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1.
Appl Opt ; 61(9): 2207-2212, 2022 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-35333235

RESUMEN

We present the performance analysis and specifications of a portable auto-phoropter system that can be employed for fast refractive assessment of a large population. A customized Shack-Hartmann wavefront sensor is developed to accurately measure the defocus and astigmatism of the eye within ±10D and ±6D, respectively. Three fluidic lenses are designed to correct the vision in real time. A digital Snellen chart is integrated into the system to validate the accuracy of the measurement and the correction by means of achieving 20/20 vision. The refractive error of eight subjects (16 eyes) has been measured objectively (without patient's feedback) using the proposed system and the results are compared with their clinical prescription through the Bland-Altman method. It is shown that the auto-phoropter takes less than 8 s to measure and correct the eye refractive error with an accuracy of ±0.25D.


Asunto(s)
Astigmatismo , Cristalino , Lentes , Errores de Refracción , Astigmatismo/diagnóstico , Humanos , Errores de Refracción/diagnóstico , Agudeza Visual
2.
J Cataract Refract Surg ; 47(8): 1006-1010, 2021 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-34290196

RESUMEN

PURPOSE: To validate a new methodology of intraocular lens (IOL) assessment using acuity reserve analysis via area under the curve (AUC) to assess intermediate vision. SETTING: Study 1 was conducted at 17 sites in Australia, Chile, and Europe. Study 2 was conducted at 15 sites in Australia, Brazil, and Europe. DESIGN: Post hoc analyses of defocus curve results from 2 clinical trials (study 1: single-arm investigation of the AcrySof IQ PanOptix Trifocal IOL [model TFNT00; Alcon Research LLC]; study 2: comparative investigation of AcrySof PanOptix Trifocal IOL vs the AT LISA Trifocal IOL [model 839MP; Carl Zeiss Meditec AG]). METHODS: Acuity reserve was calculated using AUC compared with visual demand (logMAR) at various distances. Study 1 validated the model; study 2 compared acuity reserve, for a range of defocus levels, for the 2 IOLs. RESULTS: The defocus curve (study 1 [149 patients; 298 eyes]) showed good visual acuity (ie, >20/25) at all defocus levels; the AUC estimate showed 2 lines or more of reserve at -2.50 diopters. Comparative post hoc analysis (study 2 [182 patients]) demonstrated significantly improved acuity reserve with PanOptix IOL vs AT LISA IOL at 20 to 40 days postoperatively (P < .001) and 120 to 180 days postoperatively (P < .001). CONCLUSIONS: Acuity reserve analysis using AUC represents a new methodology for comparative IOL assessment, providing additional detail beyond defocus curve analysis. This method demonstrated that the PanOptix Trifocal IOL was superior to the AT LISA Trifocal IOL (model 839MP) for visual acuity at near to intermediate distances with visual acuity reserve analysis.


Asunto(s)
Lentes Intraoculares , Facoemulsificación , Australia , Brasil , Europa (Continente) , Humanos , Satisfacción del Paciente , Estudios Prospectivos , Diseño de Prótesis , Seudofaquia/cirugía , Refracción Ocular , Visión Binocular
3.
J Opt Soc Am A Opt Image Sci Vis ; 37(2): 192-198, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32118897

RESUMEN

Contrast threshold and visual Strehl ratio methods are used to predict visual acuity from wavefront error for a sample population of pre- and post-LASIK patients. Relative error (in logMAR) between predicted and measured visual acuity values are computed for each method and compared using paired t-tests. Differences in aberration data between pre- and post-LASIK eyes are then evaluated. The visual acuity prediction using visual Strehl proved to be more accurate for pre-LASIK patients than contrast threshold. However, both methods are comparable for post-LASIK patients.


Asunto(s)
Aberración de Frente de Onda Corneal/fisiopatología , Ojo/fisiopatología , Queratomileusis por Láser In Situ , Agudeza Visual/efectos de la radiación , Humanos , Resultado del Tratamiento
4.
J Cataract Refract Surg ; 46(4): 581-590, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32050208

RESUMEN

PURPOSE: To evaluate the precision of elevation and wavefront aberration measurements with the Pentacam HR (Oculus Optikgeräte GmbH). SETTING: Flinders University, Australia. DESIGN: Instrument evaluation study. METHODS: A randomly selected eye of 100 participants was scanned twice with the Pentacam HR by 1 observer on the 3 measurement modes: 25-picture, 50-picture, and cornea fine. A second observer performed 2 scans on the same random eye with the 25-picture mode. Repeatability and reproducibility were assessed using the within-subject SD (Sw) statistic from a 1-way analysis of variance. RESULTS: From the 100 scanned eyes, the higher-order aberration root mean square (RMS) repeatability limit for both elevation and wavefront, and anterior and posterior measurements was 0.03 µm for all 3 measurement modes. Anterior, posterior, and total corneal wavefront Zernike terms were highly precise, with most Zernike terms displaying a repeatability limit of 0.03 µm. The least repeatable measurement was the posterior elevation Zernike term with the 25-picture scan (repeatability limit 1.50 µm). The cornea fine measurement mode provided the most precise measurements. Reproducibility limits (second observer) were similar to repeatability limits with the 25-picture scan mode. CONCLUSIONS: The Pentacam HR provided highly precise aberration outputs. The most precise measurements are achievable with the cornea fine measurement mode and wavefront aberrations. One should be cognizant of posterior elevation aberration precision, particularly for lower radial order and higher azimuthal frequency terms. Accounting for tilt and misalignment of aberrations, all RMS and Zernike aberrations were extremely precise (repeatability and reproducibility limit less than 0.000001 µm).


Asunto(s)
Córnea/diagnóstico por imagen , Aberración de Frente de Onda Corneal/diagnóstico por imagen , Fotograbar/métodos , Tomografía/instrumentación , Adulto , Anciano , Córnea/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Refracción Ocular/fisiología , Reproducibilidad de los Resultados , Agudeza Visual/fisiología , Adulto Joven
5.
Clin Ophthalmol ; 12: 71-78, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29379267

RESUMEN

PURPOSE: The aim of the study was to quantify the isolated tear film adhesion error in a Goldmann applanation tonometer (GAT) prism and in a correcting applanation tonometry surface (CATS) prism. METHODS: The separation force of a tonometer prism adhered by a tear film to a simulated cornea was measured to quantify an isolated tear film adhesion force. Acrylic hemispheres (7.8 mm radius) used as corneas were lathed over the apical 3.06 mm diameter to simulate full applanation contact with the prism surface for both GAT and CATS prisms. Tear film separation measurements were completed with both an artificial tear and fluorescein solutions as a fluid bridge. The applanation mire thicknesses were measured and correlated with the tear film separation measurements. Human cadaver eyes were used to validate simulated cornea tear film separation measurement differences between the GAT and CATS prisms. RESULTS: The CATS prism tear film adhesion error (2.74±0.21 mmHg) was significantly less than the GAT prism (4.57±0.18 mmHg, p<0.001). Tear film adhesion error was independent of applanation mire thickness (R2=0.09, p=0.04). Fluorescein produces more tear film error than artificial tears (+0.51±0.04 mmHg; p<0.001). Cadaver eye validation indicated the CATS prism's tear film adhesion error (1.40±0.51 mmHg) was significantly less than that of the GAT prism (3.30±0.38 mmHg; p=0.002). CONCLUSION: Measured GAT tear film adhesion error is more than previously predicted. A CATS prism significantly reduced tear film adhesion error by41%. Fluorescein solution increases the tear film adhesion compared to artificial tears, while mire thickness has a negligible effect.

6.
BMC Ophthalmol ; 18(1): 2, 2018 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-29301514

RESUMEN

BACKGROUND: Compare Goldmann applanation tonometer (GAT) prism and correcting applanation tonometry surface (CATS) prism to intracameral intraocular pressure (IOP), in vivo and in vitro. METHODS: Pressure transducer intracameral IOP was measured on fifty-eight (58) eyes undergoing cataract surgery and the IOP was modulated manometrically to 10, 20, and 40 mmHg. Simultaneously, IOP was measured using a Perkins tonometer with a standard GAT prism and a CATS prism at each of the intracameral pressures. Statistical comparison was made between true intracameral pressures and the two prism measurements. Differences between the two prism measurements were correlated to central corneal thickness (CCT) and corneal resistance factor (CRF). Human cadaver eyes were used to assess measurement repeatability. RESULTS: The CATS tonometer prism measured closer to true intracameral IOP than the GAT prism by 1.7+/-2.7 mmHg across all pressures and corneal properties. The difference in CATS and GAT measurements was greater in thin CCT corneas (2.7+/-1.9 mmHg) and low resistance (CRF) corneas (2.8+/-2.1 mmHg). The difference in prisms was negligible at high CCT and CRF values. No difference was seen in measurement repeatability between the two prisms. CONCLUSION: A CATS prism in Goldmann tonometer armatures significantly improve the accuracy of IOP measurement compared to true intracameral pressure across a physiologic range of IOP values. The CATS prism is significantly more accurate compared to the GAT prism in thin and less rigid corneas. The in vivo intracameral study validates mathematical models and clinical findings in IOP measurement between the GAT and CATS prisms.


Asunto(s)
Errores Diagnósticos , Presión Intraocular/fisiología , Modelos Teóricos , Hipertensión Ocular/diagnóstico , Tonometría Ocular/instrumentación , Anciano , Cadáver , Diseño de Equipo , Femenino , Humanos , Masculino , Hipertensión Ocular/fisiopatología , Estudios Prospectivos , Reproducibilidad de los Resultados
7.
BMC Ophthalmol ; 17(1): 215, 2017 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-29178849

RESUMEN

BACKGROUND: Goldmann applanation tonometry (GAT) error relative to intracameral intraocular pressure (IOP) has not been examined comparatively in both human cadaver eyes and in live human eyes. Futhermore, correlations to biomechanical corneal properties and positional changes have not been examined directly to intracameral IOP and GAT IOP. METHODS: Intracameral IOP was measured via pressure transducer on fifty-eight (58) eyes undergoing cataract surgery and the IOP was modulated manometrically on each patient alternately to 10, 20, and 40 mmHg. IOP was measured using a Perkins tonometer in the supine position on 58 eyes and upright on a subset of 8 eyes. Twenty one (21) fresh human cadaver globes were Intracamerally IOP adjusted and measured via pressure transducer. Intracameral IOP ranged between 5 and 60 mmHg. IOP was measured in the upright position with a Goldmann Applanation Tonometer (GAT) and supine position with a Perkins tonometer. Central corneal thickness (CCT) was also measured. RESULTS: The Goldmann-type tonometer error measured on live human eyes was 5.2 +/-1.6 mmHg lower than intracameral IOP in the upright position and 7.9 +/- 2.3 mmHg lower in the supine position (p < .05). CCT also indicated a sloped correlation to error (correlation coeff. = 0.18). Cadaver eye IOP measurements were 3.1+/-2.5 mmHg lower than intracameral IOP in the upright position and 5.4+/- 3.1 mmHg in the supine position (p < .05). CONCLUSION: Goldmann IOP measures significantly lower than true intracameral IOP by approximately 3 mmHg in vitro and 5 mmHg in vivo. The Goldmann IOP error is increased an additional 2.8 mmHg lower in the supine position. CCT appears to significantly affect the error by up to 4 mmHg over the sample size.


Asunto(s)
Córnea/fisiología , Presión Intraocular/fisiología , Hipertensión Ocular/diagnóstico , Tonometría Ocular/métodos , Fenómenos Biomecánicos , Cadáver , Humanos , Sensibilidad y Especificidad , Tonometría Ocular/normas
8.
Sci Rep ; 7(1): 13990, 2017 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-29070904

RESUMEN

Using a phoropter to measure the refractive error is one of the most commonly used methods by ophthalmologists and optometrists. Here, we demonstrate design and fabrication of a portable automatic phoropter with no need for patient's feedback. The system is based on three tunable-focus fluidic lenses and thin-film holographic optical elements to perform automatic refractive error measurement and provide a diagnostic prescription without supervision. Three separate lenses are deployed to correct the defocus and astigmatism. The refractive error is measured using a Shack-Hartmann wavefront sensor that calculates the Zernike values of an infrared wavefront emerging from the eye. Holographic optical elements steer the emerging wavefront into the wavefront sensor, while simultaneously providing an unobstructed view for the subject. The power of each lens is controlled by pumping a liquid in and out of the lens chamber using servo motor actuated diaphragm pumps. Spherical and cylindrical correction range of -10 to +10 diopters with 0.1 diopter increments is achieved in less than 15 seconds using wavefront sensor feedback to the pumps. This system can be used in rapid screening of large patient populations especially in the developing countries that lack sufficient facilities and specialist doctors.


Asunto(s)
Cristalino , Refracción Ocular/fisiología , Errores de Refracción/diagnóstico , Refractometría/economía , Refractometría/instrumentación , Pruebas de Visión/instrumentación , Agudeza Visual/fisiología , Países en Desarrollo , Diseño de Equipo , Humanos , Errores de Refracción/terapia
9.
Biomed Opt Express ; 8(4): 2055-2068, 2017 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-28736655

RESUMEN

Spatial-light-modulators (SLM) are increasingly used as active elements in adaptive optics (AO) systems to simulate optical corrections, in particular multifocal presbyopic corrections. In this study, we compared vision with lathe-manufactured multi-zone (2-4) multifocal, angularly and radially, segmented surfaces and through the same corrections simulated with a SLM in a custom-developed two-active-element AO visual simulator. We found that perceived visual quality measured through real manufactured surfaces and SLM-simulated phase maps corresponded highly. Optical simulations predicted differences in perceived visual quality across different designs at Far distance, but showed some discrepancies at intermediate and near.

10.
J Opt Soc Am A Opt Image Sci Vis ; 34(5): 726-731, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28463340

RESUMEN

In a previous paper, a technique was developed for decomposing the incoherent optical transfer function (OTF) into a linear combination of basis functions [J. Opt. Soc. Am. A31, 2476 (2014)JOAOD60740-323210.1364/JOSAA.31.002476]. The expansion coefficients for the OTF are directly related to wavefront error coefficients and apodization factors. This earlier work assumed rotational symmetry, so that only the on-axis wavefront error components, defocus and various orders of spherical aberration, and rotationally symmetric apodization were handled. In this paper, the technique is generalized to handle arbitrary wavefront errors and apodization. Analytic expressions for the basis functions as well as an example expansion are provided.

11.
Clin Ophthalmol ; 11: 835-840, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28496302

RESUMEN

PURPOSE: Clinically evaluate a modified applanating surface Goldmann tonometer prism designed to substantially negate errors due to patient variability in biomechanics. METHODS: A modified Goldmann prism with a correcting applanation tonometry surface (CATS) was mathematically optimized to minimize the intraocular pressure (IOP) measurement error due to patient variability in corneal thickness, stiffness, curvature, and tear film adhesion force. A comparative clinical study of 109 eyes measured IOP with CATS and Goldmann prisms. The IOP measurement differences between the CATS and Goldmann prisms were correlated to corneal thickness, hysteresis, and curvature. RESULTS: The CATS tonometer prism in correcting for Goldmann central corneal thickness (CCT) error demonstrated a reduction to <±2 mmHg in 97% of a standard CCT population. This compares to only 54% with CCT error <±2 mmHg using the Goldmann prism. Equal reductions of ~50% in errors due to corneal rigidity and curvature were also demonstrated. CONCLUSION: The results validate the CATS prism's improved accuracy and expected reduced sensitivity to Goldmann errors without IOP bias as predicted by mathematical modeling. The CATS replacement for the Goldmann prism does not change Goldmann measurement technique or interpretation.

12.
ACS Macro Lett ; 6(5): 500-504, 2017 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-35610885

RESUMEN

We report on the preparation of ultrahigh refractive index polymers via the inverse vulcanization of elemental sulfur, selenium, and 1,3-diisopropenylbenzene for use as novel transmissive materials for mid-infrared (IR) imaging applications. Poly(sulfur-random-selenium-random-(1,3-diisopropenylbenzene)) (poly(S-r-Se-r-DIB) terpolymer materials from this process exhibit the highest refractive index of any synthetic polymer (n > 2.0) and excellent IR transparency, which can be directly tuned by terpolymer composition. Sulfur or selenium containing (co)polymers prepared via inverse vulcanization can be described as Chalcogenide Hybrid Inorganic/Organic Polymers (CHIPs) and are polymeric analogues to wholly inorganic Chalcogenide Glasses (ChGs), which are commonly used as transmissive materials in mid-IR imaging. Finally, we demonstrate that CHIPs composed of (poly(S-r-Se-r-DIB) can be melt processed into windows that enabled high quality mid-IR thermal imaging of human subjects and highly resolved imaging of human vasculature.

13.
Transl Vis Sci Technol ; 5(5): 4, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27642540

RESUMEN

PURPOSE: We evaluate solutions for an applanating surface modification to the Goldmann tonometer prism, which substantially negates the errors due to patient variability in biomechanics. METHODS: A modified Goldmann or correcting applanation tonometry surface (CATS) prism is presented which was optimized to minimize the intraocular pressure (IOP) error due to corneal thickness, stiffness, curvature, and tear film. Mathematical modeling with finite element analysis (FEA) and manometric IOP referenced cadaver eyes were used to optimize and validate the design. RESULTS: Mathematical modeling of the optimized CATS prism indicates an approximate 50% reduction in each of the corneal biomechanical and tear film errors. Manometric IOP referenced pressure in cadaveric eyes demonstrates substantial equivalence to GAT in nominal eyes with the CATS prism as predicted by modeling theory. CONCLUSION: A CATS modified Goldmann prism is theoretically able to significantly improve the accuracy of IOP measurement without changing Goldmann measurement technique or interpretation. Clinical validation is needed but the analysis indicates a reduction in CCT error alone to less than ±2 mm Hg using the CATS prism in 100% of a standard population compared to only 54% less than ±2 mm Hg error with the present Goldmann prism. TRANSLATIONAL RELEVANCE: This article presents an easily adopted novel approach and critical design parameters to improve the accuracy of a Goldmann applanating tonometer.

14.
J Opt Soc Am A Opt Image Sci Vis ; 33(8): 1626-7, 2016 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-27505662

RESUMEN

Efficient coding enables rapid calculation of basis functions for a linear expansion of the optical transfer function.

15.
Invest Ophthalmol Vis Sci ; 57(7): 3239-47, 2016 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-27315539

RESUMEN

PURPOSE: To evaluate light scatter and stray light in intraocular lenses (IOLs) explanted because of postoperative opacification (13 calcified hydrophilic acrylic, 1 calcified silicone, and 4 polymethylmethacrylate [PMMA] lenses with snowflake degeneration), as well as effect of opacification on other optical quality/performance indicators, in comparison with controls. METHODS: The Complete Angle Scatter Instrument (CASI) scatterometer was used to measure the forward light scattering (FLS) of the IOLs, and the stray light values at various angles were calculated from the measured FLS. Modulation transfer function (MTF) was obtained with an optical bench, and a Badal optometer was used to obtain letter chart images through the lenses. Back light scatter and light transmittance were also measured. RESULTS: Average stray light values (Log (s)) at a scattered angle of 10° were 1.79 ± 0.37 for hydrophilic acrylic IOLs (controls 0.36 ± 0.05), 1.53 for the silicone lens (control 0.41), and 1.62 ± 0.46 for PMMA IOLs (control 0.25). Stray light was significantly higher for explanted opacified lenses (N = 18) in comparison with controls (N = 7; two-tail P < 0.001 at 10°). Modulation transfer function and Badal image contrast were drastically reduced in lenses with calcification and snowflake degeneration. CONCLUSIONS: Different studies described the impact of stray light in human vision, with serious hindrance above 1.47 Log (s). Lenses explanted from patients because of clinically significant opacification are associated with a considerable increase in light scatter and stray light, as well as with a decline of other optical quality/performance indicators.


Asunto(s)
Resinas Acrílicas , Calcinosis/diagnóstico , Lentes Intraoculares , Polimetil Metacrilato , Dispersión de Radiación , Elastómeros de Silicona , Agudeza Visual/fisiología , Materiales Biocompatibles , Calcinosis/cirugía , Remoción de Dispositivos , Análisis de Falla de Equipo , Humanos , Luz , Óptica y Fotónica , Complicaciones Posoperatorias , Falla de Prótesis
16.
J Cataract Refract Surg ; 42(1): 148-56, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26948790

RESUMEN

PURPOSE: To evaluate forward light scattering and straylight in single-piece hydrophobic acrylic intraocular lenses (IOLs) (Acrysof) removed from cadaver eyes and design- and power-matched controls, as well as the effect of subsurface nanoglistenings on other optical quality and performance indicators. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Seventeen single-piece IOLs (11 blue light-filtering; 6 without blue-light filter) with subsurface nanoglistenings were removed from cadaver eyes. The Complete Angle Scatter Instrument scatterometer was used to measure the forward-scattered light; straylight values at various angles were calculated. The modulation transfer function (MTF) and Badal images were also obtained. Backscatter was measured with a Scheimpflug camera (EAS-1000) and light transmittance with a spectrophotometer (Lambda 35 UV-VIS) to confirm findings in previous studies. RESULTS: The mean straylight values at a scattered angle of 10 degrees were 1.06 ± 0.23 log(s) for blue light-filtering IOLs, 0.97 ± 0.28 log(s) for IOLs without a blue-light filter, and 0.22 ± 0.22 log(s) for controls. The MTF and Badal image contrast of IOLs removed from cadaver eyes were similar to control values (no subsurface nanoglistenings). Backscatter was significantly higher in IOLs from cadaver eyes, although light transmittance was similar to that of controls. CONCLUSION: Straylight in hydrophobic IOLs resulting from subsurface nanoglistenings was well below the value of straylight hindrance and would not cause noticeable visual impairments. FINANCIAL DISCLOSURE: Dr. Das is an employee of Alcon Laboratories, Inc. The Complete Angle Instrument scatterometer was developed by Dr. Stover at the Scatterworks, Inc. Neither of the other authors has a financial or proprietary interest in any method or material mentioned.


Asunto(s)
Deslumbramiento , Lentes Intraoculares , Óptica y Fotónica , Dispersión de Radiación , Vacuolas , Resinas Acrílicas , Cadáver , Remoción de Dispositivos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Luz
17.
ACS Macro Lett ; 5(10): 1152-1156, 2016 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-35658175

RESUMEN

The synthesis of a novel high sulfur content material possessing improved thermomechanical properties is reported via the inverse vulcanization of elemental sulfur (S8) and 1,3,5-triisopropenylbenzene (TIB). A key feature of this system was the ability to afford highly cross-linked, thermosetting materials, where the use of TIB as a comonomer enabled facile control of the network structure and dramatically improved the glass transition temperature (relative to our earlier sulfur copolymers) of poly(sulfur-random-(1,3,5-triisopropenylbenzene)) (poly(S-r-TIB)) materials over a range from T = 68 to 130 °C. This approach allowed for the incorporation of a high content of sulfur-sulfur (S-S) units in the copolymer that enabled thermomechanical scission of these dynamic covalent bonds and thermal reprocessing of the material, which we confirmed via dynamic rheological characterization. Furthermore, the high sulfur content also imparted high refractive index (n > 1.75) and IR transparency to poly(S-r-TIB) copolymers, which offered a route to enhanced optical transmitting materials for IR thermal imaging applications with improved thermomechanical properties.

18.
J Cataract Refract Surg ; 41(8): 1568-79, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26432112

RESUMEN

PURPOSE: To demonstrate the independence of visual performance over a range of preoperative refraction and age in presbyopes implanted with a corneal shape-changing inlay (Raindrop Near Vision Inlay). SETTING: Two multispecialty clinics, Monterrey and Tijuana, Mexico. DESIGN: Prospective case series. METHODS: The nondominant eyes of patients were implanted with the hydrogel corneal inlay beneath a femtosecond flap, centered on the pupil. Clinical outcomes included uncorrected near, intermediate, and distance visual acuity (UNVA, UIVA, and UDVA) and patient-assessed task performance in good light and dim light. Statistical analyses assessed the dependencies on preoperative age (45 to 60 years) and preoperative manifest refraction spherical equivalent (MRSE) (-0.5 to +1.5 diopters [D]). Using the inlay effect derived from wavefront measurements, an eye model was created through which letter charts were simulated. RESULTS: The study evaluated eyes of 188 patients. Postoperative UNVA, UIVA, and task performance at these distances in good light was independent of age and preoperative MRSE (P > .05). Postoperative UDVA was weakly dependent on preoperative MRSE, but distance task performance in good light was not (P > .05). In the treated eye, the mean postoperative UNVA was 20/25, UIVA was 20/25, and UDVA was 20/32. The clinical outcomes are explained by consideration of zones within the pupil generating good near, intermediate, and distance image quality. This was confirmed by visual acuity simulations. CONCLUSIONS: The continuous center-near power profile induced by the corneal shape-changing inlay provides good visual acuity and performance from distance through near over a 2.0 D range of preoperative refraction and presbyopic age. FINANCIAL DISCLOSURE: Drs. Steinert, Schwiegerling, Barragán-Garza, and Chayet are consultants to Revision Optics, Inc. Drs. Lang and Holliday and Mr. Roy are employees of Revision Optics, Inc. Drs. Steinert, Schwiegerling, Barragán-Garza, and Chayet have no financial or proprietary interest in any material or method mentioned.


Asunto(s)
Córnea/fisiopatología , Sustancia Propia/cirugía , Polivinilos , Presbiopía/cirugía , Implantación de Prótesis , Refracción Ocular/fisiología , Agudeza Visual/fisiología , Materiales Biocompatibles , Sustancia Propia/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Presbiopía/fisiopatología , Estudios Prospectivos , Prótesis e Implantes , Colgajos Quirúrgicos , Encuestas y Cuestionarios
19.
J AAPOS ; 19(4): 352-7.e1, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26239206

RESUMEN

PURPOSE: To determine whether higher-order aberrations (HOAs) in children from a highly astigmatic population differ from population norms and whether HOAs are associated with astigmatism and reduced best-corrected visual acuity. METHODS: Subjects were 218 Tohono O'odham Native American children 5-9 years of age. Noncycloplegic HOA measurements were obtained with a handheld Shack-Hartmann sensor (SHS). Signed (z06s to z14s) and unsigned (z06u to z14u) wavefront aberration Zernike coefficients Z(3,-3) to Z(4,4) were rescaled for a 4 mm diameter pupil and compared to adult population norms. Cycloplegic refraction and best-corrected logMAR letter visual acuity (BCVA) were also measured. Regression analyses assessed the contribution of astigmatism (J0) and HOAs to BCVA. RESULTS: The mean root-mean-square (RMS) HOA of 0.191 ± 0.072 µm was significantly greater than population norms (0.100 ± 0.044 µm). All unsigned HOA coefficients (z06u to z14u) and all signed coefficients except z09s, z10s, and z11s were significantly larger than population norms. Decreased BCVA was associated with astigmatism (J0) and spherical aberration (z12u) but not RMS coma, with the effect of J0 about 4 times as great as z12u. CONCLUSIONS: Tohono O'odham children show elevated HOAs compared to population norms. Astigmatism and unsigned spherical aberration are associated with decreased acuity, but the effects of spherical aberration are minimal and not clinically significant.


Asunto(s)
Astigmatismo/etnología , Aberración de Frente de Onda Corneal/etnología , Indígenas Norteamericanos , Trastornos de la Visión/etnología , Agudeza Visual/fisiología , Aberrometría , Arizona/epidemiología , Astigmatismo/fisiopatología , Niño , Preescolar , Topografía de la Córnea , Aberración de Frente de Onda Corneal/fisiopatología , Femenino , Humanos , Indígenas Norteamericanos/etnología , Masculino , Midriáticos/administración & dosificación , Prevalencia , Pupila/fisiología , Refracción Ocular/fisiología , Retinoscopía , Trastornos de la Visión/fisiopatología
20.
Transl Vis Sci Technol ; 4(2): 17, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25938005

RESUMEN

PURPOSE: Present an analysis methodology for developing and evaluating accommodating intraocular lenses incorporating a deformable interface. METHODS: The next generation design of extruded gel interface intraocular lens is presented. A prototype based upon similar previously in vivo proven design was tested with measurements of actuation force, lens power, interface contour, optical transfer function, and visual Strehl ratio. Prototype verified mathematical models were used to optimize optical and mechanical design parameters to maximize the image quality and minimize the required force to accommodate. RESULTS: The prototype lens produced adequate image quality with the available physiologic accommodating force. The iterative mathematical modeling based upon the prototype yielded maximized optical and mechanical performance through maximum allowable gel thickness to extrusion diameter ratio, maximum feasible refractive index change at the interface, and minimum gel material properties in Poisson's ratio and Young's modulus. CONCLUSIONS: The design prototype performed well. It operated within the physiologic constraints of the human eye including the force available for full accommodative amplitude using the eye's natural focusing feedback, while maintaining image quality in the space available. The parameters that optimized optical and mechanical performance were delineated as those, which minimize both asphericity and actuation pressure. The design parameters outlined herein can be used as a template to maximize the performance of a deformable interface intraocular lens. TRANSLATIONAL RELEVANCE: The article combines a multidisciplinary basic science approach from biomechanics, optical science, and ophthalmology to optimize an intraocular lens design suitable for preliminary animal trials.

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