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Heinzman Z, Linton E, Marín-Franch I, Turpin A, Alawa K, Wijayagunaratne A, Wall M. Validation of the Iowa Head-Mounted Open-Source Perimeter. Transl Vis Sci Technol 2023; 12:19. [PMID: 37747414 PMCID: PMC10528495 DOI: 10.1167/tvst.12.9.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 09/04/2023] [Indexed: 09/26/2023] Open
Abstract
Purpose To assess the validity of visual field (VF) results from the Iowa Head-Mounted Display (HMD) Open-Source Perimeter and to test the hypothesis that VF defects and test-retest repeatability are similar between the HMD and Octopus 900 perimeters. Methods We tested 20 healthy and nine glaucoma patients on the HMD and Octopus 900 perimeters using the Open Perimetry Interface platform with size V stimuli, a custom grid spanning the central 26° of the VF, and a ZEST thresholding algorithm. Historical data from the Humphrey Field Analyzer (HFA) were also analyzed. Repeatability was analyzed with the repeatability coefficient (RC), and VF defect detection was determined through side-by-side comparisons. Results The pointwise RCs were 2.6 dB and 3.4 dB for the HMD and Octopus 900 perimeters in ocular healthy subjects, respectively. Likewise, the RCs were 4.2 dB and 3.5 dB, respectively, in glaucomatous patients. Limits of agreement between the HMD and Octopus 900 perimeters were ±4.6 dB (mean difference, 0.4 dB) for healthy patients and ±8.9 dB (mean difference, 0.1 dB) for glaucomatous patients. Retrospective analysis showed that pointwise RCs on the HFA2 perimeter were between 3.4 and 3.7 dB for healthy patients and between 3.9 and 4.7 dB for glaucoma patients. VF defects were similar between the HMD and Octopus 900 for glaucoma subjects. Conclusions The Iowa Virtual Reality HMD Open-Source Perimeter is as repeatable as the Octopus 900 perimeter and is a more portable and less expensive alternative than traditional perimeters. Translational Relevance This study demonstrates the validity of the visual field results from the Iowa HMD Open-Source Perimeter which may help expand perimetry access.
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Affiliation(s)
- Zachary Heinzman
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Edward Linton
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Iván Marín-Franch
- Computational Optometry, Atarfe, Spain
- Southwest Eye Institute, Tavistock, UK
| | - Andrew Turpin
- Curtin School of Population Health, Curtin University, Bentley, Western Australia, Australia
| | - Karam Alawa
- Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Anushi Wijayagunaratne
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Michael Wall
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
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Marín-Franch I, Wyatt HJ, Swanson WH. Using high-density perimetry to explore new approaches for characterizing visual field defects. Vision Res 2023; 210:108259. [PMID: 37285782 PMCID: PMC10526895 DOI: 10.1016/j.visres.2023.108259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 05/08/2023] [Accepted: 05/09/2023] [Indexed: 06/09/2023]
Abstract
High-density threshold perimetry has found that conventional static threshold perimetry misses defects due to undersampling. However, high-density testing can be both slow and limited by normal fixational eye movements. We explored alternatives by studying displays of high-density perimetry results for angioscotomas in healthy eyes-areas of reduced sensitivity in the shadows of blood vessels. The right eyes of four healthy adults were tested with a Digital Light Ophthalmoscope that gathered retinal images while presenting visual stimuli. The images were used to infer stimulus location on each trial. Contrast thresholds for a Goldmann size III stimulus were measured at 247 locations of a 13°×19° rectangular grid, with separation 0.5°, extending from 11° to 17° horizontally and -3° to +6° vertically, covering a portion of the optic nerve head and several major blood vessels. Maps of perimetric sensitivity identified diffuse regions of reduced sensitivity near the blood vessels, but these showed moderate structure-function agreement that was only modestly improved when effects of eye position were accounted for. An innovative method termed slice display was used to locate regions of reduced sensitivity. Slice display demonstrated that many fewer trials could yield similar structure-function agreement. These results are an indication that test duration might be reduced dramatically by focusing on location of defects rather than maps of sensitivity. Such alternatives to conventional threshold perimetry have the potential to map the shape of defects without the extensive time demands of high-density threshold perimetry. Simulations illustrate how such an algorithm could operate.
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Affiliation(s)
- I Marín-Franch
- Computational Optometry, Atarfe, Granada, Spain; Southwest Eye Institute, Tavistock, UK.
| | - H J Wyatt
- SUNY College of Optometry, New York, NY, United States
| | - W H Swanson
- School of Optometry, Indiana University Bloomington, Bloomington, IN, United States.
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Marín-Franch I, Turpin A, Artes PH, Chong LX, McKendrick AM, Alawa KA, Wall M. The Open Perimetry Initiative: A framework for cross-platform development for the new generation of portable perimeters. J Vis 2022; 22:1. [PMID: 35385053 PMCID: PMC8994165 DOI: 10.1167/jov.22.5.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The Open Perimetry Initiative was formed in 2010 with the aim of reducing barriers to clinical research with visual fields and perimetry. Our two principal tools are the Open Perimetry Interface (OPI) and the visualFields package with analytical tools. Both are fully open source. The OPI package contains a growing number of drivers for commercially available perimeters, head-mounted devices, and virtual reality headsets. The visualFields package contains tools for the analysis and visualization of visual field data, including methods to compute deviation values and probability maps. We introduce a new frontend, the opiApp, that provides tools for customization for visual field testing and can be used as a frontend to run the OPI. The app can be used on the Octopus 900 (Haag-Streit), the Compass (iCare), the AP 7000 (Kowa), and the IMO (CREWT) perimeters, with permission from the device manufacturers. The app can also be used on Android phones with virtual reality headsets via a new driver interface, the PhoneHMD, implemented on the OPI. The use of the tools provided by the OPI library is showcased with a custom static automated perimetry test for the full visual field (up to 50 degrees nasally and 80 degrees temporally) developed with the OPI driver for the Octopus 900 and using visualFields for statistical analysis. With more than 60 citations in clinical and translational science journals, this initiative has contributed significantly to expand research in perimetry. The continued support of researchers, clinicians, and industry are key in transforming perimetry research into an open science.
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Affiliation(s)
- Iván Marín-Franch
- Computational Optometry, Atarfe, Spain.,Southwest Eye Institute, Tavistock, UK., www.optocom.es
| | - Andrew Turpin
- School of Computing and Information Systems, University of Melbourne, Melbourne, Victoria, Australia.,
| | - Paul H Artes
- Southwest Eye Institute, Tavistock, UK.,University of Plymouth, Plymouth, UK.,
| | - Luke X Chong
- School of Medicine (Optometry), Deakin University, Geelong, Australia.,
| | - Allison M McKendrick
- Department of Optometry and Vision Sciences, University of Melbourne, Melbourne, Victoria, Australia.,
| | - Karam A Alawa
- Departments of Neurology and Ophthalmology and Visual Sciences, University of Iowa, College of Medicine, Iowa City, Iowa, USA.,
| | - Michael Wall
- Departments of Neurology and Ophthalmology and Visual Sciences, University of Iowa, College of Medicine, Iowa City, Iowa, USA.,
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Abstract
Purpose It has been suggested that the detection of visual field progression can be improved by modeling statistical properties of the data such as the increasing retest variability and the spatial correlation among visual field locations. We compared a method that models those properties, Analysis with Non-Stationary Weibull Error Regression and Spatial Enhancement (ANSWERS), against a simpler one that does not, Permutation of Pointwise Linear Regression (PoPLR). Methods Visual field series from three independent longitudinal studies in patients with glaucoma were used to compare the positive rate of PoPLR and ANSWERS. To estimate the false-positive rate, the same visual field series were randomly re-ordered in time. The first dataset consisted of series of 7 visual fields from 101 eyes, the second consisted of series of 9 visual fields from 150 eyes, and the third consisted of series of more than 9 visual fields (17.5 on average) from 139 eyes. Results For a statistical significance of 0.05, the false-positive rates for ANSWERS were about 3 times greater than expected at 15%, 17%, and 16%, respectively, whereas for PoPLR they were 7%, 3%, and 6%. After equating the specificities at 0.05 for both models, positive rates for ANSWERS were 16%, 25%, and 38%, whereas for PoPLR they were 12%, 33%, and 49%, or about 5% greater on average (95% confidence interval = −1% to 11%). Conclusions Despite being simpler and less computationally demanding, PoPLR was at least as sensitive to deterioration as ANSWERS once the specificities were equated. Translational Relevance Close control of false-positive rates is key when visual fields of patients are analyzed for change in both clinical practice and clinical trials.
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Affiliation(s)
- Iván Marín-Franch
- Computational Optometry, Atarfe, Granada, Spain.,Department of Ophthalmology and Visual Sciences, University of Alabama, Alabama, USA.,Southwest Eye Institute, Tavistock, UK
| | - Paul H Artes
- Southwest Eye Institute, Tavistock, UK.,Eye and Vision Research Group, Faculty of Health and Human Sciences, University of Plymouth, Plymouth, England, UK
| | - Andrew Turpin
- School of Computing and Information Systems, University of Melbourne, Australia
| | - Lyne Racette
- Department of Ophthalmology and Visual Sciences, University of Alabama, Alabama, USA
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Abu SL, Marín-Franch I, Racette L. Detecting Progression in Patients With Different Clinical Presentations of Primary Open-angle Glaucoma. J Glaucoma 2021; 30:769-775. [PMID: 33867504 PMCID: PMC8404957 DOI: 10.1097/ijg.0000000000001843] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 03/07/2021] [Indexed: 11/25/2022]
Abstract
PRCIS Glaucoma progression was more frequently identified by assessing retinal fiber layer thickness than by monitoring visual field (VF) loss for different baseline classifications in primary open-angle glaucoma. PURPOSE The aim was to compare the detection of glaucoma progression by retinal nerve fiber layer thickness (RNFLT) and VF assessments for different baseline classifications of primary open-angle glaucoma. METHODS This study included 194 eyes from 194 patients with a minimum of 9 follow-up visits selected from the Diagnostic Innovation in Glaucoma Study (DIGS) and the African Descent and Glaucoma Evaluation Study (ADAGES). Each eye was classified according to baseline clinical signs: ocular hypertension (n=39), glaucomatous optic neuropathy only (n=60), glaucomatous visual field loss only (GVF, n=39) and definite glaucoma (concurrent optic disc and VF defect, n=56). We assessed progression by performing simple linear regression on global and sectorial mean deviations values generated for RNFLT (RNFLT-MD) and VF data (VF-MD). The proportion of eyes identified as progressing (positive rate) by RNFLT-MD and by VF-MD were compared within each classification. RESULTS Whereas both parameters performed similarly among glaucomatous optic neuropathy only and definite glaucoma eyes, the positive rate obtained with global RNFLT-MD was significantly greater compared with global VF-MD by 33.3% and 30.8% among ocular hypertension eyes and GVF eyes, respectively. This finding was consistent in the inferotemporal sector; however, similar positive rates were obtained for both parameters in the superotemporal sector. CONCLUSIONS While both RNFLT and VF parameters showed comparable abilities to identify progression across the different classifications, RNFLT assessment may be better suited to monitor progression, particularly among patients with elevated intraocular pressure and those who present with only GVF defect at baseline.
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Affiliation(s)
- Sampson L. Abu
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Alabama, AL
| | - Iván Marín-Franch
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Alabama, AL
- Computational Optometry, Atarfe, Spain
| | - Lyne Racette
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Alabama, AL
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Lara-Lacárcel F, Marín-Franch I, Fernández-Sánchez V, Riquelme-Nicolás R, López-Gil N. Objective changes in astigmatism during accommodation. Ophthalmic Physiol Opt 2021; 41:1069-1075. [PMID: 34414587 DOI: 10.1111/opo.12863] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/07/2021] [Accepted: 06/07/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE Previous studies have shown small but clinically significant changes in the power and axis of astigmatism when the eye accommodates. Monocular objective measurements of the eye during accommodation, when the object approaches the eye without convergence, also reveal small astigmatic changes. Moreover, it is known that the eye exhibits ocular cyclotorsion at different gaze angles. Since accommodation and convergence normally occur simultaneously, we studied the change in the magnitude and axis of astigmatism during accommodation for different convergence angles. METHODS The left eye of 15 subjects between 20 and 49 years old (mean 28.5 ± 9.7 years) having ≤1.5 D astigmatism was evaluated. Measurements were made using a Shack-Hartmann aberrometer for an accommodation range of +0.50 D to -10 D in 0.50 D steps, and for four monocular convergence demands: 0°, 5°, 10° and 15°. Statistical analysis used power vectors to quantify the change in cylinder power and axis for each accommodation and convergence demand with age. RESULTS Jackson cross-cylinder component J45 did not change during accommodation for all vergences tested. However, J0 changed by an average of -0.02 D per dioptre of accommodation (D/Dacc) for convergence demands of 0°, 5° and 10° and -0.03 D/Dacc for the 15° demand. This corresponds to an average cylinder power change of -0.05 D/Dacc for convergences of 0°, 5° and 10° and -0.08 D/Dacc for 15° of convergence. The cylinder axis always changed towards 90° (against-the-rule), and age did not play a significant role. CONCLUSIONS Except for accommodation demands >4 D, we did not find a clinically significant change in astigmatism for convergence angles up to 15º. The small changes in cylinder power and axis may be due to shifts in the position of the crystalline lens during accommodation.
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Affiliation(s)
| | - Iván Marín-Franch
- Faculty of Optics and Optometry, University of Murcia, Murcia, Spain.,Computational Optometry, Atarfe, Spain
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Águila-Carrasco AJD, Marín-Franch I. Predictability of sinusoidally moving stimuli does not improve the accuracy of the accommodative response. Sci Rep 2021; 11:15195. [PMID: 34312461 PMCID: PMC8313575 DOI: 10.1038/s41598-021-94642-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Accepted: 07/13/2021] [Indexed: 12/31/2022] Open
Abstract
Previous research work suggests that predictable target motion such as sinusoidal movement can be anticipated by the visual system, thereby improving the accommodative response. The validity of predictable motion for studying human dynamic accommodation is sometimes put into question. The aim of this work was to assess the effect of anticipation along with learning (and motivation, etc.) and fatigue (and boredom, loss of attention, etc.) on dynamic accommodation experiments from a practical perspective. Specifically, changes in amplitude and temporal phase lag were estimated within and between trials as 9 adult observers were instructed to focus on a stimulus that oscillated sinusoidally towards and away from the eye at specific temporal frequencies. On average, amplitude decreased whereas phase increased within trials. No evidence of anticipation or learning was observed either within or between trials. Fatigue consistently dominated anticipation and learning within the course of each trial. Even if the eye is equipped by a prediction operator as it is often assumed, fatigue confounds the results from dynamic accommodation experiments more than anticipation or learning.
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8
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Abu SL, Marín-Franch I, Racette L. A framework for assessing glaucoma progression using structural and functional indices jointly. PLoS One 2020; 15:e0235255. [PMID: 32609734 PMCID: PMC7329074 DOI: 10.1371/journal.pone.0235255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 06/11/2020] [Indexed: 11/19/2022] Open
Abstract
Purpose While many tests and indices are available to identify glaucoma progression, using them in combinations may decrease overall specificity. The aim of this study was to develop a framework for assessing glaucoma progression using structural and functional indices jointly for a fixed specificity. Methods The study included 337 eyes of 207 patients with ocular hypertension or primary open-angle glaucoma selected from the Diagnostic Innovations in Glaucoma Study or the African Descent and Glaucoma Evaluation Study. All patients had at least 9 visits. Each visit had retinal nerve fiber layer thickness (RNFLT) and mean sensitivity from static automated perimetry (SAP MS) measured within a one-month window. Simple linear regression was applied to assess deterioration in each index for series of 5 to 9 visits. To identify progression using the two indices jointly, marginal significance levels set at a specificity of 95% were derived for two criteria: ANY (worsening on either RNFLT or SAP MS) and ALL (worsening on both RNFLT and SAP MS). Positive rate (percentage of eyes flagged as progressing) was determined individually for each index, as well as for the ANY and ALL criteria. Results Compared to SAP MS, RNFLT had higher positive rates (15% to 45%) for all series lengths. For the joint analyses, the positive rate was on average 12% higher for the ANY criterion compared to the ALL criterion. While RNFLT-alone had comparable positive rates and time-to-detection as the ANY criterion, each uniquely identified a subset of eyes (Kappa = 0.55 to 0.75). Conclusions This study provides a simple framework for assessing glaucoma progression with data from two tests jointly, without compromising specificity. This framework can be extended to include two or more parameters, can accommodate global or regional indices, and can eventually be used with novel parameters identified as predictive of glaucoma progression.
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Affiliation(s)
- Sampson Listowell Abu
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Iván Marín-Franch
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Computational Optometry, Atarfe, Spain
| | - Lyne Racette
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- * E-mail:
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9
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Bartuzel MM, Robert Iskander D, Marín-Franch I, López-Gil N. Defocus vibrations in optical systems-considerations in reference to the human eye. J Opt Soc Am A Opt Image Sci Vis 2019; 36:464-470. [PMID: 30874183 DOI: 10.1364/josaa.36.000464] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 01/24/2019] [Indexed: 06/09/2023]
Abstract
Experimental visual acuity (VA) of eight subjects was measured using the Freiburg vision test in a custom-made adaptive optics system. Measurements were conducted under one control and five defocus-induced conditions. In the defocus-induced conditions, 1 diopter of myopic defocus was added to the system using the Badal stage, and defocus vibrations with five different levels of amplitude were generated by a deformable mirror at 50 Hz. Computational simulations of the visual Strehl ratio (VSOTF) were performed using average aberrations of each subject recorded in the control condition. For the first time, to the best of our knowledge, it has been shown experimentally that both the simulated VSOTF and experimentally measured VA improve when defocus vibrations are added to a defocused eye.
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Del Águila-Carrasco AJ, Lara F, Bernal-Molina P, Riquelme-Nicolás R, Marín-Franch I, Esteve-Taboada JJ, Montés-Micó R, Kruger PB, López-Gil N. Effect of phenylephrine on static and dynamic accommodation. J Optom 2019; 12:30-37. [PMID: 29602687 PMCID: PMC6318542 DOI: 10.1016/j.optom.2018.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 01/28/2018] [Accepted: 01/29/2018] [Indexed: 06/08/2023]
Abstract
PURPOSE We tested the hypothesis that changes in accommodation after instillation of Phenylephrine Hydrochloride (PHCl) observed in some studies could be caused by changes in optics. METHODS We performed two experiments to test the effects of PHCl on static and on dynamic accommodation in 8 and 6 subjects, respectively. Objective wavefront measurements were recorded of the static accommodation response to a stimulus at different distances or dynamic accommodation response to a sinusoidally moving stimulus (between 1 and 3 D of accommodative demand at 0.2Hz). The responses were characterized using two methods: one that takes into account the mydriatic optical effects on the accommodation produced by higher-order aberrations of the eye and another that takes into account only power changes paraxially due to the action of the ciliary muscle and regardless of the pupil size. RESULTS When mydriatic optical effects were taken into account, differences in responses before and after PHCl instillation were 0.51±0.53 D, and 0.12±0.15, for static and dynamic accommodation, respectively, and were statistically significant (p<0.039). When mydriatic optical effects were not taken into account, the differences in responses before and after PHCl instillation were -0.20±0.51 D, and -0.05±0.14, for static and dynamic accommodation, respectively, and were not statistically significant (p>0.313). CONCLUSIONS The mydriatic effect of the PHCl causes optical changes in the eye that can reduce the objective and subjective measurement of accommodation.
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Affiliation(s)
- Antonio J Del Águila-Carrasco
- Department of Optics, and Optometry, and Vision Sciences. University of Valencia, 46100 Burjassot, Spain; Interuniversity laboratory for research in Vision and Optometry. Mixed group UVEG-UMU, Spain.
| | - Francisco Lara
- Facultad de Óptica y Optometría, Universidad de Murcia, 30100 Murcia, Spain
| | - Paula Bernal-Molina
- Department of Optics, and Optometry, and Vision Sciences. University of Valencia, 46100 Burjassot, Spain; Interuniversity laboratory for research in Vision and Optometry. Mixed group UVEG-UMU, Spain
| | | | - Iván Marín-Franch
- Department of Optics, and Optometry, and Vision Sciences. University of Valencia, 46100 Burjassot, Spain; Interuniversity laboratory for research in Vision and Optometry. Mixed group UVEG-UMU, Spain; Department of Ophthalmology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - José J Esteve-Taboada
- Department of Optics, and Optometry, and Vision Sciences. University of Valencia, 46100 Burjassot, Spain; Interuniversity laboratory for research in Vision and Optometry. Mixed group UVEG-UMU, Spain
| | - Robert Montés-Micó
- Department of Optics, and Optometry, and Vision Sciences. University of Valencia, 46100 Burjassot, Spain; Interuniversity laboratory for research in Vision and Optometry. Mixed group UVEG-UMU, Spain
| | - Philip B Kruger
- State College of Optometry. State University of New York, USA
| | - Norberto López-Gil
- Interuniversity laboratory for research in Vision and Optometry. Mixed group UVEG-UMU, Spain; Facultad de Óptica y Optometría, Universidad de Murcia, 30100 Murcia, Spain
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11
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Abstract
It is well known that depth-of-focus (DOF) is influenced by optical factors (such as pupil size and monochromatic aberrations). However, neural factors such as blur sensitivity and defocus adaptation may play an important role on the extent of DOF. A series of experiments were conducted to study if optical or neural factors are most pertinent in explaining the variability of DOF across subjects. An adaptive optics system with a black and white target, a 3.8-mm artificial pupil, and a subjective criterion (based on objectionable blur) were used to measure depth of field ([DOFi]; DOF computed in the object space) in 11 participants, after at least 6 min of adaptation. This was done under three conditions: (a) with their own higher order aberrations (HOA); (b) after correction of their monochromatic HOA; and (c) after altering the HOA pattern for some participants to reflect the HOA pattern measured for a different participant. Natural DOFi and DOFi after HOA correction were positively correlated (R2 = 0.461), but a significant decrease in DOFi (21% on average) was found after HOA correction (p = 0.042). Effect of HOA on the intersubject variability of DOFi was 3.9 times smaller than the effect of the image neural processing. This study shows that DOFi depends on both optical and neural factors, but the latter seems to play a more important role than the former.
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Affiliation(s)
- Juan F Zapata-Díaz
- Grupo de Investigación en Ciencias de la Visión, Universidad de Murcia, Murcia, Spain.,Faculty of Biology, Medicine & Health, The University of Manchester, Manchester Academic Health Science Center, Manchester, UK
| | - Iván Marín-Franch
- Grupo de Investigación en Ciencias de la Visión, Universidad de Murcia, Murcia, Spain.,Department of Ophthalmology and Vision Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hema Radhakrishnan
- Faculty of Biology, Medicine & Health, The University of Manchester, Manchester Academic Health Science Center, Manchester, UK
| | - Norberto López-Gil
- Grupo de Investigación en Ciencias de la Visión, Universidad de Murcia, Murcia, Spain
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12
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Marín-Franch I, Artes PH, Chong LX, Turpin A, Wall M. Data obtained with an open-source static automated perimetry test of the full visual field in healthy adults. Data Brief 2018; 21:75-82. [PMID: 30338277 PMCID: PMC6187012 DOI: 10.1016/j.dib.2018.09.079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/13/2018] [Accepted: 09/25/2018] [Indexed: 11/08/2022] Open
Abstract
The data were gathered from 98 eyes of 98 ocular healthy subjects. The subject ages ranged from 18 to 79 years with a mean (and standard deviation) of 47 (17) years. Each subject underwent two visual field tests, one of the central visual field (64 locations within 26° of fixation) and one of the peripheral visual field (64 locations with eccentricity from 26° to up to 81°). Luminance thresholds for the Goldmann size V stimulus (with a diameter of 1.72° of visual angle) were obtained with the ZEST Bayesian test procedure. Each test was conducted twice within 90 days.
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Affiliation(s)
- Iván Marín-Franch
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
| | - Paul H Artes
- Eye & Vision Research Group, Institute of Health and Community, Plymouth University, UK
| | - Luke X Chong
- School of Medicine, Deakin University, Geelong, Australia
| | - Andrew Turpin
- School of Computing and Information Systems, University of Melbourne, Australia
| | - Michael Wall
- Departments of Neurology and Ophthalmology and Visual Sciences, University of Iowa, College of Medicine, Iowa City, IA, USA.,Iowa City Veterans Administration Health Care System, IA, USA
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13
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Marín-Franch I, Xu R, Bradley A, Thibos LN, López-Gil N. The effect of spherical aberration on visual performance and refractive state for stimuli and tasks typical of night viewing. J Optom 2018; 11:144-152. [PMID: 29292240 PMCID: PMC6039613 DOI: 10.1016/j.optom.2017.10.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 10/12/2017] [Accepted: 10/13/2017] [Indexed: 06/07/2023]
Abstract
PURPOSE The aim of this work was to examine the impact of Seidel spherical aberration (SA) on optimum refractive state for detecting and discriminating small bright lights on a dark background. METHODS An adaptive-optics system was used to correct ocular aberrations of cyclopleged eyes and then systematically introduce five levels of Seidel SA for a 7-mm diameter pupil: 0,±0.18, and±0.36diopters (D)mm-2. For each level of SA, subjects were required to detect one or resolve two points of light (0.54 arc min diameter) on a dark background. Refractive error was measured by adjusting stimulus vergence to minimize detection and resolution thresholds. Two other novel focusing tasks for single points of light required maximizing the perceived intensity of a bright point's core and minimizing its overall perceived size (i.e. minimize starburst artifacts). Except for the detection task, luminance of the point of light was 1000cdm-2 on a black background lower than 0.5cdm-2. RESULTS Positive SA introduced myopic shifts relative to the best subjective focus for dark letters on a bright background when there was no SA, whereas negative SA introduced hyperopic shifts in optimal focus. The changes in optimal focus were -1.7, -2.4, -2.0, and -9.2D of focus per Dmm-2 of SA for the detection task, resolution task, and maximization of core's intensity and minimization of size, respectively. CONCLUSION Ocular SA can be a significant contributor to changes in refractive state when viewing high-contrast point sources typically encountered in nighttime environments.
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Affiliation(s)
- Iván Marín-Franch
- Department of Ophthalmology, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA; Instituto Universitario de Investigación en Envejecimiento, Universidad de Murcia, 30100 Murcia, Spain.
| | - Renfeng Xu
- School of Optometry, Indiana University, Bloomington, IN, USA
| | - Arthur Bradley
- School of Optometry, Indiana University, Bloomington, IN, USA
| | - Larry N Thibos
- School of Optometry, Indiana University, Bloomington, IN, USA
| | - Norberto López-Gil
- Instituto Universitario de Investigación en Envejecimiento, Universidad de Murcia, 30100 Murcia, Spain
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Chu FI, Marín-Franch I, Ramezani K, Racette L. Associations between structure and function are different in healthy and glaucomatous eyes. PLoS One 2018; 13:e0196814. [PMID: 29723304 PMCID: PMC5933752 DOI: 10.1371/journal.pone.0196814] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/22/2018] [Indexed: 11/19/2022] Open
Abstract
Purpose To assess if there are differences in the structure-function associations between healthy and glaucomatous eyes. Methods Structure-function associations were assessed in healthy and glaucomatous eyes in three datasets, globally and in the six sectors of the optic nerve head. Structural parameters included rim area (RA) and retinal nerve fiber layer thickness (RNFLT). Functional parameters included unweighted mean of sensitivity thresholds (MS) and unweighted mean of total deviation values (MD), assessed with standard automated perimetry, short-wavelength automated perimetry, frequency-doubling technology perimetry, or contrast sensitivity perimetry. All structural and functional parameters were expressed as percent of mean normal. SF associations were assessed with correlation analyses (Pearson, Spearman and Kendall). We also assessed the SF associations with linear regression analyses: the generalized estimating equation (GEE) was used to adjust for inter-eye correlations and ordinary least squares (OLS) linear models were used when these adjustments were not necessary. We applied Bonferroni corrections to adjust for the impact of multiple comparisons. Results Overall, none of the Pearson correlations tested in healthy eyes were significant (correlations ranged from -0.17 to 0.37), whereas 77% of the correlations tested in glaucomatous eyes were significant (correlations ranged from 0.01 to 0.79). Similarly, none of the slopes obtained with GEE and OLS were significant in healthy eyes (slopes ranged from -0.30 to 0.87), whereas 82% of the slopes obtained in glaucomatous eyes were significant (slopes ranged from 0.02 to 1.38). Conclusions Significant associations between structure and function were consistently observed in glaucomatous eyes, but not in healthy eyes. These differences in association should be considered in the design of structure-function models for progression.
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Affiliation(s)
- Fang-I Chu
- Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis, Indiana, United States of America
| | - Iván Marín-Franch
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, United States of America
| | - Koosha Ramezani
- Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis, Indiana, United States of America
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, United States of America
| | - Lyne Racette
- Eugene and Marilyn Glick Eye Institute, Indiana University, Indianapolis, Indiana, United States of America
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, United States of America
- * E-mail:
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Affiliation(s)
- Iván Marín-Franch
- Department of Ophthalmology, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA.
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16
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Del Águila-Carrasco AJ, Marín-Franch I. Letter to the Editor. Vision Res 2018; 162:44. [PMID: 29551409 DOI: 10.1016/j.visres.2018.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 02/23/2018] [Accepted: 03/05/2018] [Indexed: 11/25/2022]
Affiliation(s)
| | - Iván Marín-Franch
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham School of Medicine, Birmingham, AL, USA
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López-Alcón D, Marín-Franch I, Fernández-Sánchez V, López-Gil N. Optical factors influencing the amplitude of accommodation. Vision Res 2017; 141:16-22. [DOI: 10.1016/j.visres.2016.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 09/07/2016] [Accepted: 09/09/2016] [Indexed: 10/21/2022]
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Marín-Franch I, Del Águila-Carrasco AJ, Bernal-Molina P, Esteve-Taboada JJ, López-Gil N, Montés-Micó R, Kruger PB. There is more to accommodation of the eye than simply minimizing retinal blur. Biomed Opt Express 2017; 8:4717-4728. [PMID: 29082097 PMCID: PMC5654812 DOI: 10.1364/boe.8.004717] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/02/2017] [Indexed: 06/07/2023]
Abstract
Eyes of children and young adults change their optical power to focus nearby objects at the retina. But does accommodation function by trial and error to minimize blur and maximize contrast as is generally accepted? Three experiments in monocular and monochromatic vision were performed under two conditions while aberrations were being corrected. In the first condition, feedback was available to the eye from both optical vergence and optical blur. In the second, feedback was only available from target blur. Accommodation was less precise for the second condition, suggesting that it is more than a trial-and-error function. Optical vergence itself seems to be an important cue for accommodation.
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Affiliation(s)
- I. Marín-Franch
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Spain
- Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
- Department of Ophthalmology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - A. J. Del Águila-Carrasco
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Spain
- Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
| | - P. Bernal-Molina
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Spain
- Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
| | - J. J. Esteve-Taboada
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Spain
- Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
| | - N. López-Gil
- Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
- Science Vision Group (CiViUM), Instituto Universitario de Investigación en Envejecimiento, University of Murcia, Spain
| | - R. Montés-Micó
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Spain
- Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
| | - P. B. Kruger
- State College of Optometry, State University of New York, New York, USA
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Foster D, Marín-Franch I. Universal information limit on real-world color constancy. J Vis 2017. [DOI: 10.1167/17.10.133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- David Foster
- School of Electrical and Electronic Engineering, University of Manchester, Manchester, UK
| | - Iván Marín-Franch
- Faculty of Optics and Optometry, University of Murcia, Murcia, Spain
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Bernal-Molina P, Marín-Franch I, Del Águila-Carrasco AJ, Esteve-Taboada JJ, López-Gil N, Kruger PB, Montés-Micó R. Human eyes do not need monochromatic aberrations for dynamic accommodation. Ophthalmic Physiol Opt 2017; 37:602-609. [PMID: 28681436 PMCID: PMC5600112 DOI: 10.1111/opo.12398] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 05/26/2017] [Indexed: 12/28/2022]
Abstract
Purpose To determine if human accommodation uses the eye's own monochromatic aberrations to track dynamic accommodative stimuli. Methods Wavefront aberrations were measured while subjects monocularly viewed a monochromatic Maltese cross moving sinusoidally around 2D of accommodative demand with 1D amplitude at 0.2 Hz. The amplitude and phase (delay) of the accommodation response were compared to the actual vergence of the stimulus to obtain gain and temporal phase, calculated from wavefront aberrations recorded over time during experimental trials. The tested conditions were as follows: Correction of all the subject's aberrations except defocus (C); Correction of all the subject's aberrations except defocus and habitual second‐order astigmatism (AS); Correction of all the subject's aberrations except defocus and odd higher‐order aberrations (HOAs); Correction of all the subject's aberrations except defocus and even HOAs (E); Natural aberrations of the subject's eye, i.e., the adaptive‐optics system only corrected the optical system's aberrations (N); Correction of all the subject's aberrations except defocus and fourth‐order spherical aberration (SA). The correction was performed at 20 Hz and each condition was repeated six times in randomised order. Results Average gain (±2 standard errors of the mean) varied little across conditions; between 0.55 ± 0.06 (SA), and 0.62 ± 0.06 (AS). Average phase (±2 standard errors of the mean) also varied little; between 0.41 ± 0.02 s (E), and 0.47 ± 0.02 s (O). After Bonferroni correction, no statistically significant differences in gain or phase were found in the presence of specific monochromatic aberrations or in their absence. Conclusions These results show that the eye's monochromatic aberrations are not necessary for accommodation to track dynamic accommodative stimuli.
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Affiliation(s)
- Paula Bernal-Molina
- Departamento de Óptica y Optometría y Ciencias de la Visión, Facultad de Física, Universidad de Valencia, Burjassot, Spain.,Laboratorio Interuniversitario de Investigación en Visión y Optometría - Unidad Mixta UVEG-UMU, Valencia-Murcia, Spain
| | - Iván Marín-Franch
- Departamento de Óptica y Optometría y Ciencias de la Visión, Facultad de Física, Universidad de Valencia, Burjassot, Spain.,Laboratorio Interuniversitario de Investigación en Visión y Optometría - Unidad Mixta UVEG-UMU, Valencia-Murcia, Spain
| | - Antonio J Del Águila-Carrasco
- Departamento de Óptica y Optometría y Ciencias de la Visión, Facultad de Física, Universidad de Valencia, Burjassot, Spain.,Laboratorio Interuniversitario de Investigación en Visión y Optometría - Unidad Mixta UVEG-UMU, Valencia-Murcia, Spain
| | - Jose J Esteve-Taboada
- Departamento de Óptica y Optometría y Ciencias de la Visión, Facultad de Física, Universidad de Valencia, Burjassot, Spain.,Laboratorio Interuniversitario de Investigación en Visión y Optometría - Unidad Mixta UVEG-UMU, Valencia-Murcia, Spain
| | - Norberto López-Gil
- Laboratorio Interuniversitario de Investigación en Visión y Optometría - Unidad Mixta UVEG-UMU, Valencia-Murcia, Spain.,Instituto Universitario de Investigación en Envejecimiento, Universidad de Murcia, Murcia, Spain
| | - Philip B Kruger
- Department of Biological & Vision Sciences, State University of New York, State College of Optometry, New York, USA
| | - Robert Montés-Micó
- Departamento de Óptica y Optometría y Ciencias de la Visión, Facultad de Física, Universidad de Valencia, Burjassot, Spain.,Laboratorio Interuniversitario de Investigación en Visión y Optometría - Unidad Mixta UVEG-UMU, Valencia-Murcia, Spain
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Jaskulski M, Marín-Franch I, Bernal-Molina P, López-Gil N. The effect of longitudinal chromatic aberration on the lag of accommodation and depth of field. Ophthalmic Physiol Opt 2017; 36:657-663. [PMID: 27790774 DOI: 10.1111/opo.12320] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Accepted: 08/19/2016] [Indexed: 11/28/2022]
Abstract
PURPOSE Longitudinal chromatic aberration is present in all states of accommodation and may play a role in the accommodation response and the emmetropisation process. We study the change of the depth of field (DOFi) with the state of accommodation, taking into account the longitudinal chromatic aberration. METHODS Subjective DOFi was defined as the range of defocus beyond which the blur of the target (one line of optotypes of 0.1 logMAR shown on a black-and-white microdisplay, seen through different colour filters) was perceived as objectionable. The subject's eye was paralysed and different, previously-measured accommodative states (corresponding to the accommodative demands of 0D, 2D and 4D) were simulated with a deformable mirror. Different colour conditions (monochromatic red, green and blue and polychromatic (white) were tested. The DOFi was measured subjectively, using a motorised Badal system. RESULTS Taking as reference the average accommodative response for the white stimulus, the blue response exhibits on average a lead of 0.45 ± 0.09D, the green a negligible lead of 0.07 ± 0.02D and red a lag of 0.49 ± 0.10D. The monochromatic DOFi, calculated by averaging DOFi over the red, green and blue colour conditions for each accommodative demand was 1.10 ± 0.10D for 0D, 1.20 ± 0.08D for 2D, and 1.26 ± 0.40D for 4D. The polychromatic white DOFi were greater than the average monochromatic DOFi by 19%, 9% and 14% for 0D, 2D, and 4D of accommodative demand, respectively. CONCLUSION The longitudinal chromatic aberration causes a dioptric shift of the monochromatic accommodation response. The study did not reveal this shift to depend on the accommodative demand or to have an effect on the DOFi.
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Affiliation(s)
| | - Iván Marín-Franch
- CiViUM Research Group, University of Murcia, Spain, Spain.,Grupo de Investigación en Optometría, University of Valencia, Spain
| | - Paula Bernal-Molina
- CiViUM Research Group, University of Murcia, Spain, Spain.,Grupo de Investigación en Optometría, University of Valencia, Spain
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Esteve-Taboada JJ, Del Águila-Carrasco AJ, Bernal-Molina P, López-Gil N, Montés-Micó R, Kruger P, Marín-Franch I. Dynamic accommodation without feedback does not respond to isolated blur cues. Vision Res 2017; 136:50-56. [PMID: 28619515 PMCID: PMC5512838 DOI: 10.1016/j.visres.2017.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 05/27/2017] [Accepted: 05/29/2017] [Indexed: 12/17/2022]
Abstract
The aim of this study was to determine whether dynamic accommodation responds to isolated blur cues without feedback, and without changes in the distance of the object. Nine healthy subjects aged 21-40years were recruited. Four different aberration patterns were used as stimuli to induce blur with (1) the eye's natural, uncorrected, optical aberrations, (2) all aberrations corrected, (3) spherical aberration only, or (4) astigmatism only. The stimulus was a video animation based on computer-generated images of a monochromatic Maltese cross. Each individual video was generated for each subject off-line, after measuring individual aberrations at different accommodation levels. The video simulated sinusoidal changes in defocus at 0.2Hz. Dynamic images were observed through a 0.8mm pinhole placed at a plane conjugated with the eye's pupil, thus effectively removing potential feedback stemming from accommodation changes. Accommodation responses were measured with a Hartmann-Shack aberrometer for the four different aberration patterns. The results showed that seven out of nine subjects did not respond to any stimuli, whereas the response of the other two subjects was erratic and they seemed to be searching rather than following the stimulus. A significant reduction in average accommodative gain (from 0.52 to 0.11) was obtained when the dioptric demand cue was removed. No statistically significant differences were found among the experimental conditions used. We conclude that aberration related blur does not drive the accommodation response in the absence of feedback from accommodation.
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Affiliation(s)
- José J Esteve-Taboada
- Department of Optics and Optometry and Vision Sciences, University of Valencia, 46100 Burjassot, Spain; Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain.
| | - Antonio J Del Águila-Carrasco
- Department of Optics and Optometry and Vision Sciences, University of Valencia, 46100 Burjassot, Spain; Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
| | - Paula Bernal-Molina
- Department of Optics and Optometry and Vision Sciences, University of Valencia, 46100 Burjassot, Spain; Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
| | - Norberto López-Gil
- Instituto Universitario de Investigación en Envejecimiento, University of Murcia, 30100 Murcia, Spain; Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
| | - Robert Montés-Micó
- Department of Optics and Optometry and Vision Sciences, University of Valencia, 46100 Burjassot, Spain; Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
| | - Philip Kruger
- Department of Biological and Vision Sciences, State College of Optometry, State University of New York, USA
| | - Iván Marín-Franch
- Department of Optics and Optometry and Vision Sciences, University of Valencia, 46100 Burjassot, Spain; Interuniversity Laboratory for Research in Vision and Optometry, Mixed Group UVEG-UMU, Valencia-Murcia, Spain
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Marín-Franch I, Del Águila-Carrasco AJ, Levecq X, López-Gil N. Drifts in real-time partial wavefront correction and how to avoid them. Appl Opt 2017; 56:3989-3994. [PMID: 29047526 DOI: 10.1364/ao.56.003989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In visual experiments that require real-time partial correction of wavefront aberrations, small errors occur that accumulate over time and lead to drifts in Zernike coefficients of the uncorrected aberrations. A simple algorithm that does not require the inclusion of an additional optical path to obtain independent measurements of the eye's aberrations is described here, and its effectiveness in preventing these drifts is demonstrated.
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Del Águila-Carrasco AJ, Marín-Franch I, Bernal-Molina P, Esteve-Taboada JJ, Kruger PB, Montés-Micó R, López-Gil N. Accommodation Responds to Optical Vergence and Not Defocus Blur Alone. ACTA ACUST UNITED AC 2017; 58:1758-1763. [DOI: 10.1167/iovs.16-21280] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Antonio J. Del Águila-Carrasco
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Burjassot, Valencia, Spain 2Interuniversity Laboratory for Research in Vision and Optometry, Mixed group UVEG-UMU, Valencia-Murcia, Spain
| | - Iván Marín-Franch
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Burjassot, Valencia, Spain 2Interuniversity Laboratory for Research in Vision and Optometry, Mixed group UVEG-UMU, Valencia-Murcia, Spain
| | - Paula Bernal-Molina
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Burjassot, Valencia, Spain 2Interuniversity Laboratory for Research in Vision and Optometry, Mixed group UVEG-UMU, Valencia-Murcia, Spain
| | - José J. Esteve-Taboada
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Burjassot, Valencia, Spain 2Interuniversity Laboratory for Research in Vision and Optometry, Mixed group UVEG-UMU, Valencia-Murcia, Spain
| | - Philip B. Kruger
- State College of Optometry, State University of New York, New York, United States
| | - Robert Montés-Micó
- Department of Optics and Optometry and Vision Sciences, University of Valencia, Burjassot, Valencia, Spain 2Interuniversity Laboratory for Research in Vision and Optometry, Mixed group UVEG-UMU, Valencia-Murcia, Spain
| | - Norberto López-Gil
- Interuniversity Laboratory for Research in Vision and Optometry, Mixed group UVEG-UMU, Valencia-Murcia, Spain 4Instituto Universitario de Investigación en Envejecimiento (IUIE), University of Murcia, Murcia, Spain
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Papadatou E, Del Águila-Carrasco AJ, Marín-Franch I, López-Gil N. Temporal multiplexing with adaptive optics for simultaneous vision. Biomed Opt Express 2016; 7:4102-4113. [PMID: 27867718 PMCID: PMC5102541 DOI: 10.1364/boe.7.004102] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 08/17/2016] [Accepted: 08/19/2016] [Indexed: 05/27/2023]
Abstract
We present and test a methodology for generating simultaneous vision with a deformable mirror that changed shape at 50 Hz between two vergences: 0 D (far vision) and -2.5 D (near vision). Different bifocal designs, including toric and combinations of spherical aberration, were simulated and assessed objectively. We found that typical corneal aberrations of a 60-year-old subject changes the shape of objective through-focus curves of a perfect bifocal lens. This methodology can be used to investigate subjective visual performance for different multifocal contact or intraocular lens designs.
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Affiliation(s)
- Eleni Papadatou
- Optomety Research Group, Facultad de Física, Universidad de Valencia, Spain
| | | | - Iván Marín-Franch
- Optomety Research Group, Facultad de Física, Universidad de Valencia, Spain
- CiViUM Research Group, Facultad de Óptica y Optometría, Universidad de Murcia, Spain
| | - Norberto López-Gil
- CiViUM Research Group, Facultad de Óptica y Optometría, Universidad de Murcia, Spain
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Racette L, Helm JE, Dul M, Marín-Franch I. The joint structure–function dynamics of glaucoma progression. Expert Review of Ophthalmology 2015. [DOI: 10.1586/17469899.2015.1073109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Esteve-Taboada JJ, Del Águila-Carrasco AJ, Marín-Franch I, Bernal-Molina P, Montés-Micó R, López-Gil N. Opto-mechanical artificial eye with accommodative ability. Opt Express 2015; 23:19396-19404. [PMID: 26367599 DOI: 10.1364/oe.23.019396] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The purpose of this study was to describe the design and characterization of a new opto-mechanical artificial eye (OMAE) with accommodative ability. The OMAE design is based on a second-pass configuration where a small source of light is used at the artificial retina plane. A lens whose focal length can be changed electronically was used to add the accommodation capability. The changes in the OMAE's aberrations with the lens focal length, which effectively changes the accommodative state of the OMAE, were measured with a commercial aberrometer. Changes in power and aberrations with room temperature were also measured. The OMAE's higher-order aberrations (HOAs) were similar to the ones of the human eye, including the rate at which fourth-order spherical aberration decreased with accommodation. The OMAE design proposed here is simple, and it can be implemented in an optical system to mimic the optics of the human eye.
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Hu R, Marín-Franch I, Racette L. Prediction accuracy of a novel dynamic structure-function model for glaucoma progression. Invest Ophthalmol Vis Sci 2014; 55:8086-94. [PMID: 25358735 DOI: 10.1167/iovs.14-14928] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To assess the prediction accuracy of a novel dynamic structure-function (DSF) model to monitor glaucoma progression. METHODS Longitudinal data of paired rim area (RA) and mean sensitivity (MS) from 220 eyes with ocular hypertension or primary open-angle glaucoma enrolled in the Diagnostic Innovations in Glaucoma Study or the African Descent and Glaucoma Evaluation Study were included. Rim area and MS were expressed as percent of mean normal based on an independent dataset of 91 healthy eyes. The DSF model uses centroids as estimates of the current state of the disease and velocity vectors as estimates of direction and rate of change over time. The first three visits were used to predict the fourth visit; the first four visits were used to predict the fifth visit, and so on up to the 11th visit. The prediction error (PE) was compared to that of ordinary least squares linear regression (OLSLR) using Wilcoxon signed-rank test. RESULTS For predictions at visit 4 to visit 7, the average PE for the DSF model was significantly lower than OLSLR by 1.19% to 3.42% of mean normal. No significant difference was observed for the predictions at visit 8 to visit 11. The DSF model had lower PE than OLSLR for 70% of eyes in predicting visit 4 and approximately 60% in predicting visits 5, 6, and 7. CONCLUSIONS The two models had similar prediction capabilities, and the DSF model performed better in shorter time series. The DSF model could be clinically useful when only limited follow-ups are available. (ClinicalTrials.gov numbers, NCT00221923, NCT00221897.).
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Affiliation(s)
- Rongrong Hu
- Department of Ophthalmology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China Indiana University, Eugene and Marilyn Glick Eye Institute, Indianapolis, Indiana, United States
| | - Iván Marín-Franch
- Departamento de Óptica, Facultad de Física, Universitat de València, Burjassot, Spain
| | - Lyne Racette
- Indiana University, Eugene and Marilyn Glick Eye Institute, Indianapolis, Indiana, United States
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Marín-Franch I. Passing-Bablok regression is inappropriate for assessing association between structure and function in glaucoma. Invest Ophthalmol Vis Sci 2013; 54:5848-9. [PMID: 23985952 DOI: 10.1167/iovs.13-12372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Marín-Franch I, Malik R, Crabb DP, Swanson WH. Choice of statistical method influences apparent association between structure and function in glaucoma. Invest Ophthalmol Vis Sci 2013; 54:4189-96. [PMID: 23640041 PMCID: PMC3687963 DOI: 10.1167/iovs.12-10377] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 04/25/2013] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The aim of this study was to explore how different statistical methods may lead to inconsistent inferences about the association between structure and function in glaucoma. METHODS Two datasets from published studies were selected for their illustrative value. The first consisted of measurements of neuroretinal rim area in the superior-temporal sector paired with the corresponding visual field sensitivity. The second consisted of measurements of average retinal nerve fiber layer thickness over all sectors paired with the corresponding visual field sensitivity. Statistical methods included linear and segmented regression, and a nonparametric local-linear fit known as loess. The analyses were repeated with all measurements expressed as percent of mean normal. RESULTS Slopes from linear fits to the data changed by a factor of 10 depending on the linear regression method applied. Inferences about whether structural abnormality precedes functional abnormality varied with the statistical design and the units of measure used. CONCLUSIONS The apparent association between structure and function in glaucoma, and consequent interpretation, varies with the statistical method and units of measure. Awareness of the limitations of any statistical analysis is necessary to avoid finding spurious results that ultimately may lead to inadequate clinical recommendations.
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Abstract
This paper introduces the R package visualFields, a contributed, open-source software for the analysis of the visual field. The package aims to provide a framework for collaborative research, including data sharing and conventional and novel methods. Single visual field and progression analyses, such as Permutation of Pointwise Linear Regression can be performed with visualFields using simple scripts. The package can be easily customized and it allows the inclusion of custom test locations and different normative values. Here, we demonstrate how to use the visualFields package and discuss its capabilities. The analyses presented here are easy to replicate upon installation of the package, which is freely available for download from the Comprehensive R Archive Network. The relevant R code is shown and commented on. A shift from proprietary to an open-source research platform is an important step towards more direct collaborative research. The visualFields package is part of the Open Perimetry Initiative, which is expected to grow as researchers contribute new routines and datasets.
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Marín-Franch I, Foster DH. Estimating information from image colors: an application to digital cameras and natural scenes. IEEE Trans Pattern Anal Mach Intell 2013; 35:78-91. [PMID: 22450817 DOI: 10.1109/tpami.2012.78] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The colors present in an image of a scene provide information about its constituent elements. But the amount of information depends on the imaging conditions and on how information is calculated. This work had two aims. The first was to derive explicitly estimators of the information available and the information retrieved from the color values at each point in images of a scene under different illuminations. The second was to apply these estimators to simulations of images obtained with five sets of sensors used in digital cameras and with the cone photoreceptors of the human eye. Estimates were obtained for 50 hyperspectral images of natural scenes under daylight illuminants with correlated color temperatures 4,000, 6,500, and 25,000 K. Depending on the sensor set, the mean estimated information available across images with the largest illumination difference varied from 15.5 to 18.0 bits and the mean estimated information retrieved after optimal linear processing varied from 13.2 to 15.5 bits (each about 85 percent of the corresponding information available). With the best sensor set, 390 percent more points could be identified per scene than with the worst. Capturing scene information from image colors depends crucially on the choice of camera sensors.
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Affiliation(s)
- Iván Marín-Franch
- Indiana University School of Optometry, 800 East Atwater Avenue, Bloomington IN 47405, USA.
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Abstract
The ability to perceptually identify distinct surfaces in natural scenes by virtue of their color depends not only on the relative frequency of surface colors but also on the probabilistic nature of observer judgments. Previous methods of estimating the number of discriminable surface colors, whether based on theoretical color gamuts or recorded from real scenes, have taken a deterministic approach. Thus, a three-dimensional representation of the gamut of colors is divided into elementary cells or points which are spaced at one discrimination-threshold unit intervals and which are then counted. In this study, information-theoretic methods were used to take into account both differing surface-color frequencies and observer response uncertainty. Spectral radiances were calculated from 50 hyperspectral images of natural scenes and were represented in a perceptually almost uniform color space. The average number of perceptually distinct surface colors was estimated as 7.3 × 10(3), much smaller than that based on counting methods. This number is also much smaller than the number of distinct points in a scene that are, in principle, available for reliable identification under illuminant changes, suggesting that color constancy, or the lack of it, does not generally determine the limit on the use of color for surface identification.
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Affiliation(s)
- Iván Marín-Franch
- Department of Biomedical Sciences and Human Oncology, University of Torino, Torino, Italy.
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Foster DH, Marín-Franch I, Amano K, Nascimento SMC. Approaching ideal observer efficiency in using color to retrieve information from natural scenes. J Opt Soc Am A Opt Image Sci Vis 2009; 26:B14-B24. [PMID: 19884913 DOI: 10.1364/josaa.26.000b14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Variations in illumination on a scene and trichromatic sampling by the eye limit inferences about scene content. The aim of this work was to elucidate these limits in relation to an ideal observer using color signals alone. Simulations were based on 50 hyperspectral images of natural scenes and daylight illuminants with correlated color temperatures 4000 K, 6500 K, and 25,000 K. Estimates were made of the (Shannon) information available from each scene, the redundancies in receptoral and postreceptoral coding, and the information retrieved by an observer identifying corresponding points across image pairs. For the largest illuminant difference, between 25,000 K and 4000 K, a postreceptoral transformation providing minimum redundancy yielded an efficiency of about 80% in the information retrieved. This increased to about 89% when the transformation was optimized directly for information retrieved, corresponding to an equivalent Gaussian noise amplitude of 3.0% or to a mean of 3.6 x 10(4) distinct identifiable points per scene. Using color signals to retrieve information from natural scenes can approach ideal observer efficiency levels.
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Affiliation(s)
- David H Foster
- School of Electrical and Electronic Engineering, University of Manchester, Manchester M60 1QD, United Kingdom.
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