Pupil Diameter in Patients With Multifocal Intraocular Lenses

Investigation of Pupillary Responses in Healthy Eyes and Eyes Implanted with Multifocal or Monofocal Intraocular Lenses

PURPOSE

Comparison of dynamic pupillary parameters (DPPs) between healthy volunteers and multi- or monofocal intraocular lens (IOL) implanted eyes, and examination of the correlation between postoperative visual acuity (VA), contrast sensitivity (CS), visual dysphotopsias (VD), and these parameters in IOL-implanted eyes.

METHODS

This cross-sectional study classified and analyzed DPPs from healthy volunteers (308 eyes) according to age. In the multifocal IOL group (119 eyes), 51 eyes were implanted with Lentis Comfort® (L group), 32 with PanOptix® (P group), and 36 with Synergy® (S group). The monofocal IOL group included 33 eyes implanted with Vivinex Impress® (V group). DPPs by the pupillometer (PLR-3000), distance, intermediate and near VA, and CS and VD were examined one month postoperatively in 152 eyes.

RESULTS

Significant decreases in maximum or minimum pupillary diameter (INIT, END), percentage of pupillary constriction (DELTA), latency between light stimulation and constriction (LAT), and average and maximum constriction velocity (ACV, MCV), average dilation velocity (ADV), were observed with aging in the healthy eyes group. The preoperative group showed a significant age-related decrease in DELTA and increase in LAT. The postoperative group showed a significant age-related decrease in INIT, END, and ADV. The L group exhibited a significant positive correlation between ADV and uncorrected intermediate VA (UIVA), while the P group exhibited a significant positive correlation between ACV and UIVA, and the S group exhibited a significant negative correlation between ACV and uncorrected near VA. For CS, the S group exhibited a significant positive correlation with ADV at 1.0 and 0.7 degrees, and the P group exhibited a significant negative correlation between ACV and glare.

CONCLUSION

DPPs are greatly affected by age. DPPs for multi- or monofocal IOL eyes correlate with uncorrected VA, CS, and VD.

Comparison of pupil size measurement: Repeatability and agreement across four devices with different measurement principles under varied lighting conditions

AIM

To evaluate the repeatability of pupil size measurements obtained with four different devices under varying lighting conditions and to assess the agreement between them.

METHODS

This prospective study included 80 healthy participants with a mean age of 27.5 ± 8.8 years (range 19-58). Pupil size was measured under mesopic (4 lux) and low photopic (50 lux) conditions using two open-field devices (tabletop and handheld PowerRefractors) and two closed-field devices (MS-39 and NIDEK Tonoref III). Three consecutive measurements were taken per eye for each device. Repeatability was analysed using the repeatability limit (R Limit), while the agreement was assessed with Bland-Altman analysis.

RESULTS

All devices demonstrated R Limits lower than 1 mm under both low photopic and mesopic conditions. The NIDEK Tonoref III had the best repeatability under low photopic conditions (R Limit = 0.52 mm), while the tabletop PowerRefractor had the best R Limit under mesopic conditions (0.68 mm). The agreement analysis under mesopic conditions revealed smaller mean differences and narrower limits of agreement (LoA) (approximately 2 mm) among devices with similar designs (tabletop with handheld PowerRefractor and MS-39 with NIDEK Tonoref III), while combinations of designs exhibited wider variability. Mesopic conditions yielded more consistent LoA across all device pairs.

CONCLUSIONS

All devices showed excellent repeatability. Instruments with similar measurement designs demonstrated better agreement, particularly under low photopic conditions. Significant variability existed when comparing open- and closed-field devices. These findings underscore the importance of selecting appropriate instruments for clinical and research applications, and highlight the need for further validation of pupillometry devices.

Influence of Corneal Higher Order Aberrations on Visual Performance With a Multifocal Intraocular Lens

PURPOSE

To evaluate the impact of corneal aberrations on the visual performance of patients who received a multifocal intraocular lens (MIOL) implant.

METHODS

Two hundred seventy patients who underwent cataract or refractive lens exchange and were implanted with an apodized diffractive MIOL were included in the analysis. Relationships between total higher order aberrations (HOAs), coma, trefoil, and spherical aberration (SA) measured with a Scheimpflug topographer at 4 mm versus visual acuity and contrast sensitivity areas under the defocus curves (AUC) were evaluated. Relationships between other demographic and biometric variables with total AUCs were also explored.

RESULTS

Eyes rarely showed coma and trefoil aberrations exceeding 0.2 μm, 0.1 μm for SA, and 0.3 μm for the total HOAs. The total HOAs showed correlations with age (rho = 0.32, P < .0005) and anterior chamber depth (rho = -0.21, P = .001). The mesopic pupil size, age, and chart luminance, in the following order, were mainly correlated with total AUCs. A correction by mesopic pupil was required to unmask weak correlations of AUCs with the corneal aberrations. These were found particularly for total HOAs and total and near AUCs (P < .05).

CONCLUSIONS

Values below 0.3 μm for total HOAs, 0.2 μm for coma and trefoil, and 0.1 μm for SA at 4 mm are safe for the study IOL. Higher values are rare but still can be safe, and the 0.5 μm cut-off at 4 mm for contraindication merits further research with this and other IOLs. [J Refract Surg. 2025;41(4):e291-e299.].

Correlation between pupillary size and depth of focus after the implantation of extended depth of focus intraocular lenses

PURPOSE

To evaluate whether depth of focus after the implantation of extended depth of focus (EDoF) intraocular lenses (IOLs) correlates with pupillary size.

METHODS

This retrospective case series study evaluated eyes undergoing cataract surgery with implantation of EDoF IOLs. At least one month postoperatively, the depth of focus (DoF) was measured to determine the correlation with pupillary size, age, anterior chamber depth (ACD), axial length (AXL), and corneal spherical aberrations (SA).

RESULTS

The study evaluated 64 eyes of 49 patients. The mean depth of focus was 2.67 diopters (D). The mean preoperative photopic pupil size was 3.36 mm. A significant negative association was found between preoperative photopic pupil size and depth of focus (r = 0.30, Pearson's correlation coefficient) and between preoperative mesopic pupil size and depth of focus (r = 0.274, Pearson's correlation coefficient).

Visual simulation of intraocular lenses: from on-bench performance to computational and experimental validations

This study presents a systematic method to simulate various intraocular lenses (IOLs) available in the market. Five IOLs (two trifocals, one bifocal, one enhanced monofocal, and one extended depth of focus (EDOF)) were evaluated in terms of through focus visual Strehl (TFVS) utilizing the OptiSpheric IOL PRO2 device (Trioptics GmbH). Then, the estimated TFVS (ETFVS) and the temporal coefficients necessary for temporal multiplexing were computed, and through an iterative process, the SimVis TFVS was obtained. Finally, a high-speed focimeter was used to measure the opto-tunable lens responses to the temporal profile, and the experimental SimVis TFVS was acquired. Therefore, results are analyzed in terms of ETFVS (computed from the VSR-OTF), SimVis TFVS (computed from the TCs through temporal multiplexing), and experimental SimVis TFVS (acquired from the high-speed focimeter setup). The ETFVS and the SimVis TFVS curves demonstrated excellent alignment across all IOLs with cross-correlation coefficients > 0.94. Similarly, the experimental SimVis TFVS and the SimVis TFVS curves showed high correlation with cross-correlation coefficients > 0.97 and root mean square error (RMSE) < 0.05 for each lens. We demonstrated that different IOL designs can be visually simulated using its TFVS to obtain the corresponding temporal coefficients for simulations through temporal multiplexing using the SimVis technology.

Modulation transfer function of implantable phakic intraocular contact lens (IPCL) for myopia and presbyopia

PURPOSE

This study aimed to assess the optical quality of myopic and presbyopic IPCLs with different additional powers, and to investigate the effects of pupil size on the optical quality of these IPCLs using an in-vitro modulation transfer function (MTF) measurement system.

METHODS

Linear scatter functions (LSFs) were recorded using the OPAL Vector system and an eye phantom consisting of wet cells filled with a balanced salt solution. A myopic IPCL or a presbyopic IPCL was placed in the posterior chamber of this model. The MTF was calculated from the LSF using the fast Fourier transform techniques. The effective apertures were set at 2.0 to 5.0 mm in 1.0 mm steps.

RESULTS

The in-focus MTF values of the myopic IPCL and presbyopic IPCL with additional powers of + 2.0 and + 4.0 diopters at 100 cycles/mm for an effective aperture of 3.0 mm were 43%, 27%, and 24%, respectively. The in-focus MTF value of both myopic and presbyopic IPCLs was the highest when the effective aperture was set at 3.0 mm, and it gradually worsened when the effective aperture became larger than 3.0 mm at 20, 60, and 100 cycles/mm.

CONCLUSIONS

Both myopic and presbyopic IPCLs provided excellent MTF values, but the additional power profile can deteriorate optical performance in presbyopic IPCL-implanted eyes, even with a low additional power. Pupil size can influence visual quality in IPCL-implanted eyes for both myopia and presbyopia.

Risk Factors for Corneal Monochromatic Aberrations and Implications for Multifocal and Extended Depth-of-Focus Intraocular Lens Implantation

PURPOSE

To discuss factors influencing corneal aberrations that might influence the optical quality after intraocular lens (IOL) implantation.

METHODS

PubMed and Scopus were the main resources used to search the medical literature. An extensive search was performed to identify relevant articles concerning factors influencing the level of corneal aberrations as of August 27, 2023. The following keywords were used in various combinations: corneal, aberrations, defocus, astigmatism, spherical aberration, coma, trefoil, quadrafoil, intraocular lens, and IOL.

RESULTS

Conclusive evidence is lacking regarding the correlation between age and changes in corneal aberrations. Patients with astigmatism have greater corneal higher-order aberrations than those with minimal astigmatism, particularly concerning trefoil and coma. Increased levels of corneal higher-order aberrations are noted following contact lens wear, in patients with dry eye disease, and with pterygium. Increased higher-order aberrations have been reported following corneal refractive surgery and for 3 months following trabeculectomy; regarding intraocular lens surgery, the results remain controversial.

CONCLUSIONS

Several factors influence the level of corneal higher-order aberrations. Multifocal and extended depth-of-focus IOLs can share similarities in their optical properties, and the main difference arises in their design and performance with respect to spherical aberration. Preoperative evaluation is critical for proper IOL choice, particularly in corneas with risk of high levels of aberrations. [J Refract Surg. 2024;40(6):e420-e434.].

Spherical aberrations and their role in modern ophthalmology

Spherical aberration is an imperfection of the optical system of the human eye. The role of spherical aberration of the human eye in the quality of vision and pseudoaccommodation is reviewed. Spherical aberration is an imperfection of the optical system of the human eye. In most cases, due to well-developed neuroadaptation, it is insignificant for the perception of the image. Nevertheless, its role in modern ophthalmology is far from straightforward. On the one hand, there are clinical scenarios in which an excess of spherical aberration degrades the retinal image and leads to a high dissatisfaction rate among patients.©Recently, there is a growing interest in the modulation of spherical aberration in the clinical setting. Modern intraocular lenses as well as laser refractive procedures are aimed at interfering with spherical aberrations of the optical system in order to increase range of pseudoaccommodation. Here, we review the role of spherical aberration of the human eye in the quality of vision and pseudoaccommodation.

Influence of a multifocal intraocular lens centration and eye angles on light distortion and ocular scatter index

PURPOSE

To assess how eye axes and multifocal intraocular lens (MIOL) centration may impact the light distortion index (LDI) and ocular scatter index (OSI).

METHODS

Fifty-eight subjects implanted with the trifocal MIOL Q-Flex M 640PM or Liberty 677MY (Medicontur) were included in this retrospective analysis. The following variables were collected with the Pentacam Wave (Oculus) considering the vertex normal as the coordinates center: chord-mu to the center of the pupil, chord-alpha to the geometrical center of the cornea, and chord-MIOL to the center of the diffractive ring. These measurements were correlated with OSI (HD Analyzer, Visiometrics) and LDI (light distortion analyzer, CEORLab).

RESULTS

Chord-MIOL centroid was 0.12 mm at 62°, chord-mu was 0.09 mm at 174°, and chord-alpha was 0.38 mm at 188°. A relationship was found between OSI and LDI, rho = 0.58, p < 0.0005). No relationships were found between chord-mu or chord-alpha and the LDI or OSI, neither for the total magnitude, nor the decomposition in orthogonal components (p > 0.05). The LDI was significantly correlated with the temporal centration of the MIOL versus the vertex normal (rho = 0.32, p = 0.02).

CONCLUSIONS

As opposed to what has been previously described, the temporal centration of the MIOL was related to a decrease in the LDI. Future studies with extreme values of the included variables are required to establish cut-offs for considering these variables as exclusion criteria in the implantation of a MIOL.

Comparison of corneal aberrations from anterior segment swept source OCT versus Placido-topography combined spectral domain OCT in cataract patients

BACKGROUND

To comprehensively evaluate the agreement of component corneal aberrations from the newly updated wavefront analysis software of a swept-source optical coherence tomographer (SS-OCT) and a referential Placido-topography combined OCT device in elderly cataract patients.

METHODS

Retrospective study including 103 eyes from 103 elderly patients scheduled for cataract surgery that were measured on the same day with a SS-OCT (Heidelberg Engineering, Germany) device and a Placido-topography combined OCT device (CSO, Italy). Anterior, total, and posterior corneal wavefront aberrations were evaluated for their mean differences and limits of agreement (LoA) via Bland-Altman plots. Vector analysis was additionally employed to compare corneal astigmatism measurements in dioptric vector space.

RESULTS

Mean differences of all corneal aberrometric parameters did not exceed 0.05 μm. Total corneal aberrations were not significantly different from 0 except for vertical coma (- 0.04 μm; P = 0.003), spherical aberration (- 0.01 μm, P < 0.001), and root mean square (RMS) higher-order aberration (HOA) (0.03 μm, P = 0.04). The 95% LoA for total corneal aberration parameters between both devices were - 0.46 to 0.42 μm for horizontal astigmatism, - 0.37 to 0.41 μm for oblique astigmatism, - 0.19 to 0.17 μm for oblique trefoil, - 0.33 to 0.25 μm for vertical coma, - 0.20 to 0.22 μm for horizontal coma, - 0.22 to 0.20 μm for horizontal trefoil, - 0.11 to 0.08 μm for spherical aberration, and - 0.22 to 0.28 μm for RMS HOA. Vector analysis revealed no statistically significant mean differences for anterior, total, and posterior corneal astigmatism in dioptric vector space.

CONCLUSION

In eyes undergoing cataract surgery with a regular elderly cornea, corneal wavefront analysis from the SS-OCT device showed functional equivalency to the reference device. Nevertheless, clinically relevant higher order aberration parameters should be interpreted with caution for surgical decision-making.

Agreement between Two Devices for Measuring Pupil Diameter in Patients Implanted with Multifocal Intraocular Lenses

The purpose of this study was to evaluate the agreement between three methods for measuring pupil size in patients implanted with multifocal intraocular lenses (MIOLs): Keratograph 5M (K5M), Pentacam AXL Wave (PW), and a simple hand ruler. Sixty-nine subjects implanted with MIOLs and measured at the three-month follow-up visit were included in this retrospective analysis. K5M and PW were used to measure the photopic (PP) and mesopic (MP) pupil sizes, and a hand ruler was used to measure the pupil under environmental light conditions (135 lux). The Bland-Altman method with its limits (LoAs) was used to assess the agreement. The median PP was 2.8, 2.95, and 3 mm for K5M, PW, and the ruler, respectively (p < 0.05). Differences in PP were statistically significant for all paired comparisons (p < 0.0005) except between PW and the ruler (p = 0.44). The LoAs for the difference in PP between K5M and PW was 0.63 mm. The mean difference for MP between K5M and PW was 0.04 mm (p = 0.34) with LoAs of 0.72 mm. MP measured with K5M and PW could be considered interchangeable, although a correction of -0.3 mm (IC95%: -0.23 to -0.39) should be applied to PP measured with PW to attain the K5M mean.

Analysis of Daily Visual Habits in a Presbyopic Population

Purpose

To evaluate and report the visual habits and requirements of a sample of presbyopic patients using an advanced sensor.

Methods

Transversal study collecting clinical data from 40 presbyopes candidates for presbyopia-correction intraocular lens (IOL) implantation with mean age of 61.0 years (43-80 years). A complete ophthalmological examination was performed in all patients including visual, refractive, an ocular biometric analysis. Furthermore, patients were instructed about the use of the Vivior Monitor system (Vivior AG, Zürich, Switzerland), which consists of a series of sensors attached to the rim of the patient's glasses that capture information about the visual behavior of the patient. This device was worn for a period of 36 hours or more. The data collected were transferred to a database and analyzed.

Results

Mean percentages of time dedicated to distance, intermediate, and near vision were 27.25 ± 11.93% (5-65%), 30.23 ± 9.36% (12-50%), and 42.53 ± 14.96% (13-78%), respectively. Mean percentages of time performing activities under photopic, mesopic, and scotopic conditions were 37.08 ± 23.20% (5-87%), 33.65 ± 13.84% (6-67%), and 29.28 ± 17.03% (4-65%). The percentage of time with digital screens ranged from 2% to 48%. Age was significantly correlated with the percentage of time dedicated to distance vision (r = 0.317, p=0.047) and to activities performed under photopic conditions (r = -0.344, p=0.030).

Conclusions

Distance and illumination conditions used to perform different daily life visual activities vary significantly among presbyopes, with a trend to the dedication of more time to intermediate and near visual activities performed under photopic and mesopic conditions. Data interpretation should be done with care until a proper validation of the device used.

Comparison of visual performance between two aspheric monofocal intraocular lens models

CLINICAL RELEVANCE

It is important to distinguish between visual acuity, optical quality and quality of vision when outcomes obtained with intraocular lenses are evaluated. These parameters, that includeobjective and subjective tests, should be assessed to obtain results that are not biased.

BACKGROUND

To assess the difference in visual and optical quality between two monofocal intraocular lens models.

METHODS

: This was a prospective, parallel and randomised clinical study conducted at Miranza IOA, a private clinic in Madrid, Spain. Sixty patients were implanted bilaterally, 30 per group, with two aspheric IOLs with induced spherical aberration of -0.27 μm for Group A and -0.20 μm for Group B. Visual outcomes obtained at 1 and 3 months after surgery included both uncorrected (UCVA) and corrected monocular distance visual acuity (DCVA), objective scattering index (OSI), modulation transfer function (MTF) cut-off, Strehl Ratio (SR), contrast sensitivity defocus curve (CSDC), intraocular lens spherical aberration (SA), and longitudinal chromatic aberration of the eye. Activity limitations in daily life were assessed using CatQuest-9SF questionnaire.

RESULTS

There were statistically significant differences for DCVA (0.04 LogMAR; p = .008) and SR (0.03; p = .003) between groups. Outcomes related to CSDC showed statistically significant differences for vergences between -0.50 D and +1.00 D (3 mm pupil) and for vergences of 0.00 D and +0.50 D (4.5 mm pupil) between groups. Overall, Group A showed better results regarding visual and optical quality, including a lower longitudinal chromatic aberration result in comparison to Group B. Patient satisfaction evaluated with CatQuest-9SF showed that Group A achieved better outcomes, although the differences were statistically significant only for the 'Reading text on television' item (p = 0.027).

CONCLUSIONS

Both intraocular lens models showed excellent quantity of vision, optical and visual quality as well as high patient satisfaction. Despite this, the the Group A model provided slightly better outcomes than the Group B model.

Effect of larger corneal spherical aberration in improving the near visual acuity of eyes implanted with the TECNIS Symfony

Purpose

To explore the effect of corneal spherical aberration on the visual acuity and visual quality of eyes implanted with the TECNIS Symfony intraocular lens (IOL).

Methods

A total of 43 patients with age-related cataract (60 eyes) undergoing phacoemulsification and TECNIS Symfony IOL implantation were enrolled in this study. The uncorrected distance (UDVA), intermediate (UIVA), near visual acuity (UNVA), corrected distance visual acuity (CDVA), contrast sensitivity, and ocular spherical aberration were recorded 3 months after surgery. Preoperative and postoperative corneal spherical aberration were also measured using the iTrace device. Objective scattering index (OSI), modulation transfer function cut-off frequency (MTF cut-off), and Strehl ratio (SR) were measured by the Optical Quality Analyzing System. Catquest-9SF questionnaire were applied too. Spearman's correlation analysis was used to evaluate the relationship between spherical aberration and visual quality parameters.

Results

Patients were satisfied with their postoperatively visual quality. And the postoperative logMAR UDVA, UIVA, UNVA, and CDVA was 0.05 ± 0.07, 0.04 ± 0.06, 0.15 ± 0.07, and 0.03 ± 0.05, respectively. The mean preoperative corneal spherical aberration was 0.24 ± 0.10 μm, which is the only factor influencing postoperatively UNVA, and it was negatively correlated with UNVA and glare contrast sensitivity under 18 cpd (cycle/degree, cpd) spatial frequency (r = -0.403, -0.300, -0.360; all P < 0.05). Additionally, the greater the residual spherical aberration of the cornea, the better the near vision after operation. The mean postoperative ocular spherical aberration was -0.03 ± 0.07 μm, it was not correlated with visual acuity, contrast sensitivity, and visual quality (all P > 0.05).

Conclusion

Preoperative positive spherical aberration can benefit near vision while decrease contrast sensitivities at high spatial frequencies when implanted with the TECNIS Symfony IOL.

Spherical aberration for expanding depth of focus

The increase in the depth of focus (DoF) for the treatment of presbyopia or cataracts is a topic of great interest for anterior segment surgeons who have seen how new surgical possibilities to achieve DoF enlargement have emerged. Nowadays, several technologies to extend the DoF are available, from corneal laser refractive surgery procedures in presbyopia to intraocular lens (IOL) implantation in cataract or refractive lens exchange. Some of these procedures are based on aspheric profiles, either in the cornea or in the IOL, which modulate the spherical aberration (SA) and, therefore, extend the light energy on different focal planes. The aim of this narrative review was to give an overall picture about the reasons why there is not a general solution persistent along time of SA induction to extend DoF, especially considering that SA depends on pupil diameter and this decreases with age.