Aspheric Intraocular Lens Research Articles

Wave front aberrations and patient satisfaction of aspheric intraocular lenses

Aim The aim was to study postoperative wave front higher order aberrations of eyes implanted with aspheric intraocular lens (IOL) in comparison with those with standard spherical IOL and to assess the subjective satisfaction in relation to both IOL designs. Patients and methods The study included 40 patients with bilateral cataract. Patients were enrolled in a prospective comparative case series from December 2013 till January 2015. All patients underwent a complete preoperative assessment. Phacoemulsification was done for all patients in both eyes. Aspheric IOL (Acrysof IQ SN60WF) was implanted in the right eye and standard spherical IOL (AcrySof SA60AT) in the left eye. Wave front examination was done at 3 months postoperatively to measure the higher order aberrations. A questionnaire was used to record the patients’ satisfaction regarding the two IOL designs. Results There were no significant differences between the two IOLs regarding the postoperative visual acuity or the mean refractive spherical equivalent. Spherical aberrations were significantly lower in the aspheric IOL group, with only 35% of the patients reported that it was the best eye. There were no significant differences in other aberrations. Conclusion Aspheric IOLs and standard IOLs have the same visual outcome regarding visual acuity. However, aspheric IOLs induced significantly less spherical aberrations. Aspheric IOL gave better qualitative visual functions in some patients especially during night.

Clinical Outcomes of Diffractive Aspheric Trifocal Intraocular Lens Implantation

Clinical Outcomes of Diffractive Aspheric Trifocal Intraocular Lens Implantation

Anterior corneal high-order aberrations in eyes with senile cataract in a Chinese population

Objective: To investigate the distribution of anterior corneal high-order aberrations (HOAs) in Chinese eyes with cataract and their correlations with age and axial length for the choice of aspheric intraocular lens. Methods: Retrospective study. Six hundred twenty-five Chinese patients with cataract[male: 260, female: 365, age: (71.2±8.0) years] were categorized into 4 groups in accordance with their axial lengths. Anterior corneal HOAs in the central 6- mm zone was measured with an iTrace wavefront analyzer. The correlations between axial length, age and total HOAs, spherical aberration, trefoil aberration, and coma aberration were analyzed using Spearman analysis. The differences in total HOAs, spherical aberration, trefoil aberration, and coma aberration among 4 groups were assessed using the Krusal-Wallis H test. Results: Anterior corneal HOAs showed the nonnormal distribution. The median of corneal total HOAs was 0.666 μm (range 0.246 to 4.115 μm). Medians of coma aberration, spherical aberration and trefoil aberration were 0.313 μm (range 0.015 to 1.879 μm), 0.275 μm (range 0.005 to 1.797 μm) and 0.341 μm (range 0.019 to 2.319 μm), respectively. A significant negative correlation was found between axial length and total HOAs, coma aberration, spherical aberration, trefoil aberration (r=-0.230, -0.235, -0.143, -0.153, P<0.05). But no correlation was found between age and them (r=0.056, 0.045, 0.065, 0.022, P>0.05). Differences in total HOAs, coma aberration, spherical aberration, trefoil aberration were found among various axial groups (H=21.953, 20.665, 15.368, 16.881, P<0.05). Conclusions: Anterior corneal HOAs varied greatly among the majority of the patients. A significant negative correlation was found between axial length and anterior corneal HOAs, but no correlation was found between age and them. (Chin J Ophthalmol, 2017, 53: 828-834).

Depth of focus after implantation of spherical or aspheric intraocular lenses in hyperopic and emmetropic patients

To evaluate whether hyperopic patients with short axial length and high dioptric intraocular lens (IOL) power can achieve a higher depth of focus after implantation of a monofocal spherical or aspheric IOL than emmetropic patients. Department of Ophthalmology, Medical University Graz, Graz, Austria. Prospective case series. Patients presenting for cataract surgery were divided by calculated IOL power into a hyperopic (≥22.0 diopters [D]) or emmetropic (18.0 to 21.5 D) groups and received an aspheric (Tecnis ZA9003) or a spherical IOL (Sensar AR40e). Postoperative measurements included corrected (CDVA) and uncorrected (UDVA) distance visual acuities, distance-corrected intermediate (DCIVA) and near (DCNVA) visual acuities, root-mean-square values of corneal and total eye higher-order aberrations and spherical aberrations, and photopic and mesopic contrast sensitivity. Sixty-two eyes of 62 patients were enrolled in this study, 34 eyes (15 hyperopic, 19 emmetropic) in the aspheric IOL group and 28 eyes (14 hyperopic, 14 emmetropic) in the spherical IOL group. The UDVA, CDVA, and contrast sensitivity did not differ significantly between the 2 IOL groups, whereas the DCIVA and DCNVA were significantly better in the spherical IOL group (P=.004 and P=.001, respectively). No significant differences were found in DCIVA and DCNVA between hyperopic patients and emmetropic patients with aspheric or spherical IOLs. Implantation of a monofocal spherical IOL resulted in an increased depth of focus without significant degradation of distance visual acuity or contrast sensitivity. There were no differences in the depth of focus between hyperopic eyes and emmetropic eyes.

The efficiency of aspheric intraocular lens according to biometric measurements.

PurposeTo analyze internal spherical aberration in pseudophakic eyes that underwent aspheric intraocular lens (IOL) implantation, and to investigate the relationships between biometric data and the effectiveness of aspheric IOL implantation.MethodsThis retrospective study included 40 eyes of 40 patients who underwent implantation of an IOL having a negative spherical aberration of -0.20 μm (CT ASPHINA 509M; Carl Zeiss Meditec Inc., Germany). The IOLMaster (version 5.0; Carl Zeiss AG, Germany) was used for preoperative biometric measurements (axial length, anterior chamber depth, central corneal power) and the measurement of postoperative anterior chamber depth. The spherical aberrations were measured preoperatively and 3 months postoperatively using the iTrace (Tracey Technologies, Houston, TX, USA) at a pupil diameter of 5.0 mm. We investigated the relationships between preoperative biometric data and postoperative internal spherical aberration, and compared biometric measurements between 2 subgroups stratified according to internal spherical aberration (spherical aberration ≤ -0.06 μm vs. spherical aberration > -0.06 μm).ResultsThe mean postoperative internal spherical aberration was -0.087 ± 0.063 μm. Preoperative axial length and residual total spherical aberration showed statistically significant correlations with internal spherical aberration (p = 0.041, 0.002). Preoperative axial length, postoperative anterior chamber depth, IOL power, and residual spherical aberration showed significant differences between the 2 subgroups stratified according to internal spherical aberration (p = 0.020, 0.029, 0.048, 0.041 respectively).ConclusionThe corrective effect of an aspheric IOL is influenced by preoperative axial length and postoperative anterior chamber depth. Not only the amount of negative spherical aberration on the IOL surface but also the preoperative axial length should be considered to optimize spherical aberration after aspheric IOL implantation.

Clinical study inpatient-reported outcomes after binocular implantation of aspheric intraocular lens of different negative spherical aberrations.

To compare patient-reported outcomes after implantation of the ZA9003 intraocular lens (IOLs), or the MCX11 ASP IOLs or the spherical IOLs (HQ-201HEP). Prospective nonrandomized controlled trial was used. A total of 105 patients (210 eyes) were divided into three groups according to the type of IOLs: ZA9003 (35 patients, 70 eyes), MCX11 ASP (35 patients, 70 eyes) or HQ-201HEP (35 patients, 70 eyes). The main outcome was scores of Catquest nine-item short-form questionnaire. Additional outcome was best corrected visual acuities, spherical aberration (SA) and total higher-order aberrations (HOAs). The global score was significantly lower in the spherical IOL group than the aspherical IOL group of-020μm SA (P<0.05) and the aspherical IOL group of-027μm SA (P<0.05), and no significant difference was found in the global score between the aspherical IOL group of-020μm SA than the aspherical IOL group of-027μm SA (P>0.05). Significant differences were also found in question 2, question 5, question 6 and question 8 between the spherical IOLs and the aspherical IOLs. Implantation of an aspherical IOL could improve vision-related quality of life compared with a spherical IOL. However, there were no statistically significant differences in vision-related quality of life between aspheric IOLs with different negative spherical aberrations.

Prospective multicenter trial of a small-aperture intraocular lens in cataract surgery

To evaluate the clinical acceptability of monocular implantationof the small-aperture (IC-8) intraocular lens (IOL) in 1eye and an aspheric monofocal IOL in the fellow eye of bilateral cataract patients over 6months postoperatively. Twelve clinics in Austria, Belgium, Germany, Italy, Spain, and Norway. Prospective case series. The visual acuity, depth of focus, contrast sensitivity, patient satisfaction, visual symptoms, and adverse events were assessed in patients who had bilateral cataract surgery followed by implantation of the small-aperture IOL in 1 eye and an aspheric monofocal IOL in the fellow eye. Uncorrected distance (UDVA), intermediate (UIVA), and near (UNVA) visual acuities were reported in Snellen notation. The study comprised 105 patients. At 6months, the UDVA, UIVA, and UNVA in eyes with the small-aperture IOL were 20/23, 20/24, and 20/30, respectively. Ninety-nine percent, 95%, and 79% of patients achieved 20/32 or better binocular UDVA, UIVA, and UNVA, respectively. Ninety-three patients (95.9%) reported they would have the procedure again versus 4 patients (4.1%) who reported they would not have the procedure again. In eyes with the small-aperture IOL, the target-corrected defocus curve measured with 0.75 diopter (D) of myopia extended the range of functional near vision by an additional diopter without loss of distance vision compared with the distance-corrected defocus curves. The mean UIVA and UNVA remained at 20/25 and 20/32, respectively, for up to 1.5 D of residual astigmatism in eyes with the small-aperture IOL. The small-aperture IOL showed excellent visual performance, safety, patient satisfaction, and tolerance to residual astigmatism 6months after implantation.

Subjective evaluation of uncorrected vision in patients undergoing cataract surgery with (diffractive) multifocal lenses and monovision.

PurposeTo analyze patient satisfaction and difficulties with bilateral multifocal intraocular lenses (IOLs) implantation and aspheric monofocal IOLs implantation using monovision, after cataract surgery.Materials and methodsA total of 61 participants were included in the study, 29 with monovision and 32 with multifocal lenses. The inclusion criteria were patients undergoing phacoemulsification for bilateral visual impairment due to cataracts and presenting with postoperative visual acuity of 20/30 or better for distance and line J3 or better for near vision.ResultsThe 2 groups had similar results regarding difficulties with daily activities such as distance vision, near vision, watching television, reading, cooking, using a computer or cellphone, shaving/putting on makeup and shopping. There were differences in responses between the groups regarding difficulty with night vision (P=0.0565) and night driving (P=0.0291). Degree of satisfaction in terms of distance vision without glasses was statistically significantly better in monovision group (P=0.0332), but not for near (P=0.9101).ConclusionBoth techniques yielded satisfactory results regarding visual acuity for different activities without the need to use glasses. Multifocal lenses are a good option for patients with the exception of night driving, and who desire independence from glasses.

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

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). 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. 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. 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.

A New Extended Depth of Focus Intraocular Lens Based on Spherical Aberration.

To describe a new extended depth of focus intraocular lens (IOL) design offering multifocality by the variation of spherical aberration in the central optical zone. The new IOL (Mini WELL; SIFI, Catania, Italy) is an aspheric IOL with positive spherical aberration in the central 2-mm zone and negative spherical aberration in the pericentral 1-mm annulus, the amount of which was determined by specific optic calculation. The new IOL design was tested at the optical bench to investigate depth of focus and sensitivity to tilt, decentration, and angle Kappa. Visual acuity simulations were obtained from distance (4 m) to near (0.5 m). Modulation transfer function (MTF) for a 3-mm pupil was 0.35 to 0.40 for distance vision and 0.25 to 0.30 for intermediate and near vision. MTF for a 4.5-mm pupil was 0.40 to 0.55 and 0.10 to 0.20, respectively. These values were not influenced by tilt up to ±2.5°, by decentration up to ±0.5 mm, or by angle Kappa up to 9°. Visual acuity simulations indicated good visual acuity up to 2.00 D of pseudoaccommodation. The new IOL with double spherical aberration in the central 3-mm zone offered good MTF over a wide dioptric interval, suggesting good visual acuity between 4 m and 50 cm. This extended depth of focus IOL with no diffractive rings is expected to produce lower unwanted optical phenomena than current multifocal IOLs. [J Refract Surg. 2017;33(6):389-394.].

Comparison on the efficacy between the multifocal and monofocal aspheric toric intraocular lens in cataract patients

Objective To compare the clinical efficacy between the multifocal and monofocal aspheric toric intraocular lens in cataract patients. Methods Seventy-two eyes of 56 patients with age-related cataract underwent phacoemulsification were randomly divided into 2 groups. In group A, the aspheric multifocal toric intraocular lens were implanted in 37 eyes of 29 patients. In group B, the aspheric monofocal toric intraocular lens were implanted in 35 eyes of 27 patients. After surgery, the visual acuity, postoperative residual corneal astigmatism, the IOL axis rotational stability, higher-order aberrations and contrast sensitivity were observed and statistically analyzed. Results At 3 months after surgery, the differences in uncorrected near visual acuities (log MAR) were statistically significant between two groups (t=8.569, P=0.003). There was no significant difference in the uncorrected distance, corrected distance or near visual acuity (log MAR) between two groups (t=1.578、1.325、1.098, P= 0.236、0.281、0.217). There was no significant difference in postoperative residual corneal astigmatism between two groups (t=1.775, P=0.135). There was no significant difference in the axis rotation between two groups (t=2.165, P=0.117). There was no significant difference in the general higher-order aberration, 3-order aberration, 4-order aberration or 5-order aberration root mean square value between two groups (t=1.567, 1.256, 1.457, 1.298, P=0.167, 0.158, 0.136, 0.237). There was no significant differrence at any spatial frequenciy of contrast sensitivity function between two groups (t=1.256, 2.359, 1.238, 2.258, 2.156, 1.982, 2.032, 2.987, P= 0.982, 0.758, 0.875, 0.702, 0.112, 0.189, 0.238, 0.356). Conclusion Phacoemulsification combined with aspheric multifocal toric intraocular lens implantation is an effective method for the correction of preexisting corneal astigmatism in cataract patient. The better uncorrected distance and near visual acuities are obtained for cataract patients. The surgery improves spectacles independence for distance vision and spectacles independence for near vision, with a high patient satisfaction. Key words: Cataract, age-related; Lens, intraocular, multifocal, monofocal, astigmatism-correcting, aspherical

Correlation between axial length and corneal curvature and spherical aberration

Objective: To discuss the correlation between axial length and corneal curvature and corneal spherical aberration in a group of cataract patients with axial length greater than 24 mm. Methods: Retrospective case series. This study comprised 117 (234 eyes) age-related cataract patients. There were 51 men (43.59%) and 66 women (56.41%) with mean age of (69.0±8.7) years (range from 52.0 to 85.0 years). The average axial length was 27.6±1.8 (range from 24.2 to 31.9 mm). We devided them into four groups according to the axial length. A-scan was used to measure the axial length and Pentacam was used to get the corneal curvature and corneal spherical aberration of both anterior and posterior surface. kolmogorov-smirnov test was used to check the normal distribution. ANOVA test was used to compare eachcorneal parameter among different groups. Pearson correlation analysis was used to obtain the correlation of corneal parameters in groups. Results: There were correlations between the axial length and the anterior and posterior corneal curvature (r=-0.213, r=0.174, respectively, P<0.05). No correlation was found between the axial length and anterior or posterior corneal spherical aberration (r=-0.114, 0.055, respectively, P>0.05). Mean values of corneal anterior surface curvature were (45.26±1.60) D (group 1), (44.17±1.45) D (group 2), (44.40±1.99)D (group 3), and (44.53±1.69) D (group 4) respectively. Mean values of corneal posterior surface curvature were(-6.57±0.26)D (group 1), (-6.40±0.24)D (group 2), (-6.41±0.38)D (group 3), and (-6.43±0.26)D (group 4) respectively. There were significant difference of corneal anterior and posterior surface curvature among 4 groups (P=0.004, P=0.001). There was significant difference of corneal curvature of anterior surface in group 1 compared to group 2 and group 3(P<0.01, P=0.01). There was significant difference of curvature of posterior surface in group 1 compared to group 2 and group 3, respectively (P<0.01). Mean values of anterior surface corneal spherical aberration were (2.09±0.53) μm (group 1), (1.90±0.44) μm (group 2), (2.00±0.74) μm (group 3), and (1.78±0.52) μm (group 4) respectively. Mean values of posterior surface corneal spherical aberration were (2.69±1.15) μm (group 1), (2.46±1.16) μm (group 2), (2.92±2.51) μm (group 3), and (2.69±1.13) μm (group 4) respectively. No correlation was found in anterior and posterior surface corneal spherical aberration(P>0.05) among different groups. Conclusions: The eye with a longer axial length have a flatter cornea. Cornea fails to compensate for axial length elongation when the axial length is longer than 28mm. The corneal spherical aberration varies among individuals, which suggests us to do the customized measurement before cataract surgery to make a decision on choosing the aspherical intraocular lens. (Chin J Ophthalmol, 2017, 53: 255-259).

Achromatic doublet intraocular lens for full aberration correction.

A doublet intraocular lens optimized for both chromatic and monochromatic aberration correction in pseudophakic eyes is presented. Ray-tracing techniques were applied to design the lens in white light within a chromatic eye model. Combinations of two materials, already commonly used in intraocular lenses, as acrylic and silicone, were used. Iterative optimization algorithms were employed to correct for longitudinal chromatic aberration, spherical aberration and off-axis aberrations within 10 degrees of visual field. The performance of this lens was compared with a standard single-material aspheric intraocular lens. Near full aberration correction was achieved with the doublet intraocular lens. The modulation transfer function and Strehl ratio were superior for the doublet lens. Through-focus calculations were also conducted showing better optical quality for the doublet. Real higher-order aberrations from normal eyes were incorporated in the model to evaluate the effect on the doublet intraocular lens performance. Results showed that the doublet lens preserved its benefits under realistic conditions. This doublet intraocular lens should provide patients with a better quality of vision after it is further developed in terms of manufacturing and surgical limitations.

In vitro comparative optical bench analysis of a spherical and aspheric optic design of the same IOL model

BackgroundTo analyse objective optical properties of the spherical and aspheric design of the same intraocular lens (IOL) model using optical bench analysis.MethodsThis study entailed a comparative analysis of 10 spherical C-flex 570 C and 10 aspheric C-flex 970 C IOLs (Rayner Intraocular Lenses Ltd., Hove, UK) of 26 diopters [D] using an optical bench (OptiSpheric, Trioptics, Germany). In all lenses, we evaluated the modulation transfer function (MTF) at 50 lp/mm and 100 lp/mm and the Strehl Ratio using a 3-mm (photopic) and 4.5-mm (mesopic) aperture.ResultsAt 50 lp/mm, the MTF values were 0.713/0.805 (C-flex 570 C/C-flex 970 C) for a 3-mm aperture and 0.294/0.591 for a 4.5-mm aperture. At 100 lp/mm, the MTF values were 0.524/0.634 for a 3-mm aperture and 0.198/0.344 for a 4.5-mm aperture. The Strehl Ratio was 0.806/0.925 and 0.237/0.479 for a 3-mm and 4.5-mm aperture respectively. A Mann–Whitney U test revealed all intergroup differences to be statistically significant (p < 0.01).ConclusionThe aspheric IOL design achieved higher MTF values than the spherical design of the same IOL for both apertures. Moreover, the differences between the two designs of the IOL were more prominent for larger apertures. This suggests that the evaluated IOL provides enhanced optical quality to patients with larger pupils or working under mesopic conditions.

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 Ocular Aberration and Clinical Outcome between Different Aspheric Intraocular Lenses in Both Eyes

Comparison of Ocular Aberration and Clinical Outcome between Different Aspheric Intraocular Lenses in Both Eyes

Comparison of visual performance and after cataract formation between two monofocal aspheric intraocular lenses following phacoemulsification for senile cataract: A randomized controlled study.

Purpose:Monofocal aspheric intraocular lenses (IOLs) provide better visual outcome compared to other available IOLs following cataract surgery. However, the imported IOLs are expensive and are not affordable by all subset of patients in low- to middle-income countries like India. The aim of this study is to compare the safety and efficacy of a relatively low cost indigenous IOL (Acriol EC) with an imported aspheric IOL (AcrySof IQ).Methods:A randomized controlled trial was conducted at a tertiary care centre. Two hundred and five eyes of 137 patients >45 years of age with uncomplicated age-related cataract were recruited. All cases underwent standard phacoemulsification and randomly assigned to one of the IOL implantations (Group I: AcrySof IOL; Group II: Acriol EC IOL). Primary outcome measure was best-corrected visual acuity (BCVA). Secondary outcomes included visual function (VF) score, spherical equivalent, contrast sensitivity, optical aberrations, and posterior capsular opacification. Independent t-test to compare two means; Mann–Whitney test; Pearson's Chi-square test, and McNemar's test were used for analyzing the nonparametric data such as incidence of posterior capsule opacification.Results:There was no significant difference in the mean postoperative BCVA at 1, 3, 6, and 12 months in either group (P > 0.05). The contrast sensitivity, wavefront aberrations, VF score, and posterior capsular opacification were comparable between the groups except for higher-order aberrations and spherical aberration, which were higher in Group II.Conclusions:Acriol EC IOL provides visual outcomes comparable to other commonly used aspheric IOLs with comparable safety and efficacy at an affordable cost.

The clinical depth of field achievable with trifocal and monofocal intraocular lenses: theoretical considerations and proof of concept clinical results.

To estimate the depth of field (DOF) achievable with multi-and monofocal intraocular lenses (IOLs) and compare with actual measurements of DOF in cases implanted with a trifocal IOL and biconvex monofocal IOL METHODS: I) Computer simulations were produced to describe the relationship between DOF, pupil size, preoperative ametropia, and retinal blur tolerance limit for a model eye implanted with either multi- or monofocal IOLs. II) Monocular DOF and pupil size were measured under distance viewing conditions between 3 and 6months postoperative following uneventful cataract surgery. Cases were implanted with either i) trifocal aspheric IOL (n = 36), or ii) biconvex aspheric monofocal IOL (n = 26). DOF was also measured at 0.33m in cases implanted with i). Simulations revealed significant associations between DOF, pupil size, and retinal blur tolerance limit. The mean (±SD) DOF & pupil sizes were at distance for i) above 2.59D(0.68) & 3.54mm(0.377), and for ii)above 1.67D(0.51) & 2.90mm(0.351), and for i) above 3.16D(0.46) at near. The difference between groups were significant for DOF and pupil size at distance (p < 0.001). DOF was significantly greater at near compared with distance in i) above (p < 0.001). For a pupil size of 3mm, the simulations produce similar DOF values when the tolerance limit of retinal blur is 10μ. The DOF was significantly better after implanting the trifocal IOL compared with the monofocal IOL, and DOF is increased under near viewing conditions. The clinical results are similar to calculated DOF values when the tolerance limit of retinal blur is 10μ.

The comparative analysis of the effectiveness of implantation of toric, spherical and aspherical intraocular lenses for the surgical treatment of congenital cataract

Objective. The comparative analysis of the outcomes of the surgical treatment of the children presenting with congenital cataract and astigmatism following the implantation of toric, spherical, and aspherical intraocular lenses (IOLs). Materials and methods. A total of 97 children (127 eyes) presenting with congenital cataract were selected for the present study. Group 1 consisted of the patients suffering from corneal astigmatism of more than 1,0 D who had undergone toric IOLs implantation (25 children, 38 eyes). Group 2 was comprised of the patients with corneal astigmatism of more than 1,0 D who had undergone implantation of spherical and aspherical intraocular lenses (40 children, 48 eyes). Group 3 was composed of 32 children (41 eyes) with corneal astigmatism of less than 1,0 D who had undergone implantation of non-toric intraocular lenses. Lensectomy was performed with the use of the small (1,8 mm and 2,2 mm) incision technique. Various IOL models (Alcon, USA) were used for implantation. The vector analysis of astigmatic correction (Alpinus) was employed to evaluate the quality of astigmatism correction. Results. The patients of all groups experienced a significant improvement of postoperative non-correctable and maximally correctable visual acuity during the long-term follow-up period (over 3 years in duration). In the children comprising group 1, the estimated value of vector astigmatism (-0,72) was close to the actual postoperative value (-0,81). The TIA axis was 113,7 degrees and the SIA axis 92,6 degrees. The vector difference was 0,18 diopters which suggested the high precision of astigmatism correction. The correction index averaged 1,12 ± 0,14. The IOL index was 0,25 ± 0,16 in comparison with its ideal value of 0.0. In the children of group 2, the estimated value of vector astigmatism (-0,87) was significantly higher than the actual postoperative values (-0,56). The TIA axis was 134,3 degrees and the SIA axis 77,1 degrees (p

Comparison of visual function and patient satisfaction with AcrySof ReSTORSN6AD1 multifocal intraocular compared to monofocal intraocular lenses 5

Aim. To compare visual function and satisfaction in patients after implantation of AcrySof ReSTOR SN6AD1 multifocal intraocular lens (IOL), AcrySof SA60AТ spherical monofocal IOL, or Akreos АО aspheric monofocal IOL during cataract surgery.&#x0D; Materials. Overall, 34 patients received SN6AD1 multifocal (group 1, 48 eyes), 19 patients received Akreos АО monofocal aspheric (group 2, 30 eyes), and 13 patients received AcrySof SA60AТ monofocal spherical (group 3, 18 eyes) IOL. Patients with multifocal IOL were closely matched for age, sex, and ocular findings with patients who had monofocal IOL implantation. Six months postoperatively, uncorrected/corrected distance visual acuity (UDVA/CDVA), uncorrected intermediate (60 cm) and near (35 cm) visual acuity (UNVA), defocus curve, contrast sensitivity, and a quality-of-life questionnaire were evaluated. Furthermore, independence from glasses and presence of optical phenomena were assessed.&#x0D; Results. Patients in group 2 had statistically significant increase in UDVA than that in group 1 (p = 0.037). There was no significant difference in the mean uncorrected intermediate and best corrected distance visual acuities between the groups. UNVA was better in group 1 than that in groups 2 and 3 (p 0.0001). Photopic contrast sensitivity for high spatial frequencies was better in groups 2 and 3. Glare was reported in 5.9% of patients in group 1. Halos occurred in 32.4% of patients in group 1. No one reported undesirable visual symptoms in groups 2 and 3.&#x0D; Conclusion. Multifocal IOLs provided higher spectacle independence and satisfactory functional vision over a broad range of distances but were associated with increased subjective visual symptoms and reduced photopic contrast sensitivity for high spatial frequencies and distance visual quality compared with monofocal IOLs.