Assessment of dysphotopsia in pseudophakic subjects with multifocal intraocular lenses

2022 Glenn A. Fry Award lecture: Enhancing clinical assessment for improved ophthalmic management

ABSTRACT

Detailed clinical assessment is critical to allow sensitive evaluation of the eye and its management. As technology advances, these assessment techniques can be adapted and refined to improve the detection of pathological changes of ocular tissue and their impact on visual function. Enhancements in optical medical devices including spectacle, contact, and intraocular lenses have allowed for a better understanding of the mechanism and amelioration of presbyopia and myopia control. Advancements in imaging technology have enabled improved quantification of the tear film and ocular surface, informing diagnosis and treatment strategies. Miniaturized electronics, large processing power, and in-built sensors in smartphones and tablets capacitate more portable assessment tools for clinicians, facilitate self-monitoring and treatment compliance, and aid communication with patients. This article gives an overview of how technology has been used in many areas of eye care to improve assessments and treatment and provides a snapshot of some of my studies validating and using technology to inform better evidence-based patient management.

Visual performance and subjective experience 3 months and 12 months after combined implantation of 2 new complementary continuous phase multifocal intraocular lenses

PURPOSE

To assess the 3-month and 12-month postoperative visual performance and subjective quality of vision (QoV) after combined implantation of complementary continuous phase multifocal intraocular lenses (IOLs).

SETTING

Private practice, United Kingdom.

DESIGN

Case series.

METHODS

The study enrolled 44 patients undergoing phacoemulsification with implantation of an Artis Symbiose Mid in the dominant eye and an Artis Symbiose Plus in the nondominant eye. Refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity, uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), electronic reading desk, and a QoV questionnaire were evaluated at 3 months and 12 months postoperatively.

RESULTS

The mean binocular UDVA was -0.06 ± 0.08 logMAR and -0.07 ± 0.06 logMAR at 3 months and 12 months ( P = .097), respectively. The mean binocular UIVA was 0.03 ± 0.13 logMAR and 0.03 ± 0.10 logMAR ( P = 1.0), respectively. The mean binocular UNVA was 0.07 ± 0.10 logMAR and 0.07 ± 0.08 logMAR ( P = .875), respectively. There was a significant improvement in QoV for both day and night between 3 and 12 months, with a significant reduction in halos at 12 months. Spectacle independence was reported in 93.2% of cases at 12 months.

CONCLUSIONS

The Artis Symbiose Mid and Plus IOL combined implantation provided an excellent range of uncorrected vision at 3 and 12 months. There was a significant improvement in QoV and less halos at 12 months. This IOL combination provided very high rates of complete spectacle independence.

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.

Combined finite-element and scalar diffraction simulation of light scattering on zone edges of diffractive intraocular lenses

A method has been developed to simulate the effects of scattered light on the image quality of optical systems. The coherent model is based on geometrical optics to take account of wavefront aberrations caused by lenses, applies finite-element calculation to solve Maxwell's equations around small scattering structures such as edges of diffractive surface zones, and uses scalar diffraction for free-space light propagation. The implementation is discussed in detail, and the operation is demonstrated on diffractive intraocular lenses. Point spread and modulation transfer functions are evaluated for an axial object point, taking account of scattered light as a function of slant angle and round radius of diffractive zone edges. Results show that, at a distance of ±200 Airy radius (i.e., ±2.1∘) from the axis, scattered irradiance is about 5 times more than without considering edge effects. Optimum round radius was found to be 7% of the step height, which agrees with simple geometrical optical estimations.

Orientation of the intermediate-vision zone of rotationally asymmetric multifocal intraocular lenses and photic phenomena

PURPOSE

To evaluate the association between the orientation of the intermediate-vision zone and postoperative photic phenomena in eyes implanted with rotationally asymmetric multifocal intraocular lenses with + 1.5 diopters near addition.

STUDY DESIGN

Retrospective comparative case series.

METHODS

We performed the photic phenomena test (PPT) to quantitatively evaluate photic phenomena at 1-3 months after cataract surgery with Lentis Comfort LS-313 MF15 or Lentis Comfort Toric LS-313 MF15T insertion (Oculentis; Santen Pharmaceutical). In cases of bilateral surgeries, only the right eye was included in the analysis. We also conducted a questionnaire survey about the photic phenomena.

RESULTS

The study included 96 eyes from 96 patients. The intermediate-vision zones of 44, 19, 19, and 14 eyes were fixed in the inferior, superior, nasal, and temporal directions, respectively. The measured PPT values for halo, glare, and starburst were equivalent in all the fixed directions. Eighty-four eyes (87.5%) perceived a triangle-shaped halo, and the direction of fixation for the intermediate-vision zone and the extension direction of this photic phenomenon were consistent in 94.0% of the eyes. Less than 10% of the patients responded "moderate" or "severe" for the triangle-shaped halo, glare, and starburst in fixed directions with low frequency in the questionnaire.

CONCLUSION

No qualitative or quantitative difference was found in photic phenomena in eyes implanted with the LS-313 MF15 or the MF15T regardless of the fixation direction. Our study revealed that many patients were aware of a triangle-shaped halo extending in the direction of the intermediate-vision zone.

Visual Performance of Eyes with Residual Refractive Errors after Implantation of an Extended Vision Intraocular Lens

Background

To analyze the tolerance on distance vision of different combined residual astigmatic situations in patients implanted with a novel wavefront shaping extended depth of focus (EDoF) intraocular lens (IOL).

Methods

The study included patients implanted with the Acrysof® IQ Vivity® IOL. Uncorrected (UDVA) and corrected distance visual acuity (CDVA) were measured three months after surgery, considering CDVA as the reference situation of the study. Distance VA was also measured in different refractive situations: (A) with 0.50 diopters (D) of positive (myopization) and negative (hyperopization) defocus and (B) with a residual mixed astigmatic refraction induced by adding a combination of -0.25 D spherical and 0.50 D cylindrical lenses placed in vertical (against the rule-ATR), oblique, and horizontal (with the rule-WTR) positions.

Results

The study included 30 eyes of 30 patients. UDVA and CDVA were -0.04 ± 0.05 and -0.05 ± 0.05 logMAR, respectively. VA values with +0.50 D and -0.50 D of defocus were 0.01 ± 0.06 and 0.00 ± 0.04 logMAR, respectively. VA was better with distance correction (p < 0.001) and no differences were found between the myopic and the hyperopic situations (p=0.09). Distance VA for the ATR, oblique, and WTR astigmatic situations was 0.01 ± 0.05, 0.01 ± 0.06, and 0.01 ± 0.04 logMAR, respectively. VA was better for the reference situation (p < 0.001) and no differences were found among the three astigmatic situations (p=0.21).

Conclusions

Low residual defocus and mixed astigmatic errors, regardless of its orientation, seem to be tolerated by patients implanted with the studied EDoF IOL. This trial is registered with NCT05392998. Registered 26 May 2022-Retrospectively registered.

Astigmatism Tolerance and Visual Outcomes After Bilateral Implantation of a Hybrid Continuous Transitional Focus IOL

PURPOSE

To evaluate the astigmatism tolerance and the visual outcomes after implantation of a premium intraocular lens (IOL) with a continuous transitional focus (Precizon Presbyopic; Ophtec BV) in pseudophakic presbyopia correction.

METHODS

This prospective study enrolled 20 patients (40 eyes) after bilateral phacoemulsification and IOL implantation. Corrected and uncorrected visual acuities at 4 m and 80, 67, and 40 cm (CDVA, UDVA, DCI80VA, UI80VA, DCI67VA, UI67VA, DCNVA, and UNVA), astigmatic and spheric defocus curve, mean reading speed (MRS), critical print size (CPS), contrast sensitivity, optical aberrations (modulation transfer function [MTF] cut-off, Strehl ratio, and higher order aberration root mean square [HOA RMS]), objective halometry, and National Eye Institute Refractive Error Quality of Life Instrument 42 [NEI RQL-42] questionnaire were evaluated 3 months after surgery.

RESULTS

Astigmatic defocus curves revealed a tolerance up to -1.00 and +0.75 diopters (D) for with-the-rule astigmatism, and up to -1.00 and +1.00 D for against-the-rule astigmatism. Binocular spheric defocus curve showed that the mean visual acuity was greater than 0.15 logMAR from 1.00 to -1.00 D. MRS, CPS, MTF cut-off, Strehl ratio, and HOA RMS were 116.97 ± 21.94 words/min, 0.45 ± 0.06 logRDA, 20.03 ± 4.86 cycles/degree, 0.11 ± 0.07, and 0.28 ± 0.09, respectively. Contrast sensitivity was within the normal range for all tested light conditions. The NEI RQL-42 evidenced high subjective satisfaction for all subscales, especially for far vision, activity limitations, dependence on correction, suboptimal correction, appearance, and satisfaction with correction.

CONCLUSIONS

The Precizon Presbyopic IOL allows good astigmatism tolerance and both objective and subjective high quality of vision. [J Refract Surg. 2023;39(1):33-39.].

Dysphotopsias or Unwanted Visual Phenomena after Cataract Surgery

Dysphotopsias are unwanted visual phenomena that occur after cataract surgery. They represent some of the most common reasons for patient dissatisfaction after uncomplicated surgery for cataract phacoemulsification with in-the-bag intraocular lens (IOL) implantation. Depending on the form of the optical phenomenon and the effect it poses on vision, dysphotopsias are divided into positive and negative type. Positive dysphotopsias are usually described by patients as glare, light streaks, starbursts, light arcs, rings, haloes, or flashes of light. Negative dysphotopsias are manifested as an arc-shaped shadow or line usually located in the temporal part of the visual field, similar to a temporal scotoma. In addition to their different clinical manifestations, positive and negative dysphotopsia also have different risk factors. Even though up to 67% of patients may experience positive dysphotopsia immediately after surgery, only 2.2% of the cases have persistent symptoms up to a year postoperatively. Surgical intervention may be indicated in 0.07% of cases. The incidence of negative dysphotopsias is up to 26% of all patients; however, by one year postoperatively, the symptoms usually persist in 0.13 to 3% of patients. For both types of dysphotopsia, preoperative patients' education, accurate preoperative diagnostics, and use of an appropriate IOL design and material is mandatory. Despite all these measures, dysphotopsias may occur, and when noninvasive measures fail to improve symptoms, a surgical approach may be considered.

Monofocal intraocular lens with enhanced intermediate function as substitute for multifocal intraocular lens in positive dysphotopsia

Purpose

To present a case of a 62-year-old patient implanted with multifocal intraocular lenses (IOLs) who underwent a bilateral IOL exchange due to positive dysphotopsia. In an attempt to reduce the symptoms and compensate for the loss of multifocality, we implanted an aspheric monofocal IOL with enhanced intermediate function in one eye and a spherical monofocal IOL in the other eye.

Observations

The patient presented with complaints of halo and glare, measured with a simulator, following the implantation of segmented multifocal IOLs two years earlier. The uncorrected distance visual acuity (UDVA) was 20/20 in both eyes. Before presentation at our clinic, a laser capsulotomy had been performed on the right eye. We proceeded with a bilateral IOL exchange. Because of capsular insufficiency in the right eye, we implanted a spherical monofocal three-piece IOL in the ciliary sulcus with optic capture. In the left eye, we used a monofocal IOL with an enhanced intermediate function. Two weeks postoperatively, UDVA (monocularly) was 20/20 in OD and OS, the uncorrected intermediate visual acuity (UIVA) was 20/32, and the uncorrected near visual acuity (UNVA) was 20/50. Binocularly, UDVA was 20/20, UIVA was 20/25 and UNVA was 20/25. The patient reported a marked decrease in halos and glare.

Conclusions and importance

When planning IOL exchange surgery, in cases of intolerance to multifocal IOLs, the clinician should consider the dilemma of loss of multifocality. Recent developments in monofocal IOL technology present new options to improve visual function in cases of multifocal IOL explantation.

Twelve-Month Clinical Outcomes After Implantation of a Novel, Modular, Anterior Shape-Changing Fluid Optic Intraocular Lens

PURPOSE

To report the initial safety and effectiveness profile for an anterior shape-changing, modular IOL, Juvene (JIOL), for the treatment of aphakia and presbyopia after removal of the natural crystalline lens due to cataract.

SETTING

Two private practices in Monterrey and Tijuana, Mexico.

DESIGN

Exploratory, prospective, multi-center, open-label, non-comparative clinical trial.

METHODS

A convenience sample of subjects aged 50-80 years with planned cataract surgery were recruited to undergo unilateral or bilateral implantation with the JIOL. Subjects were required to complete an informed consent and be able to dilate to at least 6.0 mm pharmacologically, be in good overall health, and have no significant eye health history to qualify. Visual acuities, defocus curves, and contrast sensitivity were measured for all subjects 12 months postoperatively.

RESULTS

Fifty-one of 58 eyes completed the 12-month visit. Intraoperative complication rates were extremely low (N=1; missed base lens tab). The most frequent adverse events (AE) were prolonged inflammation (N=6) and cystoid macular edema (N=4); all AEs were resolved without sequelae by the 12-month visit. Mean monocular logMAR corrected distance visual acuity (CDVA), distance-corrected intermediate (DCIVA) and near (DCNVA) were 0.01, 0.08, and 0.24, respectively. Defocus testing showed VA > 20/40 from approximately +1.00 D through -2.00 D. Binocular implantation (n=16) provided superior performance over monocular implantation.

CONCLUSIONS

The Juvene IOL offers a novel solution to treat presbyopia, providing clear functional vision performance across a range of distances with an acceptable initial safety profile.

Extended Depth of Focus Versus Monofocal IOLs in Patients With High Myopia: Objective and Subjective Visual Outcomes

PURPOSE

To compare the objective and subjective outcomes between the extended depth of focus (EDOF) Mini Well intraocular lens (IOL) and the aspheric monofocal Mini-4-Ready IOL (both SIFI S.p.A.) in patients with high myopia.

METHODS

In this prospective comparative study, 40 patients with high myopia (axial length ≥ 26 mm) were enrolled: 20 patients were bilaterally implanted with the EDOF Mini Well IOL (EDOF group) and 20 patients were bilaterally implanted with the Mini-4-Ready IOL (monofocal group). Three-month follow-up data included corrected and uncorrected distance visual acuity at 4 m and 80, 67, and 40 cm, defocus curves, subjective and objective contrast sensitivity, objective optical quality (calculated with Optical Quality Analysis System; Visiometrics SL), halometry, and reading performance. Subjective visual quality was evaluated with National Eye Institute Refractive Error Quality of Life Instrument 42 scores.

RESULTS

All visual acuities were significantly better in the EDOF group (P ⩽ .04) except monocular and binocular uncorrected and corrected distance visual acuities for distance (P ≥ .50). Defocus curves for myopic and hyperopic values were better in the EDOF group (P ⩽ .05), apart from +0.50 to -0.50 D (P ≥ .16). Contrast sensitivity curves was worse in the EDOF group in the mesopic-with-glare condition (P ⩽ .04). No differences were found in halometric values (P ≥ .15) and OQAS outcomes (P ≥ .47). National Eye Institute Refractive Error Quality of Life Instrument 42 subscale scores were better for expectation, near vision, activity limitations, and dependence on correction in the EDOF group (P ⩽ .04).

CONCLUSIONS

Intermediate and near visual acuities were better in the EDOF group than in the monofocal group, with a comparable visual quality index between groups. [J Refract Surg. 2022;38(3):158-166.].

Preliminary Clinical Outcomes of a New Enhanced Depth of Focus Intraocular Lens

Purpose

To assess the preliminary clinical outcomes and patient satisfaction of the new enhanced depth of focus (EDOF) LuxSmart™ intraocular lens IOL and to compare with a conventional monofocal IOL (Akreos™) in patients who had undergone bilateral cataract surgery.

Methods

Twelve patients underwent bilateral LuxSmart IOL implantation, and twelve underwent bilateral Akreos IOL implantation. Best-corrected distance (CDVA) and uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA) at 66cm, uncorrected near visual acuity (UNVA) at 40cm and defocus curve were assessed. Patients-reported visual function was inquired by Catquest-9SF. The presence of photic phenomena was evaluated. A p-value lower than 0.05 was considered for statistical significance.

Results

The mean IOL power was +21.90D in LuxSmart group and +22.30D in Akreos. Monocular UDVA (p = 0.32) and CDVA (p = 0.52) did not differ between groups. The average binocular UIVA (0.18 ± 0.12 logMAR vs. 0.30 ± 0.13 logMAR, p < 0.001) and UNVA (0.38 ± 0.14 logMAR vs. 0.44 ± 0.17 logMAR, p = 0.02) were higher in LuxSmart IOL group. No patients reported disabling photic phenomena in either group.

Conclusion

This study shows that new LuxSmart EDOF IOL achieved higher performance for intermediate and near vision compared with a conventional monofocal IOL, without increasing the risk of dysphotopsias. LuxSmart may be an attractive and safe option for patients who desire spectacle independence for distance and intermediate vision after cataract surgery.

Comparison of Clinical Outcomes, Visual Quality and Visual Function of Two Presbyopia-Correcting Intraocular Lenses Made from the Same Material, but with Different Design and Optics

This semi-prospective, parallel, comparative investigation evaluated the clinical outcomes and quality of vision (contrast sensitivity, visual function, dysphotopsia, spectacle use, overall satisfaction) after mono- or bilateral implantation of two presbyopia-correcting intraocular lenses (IOL)—the Liberty^® 677MY or the AT LISA^® tri 839M—in 50 eyes of 25 cataract patients. Clinical outcomes were assessed 3 and 12 months postoperatively. Eighty-nine percent of eyes implanted with the Liberty IOL and 59% of eyes implanted with the AT LISA IOL achieved a refractive outcome ±0.5 diopters of the target (emmetropia). Refractive outcomes were stable with both lenses. The proportions of eyes with 20/20 uncorrected distance visual acuity (UDVA) and 20/20 uncorrected near visual acuity (UNVA) were higher in the Liberty group than in the AT LISA group (UDVA: 56% vs. 41%; UNVA: 83% vs. 66%). Optical quality assessment results were comparable for the two IOLs. Superior photopic contrast sensitivity was found with the Liberty lens. The rate of Nd:YAG capsulotomy at the 12-month follow-up was 16.7% in the Liberty group and 40.6% for the AT LISA IOL. Considering that both lenses are made from the same material, we propose that the noted differences in clinical outcomes may derive from differences in design and optical surface between the two IOLs.

Clinical Outcomes With a New Continuous Range of Vision Presbyopia-Correcting Intraocular Lens

PURPOSE

To evaluate the clinical outcomes including patient-reported outcome measures in a sample of eyes undergoing bilateral cataract surgery with implantation of a new model of presbyopia-correcting intraocular lens (IOL).

METHODS

This non-randomized prospective case series enrolled 206 eyes of 103 patients undergoing phacoemulsification cataract surgery with bilateral implantation of the TECNIS Synergy IOL (Johnson & Johnson Vision). High and low contrast visual acuity, refractive, defocus curve, and patient-reported visual performance (Catquest-9SF questionnaire) outcomes were evaluated during a 3-month follow-up.

RESULTS

A total of 96.1% (99 of 103) and 91.3% (94 of 103) of patients achieved binocular postoperative uncorrected distance (UDVA) and near visual acuity (UNVA) of 0.00 logMAR (20/20), respectively. Mean postoperative mesopic UNVA for both eyes was 0.14 ± 0.03 logMAR. Likewise, mean binocular UDVA and UNVA were 0.00 ± 0.03 and 0.04 ± 0.02 logMAR. An almost flat mean defocus curve was obtained, with visual acuities between 0.00 and 0.10 logMAR for most defocus levels in both eyes. A reduction of contrast led to a limited but statistically significant change in UNVA in both eyes (P < .001). The Rasch calibrated scoring of item 2 and the Rasch calibrated mean score of the Catquest-9SF questionnaire increased significantly with surgery (P < .001).

CONCLUSIONS

This new presbyopia-correcting IOL provides a continuous range of functional focus, with a limited deterioration under mesopic conditions, which is perceived as a satisfactory outcome by the patient if proper patient selection is performed. [J Refract Surg. 2021;37(4):256-262.].

Predictors of Photic Phenomena with a Trifocal IOL

Aim

To assess predictive factors associated with glares and halos in patients undergoing cataract surgery with PanOptix trifocal IOL implantation.

Methods

Single-center retrospective study. One hundred and forty eyes from 70 patients with cataract were bilaterally implanted with a trifocal PanOptix aspherical diffractive lens between 2017 and 2019 and followed-up for six months. All patients were evaluated for refraction, corneal topography, and aberrometry pre- and post-operatively. Patients were assessed at 1 day, 6 days, 1 and 6 months after surgery. One and six months post-operatively patients were asked to complete a satisfaction questionnaire that included photic phenomena assessment. Main outcome measures were photic phenomena at 1 and 6 months of follow-up. Predictors of photic phenomena at 1 and 6 months were also analyzed.

Results

A higher corneal coma was associated with more mild halos at 6 months with no association regarding other degrees of severity. The lower the age the higher the glare or halos, the higher the lens thickness and the lower the anterior chamber depth or chord µ the less halos at 1 month. A significant proportion of patients had more none/mild compared to moderate/severe glare and halos both at 1 and 6 months post-operatively. Baseline BCVA was the only predictor of halos at 1 month and glare and halos at 6 months post-surgery.

Conclusion

On multivariate regression analyses, the only predictor of photic phenomena was baseline visual acuity, suggesting that patients that have a better visual acuity before surgery are more demanding regarding visual outcomes after surgery.

Extended Depth of Focus Versus Monofocal IOLs: Objective and Subjective Visual Outcomes

PURPOSE

To evaluate and compare the objective and subjective outcomes between bilateral implantation of the extended depth of focus (EDOF) Mini Well intraocular lens (IOL) and the aspheric monofocal Mini-4-Ready IOL (both SIFI S.p.A., Catania, Italy).

METHODS

This prospective comparative study included 25 patients (50 eyes) bilaterally implanted with an EDOF Mini Well IOL (EDOF group) and 25 patients (50 eyes) bilaterally implanted with a Mini-4-Ready IOL (monofocal group). Three-month follow-up data included corrected and uncorrected distance visual acuity at 4 m and 80, 67, and 40 cm. Defocus curves, subjective and objective contrast sensitivity, and objective optical quality (modulation transfer function cutoff and Strehl ratio calculated with Optical Quality Analysis System [OQAS]; Visiometrics SL, Terrassa, Spain), halometry, and reading performance were measured. Subjective visual quality was evaluated based on National Eye Institute Refractive Error Quality of Life Instrument 42 (NEI RQL-42) scores.

RESULTS

Postoperative uncorrected and corrected monocular and binocular intermediate and near visual acuity was significantly better in the EDOF group (P < .001). No differences were observed for distance visual acuity (P ⩾ .312). Defocus curve outcomes for myopic values were better in the EDOF group (P < .001). No significant differences were found in hyperopic (obtained in steps of +0.50 diopters [D] from emmetropia to 1.50 D) values (P ⩾ .095), contrast sensitivity curves (P ⩾ .087), or OQAS outcomes (P ⩾ .138). Halometric values were significantly better in the monofocal group (P < .05). There was a correlation between mean keratometry values and intermediate/near visual acuity. Significantly better NEI RQL-42 subscale scores for near vision, far vision, activity limitations, glare, dependence on correction, and suboptimal correction were noted in the EDOF group (P < .05).

CONCLUSIONS

Intermediate and near visual acuity was better after EDOF IOL than after aspheric monofocal IOL implantation while maintaining similar levels of visual quality, except for halo perception. [J Refract Surg. 2020;36(4):214-222.].

Measures of visual disturbance in patients receiving extended depth-of-focus or trifocal intraocular lenses

The degree of visual disturbance associated with a particular model of intraocular lens (IOL) depends on several factors, including IOL optic, material, and mechanics. Characterization of visual disturbance profiles is paramount for informing clinical IOL selection. Although many studies evaluating presbyopia-correcting IOLs include subjective assessment of visual symptoms, the types of patient-reported outcome measures (PROMs) used to capture these outcomes are inconsistent across studies, complicating data contextualization. Furthermore, some tools produce more meaningful results than others. This review presents a discussion on the scientific literature published on the subjective and semiobjective (halo and glare simulator, light-distortion analyzer, vision monitor, and halometers) methods used to assess visual disturbances in patients implanted with trifocal or extended depth-of-focus IOLs, highlighting their advantages and limitations. It underscores the importance of between-study comparisons and the need for standardized PROMs in clinical IOL research to provide more accurate information for IOL selection.

The effects of light scatter when using a photochromic vs. non-photochromic contact lens

PURPOSE

To assess the visual effects of wearing both an activated and an inactivated photochromic contact lens, with a direct comparison to a non-photochromic contact lens worn in the fellow eye. This study focused on the visual effects of scatter quantified as the minimum distance between two points of light, and the diameter of the halo and starbursts that surround a bright white point source.

METHODS

60 subjects (aged 18-65 years) were measured in a contralateral design where lens type was randomly assigned, one type to each eye. During activated testing, all visual measures of both study lenses were made while each eye was illuminated by a violet (λ_max=365, half bandwidth 20nm) activator, which caused steady-state activation of the photochromic lens during the period of testing. Two-point thresholds were determined by measuring the minimum distance between two points of broadband xenon light. Glare geometry was measured using an aperture (∼4mm) that created a bright point source of light 45 inches from the plane of the eye. Between the point source and subject, a centering precision caliper was used to measure lateral spread of halos (diffusion around the source) and visual spokes. The head was stabilized using an adjustable head-rest assembly and the eye was aligned and monitored with a bore camera.

RESULTS

Compared to the non-photochromic lens, and based on the stimulus conditions used in these measurements, the activated and inactivated photochromic lens reduced the light spread using the two-point threshold technique by 32% and 19% respectively; the diameter of the halos were reduced by 44% and 16% respectively; and the spokes were narrowed by 39% and 20% respectively. Based on 95% confidence interval testing, these effects were all statistically significant (p<0.05).

CONCLUSIONS

These results are consistent with previous data showing that soft contact lenses with a photochromic additive can improve many aspects of visual function, consistent with their level or activation. Our past data focused on visual function under bright light conditions (e.g., glare disability, discomfort, photostress recovery and chromatic contrast) with an activated photochromic. In this study, we found differences even in the inactivated state, using less intense stimuli (10cd/m² at the source). This suggests that the photochromic lens improves the effects of light scatter even at lower luminance.

Evaluation of retinal light scattering, visual acuity, refraction and subjective satisfaction in patients after Acrysof IQ PanOptix intraocular lens implantation

AIM

To evaluate the retinal light scattering, visual acuity, refraction and subjective satisfaction in patients after implantation of Acrysof IQ PanOptix intraocular lens.

METHODS

Our group included 32 eyes of 21 patients who underwent cataract surgery or refractive lensectomy with Acrysof IQ PanOptix multifocal intraocular lens implantation at the Ophthalmology Clinic of Faculty Hospital Hradec Králové during the time from September 2015 to December 2017. The observed parameters were visual acuity, subjective refraction, retinal light scattering and patient subjective satisfaction. Preoperative refractive values and visual acuity values were compared with results obtained on day 1, 1 month and at an average of 27 months postoperatively. Subjective satisfaction and degree of light scattering on the retina were evaluated at the end of the follow-up period.

RESULTS

Preoperative, uncorrected distant visual acuity improved from an average of 0,51 ± 0,29 (expressed in decimal values) to 0,94 ± 0,10 at the end of the follow-up period. Preoperative best-corrected distance visual acuity improved from an average of 0,95 ± 0,19 to 1,00 ± 0,09 at the end of the follow-up period. The mean value of preoperative uncorrected near visual acuity was 8,29 ± 4,93 of Jaeger charts, the mean value of uncorrected near visual acuity at the end of the follow-up period was 1,00 ± 0 of Jaeger charts. Subjective satisfaction was assessed using a standardized VF-14 questionnaire at least 1 year after surgery (mean follow-up of 27 months). Retinal light scattering was examined using an Oculus C-Quant instrument. The retinal light scattering value in our sample was 1,12 ± 0,19. In only 6 eyes of 4 patients, the resulting value was outside the physiological range used for eyes with lens crystallina Conclusion: The value of light scattering on the retina is a factor affecting the degree of sensitivity to glare after implantation of multifocal intraocular lenses. In our group, we observed a deviation from the physiological range of retinal light scattering in only 6 eyes of 4 patients, but this did not lead to a deterioration in subjective postoperative satisfaction.

Patient-Reported Outcomes/Satisfaction and Spectacle Independence with Blended or Bilateral Multifocal Intraocular Lenses in Cataract Surgery

Purpose

To compare patient-reported outcomes (PROs) and satisfaction results after multifocal intraocular lens (IOL) implantation in three groups: two receiving bilateral implantation of the same IOL and another undergoing blended vision with two different multifocal IOLs.

Patients and methods

A questionnaire was administered to patients who had undergone uncomplicated cataract surgery and 2 months of follow-up: the first group underwent bilateral implantation with Alcon’s AcrySof ReSTOR 3.0 lens (“3.0/3.0,” n=78); the second group underwent implantation with the ReSTOR ActiveFocus 2.5 or the ReSTOR ActiveFocus 2.5 toric lens (“2.5 mini-monovision,” n=102); and the third group underwent implantation with the ReSTOR 2.5 lens in the dominant eye and the ReSTOR 3.0 lens in the non-dominant eye (“2.5/3.0,” n=89).

Results

Overall PROs and satisfaction was similar among the groups. Refractive outcomes and accuracy were similar among the groups, but the 2.5 mini-monovision group reported better intermediate vision. Refractive outcome differences were not meaningful among the groups and were not a differentiating factor in PROs. Substantially fewer patients in the 2.5 mini-monovision group noticed glare and halo compared with the 3.0/3.0 group (P<0.0001, chi-square test). No new safety concerns were reported.

Conclusion

The 2.5 mini-monovision results in a higher percentage of patients being satisfied with intermediate vision than bilateral ReSTOR 3.0 or blended vision with ReSTOR 2.5/3.0 implants, but overall PRO differences were not statistically significant.

Light distortion of soft multifocal contact lenses with different pupil size and shape

PURPOSE

To study the light distortion effects of soft multifocal contact lenses and the influence of different pupil size and shape.

METHODS

A total of 14 eyes of 7 healthy contact lens users (mean age 28.6 ± 8.5 years) were recruited. The "Light Disturbance Analyser" device was employed for light characterization. The selected lenses were the monthly disposable "Biofinity multifocal" (CooperVision, CA, USA), both centre-distance and centre-near designs (addition power +2.50 D). Two circular pupils of 3 mm and 5 mm of diameter, and an elliptical shape (3 horizontal and 5 vertical mm) were used. Metrics such as the light distortion index (LDI), best-fit circle radius and its irregularity were analysed, among others.

RESULTS

The LDI was generally higher with multifocal lenses, varying from 3.7 ± 0.3 % of the single vision lens to 6.1 ± 3.3 % of the multifocal centre-distance design and the 5-mm pupil. Larger pupils gave higher LDI values, changing from 4.5 ± 2.0 % (3 mm) to 6.1 ± 3.3 % (5 mm) with the centre-distance design. The elliptical pupil produced the largest discrepancy in the distortion size between the vertical and horizontal directions. The centre-distance and centre-near designs behaved similarly in terms of light distortion.

CONCLUSIONS

The multifocal contact lenses of the study increased light distortion effects under low light conditions, especially with larger pupils. The shape of the distortion pattern is associated with the shape of the pupil. It seems that not all, but a big percentage of light distortion would be produced by the presence of the out-of-focus images given by a multifocal lens.

Cost-Effectiveness Analysis of Multifocal Intraocular Lenses Compared to Monofocal Intraocular Lenses in Cataract Surgery

PURPOSE

To determine the cost-effectiveness of multifocal intraocular lenses (IOLs) compared to that of monofocal IOLs from a societal and health care sector perspective.

DESIGN

Cost-effectiveness analysis.

METHODS

A Markov model was constructed that simulated patients who received either multifocal or monofocal IOLs during cataract surgery. Postoperatively, patients could experience spectacle dependence, glare, and haloes. Cost-effectiveness was determined by measuring the incremental cost-effectiveness ratio (ICER) as the incremental cost in dollars per quality-adjusted life year (QALY) gained. Treatments with an ICER below the standard willingness-to-pay (WTP) threshold of $50,000/QALY were considered cost effective. One-way sensitivity analyses and probabilistic sensitivity analyses were used to evaluate model sensitivity to cost, utilities, and other model inputs.

RESULTS

Multifocal IOLs were associated with a 0.71 QALY increase at an increased cost of $3,415 compared with monofocal IOLs, leading to an ICER of $4,805/QALY from the societal and health care sector perspectives. The cost-effectiveness model was most sensitive to patient age, probability of spectacle dependence with multifocal IOLs and monofocal IOLs, and the disutility of glasses. Probabilistic sensitivity analysis found multifocal IOLs to be the cost-effective option compared with monofocal IOLs 99.9% of the time at a WTP threshold of $50,000/QALY.

CONCLUSIONS

From a societal and health care perspective, multifocal IOLs would be considered a cost-effective strategy compared to monofocal IOLs for patients who desire a higher chance to be spectacle-free. However, more studies need to be conducted to further evaluate the efficacy of multifocal IOLs.

Spectacle Independence And Patient Satisfaction With Pseudophakic Mini-Monovision Using Aberration-Free Intraocular Lens

Purpose

To assess spectacle independence and patient satisfaction with pseudophakic mini-monovision in patients undergoing routine bilateral cataract surgery with implantation of an aspherical aberration-free intraocular lens (Akreos AO, Bausch and Lomb, USA).

Methods

This study was a retrospective analysis that included 60 eyes of 30 consecutive patients between 2016 and 2018. The included patients had undergone sequential bilateral routine phacoemulsification after choosing the mini-monovision option. Test for ocular dominance was done using a sighting test. Emmetropia was aimed at in the dominant eye, while in the non-dominant eye the aim was myopia between -1 D and -1.5 D. The main outcome parameters were uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), and data reported from a questionnaire given to the patients at 3 months postoperative visit.

Results

The study included 60 eyes of 30 consecutive patients. The mean binocular UDVA was 0.09 ± 0.07 logMAR. Twenty-eight patients (93%) had binocular UDVA of 0.2 logMAR or better. The mean binocular uncorrected intermediate distance visual acuity (at 65 cm) was 0.16 ± 0.12 logMAR. Twenty-six patients (87%) had binocular uncorrected intermediate distance visual acuity of 0.2 logMAR or better. The mean binocular UNVA (at 35 cm) was 0.30 ± 0.21 logMAR. Fourteen patients (47%) had binocular UNVA of 0.2 logMAR or better. The patients score in the questionnaire was significantly higher in far and intermediate vision than near vision (p = 0.022). The patients score was significantly higher in day vision than night vision (p = 0.031). The mean overall patient satisfaction was good (9.1 ± 1.54). Twenty-eight patients (93%) reported high spectacle independence for far vision (score 8, 9, or 10).

Conclusion

Pseudophakic mini-monovision shows good results for spectacle independence and high patient satisfaction. It is a safe and inexpensive option after bilateral cataract surgery for correcting distance and intermediate vision. However, it might show lower results with near and night vision which is generally acceptable. Using aberration-free monofocal IOL allows for the residual normal positive corneal aberration that may augment the effect of monovision.

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.

Simulated images of intraocular lens negative dysphotopsia and visual phenomena

Simulated images were generated using an extended source to illustrate peripheral dark shadows in pseudophakic eye models. The shadows are a consequence of the intraocular lens being much smaller than the natural crystalline lens, which limits the extent of the focused image. Compensation is made for the cosine intensity falloff due to pupil obliquity, and the images are envisaged as being displayed on polar plots of visual angle corresponding to approximate retinal locations. Additional retinal illumination from light missing the lens reduces the shadow effect as the pupil diameter increases, in agreement with clinical observations. Lenses with two different cross-sectional profiles were evaluated, which both have shadows at about 85°, but with different characteristics. The iris thickness was found to affect the shadows by occluding peripheral rays. Images were also generated for a point source with a 5 mm pupil, where a double image is created for visual angles as low as 50°, which may contribute to visual phenomena at night. This type of modeling may help with patient evaluations and discussions.

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.