., Ltd., China] and the AT LARA 829MP [Carl Zeiss Meditec, Germany]. An experimental set-up with 0.01% fluorescein solution and monochromatic light (532 nm) was used to visualize the IOLs' ray propagation. In addition, the optical quality of the IOLs was assessed by measuring the modulation transfer function (MTF) values at 50lp/mm and 3.0 and 4.5 mm apertures on the optical bench OptiSpheric® IOL PRO II [Trioptics GmbH, Germany].

RESULTS

The ray propagation of the two IOLs showed two distinct foci. Light intensity assessment revealed that both IOLs allocate more energy to primary than secondary focus. At 3.0 mm pupil, the MTF values at 50lp/mm for the primary focus were 0.39 and 0.37, and for the secondary focus, 0.29 and 0.26 for the AT LARA and Proming IOLs, respectively. At 4.5 mm pupil, the single-frequency MTF for the primary focus was 0.51 and 0.24 and for the secondary focus 0.21 and 0.15 for the AT LARA and Proming IOLs, respectively.

CONCLUSIONS

When tested with an aberration-free model cornea under monochromatic conditions, the Proming behaved as a low-add bifocal lens; however, its properties did not differ much from the well-established AT LARA EDOF IOL. The AT LARA outperformed the Proming at low defocus (up to 2D), while the latter demonstrated better image quality in the 2-3D range.

A narrative review of intraocular lens opacifications: update 2020

The opacifications of intraocular lenses (IOLs) can significantly impact patients visual quality. Despite the identification of specific risk factors, manufacturing changes, opacifications are not eliminated. Likewise, more attention in recent studies was paid to possible new risk factors, however one of the most important purposes of the studies remains opacifications effect on visual performance, which could be disturbed in different aspects. The aim of this review is to discuss the main risk factors of IOLs opacification in particular IOL types, and its impact on vision quality. Different risk factors were discussed in the study, including the material of IOLs, the impact of the breakdown of blood-aqueous barrier (BAB), and certain surgeries that can be associated with opacification formation. Glistenings occur more often in a hydrophobic material, however, the changes in water content of the IOLs can significantly reduce the formation of glistenings. The studies showed a significant effect of intraocular injection of exogenous air or gas during Descemet-stripping endothelial keratoplasty, Descemet-stripping automated endothelial keratoplasty, Descemet membrane endothelial keratoplasty, and pars plana vitrectomy on calcification formation. It raises a concern, as the incidence of these surgeries is increasing. Visual acuity decreases significantly after the calcification in IOLs occurs, and it usually causes IOLs exchange. However, disability glare seems to be more affected in patients with IOLs, which were affected by glistenings than visual acuity. Disability glare is associated with increased levels of straylight, which was widely evaluated in recent studies and it was reported to be a susceptible measurement to detect the presence of IOLs pathology. For future researches, it should be noticed that disability glare and straylight are more appropriate in evaluating IOLs opacification effect on visual quality than visual acuity. While reviewing the main risk factors of IOLs opacifications particular attention must be paid on calcification occurrence in hydrophilic acrylic IOLs after surgeries with intraocular injection of exogenous air or gas.