Optimizing higher-order aberrations with intraocular lens technology

Comparative visual performance of diffractive bifocal and rotationally asymmetric refractive intraocular lenses

We compared the visual performance of a diffractive bifocal intraocular lens (IOL) with + 4.0 D near addition (ZMB00 [Johnson & Johnson Surgical Vision]) and a rotationally asymmetric refractive IOL with + 1.5 D near addition (LS-313 MF15 [Teleon Surgical BV]) 10 weeks after cataract patients' last surgery for bilateral ZMB00 or LS-313 MF15 implantation between 2011 and 2020, with the lenses of each eye implanted within 3 months of each other. The ZMB00 and LS-313 MF15 groups comprised 1326 eyes of 663 patients (age: 67.0 ± 7.8 years; females/males, 518/145) and 448 eyes of 224 patients (73.6 ± 7.0 years; females/males, 125/99), respectively. A linear mixed-effects model using data for both eyes, with strict adjustments for sex, age, subjective refraction spherical equivalent, subjective refraction cylinder, corneal astigmatism, axial length, corneal higher-order aberrations, and pupil diameter, ensured statistical validity. Compared to LS-313 MF15, ZMB00 achieved significantly superior uncorrected near visual acuity, reduced higher-order aberrations (ocular/internal, scaled to a 4-mm pupil; Wavefront_4_post_Ocular_Total Higher-Order Aberration/Third/Fourth/Trefoil/Coma/Tetrafoil/Spherical, Wavefront_4_post_Internal_Astigmatism/Total Higher-Order Aberration/Third/Trefoil/Coma/Tetrafoil/Spherical), and superior distance and near spectacle independence (p < 0.00068, Wald test). Contrast sensitivity, measured without (visual angle of the test target: 6.3°/4.0°/2.5°/1.6°/1.0°/0.7°) or with glare (4.0°/2.5°/1.6°/1.0°/0.7°), was significantly better in the LS-313 MF15 than the ZMB00 group (p < 0.00068, Wald test).

Effect of cataract incision type on corneal spherical aberration

Corneal spherical aberration (CSA) plays an important role in the ocular refractive system. However, ophthalmologists have not considered the effect of difference cataract incisions on it. The purpose of this study is to investigate the effect of transparent corneal incision (TCI) and scleral tunnel incision (STI) on CSA after the cataract phacoemulsification with foldable IOLs. One hundred ninety-three eyes (61 males and 79 females) for 1-month observation and 114 eyes (29 males and 51 females) for 3-month observation with age-related cataracts (ARC) were included in this study. CSA was measured with dilated pupil by Pentacam Scheimpflug system at 1 day preoperative and 1, 3-month postoperative. Preoperative CSA >1.00 μm was excluded. Both TCI and STI are 3 mm incisions with Infiniti system and Ozil handpiece. No significant difference of age or gender was found between TCI and STI groups in 1 or 3-month observation. In 1-month observation, preoperative CSA for TCI and STI are 0.31 ± 0.29 and 0.41 ± 0.19 μm, which of postoperative are 0.42 ± 0.17 and 0.44 ± 0.35 μm, respectively. The change of CSA is 0.11 ± 0.32 and 0.04 ± 0.33 μm (P = .233). For 3-month observation, preoperative CSA for TCI and STI are 0.32 ± 0.28 and 0.36 ± 0.23 μm, which of postoperative are 0.43 ± 0.16 and 0.39 ± 0.26 μm, respectively. The change of CSA is 0.10 ± 0.34 and 0.03 ± 0.21 μm (P = .312). For the phacoemulsification combined with foldable IOL implantation, STI has minimal effect on CSA, but TCI might increase postoperative CSA.

Comparison of visual performance between monofocal and multifocal intraocular lenses of the same material and basic design

To compare the visual performance of a monofocal intraocular lens (IOL) (ZCB00) and a multifocal IOL (ZMB00) of the same material and basic design, we evaluated postoperative parameters at 10 weeks after the last surgery in cataract patients who underwent bilateral ZCB00 or ZMB00 implantation from December 13, 2010, to July 29, 2019, with the right and left lenses implanted within 3 months of each other. The study enrolled 2,230 eyes of 1,115 patients. The monofocal group comprised 904 eyes of 452 patients (72.3 ± 6.8 years; females/males, 268/184), and the multifocal group comprised 1,326 eyes of 663 patients (67.0 ± 7.8 years; females/males, 518/145). Contrast sensitivity (4.0/2.5/1.6/1.0/0.7 degrees), contrast sensitivity with glare (1.6/1.0/0.7 degrees), and the VFQ-25 score for driving at night were significantly better in the monofocal group (p < 0.00068, Wald test). Uncorrected intermediate/near visual acuity and near spectacle independence were significantly better in the multifocal group (p < 0.00068, Wald test). The two IOL groups had different characteristics in terms of contrast sensitivity, night-time driving, uncorrected intermediate/near visual acuity and near spectacle independence.

Influence of Intraocular Lens Asphericity and Blue Light Filtering on Visual Outcome, Contrast Sensitivity, and Aberrometry after Uneventful Cataract Extraction

Purpose

To evaluate the effect of asphericity and blue light filter (BLF) of three different intraocular lenses (IOLs) on the visual performance, second- and third-order aberrations (defocus, coma, trefoil), and contrast sensitivity after uneventful cataract surgery.

Methods

One hundred and twenty eyes of 60 patients with clinically significant cataract were randomly assigned to receive one of the three IOL types: Bioline Yellow Accurate (aspheric, with BLF, i-medical, Germany), BioAcryl 60125 (spherical, without BLF, Biotech, France), and H65C/N (aspheric, without BLF, PhysIOL, Belgium). Each IOL was implanted in 40 eyes. Complete ophthalmologic examination, functional acuity contrast testing and wavefront analysis were performed 60 days postoperatively.

Results

The mean postoperative best-corrected visual acuity (BCVA) was 0.95 ± 0.08, not differing statistically among the IOL groups (P = 0.83). Mean defocus and coma values did not yield any statistically significant difference through the IOL groups varying from –0.784 to –0.614 μm and 0.129 to 0.198 μm (P = 0.79 and 0.34, respectively). Bioline Yellow Accurate IOL presented less trefoil aberrations, 0.108 ± 0.05 μm, compared to the other two IOL types (BioAcryl [0.206 ± 0.19 μm] and Physiol [0.193 ± 0.17 μm], P< 0.05). Contrast sensitivity values did not differ among the groups under all lighting conditions. Bioline Yellow IOL showed a statistically higher loss of contrast sensitivity (between mesopic and mesopic with glare conditions) compared to the BioAcryl and PhysIOL in 12 and 3 cpd spatial frequencies, respectively (P< 0.05).

Conclusion

Bioline Yellow IOL indicated lower contrast sensitivity under mesopic conditions when glare was applied but resulted in less trefoil aberrations after uneventful cataract surgery. No further differences were noted in postoperative visual performance among three IOL groups.

Higher-Order Aberrations in Children and Adolescents of Southwest China

SIGNIFICANCE

This study provides a descriptive characterization of higher-order optical aberrations for the eyes of a larger number of Chinese children and adolescents.

PURPOSE

To determine the distribution of higher-order aberrations (HOAs) of Han Chinese young subjects with normal vision and their relationship to age.

METHODS

Children and adolescents, aged from 3 to 17 years, with normal visual acuity were enrolled, and their wavefront aberrations for a 6-mm pupil were evaluated by the Zywave II aberrometer. Their correlations with age were analyzed, and the 95% statistical reference ranges were computed for each Zernike term.

RESULTS

A total of 1634 eyes (287 for preschool-age children, 897 for school-age children, and 450 for adolescents) were analyzed. There was a significant correlation with age and the root mean square (RMS) of total HOAs (r = 0.256, P < .0001), third-order aberrations (r = 0.062, P = .029), fourth-order aberrations (r = 0.197, P < .0001), fifth-order aberrations (r = 0.067, P = .017), and trefoil-like aberrations (r = 0.100, P < .0001) in the myopic group. There were significant differences in RMS values (except coma-like aberrations, χ = 4.179, P = .124) as well as the Zernike coefficients among three different age groups. Therefore, the 95% statistical normal reference values were calculated separately for three age groups.

CONCLUSIONS

The RMS value of total HOAs, coma-like, trefoil-like, third-order, fourth-order, and fifth-order aberrations are correlated with age, and the RMS values and Zernike coefficients of aberrations were different in different age stages of the subjects. This study described the distribution of HOAs in children and adolescents and established 95% statistical normal values of HOAs for different ages of children and adolescents by analyzing the HOAs in a large number of the Han Chinese clinical population.

Visual acuity and patient satisfaction at varied distances and lighting conditions after implantation of an aspheric diffractive multifocal one-piece intraocular lens

PURPOSE

The aim of the study is to evaluate the visual acuity and patient satisfaction at varied distances under photopic and mesopic lighting conditions in patients bilaterally implanted with aspheric diffractive multifocal one-piece intraocular lenses.

METHODS

In this retrospective-prospective study, 16 patients with a mean age of 66.2±9.2 years (range: 50-81 years) who had undergone bilateral phacoemulsification surgery with implantation of a Tecnis multifocal one-piece intraocular lens (ZMB00) were evaluated. Monocular and binocular uncorrected and distance-corrected visual acuities were measured at distance (20 ft), intermediate (70-80 cm), and near (35-40 cm) under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) lighting conditions and were compared using the paired t-test. All patients also completed a subjective questionnaire.

RESULTS

At a mean follow-up of 9.5±3.9 months, distance, near, and intermediate visual acuity improved significantly from preoperative acuity. Under photopic and mesopic conditions, 93.8% and 62.5% of patients, respectively, had binocular uncorrected intermediate visual acuity of 20/40 or better, and 62.5% and 31.3% of patients had binocular uncorrected near visual acuity of 20/20 or better. All patients were satisfied with their overall vision without using glasses and/or contact lenses when compared with before surgery. A total of 87.5% of patients reported no glare and 68.8% of patients reported no halos around lights at night.

CONCLUSION

Tecnis multifocal one-piece intraocular lenses provide good distance, intermediate, and near visual acuity under photopic as well as mesopic lighting conditions. High levels of spectacle independence with low levels of photic phenomenon were achieved, resulting in excellent patient satisfaction.

A limitation of Hartmann-Shack system in measuring wavefront aberrations for patients received laser refractive surgery

Purpose

To explore the relationship between ablation parameters of myopic laser surgery and measurement area of wavefront aberration (WA) with Hartmann-Shack wavefront sensor.

Methods

58 subjects undergone myopic laser surgeries and 74 uncorrected myopic subjects were enrolled in this experiment. The laser ablation parameters were obtained from surgical records, which included spherical error (Rx), depth, and optical zone (OZ) of ablation. The measured area of WA was tested by the WASCA, and the real pupil size was tested by Pentacam. The corneal eccentricity (E value) and curvature was also measured with the Pentacam. All the measurements were performed under mydriatic condition.

Results

For uncorrected myopic eyes, the measured area of WA was similar with the real pupil size. But for the corrected eyes, the measured area of WA was smaller than the real pupil size with a mean difference of 0.66 ± 0.54 mm for moderate myopia (t = 6.45, p < 0.0001) and 1.76 ± 0.55 mm for high myopia (t = 18.92, p < 0.0001), but not for mild myopia. The Rx (t = -3.20, p = 0.0017), OZ (t = 64.4, p < 0.0001) and postoperative corneal E value (t = 2.52, p = 0.017) were the independent factors of measured area of WA. Measured area of WA = -0.81*Rx + 1.13*OZ + 0.49*postoperative corneal E value (r² = 0.997).

Conclusions

The WASCA has a limitation in measuring wavefront aberration over the whole pupil area when it’s used for patients received myopic laser surgery. The measured area is smaller than the real pupil size and depends linearly on ablation depth, optical zone and corneal eccentricity.

Clinical study of customized aspherical intraocular lens implants

AIM

To compare if there is an improvement in visual functions with age-related cataracts between patients receiving a aspherical intraocular lens (IOL) based on corneal wavefront aberration and patients randomly assigned lenses.

METHODS

A total of 124 eyes of 124 patients with age-related cataracts were placed in experimental group and a group receiving randomly assigned (RA) lenses. The experimental group was undergone Pentacam corneal spherical aberration measurement before surgery; the targeted range for residual total spherical aberration after surgery was set to 0-0.3 µm. Patients with a corneal spherical aberration <0.3 µm were implanted with a zero-spherical aberration advanced optics (AO) aspherical IOL and patients with an aberration ≥0.3 µm received a Tecnis Z9003 aspherical lens in experimental group. RA patients were randomly implanted with an AO lens or a Tecnis Z9003 lens. Three months after surgery total spherical aberration, photopic/mesopic contrast sensitivities, photopic/mesopic with glare contrast sensitivities, and logMAR vision were measured.

RESULTS

Statistical analysis on logMAR vision showed no significant difference between two groups (P=0.413). The post-surgical total spherical aberration was 0.126±0.097 µm and 0.152±0.151 µm in the experimental and RA groups, respectively (P=0.12). The mesopic contrast sensitivities at spatial frequencies of 6, 12 and 18 c/d in the experimental group were significantly higher than of the RA group (P=0.00; P=0.04; P=0.02). The mesopic with glare contrast sensitivity in the experimental group at a spatial frequency of 18 c/d was also significantly higher vs the RA group (P=0.01).

CONCLUSION

Pre-surgical corneal spherical aberration measurement in cataract patients followed by customized selection of aspherical IOL implants improved mesopic contrast sensitivities at high spatial frequencies, and thus is a superior strategy compared to the random selection of aspherical IOL implants.

Visian implantable contact lens versus AcrySof Cachet phakic intraocular lenses: comparison of aberrmetric profiles

Purpose

To evaluate the in vivo aberrometric performance of two phakic intraocular lenses (PIOLs); the Visian implantable contact lens (ICL) and the AcrySof Cachet PIOL.

Methods

Thirty eight eyes from 29 patients with an age range of 23–32 years and more than 9 D of myopia were divided into two groups; one group of 20 eyes received a Visian ICL model V4c, another group of 18 eyes received an AcrySof Cachet PIOL. Total higher order aberrations (HOAs) root mean square, total coma, and total spherical aberrations were recorded pre and 6 weeks postoperatively to evaluate and compare the aberrometric performance of the Visian ICL and the AcrySof Cachet PIOL implanted in highly myopic patients.

Results

Preoperatively, there were no significant differences in any studied parameters, except for preoperative spherical equivalent. Postoperatively, there were no statistically significant differences in the induction of HOAs between both PIOLs. The reduction in spherical aberrations was statistically significant in each group as well as in all study patients.

Conclusion

Both AcrySof Cachet PIOL and ICLs are effective phakic implants to correct high refractive errors. They both induce small amounts of negative spherical aberration that do not affect the total HOAs, yet reduce the positive ocular spherical aberration. This result is expected to improve the quality of vision in such patients.

Full OCT anterior segment biometry: an application in cataract surgery

In vivo three-dimensional (3-D) anterior segment biometry before and after cataract surgery was analyzed by using custom high-resolution high-speed anterior segment spectral domain Optical Coherence Tomography (OCT). The system was provided with custom algorithms for denoising, segmentation, full distortion correction (fan and optical) and merging of the anterior segment volumes (cornea, iris, and crystalline lens or IOL), to provide fully quantitative data of the anterior segment of the eye. The method was tested on an in vitro artificial eye with known surfaces geometry at different orientations and demonstrated on an aging cataract patient in vivo. Biometric parameters CCT, ACD/ILP, CLT/ILT Tilt and decentration are retrieved with a very high degree of accuracy. IOL was placed 400 μm behind the natural crystalline lens, The IOL was aligned with a similar orientation of the natural lens (2.47 deg superiorly), but slightly lower amounts (0.77 deg superiorly). The IOL was decentered superiorly (0.39 mm) and nasally (0.26 mm).

Effect of a single-piece aspheric hydrophobic acrylic intraocular lens design on centration and rotation

PURPOSE

To assess the rotation and centration stability of the new design features of a 1-piece aspheric hydrophobic acrylic intraocular lens (IOL).

SETTING

National Eye Hospital, Cairo, Egypt.

DESIGN

Randomized clinical trial.

METHODS

Patients in this study had implantation of a 1-piece Tecnis 1 ZCB00 IOL or a 3-piece Sensar AR40e IOL. Decentration and rotation were recorded immediately postoperatively, and 2 to 3 days and 8 weeks postoperatively. This was done using 2 slitlamp eyepieces and referring to constant corneal landmarks (ie, the limbus and the phaco incision).

RESULTS

Thirty-two 1-piece IOLs and 30 3-piece IOLs were implanted. Although the 1-piece IOLs moved toward the corneal center more than the 3-piece IOLs between 3 days and 8 weeks postoperatively (P=.054), the difference was not statistically significant between 0 day and 3 days or during the entire follow-up (P=.546 and P=.367, respectively). There were no statistically significant differences in the horizontal or vertical components of this movement between the 2 groups (P=.883 and P=.636, respectively). The mean rotation was 2.5 degrees ± 9.1 (SD) in the 1-piece IOL group and 0 ± 6.5 degrees in the 3-piece IOL group, with no statistically significant difference between the groups (P=.521).

CONCLUSION

The new 1-piece design showed relatively good centration and stability in the horizontal, vertical, and rotational aspects.

Visual and aberrometric outcomes in eyes with an angle-supported phakic intraocular lens

PURPOSE

To evaluate the postoperative changes in spherical aberration and the point-spread function (PSF) induced by the implantation of a new angle-supported phakic intraocular lens (pIOL).

SETTING

Department of Ophthalmology, St. Bassiano Hospital, Bassano del Grappa, Italy.

DESIGN

Prospective nonrandomized cohort study.

METHODS

Eyes with high myopia had implantation of an Acrysof Cachet angle-supported pIOL. Preoperative and postoperative total spherical aberration and PSF were measured using a Luneau 80 Wave+ wavefront aberrometer (high-resolution Hartmann-Shack technology) at a fixed entrance pupil scan size of 5.0 mm under pharmacologic mydriasis. Preoperative and postoperative data were analyzed and compared using the Student t test.

RESULTS

Thirty-five eyes of 18 patients were included in the statistical analysis. The Student t test for paired data (95% confidence interval) showed a statistically significant difference between preoperative data and postoperative data. The mean preoperative total spherical aberration Z(4,0) was -0.001 μm ± 0.076 (SD) preoperatively and -0.13 ± 0.11 μm postoperatively (P≤.05). The mean PSF was 0.28 ± 0.15 preoperatively and 0.34 ± 0.16 postoperatively (P<.05).

CONCLUSION

Implantation of the angle-supported pIOL in eyes with high myopia improved the quality of vision, inducing negative spherical aberration and increasing the PSF under mesopic conditions.

Comparison of retinal image quality with spherical and customized aspheric intraocular lenses

We hypothesize that an intraocular lens (IOL) with higher-order aspheric surfaces customized for an individual eye provides improved retinal image quality, despite the misalignments that accompany cataract surgery. To test this hypothesis, ray-tracing eye models were used to investigate 10 designs of mono-focal single lens IOLs with rotationally symmetric spherical, aspheric, and customized surfaces. Retinal image quality of pseudo-phakic eyes using these IOLs together with individual variations in ocular and IOL parameters, are evaluated using a Monte Carlo analysis. We conclude that customized lenses should give improved retinal image quality despite the random errors resulting from IOL insertion.

Effect of interaction of macroaberrations and scattered light on objective quality of vision in pseudophakic eyes with aspheric monofocal intraocular lenses

PURPOSE

To assess the impact of wavefront ocular aberrations on objective vision quality and depth of focus in pseudophakic patients.

SETTING

University Hospital Bretonneau of Tours, Francois Rabelais Medicine Faculty of Tours, France.

DESIGN

Cohort study.

METHODS

Consecutive eyes having implantation of an aspheric monofocal intraocular lens (IOL) (Acri.Smart) were studied. Aberrometry measurements were performed under mesopic conditions with a 6.0 mm pupil using a Wavescan aberrometer. Objective evaluation of optical vision quality was performed using the Optical Quality Analysis System II. The 3 measurements were the modulation transfer function values (MTF cutoff); objective depth of focus, which was computed as the focus range at which Strehl ratio did not fall below 50% of the maximum; and the objective scatter index.

RESULTS

Fifty-four eyes (30 patients) were enrolled. Six months postoperatively, MTF cutoff values were increased with decreasing total ocular spherical aberration, ocular trefoil, and 2nd-order astigmatism (P<.05). Objective depth of focus was positively correlated with 2nd-order astigmatism (r(2) = 0.171, P<.001) and total spherical aberration (r(2) = 0.091, P=.028). Objective scatter was more beneficial for depth of focus, with a significantly positive correlation with this parameter (r(2) = 0.28, P=.002), than compromising of optical quality (no significant correlation with MTF measurements in same multiple regression analysis).

CONCLUSION

Three ocular aberrations (2nd-order astigmatism, trefoil, spherical aberration) seemed to interact with objective contrast sensitivity and depth of focus, whereas residual spherical aberration exerted opposite effects on image quality in individual patients.

Effects on vision with glare after correction of monochromatic wavefront aberrations

PURPOSE

To investigate effects of optical aberration correction on vision with glare.

METHODS

Correction of aberrations up to the 6th Zernike order (closed-loop correction) was compared with conventional spectacle correction in 42 healthy eyes. To create these corrections, an adaptive optics system including a thin-film transistor (TFT) monitor for displaying optotypes with additional glare sources was used. Employing both corrections, visual acuity and contrast sensitivity (CS) were tested alternately with and without glare. Disability glare was computed as the difference between log CS without and with glare. Individuals were also asked to rate subjectively the quality of three images displayed on the TFT monitor.

RESULTS

Significant improvements of CS without and with glare were found with the closed-loop correction (0.147 and 0.198 log CS, respectively), whereas no significant difference in visual acuity was found in either correction. Correlations were determined between reduction of total root-mean-square error and increase of CS with glare (Pearson correlation coefficient r=0.42) and decrease of disability glare (r=-0.33). Visual acuity was correlated with the visual Strehl ratio based on the optical transfer function (r=0.46). Subjective comparison of the images showed improvements more clearly. Depending on the image, in 57% to 78% of the eyes, closed-loop correction was rated better than spectacle correction. The subjective glare effect was reduced as well.

CONCLUSIONS

Investigation of vision with glare seems to be a reasonable additional test to evaluate the visual outcome of a customized correction.

Effect of residual ocular spherical aberration on objective and subjective quality of vision in pseudophakic eyes

PURPOSE

To determine the level of residual spherical aberration that gives the best objective and subjective quality of image after cataract surgery with intraocular lens (IOL) implantation.

SETTING

Department of Ophthalmology, CHU Bretonneau, Tours, France.

DESIGN

Cohort study.

METHODS

Six months after microincision (1.8 mm) cataract surgery with aspheric IOL implantation, total aberrations were computed using a Wavescan aberrometer. The modulation transfer function (MTF), Strehl ratio, and objective index of scattering were measured using the Objective Quality Analysis System. Objective depth of focus was computed as the focus range at which the Strehl ratio did not fall below 50% of maximum. Subjective depth of focus was calculated as the difference between the vergence of the punctum remotum and that of the punctum proximum.

RESULTS

Thirty patients (54 eyes) were evaluated. The MTF cutoff values were higher with decreasing total ocular spherical aberration (r = 0.56; P < .05). Objective and subjective depth of focus were positively correlated with total spherical aberration (r = 0.26 and r = 0.46, respectively; P < .05).

CONCLUSIONS

A final spherical aberration of zero obtained by compensation of IOL asphericity gave the greatest improvement in objective quality of vision and better MTF contrast. However, a final target ocular spherical aberration between 0.07 μm and 0.10 μm should be considered to be the best compromise between subjective depth of focus and objective contrast sensitivity.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Aspheric microincision intraocular lens implantation with biaxial microincision cataract surgery: efficacy and reliability

PURPOSE

To evaluate the efficacy and reliability of a microincision intraocular lens (IOL) and its use in biaxial microincision cataract surgery (MICS).

SETTING

Atatürk Training and Research Hospital, Ankara, Turkey.

DESIGN

Prospective clinical study.

METHODS

A microincision IOL (Akreos MI60) was implanted after cataract extraction by the biaxial MICS technique. Over a postoperative follow-up of 12 months or more, visual acuity, contrast sensitivity, surgically induced astigmatism (SIA), corneal and ocular aberrations, and early and late complications were recorded.

RESULTS

The IOLs were implanted in the capsular bag in all 100 eyes. The mean final incision size was 1.82 mm ± 0.09 (SD). Postoperatively, the mean corrected distance visual acuity was 0.06 ± 0.10 logMAR; the mean spherical equivalent, -0.48 ± 0.91 diopter (D); and the mean calculated SIA, 0.20 ± 0.22 D. Contrast sensitivity with and without glare was within normal limits. There was no statistically significant difference in the root mean square of total corneal aberrations between preoperatively and postoperatively. Ocular wavefront analysis 3 months postoperatively showed mean values of 0.15 ± 0.2 μm for spherical aberration, 0.38 ± 0.16 μm for higher-order aberrations, 0.18 ± 0.14 μm for coma, and 0.14 ± 0.08 μm for trefoil. The 4 cases (4.0%) of membranous anterior chamber reaction resolved with treatment. None of the 20 eyes (20.0%) with posterior capsule opacification required neodymium:YAG capsulotomy. All IOLs remained well centered.

CONCLUSION

The aspheric microincision IOL was safely implanted through a 1.8 mm or smaller incision during biaxial MICS and gave good postoperative outcomes.

Changes in higher order wavefront aberrations after contact lens corneal refractive therapy and LASIK surgery

PURPOSE

To compare ocular higher order aberrations induced by corneal refractive therapy (CRT, Paragon Vision) to those produced by LASIK for patients with comparable levels of myopia.

METHODS

A retrospective chart review of 11 patients who used CRT lenses and 12 patients who underwent LASIK for correction of low to moderate myopia was performed. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, and optical higher order aberrations were recorded before and 1 month after treatment for each patient.

RESULTS

The CRT group consisted of 11 patients (4 men, 7 women) with a mean age of 29.1+/-5.2 years (range: 23 to 40 years), and the LASIK group consisted of 12 patients (3 men, 9 women) with a mean age of 39.2+/-12.0 years (range: 23 to 60 years). Manifest refraction decreased statistically significantly from -2.81+/-1.05 diopters (D) at baseline to -0.77+/-0.64 D following CRT treatment at 1 month (P<.0001) and from -3.11+/-1.21 D at baseline to -0.43+/-0.27 D at 1 month after LASIK (P<.0001). Both CRT and LASIK exhibited no significant changes in total higher order aberrations for 4-mm pupils but induced statistically significant increases in total higher order aberrations for 6-mm pupils. Corneal refractive therapy and LASIK both exhibited statistically similar factors of change for total higher order aberrations and coma-like higher order aberrations for 6-mm pupils. Corneal refractive therapy demonstrated a statistically significant greater factor of increase in spherical-like higher order aberrations for 6-mm pupils (P=.01).

CONCLUSIONS

Contact lens corneal refractive therapy and LASIK can effectively correct myopia, but both increase higher order aberrations for 6-mm pupils to a similar degree. However, spherical-like aberrations were statistically significantly greater after CRT than after LASIK.

Evaluation of the aspheric tecnis multifocal intraocular lens: one-year results from the first cohort of the food and drug administration clinical trial

PURPOSE

To evaluate the safety and effectiveness of the aspheric diffractive Tecnis multifocal ZM900 (TCMF) intraocular lens (IOL; Abbott Medical Optics, Inc, Santa Ana, California, USA).

DESIGN

One-year, nonrandomized, multicenter, evaluator-masked, bilateral, parallel-group comparative clinical evaluation.

METHODS

Subjects underwent bilateral implantation with the TCMF IOL or the CeeOn 911A monofocal (CEMN) IOL (Abbott Medical Optics, Inc) according to subject preference.

RESULTS

One-year results were available for 244 eyes of 125 TCMF IOL subjects and for 245 eyes of 123 CEMN IOL subjects. Mean distance visual acuities (VAs) were statistically and clinically equivalent between the 2 groups. Mean binocular and monocular uncorrected and distance-corrected near VAs were significantly better for the TCMF IOL versus the CEMN IOL group (P < .0001). A greater proportion of TCMF IOL versus CEMN IOL subjects achieved binocular combined VAs of 20/25 distance and 20/32 near (84.2% [96/114] vs 6.2% [7/113]; P < .0001). The TCMF IOL group had excellent depth of focus, maintaining a mean of 20/40 or better for far, intermediate, and near distances. Mean contrast sensitivity scores were lower for the TCMF IOL versus the CEMN IOL group, but the differences were not considered clinically significant. Halos and night glare were more common in the TCMF IOL versus the CEMN IOL groups. Both reading acuity (20/20 vs 20/47; P < .0007) and speed (148 vs 117 words/minute; P < .0001) were significantly better for the TCMF IOL versus the CEMN IOL group, as were the proportions of the TCMF IOL group versus the CEMN IOL group that achieved spectacle independence (84.8% vs 5.2%; P < .0001) and that functioned comfortably at near without glasses (96.4% vs 30.4%; P < .0001).

CONCLUSIONS

The TCMF IOL provided enhanced near VA, reading acuity per speed, depth of focus, and spectacle independence compared with the monofocal IOL.

Ocular wavefront analysis and contrast sensitivity in eyes implanted with AcrySof IQ or AcrySof Natural intraocular lenses

PURPOSE

This study aimed to compare ocular wavefront aberrations for pupil diameters of 4 mm and 6 mm, and contrast sensitivity, in eyes with AcrySof IQ and AcrySof Natural intraocular lenses (IOLs).

METHODS

Sixty eyes of 60 patients were enrolled in this prospective randomized study. After phacoemulsification the eyes received either AcrySof IQ SN60WF or AcrySof Natural SN60AT IOLs. One month after surgery, all patients underwent complete ophthalmological examination including corneal topography, wavefront analysis for pupil diameters of 4 mm and 6 mm, and contrast sensitivity measurements with the CSV 1000E instrument under photopic and mesopic conditions with and without glare.

RESULTS

 There was no statistically significant difference between groups in age, sex or other preoperative ocular characteristics (p > 0.05). Patients with AcrySof IQ IOLs had higher contrast sensitivity at 6 c.p.d. under photopic conditions, at 6 c.p.d. and 18 c.p.d. under mesopic conditions, and at 6 c.p.d., 12 c.p.d. and 18 c.p.d. under mesopic conditions with glare (p < 0.05). Corneal spherical aberration was 0.273 ± 0.074 μm in the AcrySof Natural group and 0.294 ± 0.086 μm in the AcrySof IQ group (p = 0489). Ocular spherical aberration was 0.362 ± 0.141 μm and 0.069 ± 0.043 μm (p < 0.001) for 6-mm diameter pupils and 0.143 ± 0.091 μm and 0.017 ± 0.016 μm (p < 0.001) for 4-mm diameter pupils, with AcrySof Natural and AcrySof IQ IOLs, respectively. There were no significant differences in other higher-order aberrations between the groups (p > 0.05).

CONCLUSIONS

Aspherical AcrySof IQ IOLs significantly reduced spherical aberration for pupil diameters of both 4 mm and 6 mm and also improved contrast sensitivity more than spherical AcrySof Natural IOLs, especially in mesopic conditions.

Relationship between contrast sensitivity and spherical aberration: comparison of 7 contrast sensitivity tests with natural and artificial pupils in healthy eyes

PURPOSE

To find a contrast sensitivity test that can be used clinically to evaluate interventions aimed at minimizing spherical aberration and determine the circumstances under which these tests should be performed.

SETTING

Laboratory of Experimental Ophthalmology, University of Groningen, Groningen, The Netherlands.

METHODS

Contrast sensitivity tests were performed using 2 experimental designs. Design 1 was with a natural pupil under mesopic and photopic conditions. Design 2 was with a 5.0 mm artificial pupil after cycloplegia under photopic conditions only. Two computerized tests (vertical sine-modulated gratings [VSG] and Holladay circular sine-modulated patterns [HACSS]) and 5 chart tests (Pelli-Robson, acuity-measuring letter charts at low contrast [2.5% and 10%], VectorVision, and edge contrast sensitivity) were used. Spherical aberration was assessed with a Hartmann-Shack wavefront analyzer.

RESULTS

Forty-nine healthy subjects aged 20 to 35 years (n = 24) and 55 to 70 years (n = 25) participated. Design 2 showed a significant relationship between contrast sensitivity and spherical aberration with the HACSS at 3 cycles per degree (cpd) (P = .03) and 6 cpd (P = .01) and with the VSG at 6 cpd (P = .01). Design 1 yielded no significant relationships.

CONCLUSIONS

Using an artificial pupil, a relationship between contrast sensitivity and spherical aberration was established with the VSG and HACSS tests but not with the chart tests. No test showed a relationship using natural pupils under either lighting condition. Chart tests are unsuitable for uncovering contrast sensitivity differences related to differences in spherical aberration, as typically found in healthy phakic eyes.