Comparison of ocular straylight after implantation of multifocal intraocular lenses

Impact and visualization of scotomatic glare in central visual field perception

Strong monochromatic point light sources such as Light Emitting Diodes (LED) or Lasers have been increasingly used in recent decades. This also raises the risk of misuse resulting in glare phenomena and associated visual impairment. The objective of this prospective and partially blinded study was the visualization and characterization of glare-induced scotomas in visual field by dazzling with monochromatic point light sources in terms of disability and discomfort glare. Automated threshold perimetry under dazzling by LED exposure at three different wavelengths (470, 530 and 625 nm) and four different intensities (25, 50, 75, and 100%) was performed in 31 healthy subjects resulting in 434 visual field examinations. Visual disability was measured by sensitivity loss in the central 30°as compared to unexposed controls and visualized by reconstruction of mean visual fields for each group via backward-calculation. Psychological glare was assessed by subsequent questionnaire and evaluated based on the de Boer rating scale of discomfort. Increasing glare intensities resulted in a significant decrease in mean sensitivity for all wavelengths tested, paralleled by an increase of discomfort glare. The loss of sensitivity was scattered over all quadrants with accentuation of the corresponding mean exposure area. Reconstructed visual fields confirmed visual impairment in all quadrants at an extent of at least 30°. We conclude that even off-axis light exposure may affect central visual field perception. Our results extend previous research on directed light interaction and contribute in explaining its incapacitating impact on human performance.

Changes in straylight after cataract surgery

PURPOSE

To investigate straylight in the immediate postoperative period after cataract surgery.

SETTING

Amphia Hospital, Breda, the Netherlands.

DESIGN

Prospective, comparative, single-arm, single-center, single-surgeon study.

METHODS

Patients underwent cataract surgery on both eyes. 1 eye was randomly selected for implantation with a Clareon CNA0T0 intraocular lens (IOL); the fellow eye received a Vivinex XY1 IOL. Straylight was measured with the C-Quant straylight meter.

RESULTS

25 patients were included. Preoperatively, 1 day, 1 week, 1 month, and 3 months postoperatively, eyes with a CNA0T0 IOL had straylight levels (mean ± SD) of 1.48 ± 0.23, 1.26 ± 0.20, 1.06 ± 0.19, 1.11 ± 0.25, and 1.09 ± 0.20 log(s), respectively. For eyes with an XY1 IOL, these values were 1.48 ± 0.21, 1.41 ± 0.41, 1.10 ± 0.20, 1.13 ± 0.20, and 1.16 ± 0.20 log(s), respectively. From 1 week postoperatively, straylight values did not change (1 week vs 3 months: P = .40 and P = .14 and 1 month vs 3 months: P = .74 and P = .50 for CNA0T0 and XY1, respectively). The Pearson correlation coefficient for straylight values between the 2 eyes of individual subjects was 0.80 at 3 months.

CONCLUSIONS

Straylight levels can be considered stable 1 week after cataract surgery. We believe it is safe to use straylight measurements 1 month postoperatively for clinical trials. Straylight is highly correlated between the 2 eyes of an individual postoperatively.

Approach to the design of different types of intraocular lenses based on an improved sinusoidal profile

An approach is presented to design different types of Intraocular lenses (IOLs) with a uniform optimization algorithm. An improved sinusoidal phase function is proposed to realize adjustable energy allocations in different diffractive orders according to the design aims. By setting specific optimization goals, different types of IOLs can be designed using the same optimization algorithm. With this method, bifocal, trifocal, extended-depth-of-focus (EDoF), and mono-EDoF IOLs are successfully designed and their optical performance under monochromatic and polychromatic light is evaluated and compared with their commercial counterparts. The result shows that most of the designed IOLs, even though they don't have any multi-zones or combination of diffractive profiles, have superior or comparable performance to their commercial counterparts in terms of optical performance under monochromatic light. The result demonstrates the validity and reliability of the approach proposed in this paper. With this method, the development time of different types of IOLs could be reduced considerably.

Comparison of visual requirements and regulations for obtaining a driving license in different European countries and some open questions on their adequacy

We reviewed the current state of knowledge regarding visual function and its suitability as part of medical examinations for driving licenses. We focused only on Group 1 drivers. According to previous studies, visual acuity, which is the most common test, is weakly associated with a higher risk of road accidents, with a greater role of visual field. The inclusion of the visual field test in medical examinations is therefore important, but the actual limit value is still unclear and further research in specific situations is needed. Color vision impairment was not found a threat to traffic safety. Contrast sensitivity decreases with age and is affected by abnormal eye conditions. Resulting glare can lead to an increased risk of traffic accidents during night driving in the elderly and others with conditions that impair contrast sensitivity. However, the universal cut-off limits have not been established either. The current European Union (EU) regulations therefore reflect minimum common denominator across the member states which may not entirely translate to optimal driving safety. Due to these open questions, standardized testing in simulators or on polygons that simulate real life conditions would be needed to better determine safe limits of visual function in different conditions. As there is a need to have better standardization across Europe regarding the requirements and rules regarding driving licenses in European countries, we first analyzed existing rules and compared them with each other, also in terms of deviations from the EU directive itself. We reviewed the literature in this field and prepared proposals for a more optimal regulation of the rules in the future. Particular attention is paid to the new method of examining the visual field that was created to respect the European directive. The paper can serve as a basis of information for research teams to design further protocols, as it gathers research findings to date on the importance and impact of various visual functions on driving safety, as well as a starting point for a debate on revising existing rules for obtaining and maintaining licenses, as it compares the current regulations in European countries and differences between them.

Visual Performance of a Novel Optical Design of a New Multifocal Intraocular Lens

PURPOSE

To evaluate the optical performance and quality of vision of a novel optical design of a new trifocal intraocular lens (IOL) using a proprietary modified algorithm.

METHODS

In this prospective, non-randomized, single-armed, single-center, open-label study, a total of 20 patients (40 eyes) who were candidates for multifocal lens implantation were recruited for implantation with the multifocal Intensity SL IOL (Hanita Lenses). Evaluation performed at 1 and 7 to 10 days and 1 and 3 months after implantation included corrected and uncorrected distance visual acuities at far, intermediate (80 cm), and near (40 cm). Monocular and binocular visual acuities, defocus curves, and contrast sensitivity were measured and questionnaires for grading subjective visual quality, satisfaction, and visual function were provided.

RESULTS

Three months postoperatively, monocular uncorrected visual acuity for distance, intermediate, and near averaged 0.03 ± 0.11, 0.09 ± 0.09, and -0.22 ± 0.09 logMAR, respectively (Snellen 20/21.4, 20/24.6, and 20/12). Corrected monocular visual acuity for distance, intermediate, and near averaged -0.07 ± 0.06, 0.03 ± 0.09, and -0.25 ± 0.07 logMAR (20/17, 20/21.4, and 20/11.2), respectively. Binocular corrected visual acuity for distance, intermediate, and near was -0.1 ± 0.06, -0.02 ± 0.09, and -0.28 ± 0.04 logMAR (20/15.8, 20/19, and 20/10.5), respectively. Contrast sensitivity was similar to the normal population in photopic and mesopic conditions. Defocus curves showed that this IOL provided visual acuity of 20/28.9 or better between a defocus of +1.00 and -3.50 diopters. The Visual Function Index-14 questionnaire showed that patients reported high satisfaction. Patients specifically noted good quality of vision at near and intermediate distances.

CONCLUSIONS

The Intensity SL IOL can provide good quality distance, intermediate, and particularly strong near vision after cataract surgery and independence from spectacles with good patient satisfaction. [J Refract Surg. 2022;38(3):150-157.].

Smooth multifocal wavefronts with a prescribed mean curvature for visual optics applications

Multifocal lenses comprising progressive power surfaces are commonly used in contact and intraocular lens designs. Given a visual performance metric, a wavefront engineering approach to design such lenses is based on searching for the optimal wavefront at the exit pupil of the eye. Multifocal wavefronts distribute the energy along the different foci thanks to having a varying mean curvature. Therefore, a fundamental step in the wavefront engineering approach is to generate the wavefront from a prescribed mean curvature function. Conventionally, such a thing is done by superimposing spherical wavefront patches and maybe adding a certain component of spherical aberration to each spherical patch in order to increase the depth-of-field associated with each focus. However, such a procedure does not lead to smooth wavefront solutions and also restricts the type of available multifocal wavefronts. We derive a new, to the best of our knowledge, mathematical method to uniquely construct multifocal wavefronts from mean curvature functions (depending on radial and angular coordinates) under certain numerically justified approximations and restrictions. Additionally, our procedure leads to a particular family of wavefronts (line-umbilical multifocal wavefronts) described by 2 conditions: (1) to be smooth multiplicative separable functions in the radial and angular coordinates; (2) to be umbilical along a specific segment connecting the circle center with its edge. We provide several examples of multifocal wavefronts belonging to this family, including a smooth variant of the so-called light sword element.

Iterative-Trained Semi-Blind Deconvolution Algorithm to Compensate Straylight in Retinal Images

The optical quality of an image depends on both the optical properties of the imaging system and the physical properties of the medium in which the light travels from the object to the final imaging sensor. The analysis of the point spread function of the optical system is an objective way to quantify the image degradation. In retinal imaging, the presence of corneal or cristalline lens opacifications spread the light at wide angular distributions. If the mathematical operator that degrades the image is known, the image can be restored through deconvolution methods. In the particular case of retinal imaging, this operator may be unknown (or partially) due to the presence of cataracts, corneal edema, or vitreous opacification. In those cases, blind deconvolution theory provides useful results to restore important spatial information of the image. In this work, a new semi-blind deconvolution method has been developed by training an iterative process with the Glare Spread Function kernel based on the Richardson-Lucy deconvolution algorithm to compensate a veiling glare effect in retinal images due to intraocular straylight. The method was first tested with simulated retinal images generated from a straylight eye model and applied to a real retinal image dataset composed of healthy subjects and patients with glaucoma and diabetic retinopathy. Results showed the capacity of the algorithm to detect and compensate the veiling glare degradation and improving the image sharpness up to 1000% in the case of healthy subjects and up to 700% in the pathological retinal images. This image quality improvement allows performing image segmentation processing with restored hidden spatial information after deconvolution.

Effect of the kappa angle on depth of focus after implantation of the TECNIS Symfony intraocular lens

PURPOSE

To evaluate the clinical effect of TECNIS Symfony intraocular lens (IOL) implantation and identify the effect of kappa angle on the depth of focus (DOF) after implantation.

METHODS

This prospective clinical study included consecutive patients who underwent cataract surgery and TECNIS Symfony IOL implantation at the Daqing Oilfield General Hospital from January 2019 to September 2019. Patients were divided into three groups according to the preoperative kappa angle (r): A (0 < r ≤ 0.2), B (0.2 < r ≤ 0.4), and C (r > 0.4). Uncorrected visual acuity was performed preoperatively and at 7 days, 1 month, and 3 months postoperatively. Synthetical optometry, higher-order aberrations, and defocus examinations were performed at 3 months postoperatively. Single-factor analysis of variance and Spearman correlation coefficient were used for data analysis.

RESULTS

The uncorrected visual acuity values of the three groups were significantly improved postoperatively, compared with preoperative values (p < 0.001). Three months postoperatively, the best-corrected visual acuity values of the three groups were 0.11 ± 0.02 logarithm of the minimum angle of resolution (logMAR), 0.09 ± 0.03 logMAR, and 0.11 ± 0.03 logMAR, respectively. Spherical equivalent (SE) values were 0.37 ± 0.08 D, 0.41 ± 0.06 D, and 0.42 ± 0.06 D, respectively. Best-corrected visual acuity and SE did not significantly differ among the three groups (F = 1.254, p = 0.135; F = 0.849, p = 0.228). There was no significant difference in SE between the three groups (F = 1.658, p = 0.312). Moreover, higher-order aberrations did not significantly differ among the three groups (p > 0.05). The kappa angle was negatively correlated with the postoperative DOF (r = -4.341, p = 0.026). Three months postoperatively, 54.55% of patients exhibited DOF ≥ 3 D, while 92.42% of patients exhibited DOF ≥ 2 D. The ranges of DOF in the three groups were 3.18 ± 0.27 D, 2.83 ± 0.80 D, and 2.57 ± 0.89 D, respectively; the difference among the three groups was statistically significant (F = 5.689, p = 0.037).

CONCLUSION

Most patients achieved full-range vision after TECNIS Symfony IOL implantation, but the DOF narrowed for those with an excessively large kappa angle, which indicates a need for careful selection.

Visual quality after implantation of trifocal intraocular lenses in highly myopic eyes with different axial lengths

AIM

To analyze postoperative clinical results after implantation of trifocal intraocular lenses (IOLs) in highly myopic eyes with different axial lengths (ALs).

METHODS

This retrospective study describes 61 eyes of 44 patients that were implanted with trifocal diffractive IOLs (AT LISA tri 839MP). Twenty-one eyes (15 patients) were included in the AL<26 mm group, 19 eyes (13 patients) in the AL≥26 mm and <28 mm group, and 21 eyes (16 patients) in the AL≥28 mm group. Postoperative outcomes, including corrected and uncorrected distance visual acuity (UDVA), intermediate and near visual acuity at 167 cd/m² luminance, depth of focus at 85 cd/m² luminance, and objective optical quality parameters assessed using the Optical Quality Analysis System (OQAS), were compared among the groups at 3mo.

RESULTS

There were no significant differences in the mean UDVA, uncorrected intermediate visual acuity, uncorrected near visual acuity, corrected distance visual acuity, distance-corrected intermediate visual acuity, and distance-corrected near visual acuity (DCNVA) among the three groups (P>0.05). Better near and intermediate visual acuity (from -1.5 D to -3.0 D) were noted on the defocus curve of the AL<26 mm group (P<0.01 vs AL≥28 mm group). Significantly higher objective scatter index (OSI) values and lower modulation transfer function (MTF) cut-off values, Strehl ratio (SR), and OQAS values (OVs) were observed in the AL≥28 mm group (P<0.01 vs AL<26 mm group). All OQAS parameters had statistically significant correlations with DCNVA and visual acuity at the vergence of -2.5 D (P<0.05 to P<0.01).

CONCLUSION

Implantation of trifocal IOLs provides good short-term visual and refractive outcomes in highly myopic eyes with different ALs. However, the near vision decreases in the extremely myopic eyes at lower luminance, which is associated with the lower objective optical quality in these eyes.

The impact of visual axis position on the optical quality after implantation of multifocal intraocular lenses with different asphericity values

PURPOSE

To evaluate the effect of visual axis positioning on the optical performance of the Tecnis MIOL and the Diff-aA MIOL.

METHODS

In this prospective, randomized comparative study, 70 eyes of 35 subjects with senile cataract were implanted with the spherical aberration-correcting diffractive, bifocal Tecnis ZLB00 IOL and 60 eyes of 30 age-matched subjects with the spherical aberration neutral, diffractive, bifocal Diffractiva IOL. Observation procedure was performed 1, 3, and 6 months postoperatively. Main outcome measures included uncorrected and corrected distance and near visual acuity, manifest refraction, ocular aberrations, and visual quality metrics with 2 mm and 4 mm pupil and the position of visual axis.

RESULTS

At the 6-month visit, no significant difference was found in monocular and binocular uncorrected (UDVA) and corrected (CDVA) distance and near (UNVA, CNVA) visual acuity between the groups. Spherical and coma-like aberrations were similar measured with a 2-mm pupil, but with a 4-mm pupil, the SA was significantly larger (in negative direction) in the Diffractiva group. The higher-order Strehl ratio and MTF was significantly larger in the Diffractiva group measured at 2 mm entrance pupil; however, this difference disappeared by the 4-mm pupil measurements. Postoperative angle alpha distance had a significant influence on HO Strehl value.

CONCLUSIONS

The size of angle alpha is a predictive factor of image quality by multifocal IOL patients.

TRIAL REGISTRATION

Trial registration number and date of registration: NCT04274088, 14.02.2020.

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.

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

Presbyopia and cataract patients' wish to be increasingly independent of spectacles after surgery and this is one of the main drivers for the development of multifocal intraocular lenses (MIOL) and extended depth of focus (EDOF) intraocular lenses (IOL). As education, biometry, diagnostics, surgical techniques, and MIOL/EDOF IOL designs have improved over the past decade, an increasing number of cataract surgeons have become cataract refractive surgeons to help address this need. There is not one single MIOL/EDOF IOL, however, that suits all patients' needs. The wide variety of MIOL and EDOF IOL, their optics, and their impact on our patients' quality of vision have to be fully understood if we have to choose the appropriate IOL for each individual; MIOL/EDOF IOL surgery has to be customized. This review article looks at the different optical aspects and clinical consequences of MIOL/EDOF IOL, in order to help surgeons find an appropriate solution for each of their individual patients.

Visual performance after bilateral implantation of 2 new presbyopia-correcting intraocular lenses: Trifocal versus extended range of vision

PURPOSE

To compare the visual outcomes and quality of vision of 2 new diffractive multifocal intraocular lenses (IOLs) with those of a monofocal IOL.

SETTING

Fatebenefratelli e Oftalmico Hospital, Milan, Italy.

DESIGN

Prospective case series.

METHODS

Patients had bilateral cataract surgery with implantation of a trifocal IOL (Panoptix), an extended-range-of-vision IOL (Symfony), or a monofocal IOL (SN60WF). Postoperative examinations included assessing distance, intermediate, and near visual acuity; binocular defocus; intraocular and total aberrations; point-spread function (PSF); modulation transfer function (MTF); retinal straylight; and quality-of-vision (QoV) and spectacle-dependence questionnaires.

RESULTS

Seventy-six patients (152 eyes) were assessed for study eligibility. Twenty patients (40 eyes) in each arm of the study (60 patients, 120 eyes) completed the outcome assessment. At the 4-month follow-up, the trifocal group had significantly better near visual acuity than the extended-range-of-vision group (P = .005). The defocus curve showed the trifocal IOL had better intermediate/near performance than the extended-range-of-vision IOL and both multifocal IOLs performed better than the monofocal IOL. Intragroup comparison of the total higher-order aberrations, PSF, MTF, and retinal straylight were not statistically different. The QoV questionnaire results showed no differences in dysphotopsia between the multifocal IOL groups; however, the results were significantly higher than in the monofocal IOL group.

CONCLUSIONS

Both multifocal IOLs seemed to be good options for patients with intermediate-vision requirements, whereas the trifocal IOL might be better for patients with near-vision requirements. The significant perception of visual side effects indicates that patients still must be counseled about these effects before a multifocal IOL is implanted.

Comparison of the Clinical Performance of Refractive Rotationally Asymmetric Multifocal IOLs with Other Types of IOLs: A Meta-Analysis

Objective

To compare the clinical performance of refractive rotationally asymmetric multifocal intraocular lens (IOLs) with spherical monofocal, accommodating, and bifocal IOLs.

Methods

A comprehensive literature search of PubMed, EMBASE, Cochrane Controlled Trials Register, and Web of Science up to February 2017 was performed to identify randomized controlled trials (RCT) and comparative cohort studies. Main outcomes were uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), higher-order aberrations (HOAs), MTF, Strehl ratio, and residual sphere and cylinder.

Results

Mplus provided significantly worse UDVA than spherical monofocal IOLs (WMD: 0.13, P=0.008), but significantly better UIVA than high-add bifocal IOLs (WMD: −0.19, P < 0.00001), spherical monofocal IOLs (WMD: −0.12, P < 0.0001), and accommodating IOLs (WMD: −0.21, P < 0.00001). Mplus provided significantly worse UNVA than high-add bifocal IOLs (WMD: 0.07, P < 0.00001), but significantly better UNVA than spherical monofocal IOLs (WMD: −0.19, P < 0.00001). Mplus resulted in significantly higher HOAs than high-add bifocal IOLs (WMD: 0.38, P < 0.00001) and spherical monofocal IOLs (WMD: 0.51, P=0.0004). Mplus provided a significantly lower MTF cut-off and Strehl ratio than other type of IOLs.

Conclusion

The Mplus IOLs perform best regarding intermediate visual acuity whereas they lack in distance visual acuity compared to monofocal IOLs and near visual acuity compared to bifocal IOLs. These results may be due to structure of Mplus IOLs resulting in higher-order aberrations.

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

Purpose:

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

Methods:

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

Results:

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

Conclusion:

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

Evaluation of Optical Quality: Ocular Scattering and Aberrations in Eyes Implanted with Diffractive Multifocal or Monofocal Intraocular Lenses

PURPOSE

To compare objective optical quality, ocular scattering and aberrations of eyes implanted with an aspheric monofocal intraocular lens (IOL) or an aspheric apodized diffractive multifocal IOL three months after surgery.

METHODS

Prospective consecutive nonrandomized comparative cohort study. A total of 80 eyes from 57 cataract patients were bilaterally or unilaterally implanted with monofocal (AcrySof IQ SN60WF) or multifocal (AcrySof IQ ReSTOR SN6AD1) IOLs. Respectively, 40 eyes of 27 patients were implanted with monofocal IOLs, and 40 eyes of 30 patients were implanted with multifocal IOLs. Ocular high-order aberration (HOA) values were obtained using Hartmann-Shack aberrometer; objective scatter index (OSI), modulation transfer function (MTF) cutoff, Strehl ratio (SR), and contrast visual acuity OV at 100%, 20%, and 9% were measured using Objective Quality Analysis System II (OQAS II).

RESULTS

Ocular aberrations performed similar in both groups (p > 0.05). However, significantly higher values of OSI and lower values of MTF cutoff, SR and OV were found in the SN6AD1 group (p < 0.05).

CONCLUSIONS

Both ocular scattering and wave-front aberrations play essential role in retinal image quality, which may be overestimated when only aberrations were taken into account. Combining the effect of ocular scattering with HOA will result in a more accurate assessment of the visual and optical quality.

Multifocal Intraocular Lenses and Extended Depth of Focus Intraocular Lenses

Presbyopia and cataract patients' desire for increased spectacle independence after surgery is one of the main drivers for the development of multifocal intraocular lenses (MIOLs) and extended depth of focus (EDOF) intraocular lenses (IOLs). As education, biometry, diagnostics, surgical techniques, and MIOL/EDOF IOL designs have improved over the past decade, an increasing number of cataract surgeons have become cataract-refractive surgeons to help address this need. There is not 1 single MIOL/EDOF IOL, however, that suits all patients' needs. The wide variety of MIOLs and EDOF IOLs, their optics, and their respective impact on our patients' quality of vision have to be fully understood to choose the appropriate IOL for each individual; MIOL/EDOF IOL surgery has to be customized. This review article looks at the different optical aspects and clinical consequences of MIOLs/EDOF IOLs to help surgeons find an appropriate solution for each of their individual patients.

Assessment of dysphotopsia in pseudophakic subjects with multifocal intraocular lenses

Aim

To better understand the phenomenon of dysphotopsia in patients implanted with multifocal intraocular lenses (IOLs).

Methods

Forty-five patients (aged 61.8±8.9 years) implanted bilaterally with Tecnis ZM900 (diffractive multifocal), Lentis Mplus MF30 (segmented refractive multifocal) or Softec-1 (monofocal) IOLs (each n=15) 4-6 months previously and who had achieved a good surgical outcome were examined. Each reported their dysphotopsia symptoms subjectively, identified its form (EyeVisPod illustrations), quantified retinal straylight (C-Quant) and halo perception (Aston halometer). Retinal straylight and halometry was repeated by a second masked clinician to determine interobserver repeatability.

Results

Subjective dysphotopsia ratings were able to differentiate Tecnis ZM900 from Lentis Mplus MF30 (p<0.001), but not Lentis Mplus MF30 from groups implanted with Softec-1 (p=0.290). Straylight was similar between the monofocal and multifocal IOL designs (p=0.664). ZM900 IOLs demonstrated a uniform increase in dysphotopsia in comparison with the monofocal IOL (p<0.001) as measured with the halometer, whereas sectorial refractive multifocal IOLs demonstrated a localised increase in dysphotopsia over the inferior visual field. Intraobserver repeatability was good for the straylight (intraclass correlation coefficients (ICC)=0.77) and halometry (ICC=0.89). There was no significant correlation between the subjective dysphotopsia severity and the straylight (p=0.503) or halometry (p>0.10) quantification or between straylight and the halo area (p>0.30).

Conclusions

Multifocal IOLs induce symptoms of dysphotopsia. Straylight did not differentiate between IOL designs, however halometry identified clear differences in light scatter due to the IOL optics. Whereas, subjective rating of overall dysphotopsia are not strongly associated with straylight or halo perception, the halometry polar diagram reflected the subjective descriptions of dysphotopsia.