Double-pass system analysis of the visual outcomes and optical performance of an apodized diffractive multifocal intraocular lens

Effect of presbyopic correction lens on humphrey visual field testing in patients with multifocal intraocular lens

Most previous studies on the effects of multifocal intraocular lenses (MIOL) on Humphrey visual field (HVF) used presbyopic corrective lens (PC). There has been insufficient data from patients with MIOL performing HVF with and without PC. This study aimed to determine the effect of PC on HVF testing in patients with MIOL. This was a prospective, comparative crossover study at the Department of Ophthalmology, Faculty of Medicine, Siriraj Hospital, Mahidol University between June 2015 and July 2018. Early-stage glaucomatous and non-glaucomatous pseudophakic patients with 2 models of MIOL completed HVF testing with and without PC. Mean deviation (MD), pattern standard deviation (PSD), and reliability indices (fixation losses, false positives, and false negatives) were compared. Ninety-four eyes of 59 patients were enrolled. After excluding patients with confirmed unreliable visual field, 82 eyes of 51 patients (male, 22; female, 29) with a mean age of 65.4 years were included in the study. Forty-nine eyes were non-glaucoma and 33 eyes were early-stage glaucoma. Forty-four eyes received TECNIS ZM900 and 38 eyes received Acrysof IQ ReSTOR SN6AD1. The overall MD standard deviation was -3.5 (2.1) with PC and -3.1 (2.1) without PC (P = .01). The overall PSD standard deviation was 2.8 (1.5) with PC and 2.7 (1.5) without PC (P = .93). The reliability indices were not statistically significantly different with and without PC. There was a good intraclass correlation (ICC) of MD (ICC = 0.87) and PSD (ICC = 0.88) with and without PC. Eyes with TECNIS ZM 900 had significantly better MD when performing HVF without PC (mean difference -0.7, P < .01), but not with Acrysof IQ ReSTOR SN6AD1 (mean difference -0.1, P = .74). Pseudophakic eyes with MIOL may not require PC during HVF testing regardless of the MIOL model. Although eyes with TECNIS ZM900 performed HVF without PC resulted in a significantly better MD value compared with PC, the difference was not clinically significant.

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

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

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.

Visual Performance With Bifocal and Trifocal Diffractive Intraocular Lenses: A Prospective Three-Armed Randomized Multicenter Clinical Trial

PURPOSE

To evaluate and compare quality of vision and reading performance outcomes after implantation of bifocal refractive-diffractive, bifocal apodized diffractive, or trifocal diffractive-refractive intraocular lenses (IOLs).

METHODS

This randomized, prospective, three-armed multicenter (Spain, Germany, and France) trial included 104 eyes of 52 patients (mean age: 63.2 ± 7.7 years). Patients underwent cataract surgery with bilateral implantation of either AT LISA 809M (Carl Zeiss Meditec, Jena, Germany: AT LISA group, 38 eyes), AT LISA tri 839MP (Carl Zeiss Meditec: AT LISA tri group, 32 eyes), or ReSTOR SN6AD1 (Alcon Laboratories, Inc., Fort Worth, TX: ReSTOR group, 34 eyes) IOLs. Visual and refractive outcomes, depth of focus, and reading performance were evaluated at 1, 6, and 12 months postoperatively.

RESULTS

The AT LISA tri group showed significantly better 12-month uncorrected (UIVA) and binocular distance-corrected (DCIVA) intermediate visual acuity (P ≤ .016) than the AT LISA group. The AT LISA tri group showed a significantly better 3-month UIVA compared to the ReSTOR group (P = .042). Binocular uncorrected and corrected distance visual acuities were not significantly different among groups (P ≥ .092) at the 12-month follow-up. A total of 85.3%, 90.0%, and 78.1% of eyes had a spherical equivalent within ±0.50 D in the AT LISA, AT LISA tri, and ReSTOR groups, respectively, at 12 months (P = .038). No statistically significant differences between the trifocal and bifocal groups were detected for reading performance (P ≥ .055).

CONCLUSIONS

The trifocal diffractive-refractive IOL provides enhanced intermediate visual restoration compared to bifocal diffractive-refractive or apodized diffractive IOLs. The addition of an intermediate focal point did not deteriorate far or near vision. A comparable reading performance was maintained with the trifocal lens. [J Refract Surg. 2017;33(10):655-662.].

Effect of Spherical Aberration on the Optical Quality after Implantation of Two Different Aspherical Intraocular Lenses

PURPOSE

To compare the effect of spherical aberration on optical quality in eyes with two different aspherical intraocular lenses.

METHODS

120 eyes of 60 patients underwent phacoemulsification. In patients' eyes, an aberration-free IOL (Aspira-aA; Human Optics) or an aberration-correcting aspherical IOL (Tecnis ZCB00; Abott Medical Optics) was randomly implanted. After surgery, contrast sensitivity and wavefront measurements as well as tilt and decentration measurements were performed.

RESULTS

Contrast sensitivity was significantly higher in eyes with Aspira lens under mesopic conditions with 12 cycles per degree (CPD) and under photopic conditions with 18 CPD (p = 0.02). Wavefront measurements showed a higher total spherical aberration with a minimal pupil size of 4 mm in the Aspira group (0.05 ± 0.03) than in the Tecnis group (0.03 ± 0.02) (p = 0.001). Strehl ratio was higher in eyes with Tecnis (0.28 ± 0.17) with a minimal pupil size larger than 5 mm than that with Aspira (0.16 ± 0.14) (p = 0.04). In pupils with a minimum diameter of 4 mm spherical aberration had a significant effect on Strehl ratio, but not in pupils with a diameter less than 4 mm.

CONCLUSIONS

Optical quality was better in eyes with the aberration-correcting Tecnis IOL when pupils were large. In contrast, this could not be shown in eyes with pupils under 4 mm or larger. This trial is registered with Clinicaltrials.gov NCT03224728.

Comparison of visual outcomes, spectacles dependence and patient satisfaction of multifocal and accommodative intraocular lenses: innovative perspectives for maximal refractive-oriented cataract surgery

Background

The aim of this study was to evaluate visual outcomes for different working distances (far, 60 cm and 33 cm) and impact on vision quality of multifocal IOLs AcrySof ResTOR SN6AD1 and SN6AD3 (Alcon, Inc., Fort Worth, Texas, USA) as well as REVIEW FIL611PV multifocal and OPTOFLEX FIL618 accommodative IOLs (Soleko, Ltd., Rome, Italy) in patients undergoing bilateral phacoemulsification.

Methods

In this observational prospective study 63 patients undergoing binocular cataract surgery were divided into four groups for implantation of one of the IOLs under evaluation. Visual outcomes were evaluated at 1 day, 7 days, 1 month, 3 months and 6 months after surgery. Patients’ satisfaction and spectacle independence were evaluated with questionnaires administered at the 6-months follow-up.

Results

Improvements in visual acuity for the three working distances were statistically significant in all cases compared to the preoperative status, especially after binocular implantation. The AcrySof ReSTOR SN6AD1 multifocal IOL provided the best visual acuity results and tolerability for all working distances. While performing worse than SN6AD1, FIL611PV and FIL618 provided better uncorrected visual acuity and spectacles independence for intermediate/close-up and far distances respectively, in comparison with the SN6AD3 group.

Conclusions

SN6AD1 was confirmed the best choice for all working distances. However, FIL611PV IOL may represent a valid and more cost-effective alternative, especially if surgeons intend to prioritize spectacle independence and patient autonomy at intermediate and close-up distances, in accordance to specific needs and requests.

Trial registration

Trial retrospectively registered in ISRCTN Registry on 02/02/2017. TRN: ISRCTN14145737.

Objective and subjective visual quality after implantation of all optic zone diffractive multifocal intraocular lenses: a prospective, case-control observational study

BACKGROUND AND AIMS

To evaluate the objective and subjective optical quality of all optic zone diffractive multifocal intraocular lens (IOL).

METHODS

Fifty patients (50 eyes) having phacoemulsification and IOL implantation surgery were enrolled. 25 patients were implanted with all optic zone diffractive multifocal IOL and 25 patients with monofocal IOL. Objective optical quality parameters under 4 mm pupil using Optical Quality Analysis System (OQAS), subjective visual acuity (VA) at 85 cd/m² luminance and questionnaire concerning halo and visual function were assessed.

RESULTS

The multifocal group gained similar objective optical outcomes, such as OQAS values at contrast 100%, 20%, 9%, modulation transfer function cut-off and Strehl ratio, as the monofocal group. Objective scatter index (OSI) was significantly better in the monofocal group. Distance corrected near VA, uncorrected near VA, distance corrected intermediate VA and uncorrected intermediate VA were significantly better in the multifocal group. The difference in uncorrected distance VA and best corrected distance VA between the monofocal and multifocal groups was not significant. Mild halos and glare were reported in both groups and a significant difference between the two groups was not observed; however, moderate glare and halos were reported only in the multifocal group (2/25). There was no significant difference between the two groups when visual function was compared.

CONCLUSIONS

All optic zone diffractive multifocal IOLs provided almost the same objective optical quality as monofocal IOLs did under 4 mm pupil besides good all distance visual performance, but with greater OSI, indicating that implantation provides good optical quality in daytime but with more intraocular scatter light.

TRIAL REGISTRATION NUMBER

NCT02234635, post-results.

Reproducibility of optical quality parameters measured at objective and subjective best focuses in a double-pass system

AIM

To evaluate intra-session repeatability and reproducibility of optical quality parameters measured at objective and subjective best focuses in a double-pass system.

METHODS

Thirty Chinese healthy adults (19 to 40 years old) meeting our inclusion criterion were enrolled in the study. After a basic eye examination, two methods of optical quality measurement, based on subjective and objective best focuses were performed using the Optical Quality Analysis System (OQAS) with an artificial pupil diameter of 4.0 mm.

RESULTS

With each method, three consecutive measurements of the following parameters: the modulation transfer function cutoff frequency (MTFcutoff), the Strehl(2D) ratio, the OQAS values (OVs) at contrasts of 100%, 20%, 9% and the objective scatter index (OSI) were performed by an experienced examiner. The repeatability of each method was evaluated by the repeatability limit (RL) and the coefficient of repeatability (COR). Reproducibility of the two methods was evaluated by intra-class correlation coefficient (ICC) and the 95% limits of agreement (Bland and Altman analysis). Thirty subjects, seven females and twenty three males, of whom 15 right eyes and 15 left eyes were selected randomly for recruitment in the study. The RLs (percentage) for the six parameters measured at objective focus and subjective focus ranged from 8.44% to 15.13% and 10.85% to 16.26%, respectively. The CORs for the two measurement methods ranged from 8.27% to 14.83% and 10.63% to 15.93%, respectively. With regard to reproducibility, the ICCs for the six parameters of OQAS ranged from 0.024 to 0.276. The 95% limits of agreement obtained for the six parameters (in comparison of the two methods) ranged from -0.57 to 42.18 (MTFcutoff), -0.01 to 0.23 (Strehl(2D) ratio), -0.02 to 1.40 (OV100%), -0.10 to 1.75 (OV20%), -0.14 to 1.80 (OV9%) and -1.46 to 0.18 (OSI).

CONCLUSION

Measurements provided by OQAS with either method showed a good repeatability. However, the results obtained from the two different measurement methods showed a poor reproducibility. These findings suggest that it might be best to evaluate patients' optical quality by OQAS using the best focus as chosen automatically by the instrument.

Evaluation of optical quality parameters and ocular aberrations in multifocal intraocular lens implanted eyes

PURPOSE

We investigated the correlations between optical quality parameters obtained from the double-pass system and ocular aberrations obtained from the ray-tracing aberrometer in multifocal intraocular lens (IOL) implanted eyes.

MATERIALS AND METHODS

Twenty eyes from 20 patients were enrolled in this study. Modulation transfer function cutoff frequency, The Strehl ratio, objective scatter index, and objective pseudo-accommodation obtained from the double-pass system were compared with root mean square (RMS) total aberration, RMS higher-order aberration, and spherical aberration obtained from the ray-tracing aberrometer. Additionally, parameters of the double-pass system and ray-tracing aberrometer were compared with manifested refraction values and subjective visual acuity, respectively.

RESULTS

There was no statistically significant correlation between optical quality parameters obtained from the double-pass system and ocular aberrations, except between the Strehl ratio and RMS total aberration (r=-0.566, p=0.018). No significant correlations were found between the parameters of both devices, and manifested refraction values or subjective visual acuity.

CONCLUSION

Optical quality parameters, especially the Strehl ratio, in multifocal IOL implanted eyes were affected by RMS total aberration. Further studies based on accurate measurements of ocular aberrations and additional optical quality parameters are needed to delineate relationships between optical quality parameters and ocular aberrations in multifocal IOL implanted eyes.

Clinical outcomes after cataract surgery with implantation of the Tecnis ZMB00 multifocal intraocular lens

Background

The aim of this study was to evaluate visual performance, contrast sensitivity, and patient satisfaction in patients undergoing cataract surgery with bilateral implantation of the Tecnis ZMB00 diffractive multifocal IOL (intraocular lens).

Material/Methods

This was a prospective study of 40 eyes of 20 patients with an age range from 48 to 67 years and undergoing cataract surgery with implantation of the diffractive 1-piece IOL Tecnis ZMB00 (Abbott Medical Optics) in 1 eye and 3 weeks later in the other eye. The following parameters were evaluated at 3 and 6 months after the operation: binocular uncorrected distance, intermediate and near visual acuity (UDVA, UIVA, UNVA), uncorrected binocular photopic and mesopic distance and photopic near contrast sensitivity (CSV-1000), subjective symptoms, and patient satisfaction (VF-14).

Results

No significant change was observed in logMAR UDVA between 3 and 6 months postoperatively (−0.11±0.14 vs. −0.10±0.13, p>0.05). In contrast, UNVA (0.06±0.12 vs. −0.02±0.12, p=0.004) and UIVA (0.12±0.15 vs. 0.07±0.11, p=0.005) in this period improved significantly. At 3 and 6 months after surgery, 85% of patients no longer needed to wear corrective lenses. Contrast sensitivity under different conditions was within normal age-matched limits, with significant improvements for some spatial frequencies at 3 and 6 months after surgery (p<0.04). Mean overall patient satisfaction was 9.39±1.06 and 9.19±1.20 (scale from 1 to 10, with 10 being the best score) at 3 and 6 months, respectively. Low level of halo perception was reported in 75% of patients.

Conclusions

The Tecnis ZMB00 IOL provides an effective restoration of the distance, intermediate, and near visual function, allowing patients to be totally free of need to wear corrective lenses and providing high levels of patient satisfaction.

Intraocular lens multifocality combined with the compensation for corneal spherical aberration: a new concept of presbyopia-correcting intraocular lens

The outcomes of a prospective consecutive study aimed at evaluating the visual and refractive benefit after cataract surgery with the implantation of the aspheric diffractive multifocal intraocular lens (IOL) Tecnis ZMB00 (Abbott Medical Optics) are reported. A total of 31 eyes of 19 patients (age range, 40 to 81 years) underwent phacoemulsification surgery with implantation of this aspheric multifocal IOL. At 6 months after surgery, postoperative spherical equivalent was within ±1.00 D in 96.8% of eyes, with 94.7% of patients presenting a postoperative binocular far LogMAR uncorrected visual acuity (UCVA) of 0.1 or better. Far best-corrected distance VA improved significantly (p < 0.01), with postoperative values of 0.1 or better in 96.8% of eyes. Postoperative near UCVA was 0.10 (equivalent to J1) or better in 93.55% of eyes. Furthermore, the IOL power was found to be very poorly correlated with the postoperative far LogMAR (r = 0.13) and near UCVA (r = 0.13). In conclusion, the aspheric diffractive multifocal IOL Tecnis ZMB00 provides a restoration of the far and near visual function after phacoemulsification surgery for cataract removal or presbyopia correction, which is predictable and independent from the optical power of the implanted IOL.

Comparison of through-focus image sharpness across five presbyopia-correcting intraocular lenses

PURPOSE

To assess through-focus polychromatic image sharpness of 5 FDA-approved presbyopia-correcting intraocular lenses (IOLs) through a range of object vergences and pupil diameters using an image sharpness algorithm.

DESIGN

Laboratory investigation.

METHODS

A 1951 USAF resolution target was imaged through Crystalens AO (AO), Crystalens HD (HD), aspheric ReSTOR +4 (R4), aspheric ReSTOR +3 (R3), and Tecnis Multifocal Acrylic (TMF) IOL in a model eye and captured digitally for each combination of pupil diameter and object vergence. The sharpness of each digital image was objectively scored using a 2-dimensional gradient function.

RESULTS

AO had the best distance image sharpness for all pupil diameters and was superior to the HD. With a 5-mm pupil, the R4 distance image sharpness was similar to the HD and at 6 mm the TMF was superior to the HD, R3, and R4. The R3 moved the near focal point farther from the patient compared to the R4, but did not improve image sharpness at intermediate distances and showed worse distance and near image sharpness. Consistent with apodization, the ReSTOR IOLs displayed better distance and poorer near image sharpness as pupil diameter increased. TMF showed consistent distance and near image sharpness across pupil diameters and the best near image sharpness for all pupil diameters.

CONCLUSIONS

Differing IOL design strategies to increase depth of field are associated with quantifiable differences in image sharpness at varying vergences and pupil sizes. Objective comparison of the imaging properties of specific presbyopia-correcting IOLs in relation to patient's pupil sizes can be useful in selecting the most appropriate IOL for each patient.