To evaluate the effects of a central hole contact lens-based design on visual performance and to compare it with the standard version of that same contact lens without the hole (non-hole scenario).
...The visual performance of 10 myopic patients wearing either a central hole myopic contact lens or its corresponding standard version (non-hole contact lens) was assessed on the same eye. Monocular corrected distance visual acuity was measured under photopic conditions and monocular contrast sensitivity was measured under both photopic and mesopic conditions and higher-order ocular aberrations using Hartmann-Shack aberrometry. An in vitro optical analysis of both contact lenses was performed and a symptoms questionnaire was administered to the participants.
No statistically significant differences in terms of corrected distance visual acuity were found: -0.091 and -0.098 logMAR for the hole and non-hole contact lenses, respectively (P > .05). Contrast sensitivity was comparable between lenses and no differences were found for specific spatial frequencies or a particular luminance level (P > .05). The hole contact lenses provided excellent outcomes, essentially equivalent to those of non-hole contact lenses, even in terms of subjective symptoms such as glare or halo. In vivo and in vitro optical quality analysis revealed no statistically significant differences between the hole and the non-hole contact lenses for either pupil size (P > .1).
A contact lens having a central hole provides good visual and optical quality outcomes comparable to those yielded by the same lens without a hole. The results suggest that the impact of a central hole may be clinically negligible.
To assess and compare the effects of four simultaneous-image multifocal contact lenses (SIMCLs), and those with distant-vision-only contact lenses on visual performance in early presbyopes, under dim ...conditions, including the effects of induced glare.
In this double-masked crossover study design, 28 presbyopic subjects aged 40 to 46 years were included. All participants were fitted with the four different SIMCLs (Air Optix Aqua Multifocal AOAM; Alcon, PureVision Multifocal PM; Bausch & Lomb, Acuvue Oasys for Presbyopia AOP; Johnson & Johnson Vision, and Biofinity Multifocal BM; CooperVision) and with monofocal contact lenses (Air Optix Aqua, Alcon). After 1 month of daily contact lens wearing, each subject's binocular distance visual acuity (BDVA) and binocular distance contrast sensitivity (BDCS) were measured using the Functional Visual Analyzer (Stereo Optical Co., Inc.) under mesopic conditions (3 candela cd/m) both with no glare and under the 2 levels of induced glare: 1.0 lux (glare 1) and 28 lux (glare 2).
Among the SIMCLs, in terms of BDVA, AOAM and PM outperformed BM and AOP. All contact lenses performed better at level without glare, followed by Glare 1, and with the worst results obtained under glare 2. Binocular distance contrast sensitivity revealed statistically significant differences for 12 cycles per degree (cpd). Among the SIMCLs, post hoc multiple comparison testing revealed that AOAM and PM provided the best BDCS at the three luminance levels. In both cases, BDVA and BDCS at 12 cpd, monofocal contact lenses outperformed all SIMCL ones at all lighting conditions.
Air Optix Aqua Multifocal and PM provided better visual performance than BM and AOP for distance vision with low addition and under dim conditions, but they all provide worse performance than monofocal contact lenses.
AIM： To evaluate the clinical utility of automated refraction（AR） and keratometry（KR） compared with subjective or manifest refraction（MR） after cataract or refractive lens exchange surgery with ...implantation of Lentis Mplus X（Oculentis GmbH） refractive multifocal intraocular lens（IOL）.METHODS： Eighty-six eyes implanted with the Lentis Mplus X multifocal IOL were included. MR was performed in all patients followed by three consecutive AR measurements using the Topcon KR-8000 autorefractor. Assessment of repeatability of consecutive AR before and after dilation with phenylephrine 10%, and comparison of the AR and KR with MR using vector analysis were performed at 3 mo follow-up.RESULTS： Analysis showed excellent repeatability of the AR measurements. Linear regression of AR versus MR showed good correlation for sphere and spherical equivalent, whereas the correlation for astigmatism was low. The mean difference AR-MR was-1.28±0.29 diopters（D） for sphere. Astigmatism showed better correlation between KR and MR. CONCLUSION： We suggest AR sphere plus 1.25 D and the KR cylinder as the starting point for MR in eyes with a Lentis Mplus X multifocal IOL. If AR measurements are equal to MR, decentration of the IOL should be suspected.
To compute and compare visual acuity, refractive outcomes, and anterior corneal aberration changes after myopic laser in situ keratomileusis (LASIK) with flap creation by a mechanical microkeratome ...and by a femtosecond laser.
Private practice refractive surgery center, Valencia, Spain.
Comparative case series.
Patients were assigned to have LASIK flap creation with a mechanical microkeratome (Carriazo-Barraquer) or a femtosecond laser (IntraLase). The Visx S2 excimer laser was used for myopic ablation in all cases. Main outcome measures included uncorrected and corrected distance visual acuities and the defocus equivalent. Higher-order aberrations (HOAs) were computed from the anterior corneal surface measured with topography for 4.0 mm and 6.0 mm pupil diameters before and 48 months after surgery.
The study evaluated 50 patients (98 eyes). The root mean square of HOAs increased postoperatively by a factor of approximately 1.9 in both groups and with both pupil diameters. There were no statistically significant differences between the 2 groups in the increase in anterior corneal aberrations, mean postoperative visual acuity, or residual refraction. All visual and optical performance metrics remained stable throughout the 4-year follow-up. There were no complications with flap creation and no postoperative complications.
The increase in anterior corneal aberrations after myopic LASIK was similar after mechanical microkeratome and femtosecond laser flap creation. Visual acuity, refraction, and the optical quality of the cornea after LASIK remained stable through 4 years postoperatively in both groups.
To evaluate visual quality differences between intraocular lenses (IOLs) in patients with previous myopic laser ablations and assess the impact of IOL decentration and tilt on visual quality.
...University of Valencia, Burjassot, Spain.
Cohort study.
An adaptive optics visual simulator was used to simulate the wavefront aberration pattern of 1 aberration-correcting IOL (Acrysof IQ SN60WF), 1 aberration-free IOL (Akreos Adapt AO), and 1 spherical IOL (Triplato) under 5 IOL situations: centered, 0.2 mm and 0.4 mm decentered, and 2 degrees and 4 degrees tilted in eyes with simulated low or high myopic laser corneal ablations. Monocular distance visual acuity at 100%, 50%, and 10% contrast were measured.
Ten eyes of 10 patients were evaluated. When the IOLs were centered, the aberration-correcting IOL provided the best visual quality results in both groups. When the IOLs were misaligned, there was a decrease of visual quality with all simulated IOLs except the aberration-free IOL in the high myopia group. In the misaligned situations, all simulated IOLs obtained comparable visual quality results in both groups.
The results suggest that in patients with previous myopic laser corneal ablation, aberration-correcting IOLs should be implanted. The decrease in visual quality when these IOLs are decentered or tilted demonstrates the importance of accurate implantation of these IOLs.
No author has a financial or proprietary interest in any material or method mentioned.
Purpose
Subjective refraction determines the final point of refractive error assessment in most clinical environments and its foundations have remained unchanged for decades. The purpose of this ...paper is to compare the results obtained when monocular subjective refraction is assessed in trial frames by a new clinical procedure based on a pure power vector interpretation with conventional clinical refraction procedures.
Methods
An alternative clinical routine is described that uses power vector interpretation with implementation in trial frames. Refractive error is determined in terms of: (i) the spherical equivalent (M component), and (ii) a pair of Jackson Crossed Cylinder lenses oriented at 0°/90° (J0 component) and 45°/135° (J45 component) for determination of astigmatism. This vector subjective refraction result (VR) is compared separately for right and left eyes of 25 subjects (mean age, 35 ± 4 years) against conventional sphero‐cylindrical subjective refraction (RX) using a phoropter. The VR procedure was applied with both conventional tumbling E optotypes (VR1) and modified optotypes with oblique orientation (VR2).
Results
Bland‐Altman plots and intra‐class correlation coefficient showed good agreement between VR, and RX (with coefficient values above 0.82) and anova showed no significant differences in any of the power vector components between RX and VR. VR1 and VR2 procedure results were similar (p ≥ 0.77).
Conclusions
The proposed routine determines the three components of refractive error in power vector notation M, J0, J45, with a refraction time similar to the one used in conventional subjective procedures. The proposed routine could be helpful for inexperienced clinicians and for experienced clinicians in those cases where it is difficult to get a valid starting point for conventional RX (irregular corneas, media opacities, etc.) and for refractive situations/places with inadequate refractive facilities/equipment.
To determine whether implantation of an intraocular lens (IOL) with a modified prolate anterior surface (Tecnis Z9000, AMO) results in reduced spherical aberration and improved contrast sensitivity ...after cataract surgery.
Hospital NISA Virgen del Consuelo, Valencia, Spain.
In an intraindividual randomized prospective study of 30 patients with bilateral cataract, the Tecnis Z9000 IOL was compared with 2 IOLs with spherical surfaces, the AR40e (AMO) and the Stabibag (Ioltech). Ocular aberrations for a 4.0 mm pupil and 6.0 mm pupil were measured with a Hartmann-Shack aberrometer. Quality of vision was measured by visual acuity and contrast sensitivity under mesopic and photopic conditions.
Eyes with the Tecnis Z9000 IOL had significantly less spherical aberration and a greater Strehl ratio after surgery. Significant reduction in coma aberration was also found in some cases. Refraction, visual acuity, and contrast sensitivity were not significantly different between the 3 IOL groups.
A significant reduction in spherical aberration after Tecnis Z9000 IOL implantation was achieved, but visual acuity and contrast sensitivity were not affected by the aspheric silicone IOL compared to spherical acrylic IOLs.
To assess visual performance with the combination of a zonal refractive aspheric multifocal intraocular lens (MIOL) (Lentis Mplus, Oculentis GmbH) and a diffractive aspheric MIOL (Acri.Lisa 366, ...Acri.Tech GmbH).
This prospective interventional cohort study comprised 80 eyes from 40 cataract patients (mean age: 65.5±7.3 years) who underwent implantation of the Lentis Mplus MIOL in one eye and Acri.Lisa 366 MIOL in the fellow eye. The main outcome measures were refraction; monocular and binocular uncorrected and corrected distance, intermediate, and near visual acuities; monocular and binocular defocus curves; binocular photopic contrast sensitivity function compared to a monofocal intraocular lens (IOL) control group (40 age-matched pseudophakic patients implanted with the AR-40e Abbott Medical Optics); and quality of vision questionnaire.
Binocular uncorrected visual acuities were 0.12 logMAR (0.76 decimal) or better at all distances measured between 6 m and 33 cm. The Lentis Mplus provided statistically significant better vision than the Acri.Lisa at distances between 2 m and 40 cm, and the Acri.Lisa provided statistically significant better vision than the Lentis Mplus at 33 cm. Binocular defocus curve showed little drop-off at intermediate distances. Photopic contrast sensitivity function for distance and near were similar to the monofocal IOL control group except for higher frequencies. Moderate glare (15%), night vision problems (12.5%), and halos (10%) were reported. Complete independence of spectacles was achieved by 92.5% of patients.
The combination of zonal refractive aspheric and diffractive aspheric MIOLs resulted in excellent uncorrected binocular distance, intermediate, and near vision, with low incidence of significant photic phenomena and high patient satisfaction.
To evaluate the clinical utility of spherocylindrical automated refraction (AR) compared with subjective manifest refraction (MR) after cataract surgery with implantation of ReZoom refractive ...multifocal intraocular lenses (IOLs) (Advanced Medical Optics, Inc.).
Private Practice.
This prospective nonrandomized interventional study consisted of 72 patients with bilateral cataract and a potential visual acuity of at least 20/40. Patients had bilateral nonsimultaneous cataract surgery and implantation of a ReZoom IOL. Manifest refraction was performed in all patients followed by 3 consecutive measurements using the Topcon KR-8000 autorefractor with nondilated and dilated pupils. Assessment of repeatability of multiple consecutive ARs and comparison of the AR and MR using power vector analysis were performed at the 6-month follow-up. The main outcome measures were the correlation between AR and MR with sphere, spherical equivalent, and astigmatism as well as the repeatability of AR before and after dilation with phenylephrine 10%.
Repeatability analysis showed that the initial nondilated AR was not significantly different from the mean of the 3 refractions for nondilated and dilated measurements. The mean difference between the initial AR and the MR was -0.84 +/- 0.62 diopters (D) for sphere (SD), -1.00 +/- 0.61 D for spherical equivalent, and -0.06 +/- 0.19 D and -0.01 +/- 0.17 D, respectively, for J(0) and J(45), the 2 components of astigmatism. Linear regression of AR versus MR data showed poor correlation for sphere (R(2) = 0.4852) and spherical equivalent (R(2) = 0.5529), whereas the correlation for the 2 astigmatic components of vector analysis was excellent (J(0), R(2) = 0.8881; J(45), R(2) = 0.8640). Correlation was better when the MR residual refractive defect was higher.
Although autorefraction showed excellent agreement with subjective refractive astigmatism, correlation with spherical values was poor, with a trend toward more negative values. Autorefraction after ReZoom IOL implantation can be used as a good starting point for subjective refraction of astigmatism; however, spherical values should be underestimated.
The aim was to study the interchangeability of various devices that measure anterior chamber depth (ACD) and white-to-white (WTW) distance.
Eighty right eyes of eighty patients aged 20 to 40 years ...were included. Their spherical equivalent ranged from -4.25 to +1.00 dioptres. Each eye's ACD and the WTW distance were measured using the following devices: a Castroviejo surgical calliper, CA-200F Corneal Analyser, Orbscan II, Pentacam HR and IOLMaster 500.
The Pentacam HR measured significantly greater ACD (p < 0.01) than the other two devices, whereas IOLMaster 500 and Orbscan II yielded comparable (p > 0.01) distances. Nonetheless, in every device comparison, the mean difference was within clinically acceptable limits. The device comparison showed that for WTW distance measurements IOLMaster 500 yields the greatest value (p < 0.01), whereas CA-200F Corneal Analyser yields the smallest one (p < 0.01).
Pentacam HR, Orbscan II and IOLMaster 500 can be used interchangeably to measure ACD, whereas Orbscan II, IOLMaster 500, Castroviejo surgical calliper and CA-200F Corneal Analyser cannot be considered interchangeable, when it comes to measuring WTW distance.
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