Primary Spherical Aberration Research Articles

Received power attenuation due to the wave-front aberrations induced by the receiving optical antenna in an inter-satellite laser communication link

Due to the design defect, adjustment error, thermal deformation and gravity deformation in orbit, the bad optical antenna of the communication receiving terminal in an inter-satellite laser communication link will induce aberrations to the received wave-front. This will cause attenuation of the received power and deterioration of the bit error rate (BER) performance. The calculation model of the compensated and normalized received power is established when the received light spot is pointed at the center of the focal plane and the limited receiving radius is considered. The numerical results show that, for receivers with a single first-order Zernike mode wave-front aberration, the primary spherical aberration has the most influence on the received power attenuation, and for receivers with the same type aberrations, higher-order Zernike aberrations have more influence on that. The universality of the result for different antennas is verified by introducing a characteristic radius and a relative receiving radius. Some suggestions are proposed to lower the requirements of the wave aberrations control, thus reducing the difficulty of optical design, structural design, thermal design, assembly and adjustment. The outcome of this study would contribute to the design of the inter-satellite laser communication systems.

The influence of orthokeratology compression factor on ocular higher‐order aberrations

BackgroundTo investigate the influence of compression factor upon changes in ocular higher‐order aberrations (HOAs) in young myopic children undergoing orthokeratology treatment.MethodsSubjects aged between six and < 11-years, with low myopia (0.50–4.00 D inclusive), low astigmatism (≤ 1.25 D), and anisometropia (≤ 1.00 D), were randomly assigned to wear orthokeratology lenses of different compression factors in each eye (one eye 0.75 D and the fellow eye 1.75 D). HOAs were measured weekly over one month of lens wear. Wavefront analysis was conducted over a 5‐mm pupil using a sixth order Zernike polynomial expansion. Linear mixed models were used to examine the individual Zernike co‐efficients and specific root‐mean‐square (RMS) error (spherical, comatic, total HOAs) metrics and their changes between the two eyes during the study period.ResultsTwenty‐eight myopic (mean manifest spherical equivalent refraction: −2.10 ± 0.58 D) children (median [range] age: 9.3 [7.8–11.0] years) were analysed. Significant interocular differences in HOAs at baseline were observed for Z6−6 and Z6−4 only (both p < 0.05). During the lens wear period, eyes fitted with the increased compression factor showed greater changes in primary spherical aberration (Z40, p = 0.04) and RMS values for spherical and total HOAs (both p < 0.01). Considering data from both eyes together, after adjusting for the paired nature of the data, some other Zernike terms (Z31 and Z60, both p < 0.01) and the RMS value of comatic aberrations (p < 0.001) significantly increased after one month of orthokeratology treatment. The increase in primary spherical aberration (Z40) was positively correlated with the reduction in spherical equivalent refractive error, but only in eyes fitted with the increased compression factor (r = 0.69, p < 0.001).ConclusionsIncreasing the orthokeratology compression factor by 1.00 D significantly altered some HOAs, particularly spherical aberration. Given the association between positive spherical aberration and eye growth in children, further research investigating the influence of orthokeratology compression factor on axial eye growth is warranted.

Small-pupil versus multifocal strategies for expanding depth of focus of presbyopic eyes

To compare the visually weighted image quality and depth of focus achieved with small-pupil and multifocal strategies for expanding depth of focus of presbyopic or pseudophakic eyes. School of Optometry, Indiana University, Bloomington, USA. Computational modeling. The visual Strehl ratio was computed from monochromatic optical transfer functions over a wide range of primary spherical aberration and defocus levels for pupil diameters ranging from 1.0mm to 7.0mm under high photopic light levels (retinal illuminance >900 trolands) and mesopic light levels (2candelas/m2). Pupil miosis and added spherical aberration were effective at reducing the impact of spherical defocus. With high light levels at which Weber's law makes neural contrast sensitivity independent of retinal illuminance, small pupils (eg, 1.0 to 3.0mm) generated higher peak image quality and more effective expansion of depth of focus than the small-pupil multifocal model. However, under low light levels at which the reduced retinal illuminance associated with pupil miosis lowered neural contrast sensitivity, the peak image quality was lower with small pupils (1.0 to 1.5mm) at all aberration levels. Large pupils and high levels of spherical aberration were most effective at expanding the depth of focus under mesopic light levels. When reductions in retinal illuminance created by pupil miosis have no effect on neural contrast sensitivity, small pupils produced higher image quality and larger depth of focus than multifocal optics and large pupils. In general, the reverse was true under mesopic light conditions.

Femtosecond-assisted laser in situ keratomileusis for high myopia correction: Long-term follow-up outcomes.

Report the outcomes of laser in situ keratomileusis (LASIK) for high myopia correction after long-term follow-up. Retrospective, consecutive, clinical study including 70 eyes that underwent LASIK using a 500 Hertz (Hz) repetition rate excimer laser and femtosecond technology for flap creation. Visual, refractive, corneal aberrations, and correlation among the variables were evaluated during 3 years. In addition, 34 eyes were followed during 5 years. Significant improvement of 17 logMAR lines was observed in uncorrected vision at 5 years (p < 0.01). This was consistent with spherical equivalent reduction that came from mean preoperative -7.79 diopters (D) to 5 years postoperative -0.24 D (p < 0.01). Significant induction of primary spherical aberration and coma aberration was also found (p < 0.01) at 3 months with levels of 0.61 µm and 0.47 µm, respectively, with no further changes at 5 years (p > 0.05). Pearson correlation showed that the amount of high-order aberrations at 3 months postoperativeley was significantly correlated with the changes in the keratometry throughout the 5 years (delta K) (R2 0.242 p = 0.05). Finally, preoperative corneal asphericity showed an inverse correlation with the delta K (R2 -308 p = 0.01). Results from this study suggests that LASIK for high myopia correction using 500 Hz repetition rate excimer laser provides stable visual, refractive and aberrometric results after 5 years of follow-up. A more prolate cornea and the amount of higher-order aberrations induced after LASIK are factors that negatively impact in the long-term stability of the procedure.

MEMS-in-the-lens 3D beam scanner for in vivo microscopy.

The "MEMS-in-the-lens" active lens for a laser scanning microscope comprises a high numerical aperture front element, a 3D+ MOEMS beam scanner and a collimating back lens. The scanner utilizes a silicon gimbal with SU-8 polymer flexures and deformable membrane mirror. The mirror aperture is 4 mm in diameter, and is capable of 9 μm deflection for focus control, with four annular electrodes to allow tuning of primary and secondary spherical aberration. The gimbal supports tip/tilt actuation up to ±3° for lateral beam scanning. We show confocal imaging using a benchtop mockup of the active lens, illustrating the potential for this approach to support 3D microscopy for optical biopsy applications.

Analysis of Corneal Spherical Aberrations in Cataract Patients with High Myopia

To evaluate the corneal spherical aberrations in cataract patients with and without high myopia, we conducted a retrospective case series of 502 cataract eyes with high myopia and 1500 age-related cataract eyes and measure their corneal biometric data and axial length using Pentacam and IOLMaster. Both the anterior and total corneal primary spherical aberrations were lower in the high myopia group than that in the control group (0.317 ± 0.215 vs 0.338 ± 0.148 μm, P = 0.043; and 0.281 ± 0.207 vs 0.314 ± 0.153 μm, P < 0.001). The incidence of eyes with negative total corneal primary spherical aberration increased as axial length increased in the high myopia group, and the overall incidence was higher in the high myopia group than that in the control group (2.59% vs 1.47%). These were mainly contributed to the younger age of cataract patients with high myopia (55.76 ± 13.10 vs 60.18 ± 15.72 years, P < 0.001), along with the positive correlations between age and anterior and total corneal primary spherical aberrations. In clinical practice, an aspheric IOL with a low negative or zero primary spherical aberration is recommended for cataract patients with high myopia. Negative total ocular primary spherical aberrations resulting from aspheric IOL implantation should be avoided in extremely high myopic eyes.

Corneal aberrations after small-incision lenticule extraction versus Q value-guided laser-assisted in situ keratomileusis

Previous studies compared ocular aberration and visual quality after small-incision lenticule extraction (SMILE) and Q value-guided femtosecond laser-assisted in situ keratomileusis (Q-FS-LASIK), but anterior corneal surface aberration properties are poorly known. This study aimed to compare the changes in anterior corneal surface aberration after SMILE versus Q-FS-LASIK.This was a prospective, observational cohort study. Patients with myopia and myopic astigmatism underwent SMILE or Q-FS-LASIK at Hangzhou MSK Eye Hospital between January 2015 and November 2015. High order aberration (HOA), primary spherical aberration (PSA), primary coma aberration (PCA), primary vertical coma aberration (PVCA), and primary horizontal coma aberration (PHCA) were assessed using pre- and postoperative Sirius scanning.Both surgery were associated with significant increases in postoperative HOA, PSA, and PCA (both groups P < .01). In the SMILE group (n = 51), the variations in HOA, PSA, and PCA were no longer significant after postoperative week 2 (P > .05). In the Q-FS-LASIK group (n = 73), the variations in HOA and PCA were no longer significant after postoperative day 1 (P > .05). In the SMILE group, the 3-month changes in PCA were not correlated with spherical, spherical equivalent (SE), and spherical plus cylinder measurements. Cylinder measurements were not correlated with HOA, PSA, and PCA. In the Q-FS-LASIK group, the 3-month changes in PCA correlated with spherical, SE, and spherical plus cylinder measurements.Both SMILE and Q-FS-LASIK resulted in an increase in HOA, PSA, and PCA at postoperative day 1, but Q-FS-LASIK introduced lower HOA and showed better stability. Spherical measurement was related to PSA.

Analysis of corneal higher-order aberrations in cataract patients with high myopia

To evaluate the differences in corneal higher-order aberrations (HOAs) between cataract patients with high axial myopia and normal cataract patients, and to identify the associated factors. Department of Ophthalmology and Vision Science of the Eye and ENT Hospital of Fudan University, Shanghai, China. Retrospective case series. Corneal aberrations and axial lengths (ALs) were measured using a rotating Scheimpflug camera (Pentacam) and partial coherence interferometry (IOLMaster) in the high myopia group and the control group. The study comprised 287 patients (520 eyes). There were 194 eyes in the high myopia group and 326 eyes in the control group. The 5 anterior corneal aberrations-vertical coma, vertical trefoil, horizontal coma, oblique trefoil, and primary spherical aberration-in the high myopia group were 0.07μm±0.38 (SD), -0.11±0.23μm, 0.07±0.28μm, -0.02±0.18μm, and 0.39±0.19μm, respectively. No negative primary spherical aberrations of the total or anterior corneal surface were found in the high myopia group. Differences between the 2 groups were found interms of central corneal thickness, astigmatism, primary spherical aberration, vertical coma, and oblique trefoil; however, these differences were not consistent between different age subgroups. Higher-order aberrations were correlated with age. Posterior corneal vertical coma was correlated with AL (Pearson correlation=-0.188, P=.047). Negative primary spherical aberrations of the anterior or total corneal surface were not found in the high myopia group. Age showed a strong relationship with HOAs. For cataract patients with high myopia, aspheric intraocular lens implantation is recommended.

Effects of aberrations on effective point spread function in STED microscopy.

Like other imaging techniques, stimulated emission depletion (STED) microscopy suffers from aberrations. While their effects on depletion patterns have been explicitly investigated, the study on how aberrations affect the effective point spread function (PSF) in STED microscopy is still missing. For STED researchers, however, this study is beneficial, as it directly bridges image qualities and aberrations. In this paper, we quantitatively analyze the effects of primary aberrations, including astigmatism, coma, trefoil, and spherical aberration, in two-dimensional (2D) and three-dimensional (3D) STED microscopy, and further discuss the corresponding aberration tolerance. Specifically, attention is given to the modification of the shape, the size, and the peak intensity of the effective PSF in the presence of these aberrations.

Two-dimensional simulation of eccentric photorefraction images for ametropes: factors influencing the measurement.

Eccentric photorefraction and Purkinje image tracking are used to estimate refractive state and eye position simultaneously. Beyond vision screening, they provide insight into typical and atypical visual development. Systematic analysis of the effect of refractive error and spectacles on photorefraction data is needed to gauge the accuracy and precision of the technique. Simulation of two-dimensional, double-pass eccentric photorefraction was performed (Zemax). The inward pass included appropriate light sources, lenses and a single surface pupil plane eye model to create an extended retinal image that served as the source for the outward pass. Refractive state, as computed from the luminance gradient in the image of the pupil captured by the model's camera, was evaluated for a range of refractive errors (-15D to +15D), pupil sizes (3mm to 7mm) and two sets of higher-order monochromatic aberrations. Instrument calibration was simulated using -8D to +8D trial lenses at the spectacle plane for: (1) vertex distances from 3mm to 23mm, (2) uncorrected and corrected hyperopic refractive errors of +4D and +7D, and (3) uncorrected and corrected astigmatism of 4D at four different axes. Empirical calibration of a commercial photorefractor was also compared with a wavefront aberrometer for human eyes. The pupil luminance gradient varied linearly with refractive state for defocus less than approximately 4D (5mm pupil). For larger errors, the gradient magnitude saturated and then reduced, leading to under-estimation of refractive state. Additional inaccuracy (up to 1D for 8D of defocus) resulted from spectacle magnification in the pupil image, which would reduce precision insituations where vertex distance is variable. The empirical calibration revealed a constant offset between the two clinical instruments. Computational modelling demonstrates the principles and limitations of photorefraction to help users avoid potential measurement errors. Factors that could cause clinically significant errors in photorefraction estimates include high refractive error, vertex distance and magnification effects of a spectacle lens, increased higher-order monochromatic aberrations, and changes in primary spherical aberration with accommodation. The impact of these errors increases with increasing defocus.

Ocular higher-order aberrations and axial eye growth in young Hong Kong children.

This retrospective longitudinal analysis aimed to investigate the association between ocular higher-order aberrations (HOAs) and axial eye growth in Hong Kong children. Measures of axial length and ocular HOAs under cycloplegia were obtained annually over a two-year period from 137 subjects aged 8.8 ± 1.4 years with mean spherical equivalent refraction of −2.04 ± 2.38 D. A significant negative association was observed between the RMS of total HOAs and axial eye growth (P = 0.03), after adjusting for other significant predictors of axial length including age, sex and refractive error. Similar negative associations with axial elongation were found for the RMS of spherical aberrations ({{rm{Z}}}_{4}^{0} and {{rm{Z}}}_{6}^{0} combined) (P = 0.037). Another linear mixed model also showed that greater levels of vertical trefoil ({{rm{Z}}}_{3}^{-3}), primary spherical aberration ({{rm{Z}}}_{4}^{0}) and negative oblique trefoil ({{rm{Z}}}_{3}^{3}) were associated with slower axial elongation and longer axial length (all P < 0.05). These findings support the potential role of HOAs, image quality and a vision-dependent mechanism in childhood eye growth.

Four-mirror flat-field anastigmat aplanat telescopes with simple closed-form solutions

A four-mirror anastigmat aplanat telescope can be constructed using a Gregorian-form Mersenne afocal telescope as a feeder for a concentric spherical Schwarzschild objective. A flat image field can be obtained by adjusting the ratio of the radii of the mirrors. With the tertiary at the image of the aperture stop (the primary) the primary's conic K1 can be varied, using the tertiary's conic K3 to cancel the primary's spherical aberration without affecting the system's coma or astigmatism. For a spherical primary, the tertiary is an oblate ellipsoid (K3>0). The minimum obscuration ratio is 44.7% (20% by area).

Accommodation and age-dependent eye model based on in vivo measurements

PurposeTo develop a flexible model of the average eye that incorporates changes with age and accommodation in all optical parameters, including entrance pupil diameter, under photopic, natural, environmental conditions. MethodsWe collated retrospective in vivo measurements of all optical parameters, including entrance pupil diameter. Ray-tracing was used to calculate the wavefront aberrations of the eye model as a function of age, stimulus vergence and pupil diameter. These aberrations were used to calculate objective refraction using paraxial curvature matching. This was also done for several stimulus positions to calculate the accommodation response/stimulus curve. ResultsThe model predicts a hyperopic change in distance refraction as the eye ages (+0.22D every 10 years) between 20 and 65 years. The slope of the accommodation response/stimulus curve was 0.72 for a 25 years-old subject, with little change between 20 and 45 years. A trend to a more negative value of primary spherical aberration as the eye accommodates is predicted for all ages (20–50 years). When accommodation is relaxed, a slight increase in primary spherical aberration (0.008μm every 10 years) between 20 and 65 years is predicted, for an age-dependent entrance pupil diameter ranging between 3.58mm (20 years) and 3.05mm (65 years). Results match reasonably well with studies performed in real eyes, except that spherical aberration is systematically slightly negative as compared with the practical data. ConclusionsThe proposed eye model is able to predict changes in objective refraction and accommodation response. It has the potential to be a useful design and testing tool for devices (e.g. intraocular lenses or contact lenses) designed to correct the eye's optical errors.

Vector analysis of astigmatic changes and optical quality outcomes after wavefront-guided laser in situ keratomileusis using a high-resolution aberrometer

To assess the ocular optical quality results as well as theastigmatic changes after wavefront-guided laser insitu keratomileusis (LASIK) in eyes with myopic astigmatism. Instituto Clínico-Quirúrgico Oftalmológico, Bilbao, Vizcaya, Spain. Prospective case series. Thirty-three eyes having wavefront-guided LASIK with the Star S4IR excimer laser combined with the iDesign system were enrolled in the study. Changes in visual acuity, refraction, higher-order aberrations, and ocular scattering index (OSI) were evaluated during a 3-month follow-up. The Alpins method was used to analyze the astigmatic changes. A significant reduction was observed in refraction (P<.001), with significant improvement in uncorrected (UDVA) and corrected (CDVA) distance visual acuities (P<.001). All eyes had a spherical equivalent within ±0.50 diopter (D) and UDVA of 20/25 or better at 90days after surgery. A total of 27.3% of eyes gained lines of CDVA. No significant changes were observed in primary coma and spherical aberration (P≥.551). Likewise, no significant changes were observed in OSI (P=.361), with a mean 90-day postoperative value of 0.66±0.58 (SD). A significant change to negative values of the magnitude of error (P=.007) and a significant decrease in the correction index (P=.004) were observed during the follow-up, with mean 90-day postoperative values of -0.24±0.28 D and 0.86±0.17 D, respectively. Wavefront-guided LASIK using a high-resolution aberrometer provided safe and efficacious correction of myopic astigmatism, with preservation of the ocular optical quality.

Intrasession repeatability of refractive and ocular aberrometric measurements obtained using a multidiagnostic device in healthy eyes.

PurposeTo evaluate the intrasession repeatability of refractive and ocular aberrometric measurements obtained using a new multidiagnostic device in healthy eyes.Patients and methodsA total of 107 eyes of 107 patients, age ranging from 23 to 65 years, were enrolled in this study. A complete eye examination was performed in all eyes, including an ocular examination using the VX120 system. Three consecutive measurements were obtained using this device to assess the intrasession repeatability of different refractive and ocular aber-rometric parameters. The within-subject standard deviation (Sw), intrasubject precision (1.96×Sw), and intraclass correlation coefficient (ICC) were calculated.ResultsSw and intrasubject precision for refractive data were below 0.12 and 0.20 D, respectively, in all cases. The ICC ranged from 0.947 for the J45 power vector component to 0.997 for the sphere. Concerning aberrometric measurements Sw and intrasubject precision values were below 0.05 µm and 0.10 µm, respectively. Likewise, the ICC ranged from 0.805 for the quadrafoil root mean square to 0.954 for the primary spherical aberration. Poor correlations were found between most of the refractive parameters and their Sw (–0.033≤r≤0.053, p≥0.064). Moderate and significant positive correlations were found between the magnitude of the aberrometric parameters evaluated and their Sw (r≥0.446, p<0.001).ConclusionThe new multidiagnostic device evaluated is able to provide consistent measurements of refraction and ocular aberrations in healthy eyes. Future studies should confirm if this consistency is also observed in highly aberrated eyes.

Simulation of commercial vs theoretically optimised contact lenses for presbyopia.

To compare theoretically optimised bifocal contact lens optical designs to commercially available optical designs for presbyopia. Retinal images were simulated, using a numerical eye model, from -6 (i.e., near vision) to +2D for each 0.25D. Ten optical profiles were simulated. Four of them corresponded to commercial contact lenses (i.e., Acuvue Oasys for Presbyopia®, Air Optix Aqua Multifocal®, Purevision Multifocal® and Distance Biofinity Multifocal®). We also included six optimised profiles: (1) a combination of primary and secondary spherical aberration, (2) bifocal profiles with 2, 5 and 8 concentric zones, and (3) a combination of spherical aberrations with the 5 and 8 zones profiles. Twenty subjects scored the quality of vision of calculated images (i.e., three high-contrast 0.40 logMAR letters) for each design and vergence with a five-item continuous grading scale. They viewed these images through their best sphero-cylindrical correction and a 3-mm pupil to limit the impact of their aberrations. To quantify the ability of a bifocal optic to maintain a certain level of quality of vision, we calculated two criteria: (1) the area under the through-focus quality of vision curve higher than 2 (i.e., limit between poor and fair quality of vision) normalised by the same area calculated on the naked eye's curve, and (2) the width of the curve at a level of 2 (i.e., depth-of-focus). Commercial contact lens profiles did not give an image quality and depth-of-focus as good as the theoretically optimised optical profiles. Based on these two criteria, the best bifocal profiles were those with 5 and 8 concentric zones. Important inter-individual variations were observed for all profiles. We also observed that some subjects did not obtain any benefit with all the designs whereas others seemed to be satisfied whatever the optical profiles. Our previously optimised designs with 5 and 8 zones gave the best benefit and depth-of-focus. As their image quality is better than commercially available designs, it would be interesting to prototype these designs and to test them in a clinical setting.

Assessment of intraocular pressure sensing using an implanted reflective flexible membrane

Glaucoma is a neurodegenerative condition that is the leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is the main cause for the development of the disease. The symptoms of this form, such as deterioration of vision and scotomas (loss of visual fields), appear in the latter stages of the disease. Therefore, an IOP monitoring device is needed for better, simpler, and faster diagnosis, and to enable a fast treatment response. We present a theoretical assessment as well as preliminary experimental results of a simple approach for easy, optical, IOP self-monitoring. It is based on a polydimethylsiloxane membrane coated with a reflective layer and a Hartmann–Shack wavefront sensor. Nearly linear correlation is found between membrane deformation and Zernike coefficients representing defocus primary spherical aberration, with high sensitivity and negligible dependence on the measurement distance. The proposed device is expected to provide an accurate IOP measurement resolution of less than ± 0.2 ?? mm ? Hg with a pressure dependence on working distances < 0.7 ?? mm ? Hg / cm for a thick membrane; the corresponding values for a thin membrane are ± 0.45 ?? mm ? Hg and < 0.6 ?? mm ? Hg / cm , respectively, at typical IOP values—up to 40 mm Hg.

Dual-phase-shift spherical Fizeau interferometer for reduction of noise due to internally scattered light

Internally scattered light in a Fizeau interferometer is generated from dust, defects, imperfect coating of the optical components, and multiple reflections inside the collimator lens. It produces additional noise fringes in the observed interference image and degrades the repeatability of the phase measurement. A method to reduce the phase measurement error is proposed, in which the test surface is mechanically translated between each phase measurement in addition to an ordinary phase shift of the reference surface. It is shown that a linear combination of several measured phases at different test surface positions can reduce the phase errors caused by the scattered light. The combination can also compensate for the nonuniformity of the phase shift that occurs in spherical tests. A symmetric sampling of the phase measurements can cancel the additional primary spherical aberrations that occur when the test surface is out of the null position of the confocal configuration.

Impact of Spherical Aberration Terms on Multifocal Contact Lens Performance.

To investigate the impact of the primary (PSA) and secondary (SSA) spherical aberration terms on visual performance (VP) in presbyopes, as measured using multifocal (MFCL) soft contact lenses on eye. Seventeen presbyopes (age: 55.1 ± 6.9 years) wore seven commercial lenses (four center-near (MFCL N), one center-distance (MFCL D), one bifocal, and one single vision control). Unaided and with each lens on eye, the PSA and SSA terms were obtained with an aberrometer, the BHVI-EyeMapper (low illumination, natural and 4 mm pupil diameter). High- and low-contrast distance visual acuity, contrast sensitivity, high-contrast visual acuities at near, and range of clear vision were measured. In addition, subjective VP variables included clarity of vision at distance and near, ghosting, and overall vision satisfaction. Pearson's correlation was used to determine the association between the PSA and SSA terms and the VP variables. PSA (natural pupil) was more negative (P < .05) with the MFCL N (mean PSA = -0.053 ± 0.080 μm) and bifocal (PSA = +0.005 ± 0.067 μm) lenses and more positive with the MFCL D lens (PSA = +0.208 ± 0.160 μm) than the control (+0.067 ± 0.072 μm). SSA (natural pupil) was significantly more positive for the MFCL N lenses (mean SSA = +0.025 ± 0.029 μm) compared to the control (SSA = -0.001 ± 0.017 μm). PSA and SSA terms were significantly (P < .05) correlated with 78% and 56% of VP variables, respectively, but the correlation coefficients were weak, ranging between |0.210| and |0.334|. Although distance variables showed improved VP with more positive PSA or negative SSA, most near variables showed improved VP with more negative PSA. Range of clear focus was greater for more negative PSA terms. The amount and direction of PSA and SSA terms, as measured with different MFCLs on eye, can affect VP at different distances. Results of this study may provide useful information when designing new or optimize existing MFCLs for improved VP at specific distances.

In Vitro Aberrometric Assessment of a Multifocal Intraocular Lens and Two Extended Depth of Focus IOLs.

Purpose To analyze the “in vitro” aberrometric pattern of a refractive IOL and two extended depth of focus IOLs. Methods A special optical bench with a Shack-Hartmann wavefront sensor (SH) was designed for the measurement. Three presbyopia correction IOLs were analyzed: Mini WELL (MW), TECNIS Symfony ZXR00 (SYM), and Lentis Mplus X LS-313 MF30 (MP). Three different pupil sizes were used for the comparison: 3, 4, and 4.7 mm. Results MW generated negative primary and positive secondary spherical aberrations (SA) for the apertures of 3 mm (−0.13 and +0.12 μm), 4 mm (−0.12 and +0.08 μm), and 4.7 mm (−0.11 and +0.08 μm), while the SYM only generated negative primary SA for 4 and 4.7 mm apertures (−0.12 μm and −0.20 μm, resp.). The MP induced coma and trefoil for all pupils and showed significant HOAs for apertures of 4 and 4.7 mm. Conclusions In an optical bench, the MW induces negative primary and positive secondary SA for all pupils. The SYM aberrations seem to be pupil dependent; it does not produce negative primary SA for 3 mm but increases for higher pupils. Meanwhile, the HOAs for the MW and SYM were not significant. The MP showed in all cases the highest HOAs.