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1.
Eye (Lond) ; 38(Suppl 1): 9-14, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38580741

RESUMO

BACKGROUND/OBJECTIVE: To evaluate the visual performance of a purely refractive extended depth of focus (EDF) intraocular lens (IOL). SUBJECTS/METHODS: A prospective, multi-center, randomized, subject/evaluator-masked study. Subjects were bilaterally implanted with the EDF test (Model ZEN00V, N = 60) or an enhanced monofocal control (Model ICB00, N = 57) IOL. Monocular corrected distance (CDVA), intermediate (DCIVA), near acuities (DCNVA) and patient reported visual symptoms were evaluated at the 6-month visit. Monocular mesopic contrast sensitivity (CS) and depth of focus (DOF) testing were assessed at 3 months. RESULTS: CDVA (Mean ± SD) was -0.06 ± 0.08 for test and -0.05 ± 0.08 logMAR for control groups. DCIVA was 0.13 ± 0.08 for test and 0.18 ± 0.14 logMAR for control groups (p = 0.0127). DCNVA was 0.37 ± 0.10 for test and 0.43 ± 0.16 logMAR for control groups (p = 0.0137). Test lens was statistically superior for intermediate and near. Overall, 91.7% (halos), 95.0% (starbursts) and 95.0% (glare) of test lens patients reported that they did not experience, were not bothered, or were slightly bothered by specific visual symptoms, compared to 98.2%, 100% and 96.5% in the control group. The DOF range over which monocular visual acuity was 0.20 logMAR or better was -1.6 D for the test lens. Mesopic CS was comparable between both groups, falling within 0.11 log units for all measured cycles per degree with and without glare. CONCLUSION: The EDF IOL demonstrated extended range of vision and statistically superior intermediate and near performance compared to the monofocal IOL. Distance visual acuity, contrast sensitivity and dysphotopsia profile were similar to the monofocal IOL.


Assuntos
Sensibilidades de Contraste , Percepção de Profundidade , Implante de Lente Intraocular , Lentes Intraoculares , Pseudofacia , Acuidade Visual , Humanos , Estudos Prospectivos , Acuidade Visual/fisiologia , Feminino , Masculino , Sensibilidades de Contraste/fisiologia , Idoso , Pessoa de Meia-Idade , Percepção de Profundidade/fisiologia , Pseudofacia/fisiopatologia , Desenho de Prótese , Refração Ocular/fisiologia , Facoemulsificação , Método Duplo-Cego , Satisfação do Paciente
2.
Eye (Lond) ; 38(Suppl 1): 15-20, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38580742

RESUMO

PURPOSE: To evaluate the tolerance to refractive errors of a new purely refractive extended depth of focus (EDF) intraocular lens (IOL) using preclinical and clinical metrics. METHODS: Preclinical evaluation included computer simulations of visual acuity (sVA) and dysphotopsia profile of different IOL designs (refractive EDF, diffractive EDF, multifocal, standard, and enhanced monofocals) using an appropriate eye model with and without ±0.50 D defocus and/or +0.75 D of astigmatism. Patients bilaterally implanted with a refractive EDF (Model ZEN00V) or an enhanced monofocal (Model ICB00) IOL from a prospective, randomized study were included. At the 6-month postoperative visit, uncorrected and corrected distance vision (UDVA and CDVA), visual symptoms, satisfaction and dependency on glasses were evaluated in a subgroup of patients with absolute residual refractive error of >0.25 D in one or both eyes. RESULTS: In the presence of defocus and astigmatism, sVA was comparable for all except the multifocal IOL design. The refractive EDF was more tolerant to myopic outcomes and maintained a monofocal-like dysphotopsia profile with defocus. Binocular logMAR UDVA was -0.03 ± 0.08 for ZEN00V and -0.02 ± 0.11 for ICB00. 100% ZEN00V and 97% ICB00 patients did not need glasses and were satisfied with their distance vision. Monocular CDVA, contrast sensitivity and visual symptoms were also similar between both groups. CONCLUSIONS: The clinical outcomes of the refractive EDF IOL demonstrated high quality distance vision and dysphotopsia comparable to a monofocal IOL, even in the presence of refractive error, thus matching the design expectations of the EDF IOL.


Assuntos
Implante de Lente Intraocular , Lentes Intraoculares , Desenho de Prótese , Acuidade Visual , Humanos , Acuidade Visual/fisiologia , Estudos Prospectivos , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Percepção de Profundidade/fisiologia , Pseudofacia/fisiopatologia , Erros de Refração/fisiopatologia , Facoemulsificação , Satisfação do Paciente , Simulação por Computador , Refração Ocular/fisiologia , Astigmatismo/fisiopatologia , Visão Binocular/fisiologia
3.
Eye (Lond) ; 38(Suppl 1): 4-8, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38580743

RESUMO

OBJECTIVES: The purpose of this study is to evaluate the optical and expected clinical performance of a new refractive Extended Depth of Focus (EDF) intraocular lens (IOL) designed to maintain a monofocal-like dysphotopsia profile. METHODS: Simulated visual acuity (sVA) with varying defocus was calculated using the area under the Modulation Transfer Function measured in an average eye model and from computer simulations in eye models with corneal higher-order aberrations. Tolerance to defocus was evaluated using computer simulations of the uncorrected distance sVA under defocus. To evaluate the dysphotopsia profile, halo pictures obtained using an IOL-telescope, as well as simulated images in a realistic eye model under defocus were assessed. The results of the refractive EDF were compared to those of a diffractive EDF of the same platform. RESULTS: The refractive EDF IOL provides similar range of vision to the diffractive EDF IOL with the same distance, and similar intermediate and near sVA. The refractive EDF IOL provides the same tolerance to hyperopia as the diffractive EDF but more tolerance to myopia. Halo pictures and simulations showed that the refractive EDF provides comparable dysphotopsia profile to the monofocal IOL and better than the diffractive EDF. CONCLUSIONS: The results of this preclinical study in clinically relevant conditions show that the new refractive EDF IOL is expected to provide similar range of vision to the diffractive IOL of the same platform and higher tolerance to refractive errors. The refractive EDF provides a dysphotopsia profile that is better than the diffractive EDF and comparable to that of the monofocal IOL, also in the presence of residual refractive errors.


Assuntos
Simulação por Computador , Lentes Intraoculares , Acuidade Visual , Humanos , Acuidade Visual/fisiologia , Refração Ocular/fisiologia , Percepção de Profundidade/fisiologia , Desenho de Prótese , Óptica e Fotônica , Transtornos da Visão/fisiopatologia , Implante de Lente Intraocular/métodos
4.
Optom Vis Sci ; 100(4): 248-254, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37098138

RESUMO

SIGNIFICANCE: Retinal sensitivity decreases with age and age-related eye diseases. Peripheral retinal sensitivity may also be compromised if the refractive correction is not optimized for peripheral vision. PURPOSE: This study aimed to determine the impact of using a peripheral refractive correction on perimetric thresholds and the influence of age and spherical equivalent on this impact. METHODS: We measured, in 10 younger (20 to 30 years) and 10 older (58 to 72 years) healthy subjects, perimetric thresholds for Goldmann size III stimulus in several test locations along the horizontal meridian of the visual field (eccentricity, 0, ±10, and ±25°), with default central refractive correction and with peripheral refractive corrections as measured with a Hartmann-Shack wavefront sensor. We used analysis of variance to determine the effect of age and spherical equivalent (between-subject variables) and eccentricity and correction method (central vs. eccentricity specific; within-subject variables) on retinal sensitivity. RESULTS: Retinal sensitivity was higher if the eyes were optimally corrected for the concerning test location (P = .008), and the effect of this peripheral correction differed between the younger and older subjects (interaction term between group and correction method: P = .02), primarily because of more myopia in the younger group (P = .003). The average improvement by applying peripheral corrections was 1.4 dB in the older subjects and 0.3 dB in the younger subjects. CONCLUSIONS: Peripheral optical correction has a variable impact on retinal sensitivity, and therefore, assessment of retinal sensitivity may be more accurate if peripheral defocus and astigmatism are corrected.


Assuntos
Astigmatismo , Miopia , Erros de Refração , Adulto , Humanos , Erros de Refração/diagnóstico , Refração Ocular , Retina
5.
Clin Ophthalmol ; 17: 701-709, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36891506

RESUMO

Purpose: To assess the experimental visual performance and dysphotopsia characteristics of the new Tecnis Symfony OptiBlue extended-depth-of-focus with violet light-filtering (ZXR00V) intraocular lens (IOL) compared with the colorless Tecnis Symfony (ZXR00) IOL. Methods: Range of vision was assessed with simulated visual acuity defocus curves, predicted by white light through focus modulation transfer function (MTF) measurements. The clinical visual acuity defocus curve of the ZXR00 IOL was used to validate the predicted range of vision. Image quality was compared by measuring white light MTF at a spatial frequency of 15 cycles per degree (c/deg) for 3 mm and 5 mm pupil diameters with optical powers of 5 D, 20 D, and 34 D using the average corneal eye (ACE) model with the average spherical and chromatic aberration of the cataract population. Effects on dysphotopsias were predicted by measurement and computer simulation of light scatter (straylight parameter) and subsequent determination of retinal veiling luminance (RVL) in vitro. Contrast enhancement under challenging light conditions was calculated based on the effects in RVL. Results: The simulated visual acuity defocus curves and image quality outcomes were comparable between the ZXR00V and ZXR00 IOLs. The area under the straylight curve for the straylight parameter showed a 19% improvement in halo performance with ZXR00V versus ZXR00. A 12% to 17% reduction in RVL was achieved in favor of ZXR00V over ZXR00, which enhanced contrast vision by 9% to 13% under challenging light conditions. Conclusion: The violet light-filtering technology and improved manufacturing of ZXR00V delivers a comparable range of vision and tolerance to refractive error to ZXR00 while mitigating dysphotopsias and enhancing contrast vision.

6.
BMC Ophthalmol ; 23(1): 112, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36941624

RESUMO

BACKGROUND: A new generation of enhanced monofocal IOLs has been introduced to slightly increase the depth of focus as compared to standard monofocal IOLs. The purpose of this study is to evaluate the effect of pupil size on the through-focus optical performance of three new enhanced monofocal IOLs, designed to improve the range of vision as compared to standard monofocal IOLs. METHODS: Optical bench testing in white light was performed for different pupils, using an average cornea eye. Distance image quality was evaluated using Modulation Transfer Function (MTF) measurements. Through-focus Visual Acuity (VA) was simulated from these measurements (sVA). Three enhanced monofocal IOLs (ICB00, ISOPure, and RayOne-EMV) and three standard monofocal IOLs: two aspheric (ZCB00 and SN60WF) and one spherical (AAB00) were included. RESULTS: The enhanced monofocal IOLs provided an improvement in the intermediate sVA as compared to standard monofocal IOLs. For ICB00, the improvement was independent of the pupil size, while for the ISOPure and RayOne-EMV, the intermediate sVA improved with increased pupil size. Similar to the spherical monofocal IOL, the ISOPure and RayOne-EMV showed a strong correlation between improvement in intermediate sVA and reduction of distance sVA and MTF, and increasing pupil size. ICB00 provided the same distance sVA as the aspheric monofocal IOLs and the lowest variability in MTF with pupil size. CONCLUSION: Optical bench results showed that the ISOPure and RayOne-EMV provide similar performance to a spherical monofocal IOL, with a strong pupil dependency for distance and intermediate vision. The other enhanced monofocal IOL, ICB00, provided a sustained improvement in simulated intermediate VA and maintained distance image quality comparable to that of the standard aspheric monofocal IOLs, even for larger pupils.


Assuntos
Lentes Intraoculares , Pupila , Humanos , Desenho de Prótese , Pupila/fisiologia , Visão Ocular , Acuidade Visual
7.
J Cataract Refract Surg ; 47(2): 184-191, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32932369

RESUMO

PURPOSE: To evaluate the effectiveness and safety of 2 enhanced monofocal intraocular lenses (IOLs). The TECNIS Eyhance IOL (Model ICB00) was compared with a standard monofocal IOL (TECNIS Monofocal, Model ZCB00). SETTING: European multicenter study. DESIGN: Prospective, bilateral, randomized, comparative/evaluator-masked, controlled study. METHODS: Adult subjects scheduled to undergo bilateral, primary phacoemulsification cataract extraction and posterior IOL implantation were randomized to receive the enhanced monofocal ICB00 IOL or the monofocal ZCB00 IOL in both eyes. Monocular endpoints at 6 months included distance-corrected intermediate visual acuity (DCIVA), photopic corrected distance visual acuity, and uncorrected intermediate visual acuity (UIVA). Binocular visual acuities, monocular corrected distance contrast sensitivity (first eyes), patient-reported outcomes, and safety were assessed at 6 months. RESULTS: Overall, 139 patients were bilaterally implanted with the enhanced monofocal IOL (n = 67) or standard monofocal IOL (n = 72) and available for the 6-month visit. The enhanced monofocal IOL significantly improved mean monocular and binocular DCIVA and UIVA by at least 1-line logarithm of the minimum angle of resolution vs the standard monofocal IOL (all P ≤ .0001). Distance vision for the enhanced monofocal IOL was 20/20 or better and comparable with that of the standard monofocal lens at 6 months. Contrast sensitivity, photic phenomena outcomes, and rates of adverse events were similar between the 2 groups. CONCLUSIONS: In patients undergoing cataract surgery, TECNIS Eyhance IOL Model ICB00 provided enhanced intermediate vision and similar distance performance and photic phenomena compared with a standard monofocal IOL, along with improved functional performance in daily life.


Assuntos
Catarata , Lentes Intraoculares , Facoemulsificação , Adulto , Sensibilidades de Contraste , Humanos , Implante de Lente Intraocular , Satisfação do Paciente , Estudos Prospectivos , Desenho de Prótese
8.
J Refract Surg ; 36(8): 520-527, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32785725

RESUMO

PURPOSE: To describe and evaluate a new monofocal intraocular lens (IOL) designed to improve intermediate vision using a unique refractive technology. METHODS: The new monofocal lens is based on a higher order aspheric optic and is designed to improve intermediate vision. Simulated visual acuity from far to -2.00 diopters (D) was calculated using optical bench data. The effect of corneal higher order aberrations (HOAs) on simulated visual acuity, pupil size, and decentration was assessed using realistic computer eye models. The susceptibility to photic phenomena was evaluated by measuring preclinically the intensity of the light distribution in the retinal plane. The new lens design was compared to a standard aspheric monofocal IOL that shares the same platform, material, and primary spherical aberration as the new design. RESULTS: Simulated defocus curves showed increased simulated visual acuity in the intermediate range compared to a standard aspheric monofocal IOL with comparable distance vision, independently of the pupil size and corneal HOAs. At -1.50 D, the new IOL design provided a gain of approximately 0.1 logMAR, whereas at distance, the difference was less than 0.05 logMAR. The tolerance to decentration was also similar in both designs. Finally, experimental results indicate that the susceptibility to photic phenomena with the new lens design was similar to that of a standard aspheric monofocal IOL. CONCLUSIONS: Preclinical data showed that the new lens design improves intermediate vision while maintaining comparable distance image quality and keeping the same photic phenomena profile as a standard aspheric monofocal IOL. [J Refract Surg. 2020;36(8):520-527.].


Assuntos
Desenho de Equipamento , Lentes Intraoculares , Óptica e Fotônica , Sensibilidades de Contraste/fisiologia , Percepção de Profundidade/fisiologia , Humanos , Implante de Lente Intraocular , Facoemulsificação , Estudos Prospectivos , Desenho de Prótese , Pseudofacia/fisiopatologia , Refração Ocular/fisiologia
9.
J Cataract Refract Surg ; 44(2): 168-174, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29525618

RESUMO

PURPOSE: To assess the accuracy of toric intraocular lens (IOL) power calculations of a new algorithm that incorporates the effect of posterior corneal astigmatism (PCA). SETTING: Abbott Medical Optics, Inc., Groningen, the Netherlands. DESIGN: Retrospective case report. METHODS: In eyes implanted with toric IOLs, the exact vergence formula of the Tecnis toric calculator was used to predict refractive astigmatism from preoperative biometry, surgeon-estimated surgically induced astigmatism (SIA), and implanted IOL power, with and without including the new PCA algorithm. For each calculation method, the error in predicted refractive astigmatism was calculated as the vector difference between the prediction and the actual refraction. Calculations were also made using postoperative keratometry (K) values to eliminate the potential effect of incorrect SIA estimates. RESULTS: The study comprised 274 eyes. The PCA algorithm significantly reduced the centroid error in predicted refractive astigmatism (P < .001). With the PCA algorithm, the centroid error reduced from 0.50 @ 1 to 0.19 @ 3 when using preoperative K values and from 0.30 @ 0 to 0.02 @ 84 when using postoperative K values. Patients who had anterior corneal against-the-rule, with-the-rule, and oblique astigmatism had improvement with the PCA algorithm. In addition, the PCA algorithm reduced the median absolute error in all groups (P < .001). CONCLUSIONS: The use of the new PCA algorithm decreased the error in the prediction of residual refractive astigmatism in eyes implanted with toric IOLs. Therefore, the new PCA algorithm, in combination with an exact vergence IOL power calculation formula, led to an increased predictability of toric IOL power.


Assuntos
Algoritmos , Astigmatismo/complicações , Córnea/fisiopatologia , Implante de Lente Intraocular , Lentes Intraoculares , Óptica e Fotônica , Facoemulsificação , Adulto , Astigmatismo/fisiopatologia , Biometria , Topografia da Córnea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Acuidade Visual
10.
Biomed Opt Express ; 8(3): 1405-1414, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28663837

RESUMO

In this work, we analyze the way in which pupil size, optical zone, and initial hyperopic level influence optical quality for hyperopic Q-optimized corneal refractive surgery. Different Q-optimized algorithms and the Munnerlyn formula were tested to analyze the optical quality of the final retinal image for initial hyperopic errors from 1D to 5D. Three optical zones (5.5, 6, and 6.5 mm) and two pupil diameters (5 and 7 mm) were considered. To evaluate optical quality, we computed the modulation transfer function (MTF) and the area under MTF (MTFa). Q-optimized values at around Q = -0.18 were found to provide the best optical quality for most of the conditions tested. This optimum final asphericity for hyperopic ablation was not depending on the degree of hyperopia corrected, the optical zone or the pupil size being this information important for clinical practice.

12.
J Refract Surg ; 32(9): 612-7, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27598731

RESUMO

PURPOSE: To model the effect of pupil size, optical zone, and initial myopic level on the retinal image quality after Q-optimized myopic corneal refractive surgery. METHODS: Different Q-optimized and paraxial Munnerlyn algorithms were tested using a schematic myopic eye model to analyze the optical quality of the final retinal image for initial myopic errors from -1.00 to -7.00 diopters (D). Different optical zones (5.5, 6, and 6.5 mm in diameter) and two pupil diameters (5 and 7 mm, mesopic-scotopic conditions) were included in the comparison. Modulation transfer function (MTF) and area under the MTF from 0 to 60 cycles per degree (MTFa) were calculated by ray tracing to evaluate this retinal image quality. RESULTS: The Q-optimized algorithm with Q = -0.45 provided the highest MTF and MTFa results for myopic corrections less than -5.00 D. For refractive errors greater than -5.00 D, Q = -0.26 provided the highest MTF and MTFa results. CONCLUSIONS: Q-optimized algorithms improve the visual outcomes with respect to the paraxial Munnerlyn algorithm for myopic corneal surgery. The results show that the Q value that optimizes the results of the Q-optimized algorithm depends on the degree of myopia to correct and the size of the pupil. [J Refract Surg. 2016;32(9):612-617.].


Assuntos
Visão de Cores/fisiologia , Córnea/cirurgia , Visão Mesópica/fisiologia , Modelos Teóricos , Miopia/cirurgia , Pupila/fisiologia , Procedimentos Cirúrgicos Refrativos , Algoritmos , Córnea/fisiopatologia , Humanos , Miopia/fisiopatologia , Retina/fisiologia
13.
Biomed Opt Express ; 7(5): 1877-88, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-27231628

RESUMO

This study compares the clinical through-focus visual acuity (VA) in patients implanted with different intraocular lens (IOL) to optical bench testing of the same IOLs to evaluate the suitability of optical metrics of predicting clinical VA. Modulation transfer function and phase transfer function for different spatial frequencies and US Air Force pictures were measured using an optical bench for two monofocal IOLs, three multifocal IOLs and an extended range of vision IOL. Four preclinical metrics were calculated and compared to the clinical through-focus VA collected in three different clinical studies (243 patients in total). All metrics were well correlated (R(2)≥0.89) with clinical data and may be suitable for predicting through-focus VA in pseudophakic eyes.

15.
J Vis ; 15(6): 17, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26024464

RESUMO

Monovision presbyopia interventions exploit the binocular nature of the visual system by independently manipulating the optical properties of the two eyes. It is unclear, however, how individual variations in ocular dominance affect visual function in monovision corrections. Here, we examined the impact of sensory ocular dominance on visual performance in both traditional and modified monovision presbyopic corrections. We recently developed a binocular adaptive optics vision simulator to correct subjects' native aberrations and induce either modified monovision (1.5 D anisometropia, spherical aberration of +0.1 and -0.4 µm in distance and near eyes, respectively, over 4 mm pupils) or traditional monovision (1.5 D anisometropia). To quantify both the sign and the degree of ocular dominance, we utilized binocular rivalry to estimate stimulus contrast ratios that yield balanced dominance durations for the two eyes. Through-focus visual acuity and contrast sensitivity were measured under two conditions: (a) assigning dominant and nondominant eye to distance and near, respectively, and (b) vice versa. The results revealed that through-focus visual acuity was unaffected by ocular dominance. Contrast sensitivity, however, was significantly improved when the dominant eye coincided with superior optical quality. We hypothesize that a potential mechanism behind this observation is an interaction between ocular dominance and binocular contrast summation, and thus, assignment of the dominant eye to distance or near may be an important factor to optimize contrast threshold performance at different object distances in both modified and traditional monovision.


Assuntos
Dominância Ocular/fisiologia , Presbiopia/fisiopatologia , Presbiopia/terapia , Retina/fisiopatologia , Visão Monocular/fisiologia , Adulto , Lentes de Contato , Sensibilidades de Contraste/fisiologia , Feminino , Humanos , Masculino , Acuidade Visual/fisiologia , Adulto Jovem
16.
Appl Ergon ; 44(4): 523-31, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23219003

RESUMO

The aim of this study is to examine the effects of aging as well as visual impairment on retinal-image quality and visual performance in drivers. We use a new visual test called Halo v1.0 software for quantifying the discrimination capacity, an important visual function for evaluating the visual disturbances perceived by the observer. The study included 55 subjects with normal vision and 15 older subjects with cataracts. All subjects were examined for visual acuity, contrast sensitivity, visual-discrimination capacity and optical quality. Subjects also completed a subjective Driving Habits Questionnaire (DHQ). Older drivers with and without visual impairment showed significantly (p < 0.05) worse visual performance and deteriorated retinal-image quality, even when their binocular visual acuity was ≥20/25. In conclusion, some visual functions are considerably diminished in older drivers, even when visual acuity is sufficient to get or renew a driver's license. Halo software enables easy quantification of night-vision disturbances such as halos, which could impede the detection of pedestrians, cyclists, or traffic signals, thereby making this system advisable in clinical practice, e.g. in the requirements for a driver's license, particularly for older drivers.


Assuntos
Envelhecimento/fisiologia , Condução de Veículo , Catarata/fisiopatologia , Transtornos da Visão/fisiopatologia , Testes Visuais , Percepção Visual/fisiologia , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
17.
Appl Opt ; 51(31): 7626-7; discussion 7628-9, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23128711

RESUMO

In this paper, we reply to post-surgical corneal asphericity conclusions made by Dai [Appl. Opt.51, 3966 (2012)]. We deduced, after a theoretical analysis, that the conclusions derived from this analysis are not theoretically or experimentally sound, because the author considers only the Munnerlyn formula for ablation algorithms and not the paraxial Munnerlyn formula, which is widespread in refractive surgery [J. Cataract Refract. Surg.14, 46 (1988)]. We refer to a previous paper published by Jiménez et al. [J. Opt. Soc. Am. A21, 98 (2004)] for a complete analysis on this matter that clarifies some points of confusion in Dai's paper.


Assuntos
Algoritmos , Córnea/cirurgia , Cirurgia da Córnea a Laser/métodos , Modelos Biológicos , Humanos
18.
J Biomed Opt ; 17(1): 018001, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22352674

RESUMO

Two multifocal corneal models and an aspheric model designed to correct presbyopia by corneal photoablation were evaluated. The design of each model was optimized to achieve the best visual quality possible for both near and distance vision. In addition, we evaluated the effect of myosis and pupil decentration on visual quality. The corrected model with the central zone for near vision provides better results since it requires less ablated corneal surface area, permits higher addition values, presents stabler visual quality with pupil-size variations and lower high-order aberrations.


Assuntos
Córnea/anatomia & histologia , Córnea/cirurgia , Cirurgia da Córnea a Laser/métodos , Modelos Anatômicos , Presbiopia/cirurgia , Humanos , Pupila , Acuidade Visual/fisiologia
19.
J Refract Surg ; 28(12): 901-6, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23310967

RESUMO

PURPOSE: To analyze the theoretical effect that pupil size, optical zone, and initial myopic level have on the final retinal image after corneal refractive surgery. METHODS: A schematic myopic eye model corrected by the Munnerlyn formula was used to analyze the optical quality of the final retinal image. Root-mean-square radius spot and modulation transfer function were cal- culated by ray tracing to evaluate retinal image quality. RESULTS: Pupil size had a negative effect on the retinal image only when it was greater than the diameter of the optical zone. In addition, the greater the initial myopic level, the more the pupil size affected image quality. Thus, a clear dependence exists between the initial myopic level and effect that the pupil size can have on the retinal image after laser refractive surgery. CONCLUSIONS: Pupil size may be a risk factor for night vision disturbances, but only when it is larger than the theoretical optical zones utilized in this study. Its effect depends not only on the optical zone size, but also on the initial "myopic level. Therefore, this relationship should be taken into account during patient selection for refractive surgery


Assuntos
Modelos Teóricos , Miopia/fisiopatologia , Pupila/fisiologia , Refração Ocular/fisiologia , Procedimentos Cirúrgicos Refrativos , Visão Ocular/fisiologia , Acuidade Visual/fisiologia , Ofuscação , Humanos , Miopia/cirurgia , Fatores de Risco
20.
J Refract Surg ; 27(11): 833-6, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22045574

RESUMO

PURPOSE: To evaluate the visual quality of two theoretical multifocal corneal models designed to correct presbyopia by corneal photoablation. METHODS: Two theoretical multifocal corneal surfaces were analyzed by ray tracing: a central model (with a central zone for near vision and a peripheral zone for distance vision), and a peripheral model (with a central zone for distance vision and a peripheral zone for near vision). For both models, the effect of the size of the central zone and transition zone as well as the size of the pupil was evaluated. RESULTS: Our results show that a smaller transition zone favors total visual quality in both models. The optimal size of the central zone depends both on the size of the transition zone used as well as the model. However, both models responded similarly with respect to the variations in pupil size, providing the same visual quality although in an opposite way. CONCLUSIONS: This work shows that the optimal diameter of the central zone is smaller for the central model than for the peripheral model. Also, pupil size plays a fundamental role in achieving multifocality, showing that patient's pupil size should be thoroughly evaluated prior to multifocal refractive surgery.


Assuntos
Córnea/fisiopatologia , Ceratomileuse Assistida por Excimer Laser In Situ , Lasers de Excimer/uso terapêutico , Presbiopia/fisiopatologia , Presbiopia/cirurgia , Refração Ocular/fisiologia , Acuidade Visual/fisiologia , Humanos , Modelos Teóricos , Pupila/fisiologia
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