Effect of defocus combined with rotation on the optical performance of trifocal toric IOLs

2021 ◽  
pp. 112067212110021
Author(s):  
Javier Ruiz-Alcocer ◽  
Irene Martínez-Alberquilla ◽  
Amalia Lorente-Velázquez ◽  
José F Alfonso ◽  
David Madrid-Costa
Keyword(s):  
Visual Quality ◽  
Optical Quality ◽  
Refractive Errors ◽  
Focal Points ◽  
Modulation Transfer ◽  
Optical Analysis ◽  
Toric Intraocular Lens ◽  
Toric Iols ◽  
Reference Situation

Purpose: To objectively analyze the optical quality of the FineVision Toric intraocular lens (IOL) with two cylinder powers when different combinations of rotations and residual refractive errors are induced. Methods: This study assessed the FineVision Toric IOL with two different cylinder powers: 1.5 and 3.0 diopters (D). Three different rotation positions were considered: centered, 5° and 10° rotated. An optical bench (PMTF) was used for optical analysis. The optical quality of the IOLs was calculated by the modulation transfer function (MTF) at five different focal points (0.0, 0.25, 0.50, 0.75, and 1.00 D). Results: The MTF averaged value of the reference situation was 38.58 and 37.74 for 1.5 and 3.0 D of cylinder, respectively. For the 1.5 D cylinder, the combination of 5° of rotation with a defocus of 0.25, 0.50, 0.75, and 1.0 D induced a decrease on the MTF of 12.39, 19.94, 23.43, 24.23 units, respectively. When induced rotation was 10°, the MTF decrease was 17.26, 23.40, 24.33, 24.48 units, respectively. For the 3.0 D cylinder, the combination of 5° with 0.25, 0.50, 0.75, and 1.0 D of defocus, induced a decrease on the MTF of 12.51, 18.97, 22.36, 22.48 units, respectively. When induced rotation was 10°, the MTF decrease was: 18.42, 21.57, 23.08, and 23.61 units, respectively. Conclusion: For both FineVision Toric IOLs there is a certain optical tolerance to rotations up to 5° or residual refractive errors up to 0.25 D. Situations over these limits and their combination would affect the visual quality of patients implanted with these trifocal toric IOLs.

Advanced Intraocular Lens Designs

2010 ◽  
Vol 04 (01) ◽  
pp. 82 ◽  
Author(s):  
Phillip J Buckhurst ◽  
Shehzad A Naroo ◽  
Sunil Shah ◽  
◽  
◽  
...  
Keyword(s):  
New Technology ◽  
Optical Quality ◽  
Intraocular Lenses ◽  
Age Related Macular Degeneration ◽  
Rotational Stability ◽  
Focal Points ◽  
Non Invasive ◽  
Age Related ◽  
Toric Iols

Intraocular lenses (IOLs) have evolved since their introduction and spherical monofocal designs are no longer the only pseudophakic option. IOLs with a toric surface are able to correct astigmatism, but are dependent on the accuracy of placement. Haptic design is very important with toric IOLs as different designs demonstrate different post-operative rotational stability. Multifocal IOLs produce multiple focal points within the eye and so provide the capacity for simultaneous distance and near vision. Various mechanisms for creating these focal points exist, which determine how light is distributed. Accommodating IOLs use the optic shift principle in order to restore the accommodative response. Single and dual optic variations exist; however, the restoration of accommodation has been limited and variable with the current generation of these IOLs. Aspherical IOLs are designed to improve the optical quality of the image created by the IOL. Aspherical correcting IOLs are dependent on their centration and tilt. New phacoemulsification technology allows cataract removal through a sub-2mm incision, and microincisional IOLs can be implanted through these incisions, which results in minimal surgical impact on the cornea. Blue- and violet-blocking IOLs have been introduced, which might help prevent the development of age-related macular degeneration. Light-adjustable lenses are a relatively new technology and allow non-invasive post-operative adjustment of the IOL’s refractive power. This is a fast-moving area of research and development due to the high demands of clinical practice.

scholarly journals Assessment of Visual Quality in Eyes with Forme Fruste Keratoconus and Mild and Moderate Keratoconus Based on Optical Quality Analysis System II Parameters

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhonghao Ren ◽  
Liyan Xu ◽  
Qi Fan ◽  
Kaili Yang ◽  
Shengwei Ren ◽  
...  
Keyword(s):  
Intraclass Correlation ◽  
Visual Quality ◽  
Quality Parameters ◽  
Optical Quality ◽  
Normal Group ◽  
Quality Analysis ◽  
Significant Difference ◽  
Analysis System ◽  
Forme Fruste Keratoconus

Purpose. The study aimed to evaluate the visual quality of forme fruste keratoconus (FFK) and mild and moderate keratoconus by using an optical quality analysis system II (OQAS-II) and to explore the correlation between optical quality parameters and the disease progression. Methods. Twenty-one normal eyes, twenty-one FFK eyes, twenty-one mild keratoconus eyes, and twenty-one moderate keratoconus eyes were included in this prospective study. The optical quality parameters, such as object scatter index (OSI), modulation transfer function cutoff (MTF cutoff), strehl ratio (SR), and OQAS-II values at contrasts of 100% (OV-100), 20% (OV-20), and 9% (OV-9), were measured by OQAS-II. The repeatability of these parameters was analyzed by intraclass correlation coefficient (ICC), repeatability coefficient (RC), and coefficient of variation (CVw). Correlations between optical quality parameters and mean central keratometry readings (Kmean) were evaluated. The sensitivity and specificity of the parameters were analyzed using the receiver operating characteristic (ROC). Results. All the optical quality parameters among four groups showed good repeatability (all ICC≥0.75). The MTF cutoff, SR, OV-100, OV-20, OV-9 in FFK, mild and moderate keratoconus eyes were significantly lower than those in the normal group (all P<0.05). The ROC analyses of the MTF cutoff, SR, OV-100, OV-20, and OV-9 showed significant area under the curve (AUC) in discriminating FFK form normal, mild keratoconus from FFK, and moderate keratoconus from mild keratoconus (all P<0.05). The OSI in mild and moderate keratoconus eyes were significantly higher than that in FFK and normal group (all P<0.05), while the OSI showed no significant difference between the FFK group and normal group (P>0.05). The ROC analyses of the OSI showed significant AUC in discriminating mild keratoconus from FFK and moderate keratoconus from mild keratoconus (all P<0.05). In addition, the MTF cutoff was closely correlated to Kmean in keratoconus eyes (r = −0.710, P<0.001). Conclusion. The repeatability of OQAS-II is good in measuring visual quality of normal as well as FFK, mild, and moderate keratoconus. The visual quality of the FFK, mild, and moderate keratoconus is worse than that in normal eyes. The OQAS-II has the potential value in screening FFK from normal eyes and might be a useful tool for evaluating the progression of keratoconus.

Influence of Progressive Lenses in the Retinal Image Quality

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 156-156
Author(s):  
J Gispets ◽  
M Arjona ◽  
J Pujol
Keyword(s):  
Image Quality ◽  
Retinal Image ◽  
Human Subjects ◽  
Optical Quality ◽  
Optical Systems ◽  
Modulation Transfer ◽  
Double Pass ◽  
Progressive Lenses

Progressive lenses (PL) are widely used to correct presbyopia, a visual dysfunction that affects most of the population aged over 40 years. The methods used to evaluate the optical quality of these lenses are mainly based on ray-tracing and optical bench testing. Psychophysical studies based on measurements of the contrast sensitivity function of human subjects also exist. However, all these methods exhibit important limitations because, in general, they do not take into account the optics of the eye. One of the objective techniques that permits evaluation of the retinal image in-vivo is the double pass method (Santamaria et al, 1987 Journal of the Optical Society of America A4 1109 – 1114). It has been possible to study the retinal image quality for different correcting optical systems, such as contact lenses, with this technique (Torrents et al, 1996 Perception25 Supplement, 112 – 113). We studied the retinal image quality of the optical system formed by the eye and a progressive lens. The retinal image quality, characterised by the modulation transfer function (MTF), was measured for different observers as a variety of lines of sight that covered a lens diameter of 50 mm. We show the MTF variation as a function of the lens region and the capacity of this technique to characterise these optical systems.

scholarly journals Visual acuity and image quality in 5 diffractive intraocular lenses

2017 ◽  
Vol 28 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Genís Cardona ◽  
Fidel Vega ◽  
Miguel A. Gil ◽  
Consuelo Varón ◽  
José A. Buil ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Image Quality ◽  
Optical Quality ◽  
Intraocular Lenses ◽  
Modulation Transfer ◽  
Multifocal Intraocular Lenses ◽  
Corrected Distance Visual Acuity ◽  
Good For

Purpose: To compare objective image quality at distant, intermediate, and near foci with the corresponding visual acuity (VA) in patients symmetrically implanted with 5 different diffractive multifocal intraocular lenses (IOLs) (ReSTOR SV25T0, Tecnis ZKB00, Tecnis ZLB00, AT LISA 809, and AT LISA Tri 839MP) and a monofocal lens (Tecnis ZA9003) 3 months after cataract intervention. Methods: Objective image quality, measured as the area under the modulation transfer function curve (AMTF), was tested in vitro in an eye model. In addition, corrected distance visual acuity and distance-corrected intermediate and near visual acuities (DCIVA and DCNVA) were assessed in a group of 79 patients, randomly implanted with one of the lenses. Results: Image quality and VA at the distant focus was good for all lens designs, but was similarly compromised at the intermediate focus, where the best DCIVA corresponded to the low add ZKB00. At the near focus, the monofocal lens and the distance dominant SV25T0 had the worst AMTF values, with the ZLB00 presenting the best DCNVA. The relationship between AMTF and VA was found not to be linear, with VA being similarly good for AMTF values over a certain threshold. Conclusions: Visual acuity of pseudophakic patients reflected the optical quality of the specific IOL design within a certain range of measurements, beyond which maximum VA is limited by other ocular, optical, and neuropsychophysical factors.

scholarly journals Comparison of efficacy and visual quality after CWFG-FS-LASIK, AF-FS-LASIK and SMILE for correcting myopia with asymmetry mid-to-high astigmatism

2020 ◽  
Author(s):  
zhongxiu zhao ◽  
Miaomiao Zhu ◽  
Qian Jian ◽  
Xialu Liu ◽  
Pingting Ma ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Femtosecond Laser ◽  
Visual Quality ◽  
Modulation Transfer ◽  
Surgical Methods ◽  
Uncorrected Visual Acuity ◽  
Better Than ◽  
High Order Aberrations

Abstract Background: Individualized ablation is not only able to correct corneal low-order aberrations but also to improve corneal high-order aberrations in patients with corneal asymmetry. In this study, we compared the effects of three different surgical methods, namely, corneal wavefront-guided femtosecond laser assisted in-situ keratomileusis (CWFG-FS-LASIK), aberration-free femtosecond laser assisted in-situ keratomileusis (AF-FS-LASIK) and small incision lenticule (SMILE), in patients with mid-to-high astigmatism asymmetric corneas (1-4D).Methods: One hundred-fourteen eyes from 58 patients were enrolled in this retrospective study. We measured and compared the best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), residual astigmatism, total coma, vertical coma (Z3-1), horizontal coma (Z31), modulation transfer function (MTF) and point spread function (PSF) preoperatively and three months postoperatively. Results: The visual acuity of patients in the three groups was increased after surgery, but the improvements in visual acuity and residual astigmatism among them were not significantly different. However, the improvements in 4-mm and 6-mm total coma, Z3-1 and Z31 in patients who underwent CWFG-FS-LASIK were better than those in patients who underwent AF-FS-LASIK and SMILE. Consistent with these results, the improvements in MTF and PSF (3 mm and 5 mm) in the CWFG-FS-LASIK group were better than those in the AF-FS-LASIK and SMILE groups.Conclusions: Among surgeries for treating patients with mid-to-high astigmatism in asymmetric corneas, the selective coma-guided modality was able to decrease the coma of original cornea, improve visual acuity and optimize the visual quality of patients.

scholarly journals Comparison of Objective and Subjective Visual Quality Following LASEK, FS-LASIK and SMILE for Different Myopic Corrections: A Prospective Study

2021 ◽  
Author(s):  
Gang Liang ◽  
Miao Zhou ◽  
Chen-Wei Pan
Keyword(s):  
Prospective Study ◽  
High Myopia ◽  
Cutoff Frequency ◽  
Visual Quality ◽  
Optical Quality ◽  
Quality Analysis ◽  
Laser In Situ Keratomileusis ◽  
Modulation Transfer ◽  
Significant Difference ◽  
A Prospective Study

Abstract Background: To investigate the differences in visual quality after laser epithelial keratomileusis (LASEK), femtosecond laser in situ keratomileusis (FS-LASIK) and small-incision lenticule extraction (SMILE) in different degrees of myopia.Methods: This prospective study incorporated 200 consecutive myopic subjects (200 eyes). Myopia was subdivided into 3 levels based on the preoperative spherical equivalent (SE) value: low myopia (SE ≥ -3.0 D), moderate myopia (−3.0 D > SE ≥ −6.0 D), and high myopia (SE < −6.0 D). Visual quality was recorded and analyzed both objectively using the Optical Quality Analysis System II (OQAS II), and subjectively with uncorrected distance visual acuity (UDVA) and a questionnaire, preoperatively, 1 month and 6 months postoperatively. Results: Six months after LASEK, FS-LASIK and SMILE in myopia, the logarithm of the minimum angle of resolution (LogMAR) UDVA statistically decreased compared with preoperative values (all P < 0.001). While preoperatively, in three surgical procedure groups, objective visual quality parameters demonstrated no significant difference among three degrees of myopia (all P > 0.05), at 6 months postoperatively, after FS-LASIK and SMILE, the modulation transfer function (MTF) cutoff frequency in low myopia was significantly higher than that in high myopia (both P < 0.05). Moreover, intergroup differences in LASEK, FS-LASIK and SMILE groups were not statistically significant, before and 6 months after surgery (all P > 0.05), except that FS-LASIK provided a significantly higher preoperative LogMAR UDVA than SMILE in high myopia (P < 0.05).Conclusion: LASEK, FS-LASIK and SMILE could achieve similar improvement in visual quality to each other after myopia correction. Low myopic patients may achieve better postoperative visual quality after FS-LASIK and SMILE than high myopic patients.Trial registration: This is a prospective study. The study followed the Declaration of Helsinki and was approved by the Institutional Review Board of the Second People’s Hospital of Yunnan Province.

scholarly journals Quality of Vision after Deep Anterior Lamellar Keratoplasty (Fluid Dissection) Compared to Penetrating Keratoplasty for the Treatment of Keratoconus

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Islam Mahmoud Hamdi ◽  
Momen Mahmoud Hamdi
Keyword(s):  
Penetrating Keratoplasty ◽  
Complete Removal ◽  
Quality Parameters ◽  
Optical Quality ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Modulation Transfer ◽  
Cross Sectional ◽  
Anterior Lamellar Keratoplasty

Purpose. To compare the visual quality of patients with keratoconus who underwent penetrating keratoplasty (PKP) or deep anterior lamellar keratoplasty (DALK) with fluid dissection. Design. Cross-sectional, observational study. Methods. Twelve eyes that underwent PKP (PKP group) were compared to 24 eyes that underwent DALK (DALK group) after complete removal of sutures and stability of refraction. Visual, refractive, corneal topographic, corneal aberrometry, and ocular aberrometry parameters were compared for both groups. The χ2 and Mann–Whitney U tests were used for comparisons as appropriate. P<0.05 was considered statistically significant. Results. Uncorrected and best spectacle-corrected visual acuity (UCVA and BSCVA, resp.), mean refractive spherical equivalent and mean refractive cylinder (MRSE and MRC, resp.), root mean square of the 3 mm and 5 mm OPD Scan (NIDEK Co. Ltd., Gamagori, Japan), steep and flat meridians (SimK1 and SimK2, resp.), and the difference (corneal cylinder) were not statistically significantly different between groups (P>0.05, all comparisons). All aberrations, point spread functions (PSF), and the modulation transfer function (MTF) were not statistically different between groups (P>0.05). Conclusion. For our small study, the postoperative PKP and DALK with fluid dissection patient groups had vision/optical quality parameters that were not statistically different. This may indicate that DALK with fluid dissection can replace PKP for keratoconus without compromising vision quality.

scholarly journals Laboratory analysis and ray visualization of diffractive optics with enhanced intermediate vision

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hyeck-Soo Son ◽  
Grzegorz Łabuz ◽  
Ramin Khoramnia ◽  
Timur M. Yildirim ◽  
Gerd U. Auffarth
Keyword(s):  
Monochromatic Light ◽  
Optical Quality ◽  
Single Frequency ◽  
Modulation Transfer ◽  
Intermediate Vision ◽  
Primary Focus ◽  
Set Up ◽  
Optical Behavior ◽  
532 Nm

Abstract Background To assess the optical behavior of a new diffractive intraocular lens (IOL) and compare its performance to that of an established extended-depth-of-focus (EDOF) IOL. Methods This study assessed the Proming EDOF Multifocal AM2UX [Eyebright Medical Technology (Beijing) Co., Ltd., China] and the AT LARA 829MP [Carl Zeiss Meditec, Germany]. An experimental set-up with 0.01% fluorescein solution and monochromatic light (532 nm) was used to visualize the IOLs’ ray propagation. In addition, the optical quality of the IOLs was assessed by measuring the modulation transfer function (MTF) values at 50lp/mm and 3.0 and 4.5 mm apertures on the optical bench OptiSpheric® IOL PRO II [Trioptics GmbH, Germany]. Results The ray propagation of the two IOLs showed two distinct foci. Light intensity assessment revealed that both IOLs allocate more energy to primary than secondary focus. At 3.0 mm pupil, the MTF values at 50lp/mm for the primary focus were 0.39 and 0.37, and for the secondary focus, 0.29 and 0.26 for the AT LARA and Proming IOLs, respectively. At 4.5 mm pupil, the single-frequency MTF for the primary focus was 0.51 and 0.24 and for the secondary focus 0.21 and 0.15 for the AT LARA and Proming IOLs, respectively. Conclusions When tested with an aberration-free model cornea under monochromatic conditions, the Proming behaved as a low-add bifocal lens; however, its properties did not differ much from the well-established AT LARA EDOF IOL. The AT LARA outperformed the Proming at low defocus (up to 2D), while the latter demonstrated better image quality in the 2-3D range.

scholarly journals One-year effect of wearing orthokeratology lenses on the visual quality of juvenile myopia: a retrospective study

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6998 ◽  
Author(s):  
Yewei Yin ◽  
Yang Zhao ◽  
Xiaoying Wu ◽  
Mengyang Jiang ◽  
Xiaobo Xia ◽  
...  
Keyword(s):  
Visual Quality ◽  
Wavefront Aberration ◽  
Corneal Curvature ◽  
Modulation Transfer ◽  
Year Effect ◽  
Significant Difference ◽  
Before And After ◽  
One Year ◽  
The One

Objective To study the one-year effect of wearing orthokeratology (OK) lenses on the visual quality of juvenile myopia. Methods The right eyes of 36 juvenile myopias were retrospectively studied in this work. Q-value, e-value, corneal curvature, strehl ratio (SR), modulation transfer function (MTF) and wavefront aberration (WA) were compared before and at 1, 3 and 12 months after wearing OK lenses. The SR, MTF and WA of cornea, internal optic and ocular were analyzed separately. The spherical and cylinder diopter, vision acuity, compensating factor (CF) and compensative rate (CF%) were compared before and at 12 months after wearing OK lenses. Results (1) The vision of LogMAR increased and the corneal curvature decreased significantly after wearing OK lenses. There was no significant difference for the e-value before and after wearing OK lenses. The Q-value increased at 1 month but decreased at 3 and 12 months remarkably. (2) The ocular and internal optic SR and MTF increased significantly at 1 month and then remained stable. The MTF in different spacial frequencies increased after wearing OK lenses. There was no significant difference for the corneal SR before and after wearing OK lenses, and the corneal MTF decreased significantly after wearing OK lenses. (3) For the ocular, the total higher order aberration (HOA), spherical, coma and trefoil aberrations increased, and the total aberration, total lower order aberration (LOA) and defocus aberration decreased obviously except astigmatism. The corneal aberrations increased significantly after wearing OK lenses except astigmatism. For the internal optic, the total aberration, total LOA and defocus aberration decreased, and the total HOA, coma and trefoil aberration increased significantly except the astigmatism and spherical aberrations. (4) The CF and CF% of total aberration, total LOA, total HOA and coma aberrations increased, and those of astigmatism and spherical decreased at 12 months. Conclusions Orthokeratology is effective in correcting the refractive error and improving the vision quality of juvenile myopia over the one-year follow-up period.

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