Evaluation of visual quality of spherical and aspherical intraocular lenses by Optical Quality Analysis System

AIM: To evaluate the impact of spherical and aspherical intraocular lenses on the postoperative visual quality of age-related cataract patients using Optical Quality Analysis System(OQAS).METHODS: Seventy-four eyes with age-related cataracts were randomly divided into spherical and aspherical lens implantation groups. Best-corrected visual acuity(BCVA) was measured preoperatively, one day, one week, two weeks, one month and two months after surgery. A biometric systems analysis using the OQAS objective scattering index(OSI) was performed. RESULTS: There were no significant differences in visual acuity(P>0.05) before and after spherical and aspheric lens implantation. There was a negative linear correction between the OSI value and BCVA(r=-0.634, P=0.000), and positive corrections between the OSI value and the lens LOCUS III value of nucleus color(NC), nucleus opacity(NO), cortex(C) and posterior lens capsular(P)(r=0.704, P=0.000; r=0.514, P=0.000; r=0.276, P=0.020; r=0.417, P=0.000, respectively). OSI values of spherical vs aspherical lenses were 11.5±3.6 vs 11.8±3.4, 4.1±0.9 vs 3.3±0.8, 3.5±0.9 vs 2.7±0.7, 3.3±0.8 vs 2.6±0.7, 3.2±0.7 vs 2.5±0.8, and 3.2±0.8 vs 2.5±0.8 before and 1d, 1, 2wk, 1 and 2mo after surgery, respectively. All time points varied significantly(P<0.01) between the two groups.CONCLUSION: Aspherical IOLs does not significantly affect visual acuity compared with spherical IOLs. The OSI value, was significantly lower in the aspherical lens group compared with the spherical lens. This study shows that objective visual quality of aspheric IOLs is better than that of the spherical lens by means of OQAS biological measurement method.

Objective optical quality and visual outcomes after the PresbyMAX monocular ablation profile

AIM:To assess objective visual quality after presbyopia correction using the Presby MAX monocular mode.METHODS:This prospective,nonrandomized study included 28 eyes from 18 patients(mean age 50.4±5.6 y)who underwent presbyopia correction with the Presby MAX monocular mode.Monocular and binocular visual acuities were evaluated preoperatively,1 d,1 wk,1,3 mo,and 1 y after surgery.Optical quality was analyzed by HartmannShack wavefront aberration supported cornea ablation.Modulation transfer function(MTF)cutoff frequency,Strehl ratio,and objective scattering index(OSI)were analyzed using an optical quality analysis system.RESULTS:One year after surgery,100%and 94.4%of patients achieved binocular uncorrected distance and near visual acuity of 20/25,respectively.At the last visit Spherical aberration and total higher aberration were higher than the corresponding preoperative levels(P<0.001);however,no significant difference was found in MTF,OSI,or Strehl ratio.Transient decreases in OSI and MTF mainly occurred in the nondominant eyes.There was no significant difference in optical quality between the dominant and nondominant eyes,except for spherical aberration and horizontal coma(P<0.05).CONCLUSION:The Presby MAX monocular mode is safe and effective for presbyopia correction.It has little effect on optical quality,though short-term degraded optical quality occurred mainly in the bi-aspheric ablated eyes.

Refractive outcomes and optical quality of PRESBYOND laser-blended vision for presbyopia correction

AIM: To investigate the one-year refractive outcomes and optical quality following PRESBYOND laser-blended vision(LBV).METHODS: This retrospective study included 20 patients who underwent PRESBYOND treatment between Jan 2019 and Aug 2020. The patients were asked to attend a followup outpatient visit one year after surgery. Distance and near visual acuity as well as subjective refraction were examined. Optical quality was assessed using wavefront-supported custom ablation. A questionnaire evaluating optical quality and satisfaction was completed at the last visit.RESULTS: The average patient age was 48.1±7.4 y(range, 41 to 58 y). The mean preoperative spherical equivalent was-7.59±2.39D. At the one-year follow-up, two eyes(both dominant eyes) lost one line of corrected distance visual acuity(CDVA), while the remaining eyes(38/40) maintained or gained lines of CDVA. The average binocular uncorrected distance visual acuity improved from 0.15±0.03 to 0.90±0.26(decimal vision;P<0.001). The average binocular uncorrected near visual acuity increased from 0.34±0.28 to 0.97±0.07(P<0.001). The spherical aberration was 0.04±0.06 μm in the nondominant eye and 0.09±0.09 μm in the dominant eye(P=0.02). All patients were satisfied with or accepted the outcomes of the surgery. The primary complaints were related to disturbances in night vision and relatively inferior near vision.CONCLUSION: Over the one-year observation period, PRESBYOND is a safe and effective option for presbyopia correction. The optical quality and near vision deserve further investigation.

Repeatability of in-vitro optical quality measurements of intraocular lenses with a deflectometry technique effect of the toricity

● AIM: To evaluate the repeatability of an optical device for measuring the Zernike coefficients of toric intraocular lenses(IOLs) and assess whether its toricity has any impact in its repeatability.● METHODS: An experienced technician used the NIMO TR1504 to measure the Zernike coefficients 30 times for an aperture of 4.50 mm for all lenses included. The IOLs included were divided into two group: toric and nontoric ones. The cylindrical powers of the toric lenses included in the present study were 1.00, 1.50, 2.25, 3.00 and 3.75 D. Finally, the repeatability of the NIMO TR1504 was described in terms of within subject standard deviation(Sw) and repeatability limit.● RESULTS: The Sw was smaller than 0.011 μm for both lens groups and all Zernike coefficients, and the difference between both groups was smaller than 0.004 μm for all Zernike coefficients. Regarding the repeatability limit, this value was smaller than 0.025 μm for the toric lens group, and smaller than 0.031 μm for the non-toric lens one for all Zernike coefficients. Furthermore, the maximum difference between both lens groups was 0.010 μm.● CONCLUSION: The repeatability of the NIMO TR1504 to measure the optical quality is high and independent of the lens toricity. These results reflect that this system is robust and could be used to measure the in-vitro optical quality of either toric or non-toric IOLs.

In vivo optical quality of posterior-chamber phakic implantable collamer lenses with a central port

Background: The aim of this review is to summarize the optical quality results in patients following theimplantation of the V4c implantable collamer lens with a central port (ICL, STAAR Surgical Inc.).Main text: A literature search in several databases was carried out to identify those publications, both prospective,retrospective and/or comparative with other refractive surgery procedures, reporting optical outcomes of patientswho were implanted with the V4c ICL model. A total of 17 clinical studies published between 2012 and 2021 wereincluded in this review. A detailed analysis of the available data was performed including number of eyes, follow-upand preoperative spherical equivalent. Specifically, the review focused on several optical parameters includinghigher-order aberrations (HOAs), modulation transfer function (MTF) cut-off frequency and Strehl ratio. This reviewencompassed a total of 817 eyes measured using different optical devices based on Hartmann-Shack, retinal imagequality measurement and ray-tracing technologies at different follow-ups.Conclusions: The outcomes found in this review lead us to conclude that the ICL V4c model provides good opticalquality, by means of different metrics, when implanted.

In vivo optical quality of posterior-chamber phakic implantable collamer lenses with a central port

Background:The aim of this review is to summarize the optical quality results in patients following the implantation of the V4c implantable collamer lens with a central port(ICL,STAAR Surgical Inc.).Main text:A literature search in several databases was carried out to identify those publications,both prospective,retrospective and/or comparative with other refractive surgery procedures,reporting optical outcomes of patients who were implanted with the V4c ICL model.A total of 17 clinical studies published between 2012 and 2021 were included in this review.A detailed analysis of the available data was performed including number of eyes,follow-up and preoperative spherical equivalent.Specifically,the review focused on several optical parameters including higher-order aberrations(HOAs),modulation transfer function(MTF)cut-off frequency and Strehl ratio.This review encompassed a total of 817 eyes measured using different optical devices based on Hartmann-Shack,retinal image quality measurement and ray-tracing technologies at different follow-ups.Conclusions:The outcomes found in this review lead us to conclude that the ICL V4c model provides good optical quality,by means of different metrics,when implanted.

Effect of low-degree astigmatism on the objective visual quality

AIM:To evaluate the effect of low-degree astigmatism on objective visual quality through the Optical Quality Analysis System(OQAS).METHODS:This study enrolled 46 participants(aged 23 to 30y,90 eyes)with normal or corrected-to-normal vision.The cylindrical lenses(0,0.5,0.75,1.0,and 1.25 D)were placed at the axial direction(180°,45°,90°,and 135°)in front of the eyes with the best correction to form 16 types of regular low-degree astigmatism.OQAS was used to detect the objective visual quality,recorded as the objective scattering index(OSI),OQAS values at contrasts of 100%,20%,and 9%predictive visual acuity(OV100%,OV20%,and OV9%),modulation transfer function cut-off(MTFcut-off)and Strehl ratio(SR).The mixed effect linear model was used to compare objective visual quality differences between groups and examine associations between astigmatic magnitude and objective visual quality parameters.RESULTS:Apparent negative relationships between the magnitude of low astigmatism and objective visual quality were observed.The increase of OSI per degree of astigmatism at 180°,45°,90°,and 135°axis were 0.38(95%CI:0.35,0.42),0.50(95%CI:0.46,0.53),0.49(95%CI:0.45,0.54)and 0.37(95%CI:0.34,0.41),respectively.The decrease of MTFcut-off per degree of astigmatism at 180°,45°,90°,and 135°axis were-10.30(95%CI:-11.43,-9.16),-12.73(95%CI:-13.62,-11.86),-12.75(95%CI:-13.79,-11.70),and-9.97(95%CI:-10.92,-9.03),respectively.At the same astigmatism degree,OSI at 45°and 90°axis were higher than that at 0°and 135°axis,while MTFcut-off were lower.CONCLUSION:Low astigmatism of only 0.50 D can significantly reduce the objective visual quality.

A review on magneto-optical ceramics for Faraday isolators

As a promising magneto-optical(MO)material applied in Faraday isolators,magneto-optical ceramics possess excellent comprehensive properties and have attracted much attention these years.Herein,we review the fabrication and properties of magneto-optical ceramics including garnet,sesquioxide,and A_(2)B_(2)O_(7) ceramics.Some of the ceramics have been proved to possess applicable performance,while further studies are still needed for most of the magneto-optical ceramics.Aiming at the application for isolators,the research status,existing problems,and development trends of magneto-optical ceramics are shown and discussed in this review.

The relationship between patient satisfaction and visual and optical outcome after bilateral implantation of an extended depth of focus multifocal intraocular lens

Purpose:To evaluate patient satisfaction after implantation of the Tecnis Symfony multifocal intraocular lens(MIOL).Methods:120 eyes of 60 subjects with senile cataract were bilaterally implanted with the Tecnis Symfony IOL.Follow-up examination was performed 6 months postoperatively.Main outcome measures included uncorrected and corrected distance and near visual acuity,manifest refraction,and visual quality metrics.According to their subjective symptoms patient were divided in two groups:satisfied and unsatisfied.Results:Uncorrected intermediate(0.15±0.11 vs 0.18±0.01,P=0.04)and near(0.26±0.12 vs 0.31±0.11,P=0.04)(UIVA,UNVA)log MAR visual acuity was significantly better,cylindrical error less(0.31±0.36 vs 0.67±0.29,P=0.05),axial length(AL)smaller(23.68±1.3 vs 24.22±1.6,P=0.05),Strehl ratio higher(0.08±0.08 vs 0.05±0.04,P=0.03)and mesopic pupil larger(4.3±1.1 vs 3.7±1.05,P=0.01)among satisfied patients.Residual cylinder,Strehl ratio,halos,mesopic pupil diameter and UNVA were significant predictors of patient satisfaction.Uncorrected distance visual acuity,higher order Strehl ratio and pupil diameter were significant predictors of halos.Near visual acuity significantly correlated(P=0.018,R=0.22)with axial length.Conclusions:Uncorrected cylindrical error,poor reading quality,larger pupil and halos seem to be the most disturbing factors for patients implanted with the Tecnis Symfony IOL.