1
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Fernandez-Alonso M, Finch AP, Love GD, Read JCA. Ocular accommodation and wavelength: The effect of longitudinal chromatic aberration on the stimulus-response curve. J Vis 2024; 24:11. [PMID: 38411958 PMCID: PMC10910436 DOI: 10.1167/jov.24.2.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 01/06/2024] [Indexed: 02/28/2024] Open
Abstract
The longitudinal chromatic aberration (LCA) of the eye creates a chromatic blur on the retina that is an important cue for accommodation. Although this mechanism can work optimally in broadband illuminants such as daylight, it is not clear how the system responds to the narrowband illuminants used by many modern displays. Here, we measured pupil and accommodative responses as well as visual acuity under narrowband light-emitting diode (LED) illuminants of different peak wavelengths. Observers were able to accommodate under narrowband light and compensate for the LCA of the eye, with no difference in the variability of the steady-state accommodation response between narrowband and broadband illuminants. Intriguingly, our subjects compensated more fully for LCA at nearer distances. That is, the difference in accommodation to different wavelengths became larger when the object was placed nearer the observer, causing the slope of the accommodation response curve to become shallower for shorter wavelengths and steeper for longer ones. Within the accommodative range of observers, accommodative errors were small and visual acuity normal. When comparing between illuminants, when accommodation was accurate, visual acuity was worst for blue narrowband light. This cannot be due to the sparser spacing for S-cones, as our stimuli had equal luminance and thus activated LM-cones roughly equally. It is likely because ocular LCA changes more rapidly at shorter wavelength and so the finite spectral bandwidth of LEDs corresponds to a greater dioptric range at shorter wavelengths. This effect disappears for larger accommodative errors, due to the increased depth of focus of the eye.
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Affiliation(s)
- Maydel Fernandez-Alonso
- Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
- Present address: Translational Sensory and Circadian Neuroscience Group, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | | | - Gordon D Love
- Department of Physics, Durham University, Durham, UK
- Department of Computer Sciences, Durham University, Durham, UK
- Present address: School of Computing, University of Leeds, Leeds, UK
| | - Jenny C A Read
- Biosciences Institute, Newcastle University, Newcastle Upon Tyne, UK
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2
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Rohman L, Ruggeri M, Ho A, Parel JM, Manns F. Lens Thickness Microfluctuations in Young and Prepresbyopic Adults During Steady-State Accommodation. Invest Ophthalmol Vis Sci 2023; 64:12. [PMID: 36753168 PMCID: PMC9919620 DOI: 10.1167/iovs.64.2.12] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/22/2023] [Indexed: 02/09/2023] Open
Abstract
Purpose To determine whether lens mechanical dynamics change with age and with accommodative demands. Methods Lens thickness microfluctuations were measured using a high-speed custom-built spectral domain optical coherence tomography system in five young adults (20 to 25 years old) at 0 diopters (D), 2 D, 4 D, and maximum accommodative demand and in five prepresbyopes (38 to 45 years old) under relaxed and maximal accommodation. For each state, the measurements were repeated four times during the same session. Images of the central 2-mm zone of the lens comprising 170 A-lines/frame were acquired for 10 seconds, and axial lens thickness change was measured. Lens thickness microfluctuations (µm²/Hz) were assessed by integrating the power spectrum of lens thickness microfluctuations between 0 and 4 Hz. Results The amplitude of lens microfluctuations was higher in the accommodated states than in the relaxed state in both age groups. Lens microfluctuations were higher in young adult participants than in prepresbyopes, with a significant difference in relaxed and maximally accommodated states (P = 0.04 and P = 0.04). In the young participants, the amplitude of microfluctuations reached a plateau at maximum accommodation. Conclusions Lens mechanical dynamics are both age and accommodation dependent. The decrease in lens thickness microfluctuations with age is consistent with an age-related increase in lens stiffness or decrease of the ciliary muscle displacement. The lens does not contribute to the high-frequency component of ocular dioptric microfluctuations.
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Affiliation(s)
- Leana Rohman
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
| | - Marco Ruggeri
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
| | - Arthur Ho
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
- Brien Holden Vision Institute, Sydney, New South Wales, Australia
- School of Optometry and Vision Science, University of New South Wales, Sydney, New South Wales, Australia
| | - Jean-Marie Parel
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
- Brien Holden Vision Institute, Sydney, New South Wales, Australia
| | - Fabrice Manns
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
- Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, Florida, United States
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3
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Gehring AM, Haensel JX, Curtiss MK, Roberts TL. Validation of the PowerRef 3 for Measuring Accommodation: Comparison With the Grand Seiko WAM-5500A Autorefractor. Transl Vis Sci Technol 2022; 11:25. [PMID: 36255360 PMCID: PMC9587467 DOI: 10.1167/tvst.11.10.25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/08/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose This validation study examines the PowerRef 3 as a method for measuring accommodation objectively. We assess agreement with refractive measurements obtained simultaneously by the Grand Seiko WAM-5500A autorefractor. Methods Refractive measurements were recorded simultaneously using the PowerRef 3 and WAM-5500A in 32 noncyclopleged participants aged 15 to 46 years. Accommodative states were recorded for 10 seconds at six accommodative demands (5 diopters [D], 4 D, 3 D, 2.5 D, 2 D, and 0 D) while participants fixated a high-contrast Maltese cross. WAM-5500A measurements were converted to power in the vertical meridian for comparison with PowerRef 3 data. Dioptric difference values were computed, and agreement was assessed using Bland-Altman plots with 95% limits of agreement (LOA) and intraclass correlation coefficient analyses. Results The mean absolute dioptric differences measured 0.14 D or less across accommodative demands. Analyses showed an excellent intraclass correlation coefficient across the tested demands (0.93). Bland-Altman plots indicated a bias of -0.02 D with 95% LOA of -1.03 D to 0.99 D. The 95% LOA was smallest for the 3 D demand (-0.71 D to 0.64 D), and largest at 5 D demand (-1.51 D to 1.30 D). Conclusions The mean dioptric differences between the PowerRef 3 and WAM-5500A autorefractor were small and not clinically significant. While some variability in agreement was observed depending on the tested demand, the PowerRef 3 demonstrated good agreement with the WAM-5500A. Translational Relevance The PowerRef 3 may be used to obtain objective measures of accommodation both monocularly and binocularly and provides a more flexible method, especially in pediatric populations.
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Affiliation(s)
| | - Jennifer X. Haensel
- Spencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, CA, USA
| | - Molly K. Curtiss
- Children's Vision Center, Akron Children's Hospital, Akron, OH, USA
| | - Tawna L. Roberts
- Children's Vision Center, Akron Children's Hospital, Akron, OH, USA
- Spencer Center for Vision Research, Byers Eye Institute at Stanford University, Palo Alto, CA, USA
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4
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Read JCA, Kaspiris-Rousellis C, Wood TS, Wu B, Vlaskamp BNS, Schor CM. Seeing the future: Predictive control in neural models of ocular accommodation. J Vis 2022; 22:4. [PMID: 35925580 PMCID: PMC9363677 DOI: 10.1167/jov.22.9.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Ocular accommodation is the process of adjusting the eye's crystalline lens so as to bring the retinal image into sharp focus. The major stimulus to accommodation is therefore retinal defocus, and in essence, the job of accommodative control is to send a signal to the ciliary muscle which will minimize the magnitude of defocus. In this article, we first provide a tutorial introduction to control theory to aid vision scientists without this background. We then present a unified model of accommodative control that explains properties of the accommodative response for a wide range of accommodative stimuli. Following previous work, we conclude that most aspects of accommodation are well explained by dual integral control, with a “fast” or “phasic” integrator enabling response to rapid changes in demand, which hands over control to a “slow” or “tonic” integrator which maintains the response to steady demand. Control is complicated by the sensorimotor latencies within the system, which delay both information about defocus and the accommodation changes made in response, and by the sluggish response of the motor plant. These can be overcome by incorporating a Smith predictor, whereby the system predicts the delayed sensory consequences of its own motor actions. For the first time, we show that critically-damped dual integral control with a Smith predictor accounts for adaptation effects as well as for the gain and phase for sinusoidal oscillations in demand. In addition, we propose a novel proportional-control signal to account for the power spectrum of accommodative microfluctuations during steady fixation, which may be important in hunting for optimal focus, and for the nonlinear resonance observed for low-amplitude, high-frequency input. Complete Matlab/Simulink code implementing the model is provided at https://doi.org/10.25405/data.ncl.14945550.
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Affiliation(s)
- Jenny C A Read
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom.,
| | | | - Toby S Wood
- School of Mathematics, Statistics & Physics, Newcastle University, Newcastle upon Tyne, UK.,
| | - Bing Wu
- Quantified Experience, Magic Leap Inc, Plantation, FL, USA.,
| | | | - Clifton M Schor
- Herbert Wertheim School of Optometry and Vision Science, University of California at Berkeley, Berkeley, CA, USA.,
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5
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Chinn RN, Raghuram A, Curtiss MK, Gehring AM, De Paula AJ, Roberts TL. Repeatability of the Accommodative Response Measured by the Grand Seiko Autorefractor in Children With and Without Amblyopia and Adults. Am J Ophthalmol 2022; 236:221-231. [PMID: 34699740 DOI: 10.1016/j.ajo.2021.10.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/01/2022]
Abstract
PURPOSE To assess test-retest repeatability of the accommodative response (AR) in children with and without amblyopia and adults using the Grand Seiko autorefractor. DESIGN Prospective reliability assessment. METHODS Test-retest of accommodation was obtained while participants viewed 20/150 sized letters at 33 cm using the Grand Seiko autorefractor in children 5 to <11 years with amblyopia (n=24) and without amblyopia (n=36), and adults 18 to <35 years (n=34). Bland-Altman 95% limits of agreement (LOA) and intraclass correlation coefficients (ICCs) were used to assess repeatability and reliability. The AR between the fellow and amblyopic eyes of children with amblyopia and eye 1 and eye 2 of the visually normal participants was assessed using group comparisons. RESULTS The 95% LOA of the AR was greatest in the amblyopic eyes (-1.25 diopters [D], 1.62 D) of children with amblyopia. The 95% LOA were similar between the fellow eyes (-0.88 D, 0.74 D) of children with amblyopia and both eyes of the children without amblyopia (eye 1: -0.68 D, 0.71 D; eye 2: -0.59 D, 0.70 D) and the adults (eye 1: 95% LOA = -0.49 D, 0.45 D; eye 2: LOA = -0.66 D, 0.67 D). ICCs revealed the Grand Seiko autorefractor as a reliable instrument for measuring AR. CONCLUSIONS The Grand Seiko autorefractor was more repeatable and reliable when measuring the AR in children and adults without amblyopia than in the amblyopic eye in children with amblyopia. It is recommended that multiple measures of the AR be obtained in amblyopic eyes to improve the precision of measures.
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6
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Leroux CE, Leahy C, Fontvieille C, Bardin F. The random walk of accommodation fluctuations. BIOMEDICAL OPTICS EXPRESS 2021; 12:6897-6908. [PMID: 34858687 PMCID: PMC8606129 DOI: 10.1364/boe.433926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/19/2021] [Accepted: 08/03/2021] [Indexed: 06/13/2023]
Abstract
The focusing distance of the eye fluctuates during accommodation. However, the visual role of these accommodation fluctuations is not yet fully understood. The fluctuation complexity is one of the obstacles to this long standing challenge in visual science. In this work we seek to develop a statistical approach that i) accurately describes experimental measurements and ii) directly generates randomized and realistic simulations of accommodation fluctuations for use in future experiments. To do so we use the random walk approach, which is usually appropriate to describe the dynamics of systems that combine both randomness and memory.
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Affiliation(s)
| | - Conor Leahy
- Carl Zeiss Meditec, Inc., 5300 Central Parkway, Dublin, CA 94568, USA
| | | | - Fabrice Bardin
- Laboratoire MIPA, Université de Nîmes, Sites des Carmes, Nîmes, 30000, France
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7
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Sivaraman V, Price HC, Hussaindeen JR, Ramani K, Allen PM. Nearwork-induced transient myopia and accommodation function before and after laser-assisted in situ keratomileusis surgery. Indian J Ophthalmol 2021; 69:1707-1711. [PMID: 34146011 PMCID: PMC8374790 DOI: 10.4103/ijo.ijo_3224_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Purpose To assess the change in Near Induced Transient Myopia (NITM) and other accommodation parameters, before and after undergoing LASIK surgery for myopia correction. Methods Twenty-nine myopic subjects were recruited from a tertiary eye hospital in India. Age range was 21 to 35 years with an average age of 26.1 ± 3.5 years. Mean spherical equivalent was -3.86 D ± 1.50 D presurgery. NITM, lag of accommodation, near point of convergence (NPC), accommodative amplitude (AA), and binocular near accommodative facility (AF) were measured. All data were collected 21 days prior to and 30 days after LASIK surgery. Results NITM, lag of accommodation and amplitude of accommodation were significantly lower (NITM -0.05 ± 0.15, Lag 0.38 ± 0.38, AA 10.27 ± 2.24) after surgery when compared to before (NITM 0.26 ± 0.12, Lag 0.77 ± 0.51, AA 12.18 ± 2.02; P < 0.001). Accommodative facility increased and near point of convergence was significantly more distal following surgery (AF 10.70 ± 2.29, NPC 7.96 ± 1.63) when compared to prior (AF 8.65 ± 2.74, NPC 5.62 ± 1.71; P < 0.001). Conclusion Significant changes in NITM and accommodation function should be expected in the short term following LASIK surgery. This study supports the importance of evaluating accommodative parameters and patient counselling prior to and following refractive surgery.
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Affiliation(s)
- Viswanathan Sivaraman
- Elite School of Optometry, Chennai, Tamil Nadu, India; Vision and Hearing Sciences Research Group, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge, UK
| | - Holly C Price
- Vision and Hearing Sciences Research Group, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge, UK
| | | | | | - Peter M Allen
- Vision and Hearing Sciences Research Group, School of Psychology and Sport Science, Anglia Ruskin University, Cambridge, UK
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8
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Ntodie M, Saunders KJ, Little JA. Correction of Low-Moderate Hyperopia Improves Accommodative Function for Some Hyperopic Children During Sustained Near Work. Invest Ophthalmol Vis Sci 2021; 62:6. [PMID: 33821881 PMCID: PMC8039472 DOI: 10.1167/iovs.62.4.6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Purpose This study investigated whether refractive correction improved accommodative function of hyperopic children while engaged in two sustained near activities. Methods Sustained accommodative function of 63 participants (aged 5–10 years) with varying levels of uncorrected hyperopia (>/= +1.00 D and < + 5.00 D spherical equivalent in the least hyperopic eye) was measured using eccentric infrared photorefraction (PowerRef 3; PlusOptix, Germany). Binocular accommodation measures were recorded while participants engaged in 2 tasks at 25 cm for 15 minutes each: an “active” task (reading small print on an Amazon Kindle), and a “passive” task (watching an animated movie on liquid crystal display [LCD] screen). Participants also underwent a comprehensive visual assessment, including measurement of presenting visual acuity, prism cover test, and stereoacuity. Reading speed was assessed with and without hyperopic correction. Refractive error was determined by cycloplegic retinoscopy. Results Hyperopic refractive correction significantly improved accuracy of accommodative responses in both task (pairwise comparisons: t = −3.70, P = 0.001, and t = −4.93, P < 0.001 for reading and movie tasks, respectively). Accommodative microfluctuations increased with refractive correction in the reading task (F(1,61) = 25.77, P < 0.001) but decreased in the movie task (F(1,59) = 4.44, P = 0.04). Reading speed also significantly increased with refractive correction (F(1,48) = 66.32, P < 0.001). Conclusions Correcting low-moderate levels of hyperopia has a positive impact on accommodative performance during sustained near activity in some schoolchildren. For these children, prescribing hyperopic correction may benefit performance in near vision tasks.
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Affiliation(s)
- Michael Ntodie
- Optometry and Vision Science Department, School of Allied Health Sciences, College of Health, University of Cape Coast, Cape Coast, Ghana.,Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, United Kingdom
| | - Kathryn J Saunders
- Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, United Kingdom
| | - Julie-Anne Little
- Centre for Optometry and Vision Science, Biomedical Sciences Research Institute, Ulster University, Coleraine, United Kingdom
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9
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Sudhir RR, Farhath Pattan H, Rathore M, Kuppuswamy Parthasarathy M, Padmanabhan P, Lakshminarayanan V. The effect of refractive surgery on blur thresholds. Indian J Ophthalmol 2020; 68:2998-3001. [PMID: 33229685 PMCID: PMC7856997 DOI: 10.4103/ijo.ijo_1512_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose: The aim of this study was to measure blur thresholds before and after refractive surgery. Methods: In this prospective cohort study conducted in a tertiary eye hospital in South India. Blur thresholds were measured for 30 young adult myopic patients 1 month prior to and after refractive surgery. Patients were asked to report three stages of blur, namely Detectable Blur (DB), Bothersome Blur (BB), and Non-resolvable Blur (NB). Blur was created by adding plus lenses (in steps of 0.12D) over their optimal subjective refraction. The blur judgments were made both monocularly and binocularly when looking through a 3 mm artificial pupil at one line above the best-corrected visual acuity. Results: A total of 30 participants were included in this study (mean age = 25.5 ± 3.8 (20–36) years; 77% female). The mean binocular preoperative blur of this group was: DB = 0.39 ± 0.26D, BB = 0.74 ± 0.28D and NB = 1.04 ± 0.42D. The corresponding mean binocular blur one-month post-operatively was DB = 0.46 ± 0.28D, BB = 0.83 ± 0.35D, and NB = 1.21 ± 0.44D. Although there was a marginal increase in the blur thresholds postoperatively, the difference was not statistically significant (DB: P = 0.320; BB: P = 0.229; NB: P = 0.054). Conclusion: All three blur thresholds showed an insignificant minimal increase at 1 month post-operatively suggesting that patients adapt to the induced blur following refractive surgery. A longer follow up would reveal how the adaptation to blur would change with time.
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Affiliation(s)
- Rachapalle Reddi Sudhir
- Department of Cornea & Refractive Surgery, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Hadiya Farhath Pattan
- Department of Cornea & Refractive Surgery, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Mehal Rathore
- Elite School of Optometry, Unit of Medical Research Foundation, Chennai, Affiliated to SASTRA University, Thanjavur, Tamil Nadu, India
| | | | - Prema Padmanabhan
- Department of Cornea & Refractive Surgery, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Vasudevan Lakshminarayanan
- School of Optometry and Vision Science, Departments of Physics, ECE and Systems Design Engineering, University of Waterloo, Canada
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10
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Redondo B, Vera J, Carreño--Rodríguez C, Molina-Romero R, Jiménez R. Acute Effects of Caffeine on Dynamic Accommodative Response and Pupil Size: A Placebo-controlled, Double-blind, Balanced Crossover Study. Curr Eye Res 2020; 45:1074-1081. [DOI: 10.1080/02713683.2020.1725060] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Beatriz Redondo
- Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain
| | - Jesús Vera
- Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain
| | | | - Rubén Molina-Romero
- Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain
| | - Raimundo Jiménez
- Department of Optics, Faculty of Sciences, University of Granada, Granada, Spain
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11
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Abstract
Crowding refers to the phenomenon of reduced recognition performance for peripherally presented targets that are flanked by similar stimuli. Crowding is known to vary with lateral distances (i.e., effects of target eccentricity and inter-character spacing). In the present experiment, we examined how crowding is affected by the distance of the stimuli in depth for natural viewing, i.e., for binocular observation of a real depth presentation. Superimposing the displays of two orthogonally arranged screens with a half-transparent mirror created real-depth presentation. We measured recognition performance of flanked compared to isolated targets that were presented at fixation depth, or in depths deviating from fixation depth (defocused). For both defocused directions (i.e., in front of and behind fixation depth), a near as well as a far distance from fixation was applied. Participants' task was to fixate a central cross at a constant distance (190 cm), and to indicate the gap position of an isolated or flanked Landolt ring that was presented at an eccentricity of 2°, on, in front of, or behind fixation depth. Results for natural binocular observation revealed increased crowding effects when stimuli were far compared to near from the fixation plane in depth. This resembles the common effect of eccentricity. Under monocular viewing, that is, without disparity information, crowding did not increase with increased depth distance. Thus, the result seemed to be an effect of binocular observation in real depth. This suggests that crowding in natural viewing might serve as a mechanism to stabilize and orient attention efficiently in three-dimensional space.
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12
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Roberts TL, Manny RE, Anderson HA. Impact of Visual Cues on the Magnitude and Variability of the Accommodative Response in Children With Emmetropia and Uncorrected Hyperopia and Adults. Invest Ophthalmol Vis Sci 2019; 60:1527-1537. [PMID: 30994863 PMCID: PMC6736278 DOI: 10.1167/iovs.18-25256] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Purpose We investigated the effect of blur and disparity cues on accommodative accuracy (lag) and variability (time [RMS] and frequency domain [LFC]) in the developing visual system. Methods A total of 59 children (3–9 years, spherical equivalent refractive error [RE] = −0.3– +4.91 diopters [D]) and 10 adults (23–31 years, RE = −0.37–+1.15D) participated. Accommodation was measured in the right eye for 1 minute at 100 and 33 cm using photorefraction (25 Hz) for three conditions: blur + disparity (binocular, 20/50 optotypes), blur-only (monocular, 20/50 optotypes), disparity-only (binocular, difference-of-Gaussian stimulus). The effect blur and disparity cues have on accommodative accuracy, RMS, and LFC was assessed. Results Lag, RMS, and LFC increased (P < 0.001) from 100 to 33 cm for each condition in children and adults. In children, accommodation was most accurate and stable when blur and disparity cues remained in the stimulus and became significantly less accurate and more variable (P < 0.001) when blur or disparity cues were removed at 33 cm. In adults, accommodation was significantly less accurate and more variable only when blur was removed from the stimulus (P < 0.022). Children with RE matched to adults had less accurate and more variable accommodative responses at near than adults when cues were removed (P ≤ 0.02). Conclusions In children and adults, an increase in RMS and LFC is related to an increase in accommodative lag. Children's accommodative systems do not compensate as efficiently as adults when blur and disparity cues are removed, suggesting children <10 years old do not have a mature afferent visual pathway.
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Affiliation(s)
- Tawna L Roberts
- Byers Eye Institute, Stanford University, Palo Alto, California, United States
| | - Ruth E Manny
- University of Houston, College of Optometry, Houston, Texas, United States
| | - Heather A Anderson
- University of Houston, College of Optometry, Houston, Texas, United States
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13
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Lupón N, Gispets J, Cardona G, Tàpia A, Abril H. Role of microfluctuations in accommodation: a novel approach to reduce non-accommodative noise. Int J Ophthalmol 2019; 12:681-684. [PMID: 31024826 DOI: 10.18240/ijo.2019.04.25] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 10/09/2018] [Indexed: 11/23/2022] Open
Abstract
Accommodative response and its possible role in myopia development has been explored through the study of the microfluctuations (MFs) of accommodation, which are commonly divided in high (1.0 to 2.3 Hz) and low (0.1 to 0.6 Hz) frequency components. Previous research efforts have evidenced that a certain percentage of the amplitude of MFs seems not to originate in the accommodative response. We aimed to develop and test a new approach to reduce this non-accommodative noise. For this purpose, ten healthy participants were enrolled to determine the difference between the amplitude of MFs at near and distance for each range of frequencies, which was defined as the relative amplitude of MFs. The findings support the exploration of the relative rather than absolute values of the amplitude of MFs to better understand the contribution of both accommodative and non-accommodative factors to MFs.
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Affiliation(s)
- Núria Lupón
- Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Catalonia E08222, Spain
| | - Joan Gispets
- Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Catalonia E08222, Spain
| | - Genis Cardona
- Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Catalonia E08222, Spain.,Applied Optics and Image Processing Research Group, Universitat Politècnica de Catalunya, Terrassa, Catalonia E082222, Spain
| | - Alba Tàpia
- Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Catalonia E08222, Spain
| | - Hector Abril
- Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Catalonia E08222, Spain.,Applied Optics and Image Processing Research Group, Universitat Politècnica de Catalunya, Terrassa, Catalonia E082222, Spain
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Koessler T, Hill H. Focusing on an illusion: Accommodating to perceived depth? Vision Res 2019; 154:131-141. [DOI: 10.1016/j.visres.2018.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 10/10/2018] [Accepted: 11/06/2018] [Indexed: 10/27/2022]
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Labhishetty V, Chakraborty A, Bobier WR. Is blur sensitivity altered in children with progressive myopia? Vision Res 2018; 154:142-153. [PMID: 30472331 DOI: 10.1016/j.visres.2018.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 11/07/2018] [Accepted: 11/13/2018] [Indexed: 12/25/2022]
Abstract
School aged children with progressive myopia show large accommodative lags to blur only cue which is suggestive of a large depth of focus (DOF). While DOF measures are lacking in this age group, their blur detection and discrimination capacities appear to be similar to their non-myopic peers. Accordingly, the current study quantified DOF and blur detection ability in progressive myopic children showing large accommodative lags compared to their non-myopic peers and adults. Blur sensitivity measures were taken from 12 children (8-13 years, 6 myopes and 6 emmetropes) and 6 adults (20-35 years). DOF was quantified using step changes in the lens induced defocus while the subjects viewed a high contrast target through a Badal lens at either 2 or 4D demand. Blur detection thresholds (BDT) were tested using a similar high contrast target in a 2-alternate forced-choice paradigm (2AFC) at both the demands. In addition to the large accommodative lags, micro fluctuations and DOF were significantly larger in myopic children compared to the other groups. However, BDTs were similar across the three groups. When limited to blur cues, the findings of a large DOF coupled with large response lags suggests that myopes are less sensitive to retinal defocus. However, in agreement to a previous study, refractive error had no influence on their BDTs suggesting that the reduced sensitivity to the defocus in a myopic eye appears to be compensated by some form of an adjustment in the higher visual processes to preserve the subjective percept even with a poor retinal image quality.
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Affiliation(s)
- Vivek Labhishetty
- School of Optometry and Vision Science, University of Waterloo, Waterloo, ON N2L3G1, Canada.
| | - Arijit Chakraborty
- School of Optometry and Vision Science, University of Waterloo, Waterloo, ON N2L3G1, Canada
| | - William R Bobier
- School of Optometry and Vision Science, University of Waterloo, Waterloo, ON N2L3G1, Canada
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Hynes NJ, Cufflin MP, Hampson KM, Mallen EAH. Cognitive Demand and Accommodative Microfluctuations. Vision (Basel) 2018; 2:vision2030036. [PMID: 31735899 PMCID: PMC6836075 DOI: 10.3390/vision2030036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 08/31/2018] [Accepted: 09/04/2018] [Indexed: 12/29/2022] Open
Abstract
Previous studies have shown cognition to have an influence on accommodation. Temporal variation in the accommodative response occurs during the fixation on a stationary target. This constantly shifting response has been called accommodative micro-fluctuations (AMFs). The aim of this study is to determine the effects of increasing task cognitive demand on the ocular accommodation response. AMFs for 12 myopes and 12 emmetropes were measured under three conditions of varying cognitive demand and comprising reading of numbers (Num), simple arithmetic (SA), and complex arithmetic (CA). Fast Fourier transforms were used to analyze the different frequency band components of the AMFs. Other aspects of AMFs including root mean square accommodation values and chaos analysis was applied. A repeated measures ANOVA revealed a significant main effect of cognition in the mean power of the high frequency component (HFC) (F2,44 = 10.03, p < 0.005). Pairwise analyses revealed that these differences exist between SA and CA tasks (p < 0.005) and the Num and CA (p < 0.005) tasks with the HFC power being the highest for the CA condition. It appears that the difficulty of a task does affect active accommodation but to a lesser extent than other factors affecting accommodation.
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Affiliation(s)
- Niall J. Hynes
- School of Optometry & Vision Science, University of Bradford, Bradford BD7 1DP, UK
- Correspondence:
| | - Matthew P. Cufflin
- School of Optometry & Vision Science, University of Bradford, Bradford BD7 1DP, UK
| | - Karen M. Hampson
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK
| | - Edward A. H. Mallen
- School of Optometry & Vision Science, University of Bradford, Bradford BD7 1DP, UK
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Blur Detection, Depth of Field, and Accommodation in Emmetropic and Hyperopic Children. Optom Vis Sci 2018; 95:212-222. [PMID: 29401180 DOI: 10.1097/opx.0000000000001177] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE Our results demonstrate that blur detection thresholds are elevated in young children compared with adults, and poorer blur detection thresholds are significantly correlated with the magnitude of accommodative microfluctuations. Given that accommodative microfluctuations are greater with greater accommodative responses, these findings may have implications for young uncorrected hyperopes. PURPOSE This study investigated the association between subjective blur detection thresholds and accommodative microfluctuations in children 3 years to younger than 10 years old and adults. METHODS Blur detection thresholds were determined in 49 children with habitually uncorrected refractive error (+0.06 to +4.91 diopters [D] spherical equivalent) and 10 habitually uncorrected adults (+0.08 to +1.51 D spherical equivalent) using a custom blur chart with 1° sized optotypes at 33 cm. Letters were blurred by convolution using a Gaussian kernel (SDs of 0.71 to 11.31 arc minutes in √2 steps). Subjective depth of field was determined in subjects 6 years or older and adults. Accommodative microfluctuations, pupils, and lag were measured using infrared photorefraction (25 Hz). RESULTS Children had greater blur detection thresholds (P < .001), accommodative microfluctuations (P = .001), and depth of field (P < .001) than adults. In children, increased blur detection thresholds were associated with increased accommodative microfluctuations (P < .001), increased uncorrected hyperopia (P = .01), decreased age (P < .001), and decreased pupil size (P = .01). In a multiple linear regression analysis, blur detection thresholds were associated with accommodative microfluctuations (P < .001) and age (P < .001). Increased accommodative microfluctuations were associated with increased uncorrected hyperopia (P = .004) and decreased pupil size (P = .003) and independently associated with uncorrected hyperopia (P = .001) and pupil size (P = .003) when controlling for age and lag. CONCLUSIONS Children did not have adult-like blur detection thresholds or depth of field. Increased accommodative microfluctuations and decreased age were independently associated with greater blur detection thresholds in children 3 years to younger than 10 years. Larger amounts of uncorrected hyperopia in children appear to increase blur detection thresholds because the greater accommodative demand and resulting response increase accommodative microfluctuations.
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Effects of Near Addition Lenses and Prisms on Accommodative Microfluctuations in Chinese Children. Optom Vis Sci 2017; 93:488-96. [PMID: 26808382 DOI: 10.1097/opx.0000000000000816] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE To investigate the effects of different near addition lenses and prisms on accommodative microfluctuations (AMFs) in Chinese early-onset myopic (EOM) and emmetropic (EMM) children. METHODS Twenty-one EMM and 27 EOM children aged between 9 and 14years participated in the study. At near, 23 children were exophoric (exo, <0 Δ), and 25 were esophoric (eso, ≥0 Δ). The AMFs and phoria through multiple addition lenses (-1.00, 0, +1.00, +2.00, and +3.00D on each eye) and prisms (base-in prism power: 3 Δ, 2 Δ, 1 Δ; and base-out prism power: 1 Δ and 2 Δ on each eye) were measured at 25cm under binocular viewing conditions with a Grand Seiko WAM-5500 auto-refractor and a modified Thorington card. RESULTS Higher AMFs were found in EOM than in EMM (EOM, 0.19±0.06D; EMM, 0.16±0.03D; p=0.035). Plus additions from +1.00 to +3.00D reduced the AMFs in both EMM and EOM, except +3.00D for EMM. In both refractive groups, -1.00D additions increased AMFs. Esophores showed greater AMFs compared with exophores (esophores, 0.20±0.01D; exophores, 0.16±0.01D; p=0.012). Prisms increased the AMFs in EMM and did not alter the AMFs in EOM. CONCLUSIONS Microfluctuations of accommodation decreased with plus addition lenses and increased with negative addition lenses. Plus addition lenses of +2.00 to +3.00D for EOM and +2.00D for EMM decreased AMFs the least at a 25-cm working distance. Esophores had higher AMFs than exophores, indicating that phoria status influences AMFs.
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Hampson KM, Cufflin MP, Mallen EAH. Sensitivity of Chaos Measures in Detecting Stress in the Focusing Control Mechanism of the Short-Sighted Eye. Bull Math Biol 2017. [PMID: 28639168 PMCID: PMC5517597 DOI: 10.1007/s11538-017-0310-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
When fixating on a stationary object, the power of the eye’s lens fluctuates. Studies have suggested that changes in these so-called microfluctuations in accommodation may be a factor in the onset and progression of short-sightedness. Like many physiological signals, the fluctuations in the power of the lens exhibit chaotic behaviour. A breakdown or reduction in chaos in physiological systems indicates stress to the system or pathology. The purpose of this study was to determine whether the chaos in fluctuations of the power of the lens changes with refractive error, i.e. how short-sighted a subject is, and/or accommodative demand, i.e. the effective distance of the object that is being viewed. Six emmetropes (EMMs, non-short-sighted), six early-onset myopes (EOMs, onset of short-sightedness before the age of 15), and six late-onset myopes (LOMs, onset of short-sightedness after the age of 15) took part in the study. Accommodative microfluctuations were measured at 22 Hz using an SRW-5000 autorefractor at accommodative demands of 1 D (dioptres), 2 D, and 3 D. Chaos theory analysis was used to determine the embedding lag, embedding dimension, limit of predictability, and Lyapunov exponent. Topological transitivity was also tested for. For comparison, the power spectrum and standard deviation were calculated for each time record. The EMMs had a statistically significant higher Lyapunov exponent than the LOMs (\documentclass[12pt]{minimal}
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\begin{document}$$0.64\pm 0.33$$\end{document}0.64±0.33 vs. \documentclass[12pt]{minimal}
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\begin{document}$$0.39\pm 0.20~\hbox {D}/\hbox {s}$$\end{document}0.39±0.20D/s) and a lower embedding dimension than the LOMs (\documentclass[12pt]{minimal}
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\begin{document}$$3.28\pm 0.46$$\end{document}3.28±0.46 vs. \documentclass[12pt]{minimal}
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\begin{document}$$3.67\pm 0.49$$\end{document}3.67±0.49). There was insufficient evidence (non-significant p value) of a difference between EOMs and EMMs or EOMs and LOMs. The majority of time records were topologically transitive. There was insufficient evidence of accommodative demand having an effect. Power spectrum analysis and assessment of the standard deviation of the fluctuations failed to discern differences based on refractive error. Chaos differences in accommodation microfluctuations indicate that the control system for LOMs is under stress in comparison to EMMs. Chaos theory analysis is a more sensitive marker of changes in accommodation microfluctuations than traditional analysis methods.
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Affiliation(s)
- Karen M Hampson
- School of Optometry and Vision Science, University of Bradford, Bradford, BD7 1DP, UK.
| | - Matthew P Cufflin
- School of Optometry and Vision Science, University of Bradford, Bradford, BD7 1DP, UK
| | - Edward A H Mallen
- School of Optometry and Vision Science, University of Bradford, Bradford, BD7 1DP, UK
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Barišić A, Patel S, Gabric N, Feinbaum CG. The clinical depth of field achievable with trifocal and monofocal intraocular lenses: theoretical considerations and proof of concept clinical results. Graefes Arch Clin Exp Ophthalmol 2016; 255:367-373. [PMID: 28013392 DOI: 10.1007/s00417-016-3566-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 10/07/2016] [Accepted: 11/29/2016] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND To estimate the depth of field (DOF) achievable with multi-and monofocal intraocular lenses (IOLs) and compare with actual measurements of DOF in cases implanted with a trifocal IOL and biconvex monofocal IOL METHODS: I) Computer simulations were produced to describe the relationship between DOF, pupil size, preoperative ametropia, and retinal blur tolerance limit for a model eye implanted with either multi- or monofocal IOLs. II) Monocular DOF and pupil size were measured under distance viewing conditions between 3 and 6 months postoperative following uneventful cataract surgery. Cases were implanted with either i) trifocal aspheric IOL (n = 36), or ii) biconvex aspheric monofocal IOL (n = 26). DOF was also measured at 0.33 m in cases implanted with i). RESULTS Simulations revealed significant associations between DOF, pupil size, and retinal blur tolerance limit. The mean (±SD) DOF & pupil sizes were at distance for i) above 2.59D (0.68) & 3.54 mm (0.377), and for ii) above 1.67D (0.51) & 2.90 mm (0.351), and for i) above 3.16D (0.46) at near. The difference between groups were significant for DOF and pupil size at distance (p < 0.001). DOF was significantly greater at near compared with distance in i) above (p < 0.001). For a pupil size of 3 mm, the simulations produce similar DOF values when the tolerance limit of retinal blur is 10 μ. CONCLUSIONS The DOF was significantly better after implanting the trifocal IOL compared with the monofocal IOL, and DOF is increased under near viewing conditions. The clinical results are similar to calculated DOF values when the tolerance limit of retinal blur is 10 μ.
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Affiliation(s)
- Ante Barišić
- Special Eye Hospital Svjetlost, Heinzelova 39, 10000, Zagreb, Croatia.
| | - Sudi Patel
- Special Eye Hospital Svjetlost, Heinzelova 39, 10000, Zagreb, Croatia
- NHS National Services Scotland, Edinburgh, UK
| | - Nikica Gabric
- Special Eye Hospital Svjetlost, Heinzelova 39, 10000, Zagreb, Croatia
| | - Claes G Feinbaum
- Barzilai Hospital, BenGurion University of the Negev, BerSheeba, Israel
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Abstract
PURPOSE To evaluate whether an induced astigmatism influences the subjective depth of focus. METHODS Fifty-one participants aged 18 to 35 years and with a mean spherical equivalent refractive error of -0.51 ± 2.35 DS participated in the study. The accommodation was blocked with three drops of 1% cyclopentolate. Refractive errors were corrected after subjective refraction with a 4-mm artificial pupil. To evaluate the depth of focus (DoF), defocus curves with a spherical range of ±1.5 DS were assessed. The DoF was calculated as the horizontal distance at a threshold level of +0.1 logMAR from the maximum visual acuity (VA). Defocus curves were estimated binocularly during distance (500 cm) and a near vision (40 cm) for two induced axis (ATR in 0° and WTR in 90°) and for a fixed amount of astigmatic defocus of -0.5 DC. RESULTS The mean natural DoF was 0.885 ± 0.316 D for far vision and 0.940 ± 0.400 D for near vision. With induced astigmatism, the DoF for far vision was significantly increased to 1.095 ± 0.421 D (p = 0.006, ANOVA) for the WTR astigmatism but not for the ATR astigmatism (1.030 ± 0.395 D; p = 0.164, ANOVA). The induced WTR astigmatism enhanced the DoF for near vision significantly to 1.144 ± 0.338 D (p = 0.04, ANOVA), and DoF with induced ATR astigmatism (0.953 ± 0.318 D) was not significantly different (p = 1.00, ANOVA). ATR-astigmatism reduced VA by +0.08 ± 0.08 logMAR (p < 0.01, t-test). CONCLUSIONS With an induced WTR astigmatism of -0.5 DC, the DoF can be enhanced in the near viewing distance with a marginal loss in binocular VA. The approach of using induced WTR astigmatism can lead to novel optical treatments for presbyopia.
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22
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Charman WN, Heron G. Microfluctuations in accommodation: an update on their characteristics and possible role. Ophthalmic Physiol Opt 2015; 35:476-99. [DOI: 10.1111/opo.12234] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 07/23/2015] [Indexed: 11/30/2022]
Affiliation(s)
- W Neil Charman
- Faculty of Life Sciences; University of Manchester; Manchester UK
| | - Gordon Heron
- Vision Sciences; Glasgow Caledonian University; Glasgow UK
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Abstract
Purpose To obtain experimental values of the depth-of-field (DOFi) of the human eye for different accommodative states. Methods First, the monochromatic ocular wavefront of seven eyes from young subjects (mean [±SD] age, 29.7 [±7.7] years) was measured at eight different accommodative demands (ADs) (from −1 to 6 diopters [D] in steps of 1 D). Then, in a second part, accommodation was paralyzed and an adaptive optics system was used to correct the aberrations of the paralyzed eye and to simulate, with the aid of an artificial pupil, the wavefront of the accommodated eye. The simulation was performed for each AD measured in the first part of the experiment. A Badal system was used to modify the stimulus vergence so as to obtain three repeated measurements of the subjective DOFi, based on the criterion of an objectionable blur. Results When increasing AD from 0 to 6 D, the mean intersubject pupil diameter and DOFi changed from 5.70 to 4.62 mm and from 0.85 ± 0.26 D to 1.07 ± 0.19 D, respectively. All subjects presented a similar DOFi for all AD (intrasubject SD never exceeded 0.23 D). Paraxial accommodation response showed a lag that increased with the AD. For the lowest (0 D) and the highest (6 D) values of AD, the refractive state of the eye was close to the nearest and furthermost ends of the DOFi, respectively. Conclusions The visual system takes advantage of the DOFi to change the refractive state less than necessary to form the paraxial image at the retina when it comes to focusing a near target (5 to 6 D of AD). This indicates that the main purpose of accommodation is not to maximize retinal image quality but to form one that is good enough.
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Lee TT, Cho P. Relative peripheral refraction in children: twelve-month changes in eyes with different ametropias. Ophthalmic Physiol Opt 2013; 33:283-93. [DOI: 10.1111/opo.12057] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 03/11/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Tsui-Tsui Lee
- School of Optometry; The Hong Kong Polytechnic University; Kowloon; Hong Kong
| | - Pauline Cho
- School of Optometry; The Hong Kong Polytechnic University; Kowloon; Hong Kong
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Nochez Y, Salah S, Bonneau M, Majzoub S, Pisella PJ. Influence des aberrations optiques d’ordre élevé sur la capacité accommodative des patients présentant une presbytie débutante. J Fr Ophtalmol 2011; 34:715-22. [DOI: 10.1016/j.jfo.2011.03.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Revised: 02/27/2011] [Accepted: 03/09/2011] [Indexed: 10/17/2022]
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