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Chen HC, Yang SF, Lee CY, Huang JY, Hsueh YJ, Sun MH, Chiang MC, Huang YS, Chu SM, Hsu JF, Liu CH, Chang CK, Chen KJ, Hwang YS, Lai CC, Huang CY, Wu WC. Corneal Endothelial Morphology and Ocular Biometric Indexes in Premature Children With and Without Retinopathy of Prematurity. Invest Ophthalmol Vis Sci 2024; 65:37. [PMID: 38780946 PMCID: PMC11127487 DOI: 10.1167/iovs.65.5.37] [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: 11/16/2023] [Accepted: 03/06/2024] [Indexed: 05/25/2024] Open
Abstract
Purpose The purpose of this study was to analyze human corneal endothelial cells (HCECs) morphology and ocular biometrics in premature (PM) children with or without retinopathy of prematurity (ROP). Methods Retrospective data on patient demographics, HCECs status, and ocular biometrics with at least 2 visits between 2016 and 2021 were reviewed. The main outcomes were endothelial cell density (ECD), coefficient of variation (CV), hexagonal cell ratio (HEX), central corneal thickness (CCT), axial length, anterior chamber depth, keratometry, corneal diameter, pupil diameter, and refraction status. Generalized estimating equation was used to evaluate the differences between PM no-ROP and ROP groups. We also analyzed the trend of ECD, CV, HEX, and CCT change with age between groups. Results The study included 173 PM patients without ROP and 139 patients with ROP. A total of 666 and 544 measurements were recorded in the PM no-ROP and ROP groups, respectively. The ROP group had higher spherical power, myopic spherical equivalent (SE), and steeper steep keratometry (K; P < 0.05). The ROP group had higher CV (P = 0.0144), lower HEX (P = 0.0012) and thicker CCT (P = 0.0035). In the HCECs parameters, the ROP group had slower ECD decrement (P < 0.0001), faster CV decrement (P = 0.0060), and faster HEX increment (P = 0.0001). A difference in corneal morphology changes between the ROP and PM no-ROP groups were prominent in patients with lower gestational age (GA) in the subgroup analysis. Conclusions Worse HCECs morphology and higher myopic status were initially observed in patients with prior ROP but not in PM patients with no-ROP. ECD and HCECs morphology improved with age, especially in patients with low GA.
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Affiliation(s)
- Hung-Chi Chen
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Center for Tissue Engineering, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Shun-Fa Yang
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Chia-Yi Lee
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Nobel Eye Institute, Taipei, Taiwan
- Department of Ophthalmology, Jen-Ai Hospital Dali Branch, Taichung, Taiwan
| | - Jing-Yang Huang
- Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan
| | - Yi-Jen Hsueh
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Center for Tissue Engineering, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Ming-Hui Sun
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Ming-Chou Chiang
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
- Department of Pediatrics, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Yu-Shu Huang
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
- Department of Psychiatrics, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Shih-Ming Chu
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
- Department of Pediatrics, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Jen-Fu Hsu
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
- Department of Pediatrics, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Chun-Hsiu Liu
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Chao-Kai Chang
- Nobel Eye Institute, Taipei, Taiwan
- Department of Optometry, Da-Yeh University, Chunghua, Taiwan
| | - Kuan-Jen Chen
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Yih-Shiou Hwang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Chi-Chun Lai
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Chung-Ying Huang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Wei-Chi Wu
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan, Taiwan
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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: 0] [Impact Index Per Article: 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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McLean IR, Manning TS, Cooper EA. Perceptual Adaptation to Continuous Versus Intermittent Exposure to Spatial Distortions. Invest Ophthalmol Vis Sci 2022; 63:29. [PMID: 35612838 PMCID: PMC9150834 DOI: 10.1167/iovs.63.5.29] [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: 02/11/2022] [Accepted: 04/28/2022] [Indexed: 11/24/2022] Open
Abstract
Purpose To examine perceptual adaptation when people wear spectacles that produce unequal retinal image magnification. Methods Two groups of 15 participants (10 male; mean age 25.6 ± 4.9 years) wore spectacles with a 3.8% horizontal magnifier over one eye. The continuous-wear group wore the spectacles for 5 hours straight. The intermittent-wear group wore them for five 1-hour intervals. To measure slant and shape distortions produced by the spectacles, participants adjusted visual stimuli until they appeared frontoparallel or equiangular, respectively. Adaptation was quantified as the difference in responses at the beginning and end of wearing the spectacles. Aftereffects were quantified as the difference before and after removing the spectacles. We hypothesized that intermittent wear may lead to visual cue reweighting, so we fit a cue combination model to the data and examined changes in weights given to perspective and binocular disparity slant cues. Results Both groups experienced significant shape adaptation and aftereffects. The continuous-wear group underwent significant slant adaptation and the intermittent group did not, but there was no significant difference between groups, suggesting that the difference in adaptation was negligible. There was no evidence for cue reweighting in the intermittent wear group, but unexpectedly, the weight given to binocular disparity cues for slant increased significantly in the continuous-wear group. Conclusions We did not find strong evidence that adaptation to spatial distortions differed between the two groups. However, there may be differences in the cue weighting strategies employed when spectacles are worn intermittently or continuously.
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Affiliation(s)
- Iona R McLean
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
| | - Tyler S Manning
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
| | - Emily A Cooper
- Herbert Wertheim School of Optometry and Vision Science, University of California Berkeley, Berkeley, California, United States
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California, United States
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Kumarakulasinghe ALB, Md Din N, Mohd Noh UK, Syed Zakaria SZ, Aung T, Mohd Khialdin S. Evaluation of Ocular Biometric and Optical Coherence Tomography Parameters in Preterm Children Without Retinopathy of Prematurity. Transl Vis Sci Technol 2022; 11:8. [PMID: 35258558 PMCID: PMC8914564 DOI: 10.1167/tvst.11.3.8] [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: 11/29/2022] Open
Abstract
Purpose To evaluate and compare biometric and optical coherence tomography parameters of ocular structures in preterm children without retinopathy of prematurity with term children. Methods A cross-sectional, comparative study was carried out from 2018 to 2019. In this study, 124 eyes of 62 preterm children were compared with 132 eyes of 66 term children aged between 7 and 9 years. Preterm children were born at 28 to 32 weeks with a birth weight of less than 2 kg with no ocular abnormalities, and term children were delivered at 37 or greater weeks and had a birth weight of 2 kg or more. All children had standardized eye examinations, and ocular measurements using the anterior and posterior segment optical coherence tomography and laser interferometry. Results Significant differences were found between the term and preterm children for horizontal corneal diameter: median, 12.2 mm (interquartile range [IQR], 0.4) versus median, 12.1 mm (IQR, 0.6; P < 0.005); axial length median, 23.03 mm (IQR, 1.10 mm) versus median, 22.88 mm (IQR, 1.35 mm; P = 0.017); global retinal nerve fiber layer thickness: mean ± standard deviation, 106.54 ± 10.23 µm versus mean ± standard deviation, 103.65 ± 10.178 µm (P = 0.024); temporal retinal nerve fiber layer thickness: median, 76 µm (IQR, 16 µm) vs median, 74 µm (IQR, 14 µm; P = 0.012); and the angle opening distance at 750 µm nasal: mean ± standard deviation, 0.815 ± 0.23 mm vs mean ± standard deviation, 0.749 ± 0.21 mm (P = 0.016). No significant differences were found for other anterior segment and angle parameters. Conclusions Preterm children with no retinopathy of prematurity have smaller eyes and thinner retinal nerve fiber layers than their term counterparts. The long-term effects of interrupted ocular growth in preterm children should be further studied into adulthood. Translational Relevance Preterm children maybe more predisposed to certain eye conditions because they have smaller eyes, and thus should be further monitored clinically.
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Affiliation(s)
| | - Norshamsiah Md Din
- Department of Ophthalmology, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur, Malaysia
| | - Umi Kalthum Mohd Noh
- Department of Ophthalmology, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur, Malaysia.,Department of Ophthalmology, Sunway Medical Centre Jalan Lagoon Selatan, Bandar Sunway, Petaling Jaya, Selangor, Malaysia
| | - Syed Zulkifli Syed Zakaria
- Department of Paediatrics, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latiff, Bandar TunRazak, Cheras, Kuala Lumpur, Malaysia
| | - Tin Aung
- Singapore Eye Research Institute, Singapore National Eye Center, 11 Third Hospital Avenue, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Safinaz Mohd Khialdin
- Department of Ophthalmology, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, Cheras, Kuala Lumpur, Malaysia
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Bharadwaj SR, Ravisankar C, Roy S, Satgunam P. Fluctuations of Steady-State Accommodation Is a Marker for Screening Spasm of Near Reflex. Transl Vis Sci Technol 2021; 10:9. [PMID: 34491286 PMCID: PMC8431981 DOI: 10.1167/tvst.10.11.9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/03/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose To determine the utility of root mean squared (RMS) deviations of steady-state accommodation as a noncycloplegic marker for spasm of near reflex (SNR) vis-à-vis regular refractive errors. Methods Binocular steady-state responses of accommodation, pupil, and vergence of 20 patients with accommodative spasm subtype of SNR (SNR-A; 9-23 years) and 91 with regular refractive errors (29 emmetropes, 41 myopes, 21 hyperopes; 19-38 years) was recorded in the uncorrected refractive error state for 120 seconds using a dynamic (50 frames per second), infrared photorefractor. Mean and RMS deviation of raw data was calculated for three 20-second-long epochs and their diagnostic utility was determined using standard ROC curves. Results RMS deviations of accommodation increased with mean refractive error in SNR-A (y = -0.23x + 0.38; r2 = 0.69; P < 0.001) and regular refractive error (y = -0.02x + 0.10; r2 = 0.14; P = 0.002) cohorts, albeit with steeper slope and higher y-intercept in the former rather than the latter cohort. RMS deviation of 0.19D reliably distinguished SNR-A from regular refractive errors with a sensitivity and specificity of 95.2% and 92.2%, respectively [mean (±1 SEM) area under ROC curve: 0.98 ± 0.01]. The sensitivity, specificity, and area under ROC curve for RMS deviations of pupil (66.7%, 80%, and 0.70 ± 0.09) and vergence (52.4%, 84.6%, and 0.68 ± 0.08) were smaller than accommodation. Conclusions RMS deviations of steady-state accommodation is a robust noncycloplegic marker for differentiating SNR-A from regular refractive errors. Pupil and vergence fluctuations have limited utility in this regard. Translational Relevance RMS deviations of accommodation may be easily obtained using commercial photorefractors, and the cut-off values reported herein may be implemented to identify SNR-A during refractive error screening.
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Affiliation(s)
- Shrikant R. Bharadwaj
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India
- Prof Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India
| | - Chandrika Ravisankar
- Prof Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India
| | - Saujanwita Roy
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India
| | - PremNandhini Satgunam
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Hyderabad, India
- Prof Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, India
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Logan NS, Radhakrishnan H, Cruickshank FE, Allen PM, Bandela PK, Davies LN, Hasebe S, Khanal S, Schmid KL, Vera-Diaz FA, Wolffsohn JS. IMI Accommodation and Binocular Vision in Myopia Development and Progression. Invest Ophthalmol Vis Sci 2021; 62:4. [PMID: 33909034 PMCID: PMC8083074 DOI: 10.1167/iovs.62.5.4] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The role of accommodation in myopia development and progression has been debated for decades. More recently, the understanding of the mechanisms involved in accommodation and the consequent alterations in ocular parameters has expanded. This International Myopia Institute white paper reviews the variations in ocular parameters that occur with accommodation and the mechanisms involved in accommodation and myopia development and progression. Convergence is synergistically linked with accommodation and the impact of this on myopia has also been critiqued. Specific topics reviewed included accommodation and myopia, role of spatial frequency, and contrast of the task of objects in the near environment, color cues to accommodation, lag of accommodation, accommodative-convergence ratio, and near phoria status. Aspects of retinal blur from the lag of accommodation, the impact of spatial frequency at near and a short working distance may all be implicated in myopia development and progression. The response of the ciliary body and its links with changes in the choroid remain to be explored. Further research is critical to understanding the factors underlying accommodative and binocular mechanisms for myopia development and its progression and to guide recommendations for targeted interventions to slow myopia progression.
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Affiliation(s)
- Nicola S Logan
- School of Optometry, Aston University, Birmingham, United Kingdom
| | - Hema Radhakrishnan
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Fiona E Cruickshank
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Peter M Allen
- Vision and Hearing Sciences Research Centre, School of Psychology and Sports Sciences, Anglia Ruskin University, Cambridge, United Kingdom
| | - Praveen K Bandela
- 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
| | - Leon N Davies
- School of Optometry, Aston University, Birmingham, United Kingdom
| | - Satoshi Hasebe
- Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Safal Khanal
- School of Optometry, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Katrina L Schmid
- School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Australia
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Lu R, Levy AM, Zhang Q, Pittler SJ, Yao X. Dynamic near-infrared imaging reveals transient phototropic change in retinal rod photoreceptors. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:106013. [PMID: 24165739 PMCID: PMC3809571 DOI: 10.1117/1.jbo.18.10.106013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/03/2013] [Indexed: 05/05/2023]
Abstract
Stiles-Crawford effect (SCE) is exclusively observed in cone photoreceptors, but why the SCE is absent in rod photoreceptors is still a mystery. In this study, we employed dynamic near infrared light imaging to monitor photoreceptor kinetics in freshly isolated frog and mouse retinas stimulated by oblique visible light flashes. It was observed that retinal rods could rapidly (onset: ∼10 ms for frog and 5 ms for mouse; time-to-peak: ∼200 ms for frog and 30 ms for mouse) shift toward the direction of the visible light, which might quickly compensate for the loss of luminous efficiency due to oblique illumination. In contrast, such directional movement was negligible in retinal cones. Moreover, transient rod phototropism could contribute to characteristic intrinsic optical signal (IOS). We anticipate that further study of the transient rod phototropism may not only provide insight into better understanding of the nature of vision but also promise an IOS biomarker for functional mapping of rod physiology at high resolution.
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Affiliation(s)
- Rongwen Lu
- University of Alabama at Birmingham, Department of Biomedical Engineering, Birmingham, Alabama 35294
| | - Alexander M. Levy
- University of Alabama at Birmingham, Department of Biomedical Engineering, Birmingham, Alabama 35294
| | - Qiuxiang Zhang
- University of Alabama at Birmingham, Department of Biomedical Engineering, Birmingham, Alabama 35294
| | - Steven J. Pittler
- University of Alabama at Birmingham, Department of Vision Sciences, Birmingham, Alabama 35294
| | - Xincheng Yao
- University of Alabama at Birmingham, Department of Biomedical Engineering, Birmingham, Alabama 35294
- University of Alabama at Birmingham, Department of Vision Sciences, Birmingham, Alabama 35294
- Address all correspondence to: Xincheng Yao, University of Alabama at Birmingham, Department of Biomedical Engineering, Birmingham, Alabama 35294. Tel: (205) 996-7459; Fax: (205) 934-3425; E-mail:
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Irsch K, Shah AA. Birefringence of the central cornea in children assessed with scanning laser polarimetry. JOURNAL OF BIOMEDICAL OPTICS 2012; 17:086001. [PMID: 23224188 DOI: 10.1117/1.jbo.17.8.086001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Corneal birefringence is a well-known confounding factor with all polarization-sensitive technology used for retinal scanning and other intraocular assessment. It has been studied extensively in adults, but little is known regarding age-related differences. Specifically, no information is available concerning corneal birefringence in children. For applications that are geared towards children, such as retinal birefringence scanning for strabismus screening purposes, it is important to know the expected range of both corneal retardance and azimuth in pediatric populations. This study investigated central corneal birefringence in children (ages three and above), by means of scanning laser polarimetry (GDx-VCC™, Carl Zeiss Meditec, Inc.). Children's measures of corneal retardance and azimuth were compared with those obtained in adults. As with previous studies in adults, corneal birefringence was found to vary widely in children, with corneal retardance ranging from 10 to 77 nm, and azimuth (slow axis) ranging from -11° to 71° (measured nasally downward). No significant differences in central corneal birefringence were found between children and adults, nor were significant age-related differences found in general. In conclusion, establishing knowledge of the polarization properties of the central cornea in children allows better understanding, exploitation, or bypassing of these effects in new polarization-sensitive pediatric ophthalmic applications.
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Affiliation(s)
- Kristina Irsch
- Johns Hopkins University School of Medicine, Wilmer Eye Institute, Baltimore, MD, USA.
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