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Schumacher J, Lopez RR, Larin K, Manns F, Scarcelli G. Functional effects of the spatial-varying lens mechanical properties in accommodation. JPHYS PHOTONICS 2024; 6:035021. [PMID: 38975030 PMCID: PMC11223182 DOI: 10.1088/2515-7647/ad3e55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/25/2024] [Accepted: 04/12/2024] [Indexed: 07/09/2024] Open
Abstract
Lens biomechanical properties are critical for our eyes to accommodate. While it is well understood that lens mechanical properties change with age, different experimental techniques have been used over the years, with varying results on how the lens modulus changes. In this study, we developed a spatial-varying elasticity model to characterize the overall elastic modulus of the lens and establish its effect on accommodation. First, to validate the model, ex vivo porcine lenses underwent compression testing using biopsy punches of different diameters to change the percentage of nucleus within samples. Importantly, we found that, indeed, changing nucleus/cortex spatial ratio produces dramatic (∼7-fold) increase in overall sample modulus. Comparing the model with human lens spatial ratios, we demonstrate how changing spatial mechanics are more influential than peak modulus changes on overall elastic modulus. Next, in vivo clinical measurements of the spatial-varying lens modulus were used to generate a simplified mechanical-optical model of accommodation. We defined an ellipsoid lens with patient-derived modulus and geometry measurements, and a statics simulation and ray tracing analysis were performed through the deformed and undeformed lens. The resulting accommodation estimates agree with general accommodation expectations.
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Affiliation(s)
- Justin Schumacher
- Fischell Department of Bioengineering, University of Maryland, College Park, United States of America
| | - Raymundo Rodriguez Lopez
- Fischell Department of Bioengineering, University of Maryland, College Park, United States of America
| | - Kirill Larin
- Department of Biomedical Engineering, University of Houston, Houston, TX, United States of America
| | - Fabrice Manns
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, United States of America
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Giuliano Scarcelli
- Fischell Department of Bioengineering, University of Maryland, College Park, United States of America
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Davies LN, Biswas S, Bullimore M, Cruickshank F, Estevez JJ, Khanal S, Kollbaum P, Marcotte-Collard R, Montani G, Plainis S, Richdale K, Simard P, Wolffsohn JS. BCLA CLEAR presbyopia: Mechanism and optics. Cont Lens Anterior Eye 2024:102185. [PMID: 38796331 DOI: 10.1016/j.clae.2024.102185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2024]
Abstract
With over a billion adults worldwide currently affected, presbyopia remains a ubiquitous, global problem. Despite over a century of study, the precise mechanism of ocular accommodation and presbyopia progression remains a topic of debate. Accordingly, this narrative review outlines the lenticular and extralenticular components of accommodation together with the impact of age on the accommodative apparatus, neural control of accommodation, models of accommodation, the impact of presbyopia on retinal image quality, and both historic and contemporary theories of presbyopia.
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Affiliation(s)
- Leon N Davies
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, UK.
| | - Sayantan Biswas
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, UK
| | | | - Fiona Cruickshank
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Jose J Estevez
- Caring Futures Institute, College of Nursing and Health Sciences, Optometry and Vision Science, Flinders University, Adelaide, Australia; Flinders Centre for Ophthalmology, Eye and Vision Research, Department of Ophthalmology, Flinders University, Adelaide, Australia
| | - Safal Khanal
- Department of Optometry and Vision Science, The University of Alabama at Birmingham, USA
| | | | | | | | - Sotiris Plainis
- Laboratory of Optics and Vision, School of Medicine, University of Crete, Greece
| | | | - Patrick Simard
- School of Optometry, Universite de Montreal, Montreal, Quebec, Canada
| | - James S Wolffsohn
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, UK
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Hammer M, Heggemann Y, Auffarth GU. Dynamic Stimulation Aberrometry: Objectively Measured Accommodation and Pupil Dynamics after Phakic Iris-Fixated Intraocular Lens Implantation. OPHTHALMOLOGY SCIENCE 2024; 4:100374. [PMID: 37868795 PMCID: PMC10587632 DOI: 10.1016/j.xops.2023.100374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/14/2023] [Accepted: 07/18/2023] [Indexed: 10/24/2023]
Abstract
Purpose Anterior iris-claw phakic intraocular lens (pIOL) implantation is a treatment option for refractive, ametropic patients. However, the postoperative accommodative ability has not been systematically researched. Dynamic stimulation aberrometry allows the objective and dynamical measurement of accommodation by observing ocular aberrations during the accommodation process. We investigated the dynamic accommodative ability after pIOL implantation compared with a healthy age- and gender-matched control group. Design Clinical, comparative case-control study. Subjects We included patients aged 18-50 years that either underwent pIOL implantation > 1 month ago or served as a healthy, phakic control group. Methods The accommodative ability and pupil dynamics of both groups were investigated using dynamic stimulation aberrometry. The method allows the analysis of dynamic parameters during accommodation, such as the accommodation speed. A 1:1 propensity score matching was conducted based on the patients' age and gender. Main Outcome Measures Parameters of objective accommodation, such as accommodative amplitude and pupil dynamic during accommodation. Results Fifty-eight healthy, phakic eyes < 50 years of age and 21 eyes after pIOL implantation to correct myopia (pIOL, Verisyse, AMO, Inc) were enrolled. Patients that underwent anterior pIOL implantation were examined on average 24 ± 18 months after surgery. After matching, the mean age of both groups was not significantly different (35 ± 8 vs. 34 ± 8 years). No significant difference in dynamic parameters of accommodation or the accommodative amplitude (2.8 ± 1.4 and 2.9 ± 1.4 diopters [D] for pIOL and control group, P = 0.82) were seen. Maximum and minimum pupil sizes were not significantly different. The change in pupil size during deaccommodation was significantly faster in patients after pIOL implantation (P < 0.001). Conclusions Dynamic stimulation aberrometry allowed the objective, dynamic, measurement of wavefronts in subjects with accommodative amplitudes up to 7 D. Phakic intraocular lens implantation does not impair the accommodative ability. It alters pupil dynamics during deaccommodation. Financial Disclosures Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Maximilian Hammer
- David J. Apple Laboratory for Vision Research, Heidelberg, Germany
- Department of Ophthalmology, University of Heidelberg, International Vision Correction Research Centre, Heidelberg, Germany
| | - Yvonne Heggemann
- David J. Apple Laboratory for Vision Research, Heidelberg, Germany
- Department of Ophthalmology, University of Heidelberg, International Vision Correction Research Centre, Heidelberg, Germany
| | - Gerd U. Auffarth
- David J. Apple Laboratory for Vision Research, Heidelberg, Germany
- Department of Ophthalmology, University of Heidelberg, International Vision Correction Research Centre, Heidelberg, Germany
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Shaheen G, Paul J, Fleischman D. Macrophakia: The characterization of a novel lens condition. Heliyon 2024; 10:e25161. [PMID: 38322959 PMCID: PMC10844534 DOI: 10.1016/j.heliyon.2024.e25161] [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] [Received: 07/22/2023] [Revised: 01/07/2024] [Accepted: 01/22/2024] [Indexed: 02/08/2024] Open
Abstract
Purpose To present a novel characterization of a lens condition termed macrophakia which includes large or proportionally large lenses with shallow anterior chamber dimensions that are statistically deviant of a normal population. Observations We identified five eyes from three cases to have significantly large lens parameters and small anterior chamber depths. In all five eyes, the anterior chamber depth was less than 2 mm and the anterior chamber depth to lens thickness ratio was two standard deviations outside the normative range of lens and chamber measurements. These large lenses were all observed in the absence of typical pathology and other biometric abnormalities. Conclusions and importance A novel lens characterization termed macrophakia is proposed to describe large or proportionately large lenses. Naming this condition is clinically relevant and will enhance cataract evaluations and patient education.
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Affiliation(s)
- Gulrukh Shaheen
- Department of Ophthalmology, University of North Carolina, Chapel Hill, NC, USA
| | - Joshua Paul
- Department of Ophthalmology, University of North Carolina, Chapel Hill, NC, USA
| | - David Fleischman
- Department of Ophthalmology, University of North Carolina, Chapel Hill, NC, USA
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Naujokaitis T, Auffarth GU, Łabuz G, Khoramnia R. Endothelial Cell Loss in Patients with Phakic Intraocular Lenses. Klin Monbl Augenheilkd 2024. [PMID: 38242162 DOI: 10.1055/a-2209-5251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2024]
Abstract
Although the safety of phakic intraocular lenses (pIOLs) has been continuously improved over 70-years of development, high endothelial cell losses can occur even with current pIOL models. Numerous studies have demonstrated that the distance of a pIOL to the corneal endothelium plays a crucial role in the extent of endothelial cell loss. For this reason alone, higher endothelial cell loss tends to be observed with anterior chamber lenses than with posterior chamber lenses. Adequate preoperative anterior chamber depth is essential, at least for iris-fixed pIOLs, in order to ensure a safe distance from the endothelium. However, the anterior chamber becomes shallower with age and therefore it may be useful to consider patient age in the safety criteria. Although endothelial cell loss is generally low with current pIOL models, regular monitoring of the endothelial cell density remains essential due to large interindividual differences in patients with pIOLs. If the endothelial cell loss is greater than expected and the follow-up visits confirm the trend, the pIOL should be explanted without delay. The endothelial reserve should be considered on an individual basis by taking into account patient age, physiological endothelial cell loss, and loss due to further surgery. With careful indication and long-term patient care, pIOLs remain a safe treatment option.
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Affiliation(s)
- Tadas Naujokaitis
- International Vision Correction Research Centre (IVCRC) und David J Apple International Laboratory for Ocular Pathology, Universitäts-Augenklinik Heidelberg, Deutschland
| | - Gerd U Auffarth
- International Vision Correction Research Centre (IVCRC) und David J Apple International Laboratory for Ocular Pathology, Universitäts-Augenklinik Heidelberg, Deutschland
| | - Grzegorz Łabuz
- International Vision Correction Research Centre (IVCRC) und David J Apple International Laboratory for Ocular Pathology, Universitäts-Augenklinik Heidelberg, Deutschland
| | - Ramin Khoramnia
- International Vision Correction Research Centre (IVCRC) und David J Apple International Laboratory for Ocular Pathology, Universitäts-Augenklinik Heidelberg, Deutschland
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Gupta A, Ruminski D, Villar AJ, Toledo RD, Gondek G, Pierscionek B, Artal P, Grulkowski I. Age-related changes in geometry and transparency of human crystalline lens revealed by optical signal discontinuity zones in swept-source OCT images. EYE AND VISION (LONDON, ENGLAND) 2023; 10:46. [PMID: 38037146 PMCID: PMC10691129 DOI: 10.1186/s40662-023-00365-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/26/2023] [Indexed: 12/02/2023]
Abstract
BACKGROUND The shape and microstructure of the human crystalline lens alter with ageing, and this has an effect on the optical properties of the eye. The aim of this study was to characterise the age-related differences in the morphology and transparency of the eye lenses of healthy subjects through the optical signal discontinuity (OSD) zones in optical coherence tomography (OCT) images. We also investigated the association of those changes with the optical quality of the eye and visual function. METHODS OCT images of the anterior segment of 49 eyes of subjects (9-78 years) were acquired, and the OSD zones (nucleus, C1-C4 cortical zones) were identified. Central thickness, curvature and optical density were measured. The eye's optical quality was evaluated by the objective scatter index (OSI). Contrast sensitivity and visual acuity tests were performed. The correlation between extracted parameters and age was assessed. RESULTS The increase in lens thickness with age was dominated by the thickening of the cortical zone C3 (0.0146 mm/year). The curvature radii of the anterior lens surface and both anterior and posterior nucleo-cortical interfaces decreased with age (- 0.053 mm/year, - 0.013 mm/year and - 0.006 mm/year, respectively), and no change was observed for the posterior lens radius. OCT-based densitometry revealed significant correlations with age for all zones except for C1β, and the highest increase in density was in the C2-C4 zones (R = 0.45, 0.74, 0.56, respectively, P < 0.001). Increase in OSI was associated with the degradation of visual function. CONCLUSIONS OCT enables the identification of OSD zones of the crystalline lens. The most significant age-related changes occur in the C3 zone as it thickens with age at a faster rate and becomes more opaque than other OSD zones. The changes are associated with optical quality deterioration and reduction of visual performance. These findings contribute to a better understanding of the structure-function relationship of the ageing lens and offer insights into both pathological and aging alterations.
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Affiliation(s)
- Ashish Gupta
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland
| | - Daniel Ruminski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland
| | - Alfonso Jimenez Villar
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland
| | - Raúl Duarte Toledo
- Laboratorio de Óptica, Centro de Investigación en Óptica y Nanofísica, Universidad de Murcia, Edif. CIOyN, N º34, Campus de Espinardo, 30100, Murcia, Spain
| | - Grzegorz Gondek
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland
| | - Barbara Pierscionek
- Faculty of Health, Education, Medicine, and Social Care, Medical Technology Research Center, Chelmsford Campus, Anglia Ruskin University, Bishop Hall Ln, Chelmsford, CM1 1SQ, UK
| | - Pablo Artal
- Laboratorio de Óptica, Centro de Investigación en Óptica y Nanofísica, Universidad de Murcia, Edif. CIOyN, N º34, Campus de Espinardo, 30100, Murcia, Spain
| | - Ireneusz Grulkowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland.
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Arad T, Awiszus L, Ackermann H, Schmack I, Kohnen T. Anterior Segment Biometry in a Caucasian Population with Cataracts. Curr Eye Res 2023; 48:930-938. [PMID: 37408497 DOI: 10.1080/02713683.2023.2233119] [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: 11/01/2022] [Accepted: 06/30/2023] [Indexed: 07/07/2023]
Abstract
PURPOSE To investigate biometric factors of the anterior segment of phakic eyes with cataracts. METHODS This population-based study included Caucasian patients with cataracts in the University Eye Hospital, Goethe University Frankfurt, Germany. Biometric parameters were measured using the swept-source optical coherence tomography method. Patients were grouped into intermediate stages based on decades of life. RESULTS In total, 6289 eyes of 3615 patients (age: 70.67 ± 8.42 years) were included. Age-related reductions in the anterior chamber depth (mean ± standard deviation) decreased from 3.26 ± 0.42 mm (group A: 55-59 years) to 2.94 ± 0.4 mm (group G: 85-89 years), and those in the axial length decreased from 24.37 ± 1.87 mm (group A) to 23.39 ± 1.07 mm (group G). Likewise, the white-to-white distance decreased from 12.12 ± 0.48 mm (group A) to 11.96 ± 0.47 mm (group G). Lens thickness tended to increase accordingly from 4.39 ± 0.36 µm (group A) to 4.9 ± 0.40 µm (group G). A comparison of the eyes showed no detectable lateral difference regarding the biometric parameters between the groups (axial length: p = 0.26, Rosenthal effect size = 0.03; lens thickness: p = 0.12, R = 0.03; anterior chamber depth: p = 0.63, Rosenthal effect size = 0.01). The axial length and anterior chamber depth differed significantly between sexes (r = 0.22, p < 0.0001 and r = 0.16, p < 0.0001, respectively). Multiple regression analysis of the anterior chamber depth as a function of biometry parameters as well as age and sex additionally indicated a positive correlation of anterior chamber depth with white-to-white distance (b = 0.32, p = 10-5), axial length (b = 0.10, p = 10-5), keratometry (b = 0.07, p = 10-5), and lens thickness (b=-0.05, p = 10-5) with a high effect size (Cohen f2=1.866, p = 10-5) and strong multiple correlation coefficient (Rosenthal effect size = 0.80, p = 10-5). CONCLUSIONS In the anterior segment, there are age- and sex-dependent changes in biometric parameters. In addition, changes in anterior chamber depth were noted in relation to white-to-white distance, axial length, keratometry, and lens thickness. These data should be considered in lens calculation formulas.
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Affiliation(s)
- Tschingis Arad
- Department of Ophthalmology, Goethe University, Frankfurt, Germany
| | - Lucas Awiszus
- Department of Ophthalmology, Goethe University, Frankfurt, Germany
| | - Hanns Ackermann
- Institute for Biostatistics, Goethe University, Frankfurt, Germany
| | - Ingo Schmack
- Department of Ophthalmology, Goethe University, Frankfurt, Germany
| | - Thomas Kohnen
- Department of Ophthalmology, Goethe University, Frankfurt, Germany
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Naujokaitis T, Auffarth GU, Łabuz G, Kessler LJ, Khoramnia R. Diagnostic Techniques to Increase the Safety of Phakic Intraocular Lenses. Diagnostics (Basel) 2023; 13:2503. [PMID: 37568866 PMCID: PMC10417808 DOI: 10.3390/diagnostics13152503] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/25/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Preoperative and postoperative diagnostics play an important role in ensuring the safety of patients with phakic intraocular lenses (pIOLs). The risk of endothelial cell loss can be addressed by regularly measuring the endothelial cell density using specular microscopy and considering the endothelial cell loss rate and the endothelial reserve in accordance with the patient's age when deciding whether to explant a pIOL. The anterior chamber morphometrics, including the anterior chamber depth and the distance between the pIOL and the endothelium, measured using Scheimpflug tomography and anterior segment optical coherence tomography (AS-OCT), can help to assess the risk of the endothelial cell loss. In patients undergoing posterior chamber pIOL implantation, accurate prediction of the vault and its postoperative measurements using AS-OCT or Scheimpflug tomography are important when assessing the risk of anterior subcapsular cataract and secondary glaucoma. Novel approaches based on ultrasound biomicroscopy and AS-OCT have been proposed to increase the vault prediction accuracy and to identify eyes in which prediction errors are more likely. Careful patient selection and regular postoperative follow-up visits can reduce the complication risk and enable early intervention if a complication occurs.
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Affiliation(s)
| | | | | | | | - Ramin Khoramnia
- Department of Ophthalmology, University of Heidelberg, 69120 Heidelberg, Germany
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Chen K, Wu J, Zhao F, Wong C, Liu W, Li Z, Chen X, Lin J, Huang H, Zhang Z, Zhuo X, Xu L, Yu X, Wu X, Zhu Y, Wang N, Zhuo Y. Correlation between spherical equivalent and biometry parameters in adult Cynomolgus macaque. Exp Eye Res 2023:109545. [PMID: 37406955 DOI: 10.1016/j.exer.2023.109545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 06/06/2023] [Accepted: 06/18/2023] [Indexed: 07/07/2023]
Abstract
PURPOSE To characterize the distribution of refractive and ocular biometry parameters and analyze the effect factors of the refractive status in cynomolgus monkey colonies. METHODS A Population-based cross-sectional study was conducted in adult cynomolgus macaque colonies. Animals were anesthetized with Zoletil 50. Intraocular pressure was measured using the Icare tonometer. Cycloplegic refraction (three drops of 1% tropicamide) and corneal radius of curvature (CRC) were measured using an autorefractor. The spherical equivalent (SE) was calculated. Biometric measurements, including the anterior chamber depth (ACD), lens thickness (LT), and axial length (AL), were obtained by A-scan ultrasonography. The AL-to-CR ratio (AL/CRC) was calculated. Central corneal thickness (CCT) and choroidal thickness (ChT) were measured using the Heidelberg Spectralis HRA OCT. Multiple regression analysis was performed to explore the association between refraction and ocular biometry. RESULTS Among 263 cynomolgus monkeys (aged 5-26 years), which consisted of 520 eyes, 29.42% had hyperopia, 27.12% had emmetropia, 33.27% had mild-to-moderate myopia and 10.19% had high myopia. The mean SE was -1.27 ± 3.44 Diopters (D). The mean CRC, CCT, AL, and ChT was 5.70 ± 0.22 mm, 454.30 ± 32.40 μm, 18.76 ± 0.89 mm and 188.96 ± 38.19 μm, respectively. The LT was the thickest in the hyperopic eyes. CRC was the lowest, and CCT was the thickest in high myopic eyes. AL increased, while ChT decreased as SE decreased. For the SE variance, AL alone explained 40.5%; age, AL, and CRC together explained 57.5%. CONCLUSIONS The refractive characteristics and biometry parameters of cynomolgus monkeys are highly comparable to those of humans. AL, CRC, and ChT showed the similar variation tendency in cynomolguses when compared to humans. Cynomolgus monkeys with naturally-occurring refractive errors may be a good animal model for refractive studies.
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Affiliation(s)
- Kezhe Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Jian Wu
- Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Feng Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | | | - Wei Liu
- Huazhen Biosciences, Guangzhou, China
| | - Zhidong Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Xiaohong Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Junxiong Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Haishun Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | - Zhuoyu Zhang
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Xiaohua Zhuo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China
| | | | | | | | - Yingting Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China.
| | - Ningli Wang
- Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
| | - Yehong Zhuo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, 510060, China.
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10
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Cabeza-Gil I, Fabrice M, Begoña C, Marco R. Quantification of scleral changes during dynamic accommodation. Exp Eye Res 2023; 230:109441. [PMID: 36958428 DOI: 10.1016/j.exer.2023.109441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 01/11/2023] [Accepted: 03/16/2023] [Indexed: 03/25/2023]
Abstract
The mechanics of accommodation is a complex process that involves multiple intraocular ocular structures. Recent studies suggest that there is deformation of the sclera during accommodation that may also play a role in accommodation, influencing ciliary muscle contraction and contributing to the accommodative response. However, the type and magnitude of the deformations measured varies significantly across studies. We present high-resolution synchronous OCT measurements of the anterior sclera contour and thickness and lens thickness acquired in real-time during accommodative responses to 4D step stimuli. The lens thickness was used as an assessment of objective accommodation. No changes in nasal and temporal anterior scleral contour and scleral thickness were found during accommodation within the precision of our measurements. Our results demonstrate that there are no significant scleral deformations during accommodation.
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Affiliation(s)
- Iulen Cabeza-Gil
- Aragón Institute of Engineering Research (i3A), University of Zaragoza, Spain.
| | - Manns Fabrice
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL, USA
| | - Calvo Begoña
- Aragón Institute of Engineering Research (i3A), University of Zaragoza, Spain; Bioengineering, Biomaterials and Nanomedicine Networking Biomedical Research Centre (CIBER-BBN), Zaragoza, Spain
| | - Ruggeri Marco
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Biomedical Engineering, University of Miami College of Engineering, Coral Gables, FL, USA.
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11
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Kawahara A. Predicting Residual Astigmatism in Cataract Surgery. VISION (BASEL, SWITZERLAND) 2022; 6:vision6040070. [PMID: 36548932 PMCID: PMC9785719 DOI: 10.3390/vision6040070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/12/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022]
Abstract
The purpose of this review is to evaluate the prediction of postoperative residual astigmatism and to determine the best prediction method for astigmatism correction. In recent findings for residual astigmatism in non-toric monofocal intraocular lens (IOL) implanted eyes, vector analysis can be used to correctly evaluate residual astigmatism by decomposing it. In predicting residual astigmatism, the with-the-rule (WTR) and against-the-rule (ATR) astigmatism components can now be almost predicted. This may be due to advances in inspection equipment and surgical technique. However, there are still issues with the oblique astigmatism component. In addition, corneal astigmatism is the most important predictor of postoperative residual astigmatism, and other predictors, such as refractive astigmatism, age, and lens thickness, have also been mentioned. However, all but corneal astigmatism are questionable because of the possibility of confounding variables. Total corneal astigmatism is more accurate in predicting residual astigmatism than anterior corneal astigmatism. Several predictions of residual astigmatism have been reported, but complete prediction has not been possible. Further research is needed, especially in predicting oblique astigmatism. However, I emphasize that the accuracy of predicting WTR and ATR astigmatism has improved considerably and can be predicted using regression equations with total corneal astigmatism.
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Schoeneberger V, Menghesha L, Gerlach S, Gietzelt C, Eberhardt S, Cursiefen C, Schaub F. Lens status and degree of lens opacity influence laser flare photometry (objective tyndallometry). Eur J Ophthalmol 2022; 33:11206721221137169. [PMID: 36348627 DOI: 10.1177/11206721221137169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2024]
Abstract
PURPOSE Objective tyndallometry using laser flare photometry can be utilized e.g., in management of uveitis. Previous studies showed a significant difference in flare values between pseudophakic and phakic eyes. We investigate a potential association between the degree of lens opacification and flare value in a large cohort phakic eyes. METHODS Retrospective, non-interventional single center study. Laser flare values of 460 healthy fellow eyes from two large cohorts (primary rhegmatogenous retinal detachment (RRD), macular holes (MH)) were correlated with lens status, degree of lens opacity, and age. RESULTS Out of 460 patients (mean age 64.6 ± 11.2, 57% male) 30.4% were pseudophakic (70.2 ± 10.9) and 69.6% phakic, of which 47.8% showed a clear lens (57.3 ± 9.1), 43.2% an mild cataract (65.2 ± 9.0) and 9.0% a moderate cataract (73.5 ± 9.0).In pseudophakia, flare (8.14 ± 4.6 pc/ms) was significantly higher compared to phakia (6.4 ± 3.9 pc/ms; p < 0.001). In phakic eyes, flare values increased significantly with increasing lens opacity (clear lens 5.3 ± 2.8 pc/ms; mild cataract 7.0 ± 4.0 pc/ms; moderate cataract 9.5 ± 6.1 pc/ms; p < 0.001). In clear lenses and mild cataract, age correlated significantly with flare (two-sided, p < 0.001, clear lenses R = 0.3; mild cataract R = 0.4). In clear lenses, flare values increased with age by 0.09 per year, in mild cataract by 0.17 (regression coefficients). No significant correlation was found between age and flare value in moderate cataract and pseudophakic eyes. CONCLUSION The level of objective tyndallometry seems to be dependent on lens status, degree of lens opacity and age. These factors should therefore be taken into account when interpreting laser flare values in the future.
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Affiliation(s)
- Verena Schoeneberger
- Department of Ophthalmology, 27182Medical Faculty and University Hospital of Cologne, 14309University of Cologne, Cologne, Germany
| | - Leonie Menghesha
- Department of Ophthalmology, 27182Medical Faculty and University Hospital of Cologne, 14309University of Cologne, Cologne, Germany
| | - Stefanie Gerlach
- Department of Ophthalmology, 27182Medical Faculty and University Hospital of Cologne, 14309University of Cologne, Cologne, Germany
| | - Caroline Gietzelt
- Department of Ophthalmology, 27182Medical Faculty and University Hospital of Cologne, 14309University of Cologne, Cologne, Germany
| | - Somaie Eberhardt
- Department of Ophthalmology, 27182Medical Faculty and University Hospital of Cologne, 14309University of Cologne, Cologne, Germany
| | - Claus Cursiefen
- Department of Ophthalmology, 27182Medical Faculty and University Hospital of Cologne, 14309University of Cologne, Cologne, Germany
| | - Friederike Schaub
- Department of Ophthalmology, 27182Medical Faculty and University Hospital of Cologne, 14309University of Cologne, Cologne, Germany
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13
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Amorim AR, Bret B, González-Méijome JM. Opto-Mechanical Eye Models, a Review on Human Vision Applications and Perspectives for Use in Industry. SENSORS (BASEL, SWITZERLAND) 2022; 22:7686. [PMID: 36236784 PMCID: PMC9573708 DOI: 10.3390/s22197686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/22/2022] [Accepted: 06/25/2022] [Indexed: 06/16/2023]
Abstract
The purpose of this review is to aggregate technical information on existent optomechanical eye models (OME) described in the literature, for image quality assessment in different applications. Several physical eye models have been reviewed from peer-reviewed papers and patent applications. A typical eye model includes an artificial cornea, an intraocular lens or other lens to simulate the crystalline lens, an aperture as the pupil, and a posterior retinal surface, which may be connected to a light sensor. The interior of the eye model may be filled with a fluid to better emulate physiological conditions. The main focus of this review is the materials and physical characteristics used and the dimensional aspects of the main components including lenses, apertures, chambers, imaging sensors and filling medium. Various devices are described with their applications and technical details, which are systematically tabulated highlighting their main characteristics and applications. The models presented are detailed and discussed individually, and the features of different models are compared when applicable, highlighting strengths and limitations. In the end there is a brief discussion about the potential use of artificial eye models for industrial applications.
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Affiliation(s)
- André Rino Amorim
- Clinical and Experimental Optometry Research Lab, Center of Physics, University of Minho, 4710-057 Braga, Portugal
| | - Boris Bret
- Bosch Car Multimedia Portugal, S.A., 4705-285 Braga, Portugal
| | - José M. González-Méijome
- Clinical and Experimental Optometry Research Lab, Center of Physics, University of Minho, 4710-057 Braga, Portugal
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14
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Mehta SK, Mir T, Freedman IG, Sheth AH, Sarrafpour S, Liu J, Teng CC. Emergency Department Presentations of Acute Primary Angle Closure in the United States from 2008 to 2017. Clin Ophthalmol 2022; 16:2341-2351. [PMID: 35924186 PMCID: PMC9342660 DOI: 10.2147/opth.s368453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 07/11/2022] [Indexed: 12/04/2022] Open
Abstract
Purpose Acute primary angle closure (APAC) is an ophthalmologic emergency. Nationwide data on the epidemiology and clinical characteristics of APAC are lacking despite the associated visual morbidity. Patients and Methods A retrospective cross-sectional study using the Nationwide Emergency Department Sample (NEDS). The NEDS was queried by ICD-9/10 code for cases of APAC presenting to the United States emergency departments over a ten-year period from 2008 to 2017. All identified cases were included to produce nationally representative estimates. Linear regression and seasonality tests were used to identify trends. Reported outcomes include the incidence, demographics, seasonality, and economic impact of APAC regionally and nationwide. Results A total of 23,203 APAC-related ED visits were identified. The mean (SD) and median ages were 58.8 (16.2) and 60 years, respectively. Females (59.4%, p < 0.01), those in the lowest income quartile (6983, 30.1%, p < 0.01), and those in the seventh decade of life (5599, 24.1%) presented more frequently with APAC. The incidence of ED presentations within each age group rose with age and increased significantly over the study period (p < 0.01). The Northeast region had the highest average incidence (0.93 per 100,000 population). Significant seasonal variation was seen regionally and nationally (p < 0.01), with the highest average incidence in December and lowest in April. Median inflation adjusted charge per ED visit was $2496.10, and the total inflation adjusted charges equaled $101.5 million. Conclusion The incidence of APAC-related ED visits continues to rise in the United States. High-risk groups include women, individuals of low socioeconomic status, and those between ages 50 and 70. Significant seasonal and regional trends were observed in ED presentations of APAC.
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Affiliation(s)
- Sumarth K Mehta
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT, USA
- Correspondence: Sumarth K Mehta, Department of Ophthalmology and Visual Science, Yale School of Medicine, 40 Temple Street, New Haven, CT, 06510, USA, Tel +1 203-785-2020, Email
| | - Tahreem Mir
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT, USA
| | - Isaac G Freedman
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT, USA
| | - Amar H Sheth
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT, USA
| | - Soshian Sarrafpour
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT, USA
| | - Ji Liu
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT, USA
| | - Christopher C Teng
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT, USA
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15
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Novel surgical technique of sutureless artificial iris and intraocular lens scleral fixation using Yamane technique. Am J Ophthalmol Case Rep 2022; 26:101502. [PMID: 35387386 PMCID: PMC8978273 DOI: 10.1016/j.ajoc.2022.101502] [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] [Received: 08/12/2021] [Revised: 03/16/2022] [Accepted: 03/20/2022] [Indexed: 11/21/2022] Open
Abstract
Purpose To describe a novel surgical technique of a combined implantation of an artificial iris and a scleral fixated intraocular lens (IOL) using flanged IOL haptics (“Yamane” technique). Observations The suturelessly implanted artificial iris-IOL-sandwich was stable with good functional as well as aesthetic results. However, our case showed a postoperative intraocular pressure rise. Conclusions The presented case demonstrates that a visual as well as cosmetical rehabilitation seems to be possible even after severe, penetrating ocular trauma with profound iris defects. Importance The sutureless IOL scleral fixation technique can also be used in combination with a sutureless artificial iris implantation. Further studies are needed to evaluate the long-term safety profile and rates of postoperative complications.
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16
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Espinosa J, Pérez J, Villanueva A. Prediction of Subjective Refraction From Anterior Corneal Surface, Eye Lengths, and Age Using Machine Learning Algorithms. Transl Vis Sci Technol 2022; 11:8. [PMID: 35404439 PMCID: PMC9034724 DOI: 10.1167/tvst.11.4.8] [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: 11/24/2022] Open
Abstract
Purpose To develop a machine learning regression model of subjective refractive prescription from minimum ocular biometry and corneal topography features. Methods Anterior corneal surface parameters (Zernike coefficients and keratometry), axial length, anterior chamber depth, and age were posed as features to predict subjective refractions. Measurements from 355 eyes were split into training (75%) and test (25%) sets. Different machine learning regression algorithms were trained by 10-fold cross-validation, optimized, and tested. A neighborhood component analysis provided features’ normalized weights in predictions. Results Gaussian process regression algorithms provided the best models with mean absolute errors of around 1.00 diopters (D) in the spherical component and 0.15 D in the astigmatic components. Conclusions The normalized weights showed that subjective refraction can be predicted by only keratometry, age, and axial length. Increasing the topographic description detail of the anterior corneal surface implied by a high-order Zernike decomposition versus adjustment to a spherocylindrical surface is not reflected as improved subjective refraction prediction, which is poor, mainly in the spherical component. However, the highest achievable accuracy differs by only 0.75 D from that of other works with a more exhaustive eye refractive elements description. Although the chosen parameters may have not been the most efficient, applying machine learning and big data to predict subjective refraction can be risky and impractical when evaluating a particular subject at statistical extremes. Translational Relevance This work evaluates subjective refraction prediction by machine learning from the anterior corneal surface and ocular biometry. It shows the minimum biometric information required and the highest achievable accuracy. RESUMEN Objetivo El desarrollo de un modelo de regresión de aprendizaje automático prescripción refractiva subjetiva a partir de las características mínimas de la biometría ocular y la superficie corneal. Métodos Los parámetros de la superficie corneal anterior (coeficientes de Zernike y queratometría), además de longitudes axiales y de cámara anterior, edades y las refracciones subjetivas no ciclopléjicas de 355 ojos se dividieron en un conjunto de entrenamiento (75%) y otro de test (25%) y se entrenaron diferentes algoritmos de regresión de aprendizaje automático mediante validación cruzada 10 veces, se optimizaron y se probaron sobre el conjunto test. Resultados Los algoritmos de regresión del proceso gaussiano proporcionaron los mejores modelos con un error absoluto medio fue de alrededor de 1.00 D en el componente esférico y de 0.25 D en los componentes astigmáticos. Conclusiones Los pesos normalizados mostraron que la refracción subjetiva puede predecirse utilizando únicamente la queratometría, la edad y la longitud axial como características. El aumento del detalle de la descripción topográfica de la superficie corneal anterior que supone una descomposición de Zernike de alto orden frente al ajuste a una superficie esferocilíndrica realizado por queratometría no se refleja en una mejora de la predicción de la refracción subjetiva, que es pobre, en cualquier caso, principalmente en el componente esférico. Sin embargo, la máxima precisión alcanzada difiere en sólo 0,75 D de la de otros trabajos con una descripción más exhaustiva de los elementos refractivos del ojo. De todos modos, el aprendizaje automático y los datos masivos aplicados a la predicción de la refracción subjetiva pueden ser arriesgados y poco prácticos cuando se evalúa a un sujeto concreto en los extremos estadísticos, aunque los parámetros elegidos puedan no haber sido los más ineficaces. Relevancia Traslativa El trabajo evalúa la predicción de la refracción subjetiva mediante aprendizaje automático a partir de la superficie corneal anterior y la biometría ocular, mostrando la mínima información biométrica requerida y la máxima precisión alcanzable.
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Affiliation(s)
- Julián Espinosa
- IUFACyT, Universidad de Alicante, San Vicente del Raspeig, Spain.,Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, San Vicente del Raspeig, Spain
| | - Jorge Pérez
- IUFACyT, Universidad de Alicante, San Vicente del Raspeig, Spain.,Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, San Vicente del Raspeig, Spain
| | - Asier Villanueva
- IUFACyT, Universidad de Alicante, San Vicente del Raspeig, Spain
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17
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Li L, Zhang B, Wang Z. Comparison of accommodation and accommodative micro-fluctuation after implantable collamer lens and LASIK surgery for myopia. BMC Ophthalmol 2022; 22:8. [PMID: 34983448 PMCID: PMC8725356 DOI: 10.1186/s12886-021-02217-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 12/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To longitudinally analyze and compare the accommodative micro-fluctuation (MFs) and accommodative function between myopic patients after implantable collamer lens (ICL) implantation and laser in situ keratomileusis (LASIK). METHODS Patients with good corrected visual acuity (20/20 or better) and underwent ICL (V4c) and LASIK for myopic-correction (ranging from - 3.50 to - 8.50 D) were recruited. Refraction, amplitude of accommodation (AMP), accommodative lag, higher-order aberration (HOA), and MFs were recorded before surgery and 1 and 3 months after surgery. The ACOMEREF automatic refractor was used to measure the high-frequency component (HFC) of the MFs, which suggested tension of the ciliary muscle. RESULTS The study comprised 120 eyes. At 3 months after surgery, the manifest refractive spherical equivalent of the ICL and LASIK groups were - 0.11 and - 0.09 D, respectively (p = 0.46). HFC values were significantly higher at 1 month (p = 0.03) and 3 months postoperatively (p = 0.03) in the ICL group compared to that in the LASIK group. The ocular HOA of the ICL group was 1.08 ± 0.43 μm, which was lower than the LASIK group 1.45 ± 0.54 μm (p = 0.01). No significant differences in AMP and accommodative lag between groups were noted at 3 months postoperatively. There was a positive correlation between HFC and vault of the ICL lens (r2 = 0.14, p = 0.005). There were no correlations between HFC and ocular HOA and postoperative MRSE in the two groups (all p>0.05). CONCLUSIONS The HFC increased significantly after an early period of ICL implantation compared to laser in situ keratomileusis for myopic correction, which indicated increased tension of the ciliary muscle, and had a positive correlation on the vault of the ICL lens; However, studies with longer follow-up time and more structural evaluation are needed.
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Affiliation(s)
- Li Li
- Aier School of Ophthalmology, Central South University, Fourth Floor, New Century Mansion, 198 Middle Furong Road, Changsha, China.,Department of Refractive Surgery, Guangzhou Aier Eye Hospital, Guangzhou, China.,Chongqing Eye and Vision Care Hospital, Chongqing, China.,Aier Institute of Refractive Surgery, Aier Eye Hospital Group, Changsha, China
| | - Bo Zhang
- Department of Refractive Surgery, Guangzhou Aier Eye Hospital, Guangzhou, China.,Aier Institute of Refractive Surgery, Aier Eye Hospital Group, Changsha, China
| | - Zheng Wang
- Aier School of Ophthalmology, Central South University, Fourth Floor, New Century Mansion, 198 Middle Furong Road, Changsha, China. .,Department of Refractive Surgery, Guangzhou Aier Eye Hospital, Guangzhou, China. .,Aier Institute of Refractive Surgery, Aier Eye Hospital Group, Changsha, China.
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18
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Bajtl D, Bjeloš M, Bušić M, Križanović A, Marković L, Kuzmanović Elabjer B. Macular perfusion normative data acquired with optical coherence tomography angiography in healthy four-year-old Caucasian children. BMC Ophthalmol 2021; 21:354. [PMID: 34610816 PMCID: PMC8491392 DOI: 10.1186/s12886-021-02122-y] [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] [Received: 03/11/2021] [Accepted: 09/28/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The purpose of this cross-sectional study involving healthy emmetropic four-year-old Caucasian children was to provide a macular perfusion normative database acquired with optical coherence tomography angiography (OCTA). One eye of each examinee underwent OCTA imaging. The following parameters were analyzed using AngioTool Image J software: vessels area (VA), vessels density (VD), total number of junctions (TNJ), junctions density (JD), total vessel length (TVL), average vessel length (AVL), total number of endpoints (TNEP), lacunarity (L), vessel diameter index (VDI), tortuosity (T) and foveal avascular zone (FAZ). Average central macular thickness (CMT) and average central macular volume (CMV) were measured. RESULT Sixty-two eyes of 62 children of average age 50.4 ± 3.8 months were examined. VA, VD, and T increased from the inner towards the outer layers of the retina. The intermediate capillary plexus had the highest JD and TNEP and narrowest FAZ. Retinal sexual differentiation was supported with higher values of the retinal VA, VDI and TNEP, and chorioretinal VA, VDI and L in males. The choriocapillaris presented with the highest VD, AVL, and T and the lowest L and TNEP. CONCLUSION The study provides the first detailed normative database of the macular vascular network in the youngest uniform cohort of emmetropic four-year-old children.
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Affiliation(s)
- Dunja Bajtl
- University Eye Department, University Hospital Centre Osijek, Osijek, Croatia
| | - Mirjana Bjeloš
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia. .,University Eye Department, University Hospital "Sveti Duh", Sveti Duh 64, 10 000, Zagreb, Croatia. .,Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.
| | - Mladen Bušić
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.,University Eye Department, University Hospital "Sveti Duh", Sveti Duh 64, 10 000, Zagreb, Croatia.,Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Ana Križanović
- University Eye Department, University Hospital "Sveti Duh", Sveti Duh 64, 10 000, Zagreb, Croatia.,Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Leon Marković
- University Eye Department, University Hospital "Sveti Duh", Sveti Duh 64, 10 000, Zagreb, Croatia.,Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Biljana Kuzmanović Elabjer
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia.,University Eye Department, University Hospital "Sveti Duh", Sveti Duh 64, 10 000, Zagreb, Croatia.,Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
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19
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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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20
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Biometry, Refractive Errors, and the Results of Cataract Surgery: A Large Sample Study. J Ophthalmol 2021; 2021:9918763. [PMID: 34007484 PMCID: PMC8099509 DOI: 10.1155/2021/9918763] [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] [Received: 03/12/2021] [Accepted: 04/09/2021] [Indexed: 11/18/2022] Open
Abstract
The statistical characteristics of biometry and refractive error in a large sample of cataractous Cuban patients are presented, comparing between sexes and age groups. All patients were studied at the Cuban Institute of Ophthalmology “Ramón Pando Ferrer,” La Habana. The sample consists of 28252 eyes of 25068 patients, subjected to cataract surgery during the time period between 2006 and 2019. Their biometry was obtained using IOL Master devices; also, visual acuity, refraction, and corneal power were registered. After surgery, the visual acuity and refraction were measured. The refractive prediction error was determined. For patients with both eyes registered, anisometropia was also calculated. Age and sex were used to segment the data. The preoperative biometric parameters show highly significant differences between sexes, with male eyes being longer and with a deeper anterior chamber but with a thinner lens. Also, keratometry shows highly significant differences, with female eyes being steeper than male. Before surgery, both sexes have myopic eyes as average, with males being more myopic than females (p < 0.001). After surgery, the average spherical equivalent is −0.36 D and female eyes are more myopic than males (p < 0.001). Visual acuity with and without distance correction has a significant increase after surgery. These results are of importance not only for Cuba but also for other countries with a large Cuban population and/or similar ethnic composition, such as the USA (particularly the south of Florida), Spain, and many countries in Latin America.
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21
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Popov I, Waczulikova I, Stefanickova J, Valaskova J, Tomcikova D, Shiwani HA, Delev D, Rodrigo L, Saxena S, Kruzliak P, Krasnik V. Analysis of biometric parameters of 2340 eyes measured with optical biometer Lenstar LS900 in a Caucasian population. Eur J Ophthalmol 2021; 32:213-220. [PMID: 33653160 DOI: 10.1177/1120672121998920] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To describe the pattern and mutual relationships between basic biometric characteristics of the eye in a Central European Caucasian population. METHODS A single-centre retrospective study of 2340 patients (965 males, 1375 females) scheduled for cataract surgery between 2014 and 2016. Measurements using laser interferometry included AL (axial length), K (average corneal curvature), ACD (anterior chamber depth), LT (lens thickness), CCT (central corneal thickness), AST (astigmatism) and WTW (white to white). Subjects were stratified by gender and controlled for age. Descriptive, correlation and regression analyses were performed on the data. RESULTS The mean AL was 23.33 ± 1.01 mm - higher in males (23.59 ± 0.99 mm), in comparison to females (23.15 ± 0.99 mm). The elderly had lower ACD and higher LT, while males had higher AL independent of age. Furthermore, LT and K decreased with AL, while ACD decreased with LT and increased with AL independent of age and gender. CONCLUSIONS The estimates of the biometrics are obtained on a large sample of subjects and can serve as normative values for Lenstar LS900 in the Central European Caucasian population.
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Affiliation(s)
- Ivajlo Popov
- Department of Ophthalmology, Faculty of Medicine, Comenius University and University Hospital, Bratislava, Slovakia
| | - Iveta Waczulikova
- Faculty of Mathematics, Physics and Informatics, Comenius University, Bratislava, Slovakia
| | - Jana Stefanickova
- Department of Ophthalmology, Faculty of Medicine, Comenius University and University Hospital, Bratislava, Slovakia
| | - Jela Valaskova
- Department of Ophthalmology, Faculty of Medicine, Comenius University and University Hospital, Bratislava, Slovakia
| | - Dana Tomcikova
- Department of Pediatric Ophthalmology, Faculty of Medicine, Comenius University and University Hospital, Bratislava, Slovakia
| | - Haaris A Shiwani
- Royal Lancaster Infirmary, University Hospitals of Morecambe Bay NHS Foundation Trust, Lancaster, UK
| | - Delian Delev
- Department of Pharmacology and Clinical Pharmacology, Faculty of Medicine, Medical University of Plovdiv, Plovdiv, Bulgaria
| | - Luis Rodrigo
- Faculty of Medicine, University of Oviedo, Central University Hospital of Asturias (HUCA), Oviedo, Spain
| | - Sandeep Saxena
- Department of Ophthalmology, King George's Medical University, Lucknow, Uttar Pradesh, India
| | - Peter Kruzliak
- Department of Internal Medicine, Brothers of Mercy Hospital, Brno, Czech Republic
| | - Vladimir Krasnik
- Department of Ophthalmology, Faculty of Medicine, Comenius University and University Hospital, Bratislava, Slovakia
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Koç Ş, Baysal SS. Heart aging when near vision difficulty begins. Aging Male 2020; 23:1346-1354. [PMID: 32449445 DOI: 10.1080/13685538.2020.1766438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
OBJECTIVES Heart, lens, and neuronal cells change significantly with age, and they are older than cells from renewable tissues. Near vision deterioration during aging results from a decrease in accommodation amplitude (AA). Cardiac aging is an independent risk factor for cardiovascular disease. We investigated the association between cardiac aging and AA. METHODS The subjects (500 mean 50-year-old subjects, with equal males and females) were divided into two groups according to AA measured with a Raf ruler. Biomicroscopy was used to capture images of the lens nucleus in the unaccommodated and accommodated state. The nucleus diameter change at 1 D accommodation was measured using ImageJ. Cardiac conduction system differences were evaluated using electrocardiography, and cardiac autonomic aging was assessed based on heart rate variability. Myocardial aging was assessed based on diastolic dysfunction. RESULTS For near distance vision, compared to subjects who could see clearly from 24 to 28 cm, subjects who could see clearly from 29 to 33 cm had a 2.104-fold higher risk of a lateral e' velocity <10 cm/s [95%CI: 1.312-3.374], 2.603-fold higher risk of diastolic dysfunction [95%CI: 1.453-4.662], 1.54-fold higher risk of a low/high frequency ratio >3.1 [95%CI: 1.085-2.197]. CONCLUSIONS As a simple screening test, subjective AA measurement can predict important heart aging parameters, including diastolic dysfunction. CLINICALTRIALS.GOV REGISTRY NO NCT04362215.
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Affiliation(s)
- Şahbender Koç
- Keçiören Education and Training Hospital, Unıversity of Health Sciences, Ankara, Turkey
| | - Sadettin Selçuk Baysal
- Mehmet Akif İnan Education and Training Hospital, Unıversity of Health Sciences, Urfa, Turkey
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Morphometric analysis of the lens in human aniridia and mouse Small eye. Exp Eye Res 2020; 203:108371. [PMID: 33248069 DOI: 10.1016/j.exer.2020.108371] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/17/2020] [Accepted: 11/22/2020] [Indexed: 12/16/2022]
Abstract
Congenital aniridia is caused by heterozygous mutations in the PAX6 gene. In this disease, congenital iris and foveal hypoplasia is associated with juvenile onset cataract, glaucoma, and corneal keratopathy. In rodents, Pax6 mutations result in a congenital reduction in ocular size that is not typically described in human aniridia. Here, the ocular morphometry of aniridia patients is compared with the lens phenotype of Pax6+/tm1/Pgr mice to reveal whether there are species differences in Pax6 regulation of lens development and homeostasis. Ultrasound biometry (UBM) revealed that eleven percent of aniridia patients exhibited mild microphthalmia while the anterior chamber depth of aniridic eyes was significantly reduced from 6 months of age onward. Although aniridic lens thickness was normal from birth, it was significantly decreased in aniridic lenses older than 30. Notably, 86% of aniridic lenses exhibited cataractous changes in this cohort. In addition, a significant proportion of aniridia patients develop lens subluxation as they age associated with reduced lens diameter as measured by anterior segment optical coherence tomography (AS-OCT). Analysis of young adult Pax6+/tm1/Pgr mouse lenses by micro-computed tomography (microCT), bright field and dark field imaging revealed that they are reduced in size but did not exhibit overt cataracts at this age. Overall, this study reveals that congenital microphthalmia as assessed by axial length, or microphakia, as assessed by lens thickness, are not typical in human aniridia, although these are primary manifestations of Pax6 mutations in mice, suggesting that PAX6 regulates some aspects of lens development differently between these species.
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Numerical model to predict and compare the hypotensive efficacy and safety of minimally invasive glaucoma surgery devices. PLoS One 2020; 15:e0239324. [PMID: 32991588 PMCID: PMC7523982 DOI: 10.1371/journal.pone.0239324] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 09/04/2020] [Indexed: 12/25/2022] Open
Abstract
Purpose To predict and compare the hypotensive efficacy of three minimally-invasive glaucoma surgery (MIGS) implants through a numerical model. Methods Post-implant hypotensive efficacy was evaluated by using a numerical model and a computational fluid dynamics simulation. Three different devices were compared: the XEN 45 stent (tube diameter, 45 μm), the XEN 63 stent (63 μm) and the PreserFlo microshunt (70 μm). The influence of the filtration bleb pressure (Bp) and tube diameter, length, and position within the anterior chamber (AC) on intraocular pressure (IOP) were evaluated. Results Using baseline IOPs of 25, 30 and 50 mmHg, respectively, the corresponding computed post-implant IOPs for each device were as follows: XEN 45: 17 mmHg (29% decrease), 19 mmHg (45%) and 20 mmHg (59%) respectively; XEN 63: 13 mmHg (48%), 13 mmHg (62%), and 13 mmHg (73%); PreserFlo: 12 mmHg (59%), 13 mmHg (73%) and 13 mmHg (73%). At a baseline IOP of 35 mmHg with an increase in the outflow resistance within the Bp from 5 to 17 mmHg, the hypotensive efficacy for each device was reduced as follows: XEN45: 54% to 37%; XEN 63: 74% to 46%; and PreserFlo: 75% to 47%. The length and the position of the tube in the AC had only a minimal (non-significant) effect on IOP (<0.1 mmHg). Conclusions This hydrodynamic/numerical model showed that implant diameter and bleb pressure are the two most pertinent determinants of hypotensive efficacy. In distinction, tube length and position in the AC do not significantly influence IOP.
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Uzun F, Aslan MG, Öter K, Kaim M. The acute effects of single cup of coffee on ocular biometric parameters in healthy subjects. J Curr Ophthalmol 2019; 31:394-398. [PMID: 31844789 PMCID: PMC6896472 DOI: 10.1016/j.joco.2019.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 04/27/2019] [Accepted: 05/09/2019] [Indexed: 12/02/2022] Open
Abstract
Purpose To evaluate ocular biometric changes in healthy subjects after caffeine consumption from a cup of coffee. Methods A total of 36 subjects were included in this prospective observational study. Axial length (AL) and anterior segment parameters including aqueous depth (AD), anterior chamber depth (ACD), lens thickness (LT), and central corneal thickness (CCT) were measured with optic biometry, Lenstar LS 900 (Haag-Streit, Inc., Koeniz, Switzerland) before and 1 and 4 h after ingesting a cup of coffee (60 mg caffeine/100 mL). Results Mean age of the participants was 30.05 ± 7.43 years (range, 19–45). At baseline, 1st, and 4th hour, AL values were 23.9 ± 1.04 mm, 23.91 ± 1.04 mm, and 23.89 ± 1.04 mm, respectively, and no significant difference was observed (P>0.05). At baseline, 1st, and 4th hour, AD values were 3.06 ± 0.3 mm, 3.11 ± 0.3 mm, and 3.09 ± 0.3 mm, and ACD values were 3.6 ± 0.32, 3.66 ± 0.31, and 3.64 ± 0.31, respectively. AD and ACD values were significantly greater than baseline at 1st and 4th hours following coffee ingestion. Coffee intake caused a significant reduction in LT, compared with baseline and at the 1st and 4th hours which were 3.76 ± 0.28 mm, 3.69 ± 0.32 mm, and 3.72 ± 0.27 mm, respectively. No statistically significant difference was determined in between the 3 measurements in terms of CCT (P>0.05). Conclusion Caffeine causes a significant increase in AD and ACD and a significant decrease in LT following oral intake, for at least 4 h.
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Affiliation(s)
- Feyzahan Uzun
- Recep Tayyip Erdogan University Medical School, Department of Ophthalmology, Rize, Turkey
| | - Mehmet Gökhan Aslan
- Recep Tayyip Erdogan University Medical School, Department of Ophthalmology, Rize, Turkey
| | - Kamile Öter
- Recep Tayyip Erdogan University Medical School, Department of Ophthalmology, Rize, Turkey
| | - Muhammet Kaim
- Recep Tayyip Erdogan University Medical School, Department of Ophthalmology, Rize, Turkey
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Fukuda S, Ueno Y, Fujita A, Mori H, Tasaki K, Murakami T, Beheregaray S, Oshika T. Comparison of anterior segment and lens biometric measurements in patients with cataract. Graefes Arch Clin Exp Ophthalmol 2019; 258:137-146. [DOI: 10.1007/s00417-019-04482-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 09/02/2019] [Accepted: 09/13/2019] [Indexed: 11/28/2022] Open
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Galstian T, Asatryan K, Presniakov V, Zohrabyan A. Electrically variable liquid crystal lenses for ophthalmic distance accommodation. OPTICS EXPRESS 2019; 27:18803-18817. [PMID: 31252817 DOI: 10.1364/oe.27.018803] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/09/2019] [Indexed: 06/09/2023]
Abstract
We present the example of a specific design of an electrically tunable liquid crystal lens (TLCL) with floating electrode to analyze experimentally the potential of using TLCLs in intraocular implants. An optimized voltage-frequency driving technique is demonstrated to achieve high optical powers (up to 4 diopters) with very low aberrations (below 0.1μm) for an optical aperture of 3mm. In addition, the continuous character of distance accommodation and the absence of granularity across the aperture of the lens (pixel-free) make this component an excellent choice for various ophthalmic applications.
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Anterior chamber indices in a population-based study using the Pentacam. Int Ophthalmol 2018; 39:2033-2040. [PMID: 30382464 DOI: 10.1007/s10792-018-1037-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 10/26/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE To determine the distribution of anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA) values in a rural population over 5 years of age using the Pentacam. METHODS In this cross-sectional study, samples were selected from over 1-year-old inhabitants of two villages in Iran using a multistage cluster sampling approach. All participants underwent the measurement of uncorrected and corrected visual acuity and auto-refraction, retinoscopy, subjective refraction, and slit lamp examination. Finally, corneal imaging was done for all subjects over 5 years of age using the Pentacam. RESULTS Of 3851 selected individuals, 3314 participated in the study, of whom 2681 met the inclusion criteria. The mean age of the sample was 36.03 ± 18.5 years (range 6-90 years). The mean ACD, ACA, and ACV values were 3.37 mm (95% CI: 3.37-3.39), 34.82° (95% CI: 34.45-35.2), and 159.17 µL (95% CI: 156-161.36), respectively. The results of multiple linear regression models showed that ACD, ACA, and ACV values reduced with age, and ACD and ACV values were significantly higher in males. ACA and ACV values correlated inversely with central corneal thickness, while the ACA value correlated directly with keratometry and inversely with the ACV value. CONCLUSION This study is one of the few studies in the world showing changes in ACD values in different age groups using the Pentacam. According to the results, aging was associated with a decline in the mean ACD, ACA, and ACV values. These parameters were the largest in patients with emmetropia and smallest in hyperopic subjects.
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Optical Coherence Tomography Reveals Sigmoidal Crystalline Lens Changes during Accommodation. Vision (Basel) 2018; 2:vision2030033. [PMID: 31735896 PMCID: PMC6835499 DOI: 10.3390/vision2030033] [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] [Received: 07/20/2018] [Revised: 08/15/2018] [Accepted: 08/17/2018] [Indexed: 12/02/2022] Open
Abstract
This study aimed to quantify biometric modifications of the anterior segment (AS) during accommodation and to compare them against changes in both accommodative demand and response. Thirty adults, aged 18–25 years were rendered functionally emmetropic with contact lenses. AS optical coherence tomography (AS-OCT) images were captured along the 180° meridian (Visante, Zeiss Meditec, Jena, Germany) under stimulated accommodative demands (0–4 D). Images were analysed and lens thickness (LT) was measured, applying a refractive index correction of 1.00. Accommodative responses were also measured sequentially through a Badal optical system fitted to an autorefractor (Shin Nippon NVision-K 5001, Rexxam, Japan). Data were compared with Dubbelman schematic eye calculations. Significant changes occurred in LT, anterior chamber depth (ACD), lens centroid (i.e., ACD + LT/2), and AS length (ASL = ACD + LT) with accommodation (all p < 0.01). There was no significant change in CT with accommodation (p = 0.81). Measured CT, ACD, and lens centroid values were similar to Dubbelman modelled parameters, however AS-OCT overestimated LT and ASL. As expected, the accommodative response was less than the demand. Interestingly, up until approximately 1.5 D of response (2.0 D demand), the anterior crystalline lens surface appears to be the primary correlate. Beyond this point, the posterior lens surface moves posteriorly resulting in an over-all sigmoidal trajectory. he posterior crystalline lens surface demonstrates a sigmoidal response with increasing accommodative effort.
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Shao Y, Tao A, Jiang H, Shen M, Zhu D, Lu F, Karp CL, Ye Y, Wang J. Long scan depth optical coherence tomography on imaging accommodation: impact of enhanced axial resolution, signal-to-noise ratio and speed. EYE AND VISION (LONDON, ENGLAND) 2018; 5:16. [PMID: 30003116 PMCID: PMC6036665 DOI: 10.1186/s40662-018-0111-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/23/2018] [Indexed: 11/30/2022]
Abstract
BACKGROUND Spectral domain optical coherence tomography (SD-OCT) was a useful tool to study accommodation in human eye, but the maximum image depth is limited due to the decreased signal-to-noise ratio (SNR). In this study, improving optical resolutions, speeds and the SNR were achieved by custom built SD-OCT, and the evaluation of the impact of the improvement during accommodation was investigated. METHODS Three systems with different spectrometer designs, including two Charge Coupled Device (CCD) cameras and one Complementary Metal-Oxide-Semiconductor Transistor (CMOS) camera, were tested. We measured the point spread functions of a mirror at different positions to obtain the axial resolution and the SNR of three OCT systems powered with a light source with a 50 nm bandwidth, centered at a wavelength of 840 nm. Two normal subjects, aged 26 and 47, respectively, and one 75-year-old patient with an intraocular lens implanted were imaged. RESULTS The results indicated that spectrometers using cameras with 4096 camera pixels optimized the axial resolutions, due to the use of the full spectrum provided by the light source. The CCD camera system with 4096 pixels had the highest SNR and the best image quality. The system with the CMOS camera with 4096 pixels had the highest speed but had a compromised SNR compared to the CCD camera with 4096 pixels. CONCLUSIONS Using these three OCT systems, we imaged the anterior segment of the human eye before and after accommodation, which showed similar results among the different systems. The system using the CMOS camera with an ultra-long scan depth, high resolution and high scan speed exhibited the best overall performance and therefore was recommended for imaging real-time accommodation.
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Affiliation(s)
- Yilei Shao
- Bascom Palmer Eye Institute, University of Miami, Miami, FL USA
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Aizhu Tao
- Bascom Palmer Eye Institute, University of Miami, Miami, FL USA
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Hong Jiang
- Bascom Palmer Eye Institute, University of Miami, Miami, FL USA
| | - Meixiao Shen
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Dexi Zhu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Fan Lu
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Carol L. Karp
- Bascom Palmer Eye Institute, University of Miami, Miami, FL USA
| | - Yufeng Ye
- Bascom Palmer Eye Institute, University of Miami, Miami, FL USA
- Hangzhou First People’s Hospital, Hangzhou, China
| | - Jianhua Wang
- Bascom Palmer Eye Institute, University of Miami, Miami, FL USA
- Electrical and Computer Engineering, University of Miami, Miami, FL USA
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
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Khan A, Pope JM, Verkicharla PK, Suheimat M, Atchison DA. Change in human lens dimensions, lens refractive index distribution and ciliary body ring diameter with accommodation. BIOMEDICAL OPTICS EXPRESS 2018; 9. [PMID: 29541520 PMCID: PMC5846530 DOI: 10.1364/boe.9.001272] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We investigated changes in ciliary body ring diameter, lens dimensions and lens refractive index distributions with accommodation in young adults. A 3T clinical magnetic resonance imaging scanner imaged right eyes of 38 18-29 year old participants using a multiple spin echo sequence to determine accommodation-induced changes along lens axial and equatorial directions. Accommodation stimuli were approximately 1 D and 5 D. With accommodation, ciliary body ring diameter, and equatorial lens diameter decreased (-0.43 ± 0.31 mm and -0.30 ± 0.23 mm, respectively), and axial lens thickness increased ( + 0.34 ± 0.16 mm). Lens shape changes cause redistribution of the lens internal structure, leading to change in refractive index distribution profiles. With accommodation, in the axial direction refractive index profiles became flatter in the center and steeper near the periphery of the lens, while in the equatorial direction they became steeper in the center and flatter in the periphery. The results suggest that the anatomical accuracy of lens optical models can be improved by accounting for changes in the refractive index profile during accommodation.
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Affiliation(s)
- Adnan Khan
- Weill Cornell Medicine-Qatar, Education City, Qatar Foundation, Doha, Qatar and New York, USA
- Institute of Health & Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD, Australia
- School of Optometry & Vision Science, Queensland University of Technology, Kelvin Grove, QLD, Australia
| | - James M. Pope
- Institute of Health & Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD, Australia
- School of Chemistry, Physics & Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, Australia
| | - Pavan K. Verkicharla
- Institute of Health & Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD, Australia
- School of Optometry & Vision Science, Queensland University of Technology, Kelvin Grove, QLD, Australia
- Brien Holden Institute of Optometry and Vision Sciences, L V Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, India
| | - Marwan Suheimat
- Institute of Health & Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD, Australia
- School of Optometry & Vision Science, Queensland University of Technology, Kelvin Grove, QLD, Australia
| | - David A. Atchison
- Institute of Health & Biomedical Innovation, Queensland University of Technology, Kelvin Grove, QLD, Australia
- School of Optometry & Vision Science, Queensland University of Technology, Kelvin Grove, QLD, Australia
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Lee JH, Ryu GW, Park BG. Changes in Ocular Biometrics Measured after Implantation of a Phakic Intraocular Lens. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2018. [DOI: 10.3341/jkos.2018.59.3.223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Jung Hoo Lee
- Department of Ophthalmology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
| | | | - Byung Gun Park
- Department of Ophthalmology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea
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Ferrer-Blasco T, Esteve-Taboada JJ, Monsálvez-Romín D, Aloy MA, Adsuara JE, Cerdá-Durán P, Montés-Micó R. Ocular biometric changes with different accommodative stimuli using swept-source optical coherence tomography. Int Ophthalmol 2017; 39:303-310. [PMID: 29260498 DOI: 10.1007/s10792-017-0813-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/11/2017] [Indexed: 05/09/2023]
Abstract
PURPOSE To evaluate ocular biometric changes with different accommodative stimuli using a new swept-source optical biometer. METHODS Only the right eye was analyzed. Each subject was measured six times with the IOLMaster 700 swept-source optical biometer (Carl Zeiss Meditec, Jena, Germany) with the subject looking at the stimulus shown by the instrument and with the subject looking at a target placed outside the instrument at 0D of vergence. Axial length (AL), anterior chamber depth (ACD), central corneal thickness (CCT), lens thickness (LT), white-to-white (WTW), and keratometry readings (K1 and K2) were evaluated in both cases. To assess if the changes found may affect the intraocular (IOL) power calculation for surgical applications, we have applied some formulae, using the software provided by the optical biometer manufacturer, to the ocular parameters found in both situations for three different types of IOLs. RESULTS No statistically significant differences were found for AL, CCT, WTW, K1 and K2 between the subject looking at the stimulus of the biometer and looking at the outside target at 0D of vergence (p > 0.05). However, the measurement of ACD revealed a statistically significant reduction of 20 microns (p = 0.03) and, on the contrary, LT increased significantly 30 microns (p = 0.02). ACD and LT changes were highly correlated (R2 = 0.91). As for the IOL power calculation, in all cases, the mean change was lower than 0.25 D both for IOL power selection and residual refraction. CONCLUSIONS Although ACD and LT change significantly with different accommodative stimuli measured by swept-source optical biometry, these changes are not clinically relevant.
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Affiliation(s)
- Teresa Ferrer-Blasco
- Department of Optics and Optometry and Vision Sciences, University of Valencia, C/Dr. Moliner, 50, 46100, Burjassot, Spain
| | - José J Esteve-Taboada
- Department of Optics and Optometry and Vision Sciences, University of Valencia, C/Dr. Moliner, 50, 46100, Burjassot, Spain.
| | - Daniel Monsálvez-Romín
- Department of Optics and Optometry and Vision Sciences, University of Valencia, C/Dr. Moliner, 50, 46100, Burjassot, Spain
| | - Miguel A Aloy
- Department of Astronomy and Astrophysics, University of Valencia, C/Dr. Moliner, 50, 46100, Burjassot, Spain
| | - José E Adsuara
- Department of Astronomy and Astrophysics, University of Valencia, C/Dr. Moliner, 50, 46100, Burjassot, Spain
| | - Pablo Cerdá-Durán
- Department of Astronomy and Astrophysics, University of Valencia, C/Dr. Moliner, 50, 46100, Burjassot, Spain
| | - Robert Montés-Micó
- Department of Optics and Optometry and Vision Sciences, University of Valencia, C/Dr. Moliner, 50, 46100, Burjassot, Spain
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Mechanism of accommodation assessed by change in precisely registered ocular images associated with concurrent change in auto-refraction. Graefes Arch Clin Exp Ophthalmol 2017; 256:395-402. [PMID: 29147767 DOI: 10.1007/s00417-017-3843-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/27/2017] [Accepted: 11/04/2017] [Indexed: 10/18/2022] Open
Abstract
PURPOSE Our purpose was to determine the changes in anterior chamber depth (ACD) and central lens thickness (CLT) during pharmacologically induced accommodation. METHODS Following pupillary dilation with phenylephrine 10%, baseline auto-refractions and swept-source optical coherence tomographic biometric images (Zeiss IOLMaster 700) were obtained from the right eyes of 25 subjects aged 19 to 24 years. Pilocarpine 4% and phenylephrine 10% were then instilled into these right eyes. One hour later, auto-refractions and biometric imaging were repeated. Only data from eight of 25 subjects met the following stringent criteria to be included in the study analysis: pre and post-pilocarpine biometric foveal images were registerable, the images of the corneal centers were shifted by ≤100 μm, pupils >5 mm and the pharmacologically induced refractive change was ≥ -7 diopters. RESULTS The mean auto-refractive accommodative change for the eight included subjects was -12.45 diopters (± 3.45 diopters). The mean change in CLT was 81 μm (± 54 μm) and the mean change in ACD was -145 μm (± 86 μm). Superimposition of the registered pre and post-pilocarpine biometric images of the sagittal sections of the whole eye from each subject demonstrated that the position of the whole lens did not shift either anteriorly, posteriorly or vertically during pharmacologically induced accommodation. CONCLUSIONS A small increase in lens thickness was associated with a large change in accommodative amplitude and no significant change in lens position as predicted by the Schachar theory.
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Monsálvez-Romín D, Del Águila-Carrasco A, Ferrer-Blasco T, Esteve-Taboada JJ, Montés-Micó R. Evaluation of the iridocorneal angle with accommodation using optical coherence tomography. Int J Ophthalmol 2017; 10:1614-1616. [PMID: 29062784 DOI: 10.18240/ijo.2017.10.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 07/19/2017] [Indexed: 11/23/2022] Open
Abstract
The changes in the iridocorneal angle structure during accommodation are assessed by means of anterior segment optical coherence tomography. Thirteen right eyes were included in the study. The device used for the measurement was the Visante®omni system. The stimuli were set up at different vergences (0.0 D, -1.5 D, and -3.0 D). The angle opening distance 500 and 750, the trabecular iris space area 500 and 750, and the scleral spur angle parameters were assessed at the nasal and temporal regions. The results in the iridotrabecular angle comparing the three accommodative states of the eye did not yield any statistically significant difference at nasal or temporal angle sections. In light of our results and in the conditions of our study, the structures of the iridocorneal angle are not significantly changed with accommodation.
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Affiliation(s)
- Daniel Monsálvez-Romín
- Optics and Optometry and Vision Sciences Department, University of Valencia, Burjassot 46100, Spain
| | | | - Teresa Ferrer-Blasco
- Optics and Optometry and Vision Sciences Department, University of Valencia, Burjassot 46100, Spain
| | - José J Esteve-Taboada
- Optics and Optometry and Vision Sciences Department, University of Valencia, Burjassot 46100, Spain
| | - Robert Montés-Micó
- Optics and Optometry and Vision Sciences Department, University of Valencia, Burjassot 46100, Spain
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Ocular anatomic changes for different accommodative demands using swept-source optical coherence tomography: a pilot study. Graefes Arch Clin Exp Ophthalmol 2017; 255:2399-2406. [DOI: 10.1007/s00417-017-3801-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 09/02/2017] [Accepted: 09/08/2017] [Indexed: 01/07/2023] Open
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Schachar RA, Mani M, Schachar IH. Image registration reveals central lens thickness minimally increases during accommodation. Clin Ophthalmol 2017; 11:1625-1636. [PMID: 28979092 PMCID: PMC5602687 DOI: 10.2147/opth.s144238] [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: 11/23/2022] Open
Abstract
Purpose To evaluate anterior chamber depth, central crystalline lens thickness and lens curvature during accommodation. Setting California Retina Associates, El Centro, CA, USA. Design Healthy volunteer, prospective, clinical research swept-source optical coherence biometric image registration study of accommodation. Methods Ten subjects (4 females and 6 males) with an average age of 22.5 years (range: 20–26 years) participated in the study. A 45° beam splitter attached to a Zeiss IOLMaster 700 (Carl Zeiss Meditec Inc., Jena, Germany) biometer enabled simultaneous imaging of the cornea, anterior chamber, entire central crystalline lens and fovea in the dilated right eyes of subjects before, and during focus on a target 11 cm from the cornea. Images with superimposable foveal images, obtained before and during accommodation, that met all of the predetermined alignment criteria were selected for comparison. This registration requirement assured that changes in anterior chamber depth and central lens thickness could be accurately and reliably measured. The lens radii of curvatures were measured with a pixel stick circle. Results Images from only 3 of 10 subjects met the predetermined criteria for registration. Mean anterior chamber depth decreased, −67 μm (range: −0.40 to −110 μm), and mean central lens thickness increased, 117 μm (range: 100–130 μm). The lens surfaces steepened, anterior greater than posterior, while the lens, itself, did not move or shift its position as appeared from the lack of movement of the lens nucleus, during 7.8 diopters of accommodation, (range: 6.6–9.7 diopters). Conclusion Image registration, with stable invariant references for image correspondence, reveals that during accommodation a large increase in lens surface curvatures is associated with only a small increase in central lens thickness and no change in lens position.
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Affiliation(s)
- Ronald A Schachar
- Department of Physics, University of Texas at Arlington, Arlington, TX
| | | | - Ira H Schachar
- Byers Eye Institute of Stanford University, Palo Alto, CA, USA
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Lu Y, Yang N, Li X, Kong J. Four-year Follow-up of the Changes in Anterior Segment After Phakic Collamer Lens Implantation. Am J Ophthalmol 2017; 178:140-149. [PMID: 28342721 DOI: 10.1016/j.ajo.2017.03.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 03/15/2017] [Accepted: 03/15/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE To assess the changes and relationship in central vaulting, flare intensity, and crystalline lens thickness during a follow-up period of 4 years after implantable collamer lens (ICL) implantation in eyes with high myopia. DESIGN Retrospective observational study. METHODS Ninety-eight eyes of 50 patients were followed up with routine measurements of central vaulting, crystalline lens thickness, endothelial cell density, and aqueous flare postoperatively. Data were analyzed by repeated-measures analysis of variance. The relationship between the annual change in crystal lens thickness after surgery and age was evaluated by Pearson correlation coefficient and linear regression. RESULTS There was a continuous reduction in central vaulting and endothelial cell density as well as an increase in crystalline lens thickness in ICL eyes from 1 month onward to 5 years postoperatively (P < .001). Although the trend of variation during the individual visit period was accentuated, the variation turned out to be smaller between 12 and 36 months or 60 months postoperatively (P = .42, P = .65). Aqueous flare intensity increased significantly after surgery and returned to normal 1 year later. Additionally, a positive correlation between patient age and crystalline lens thickness (r = 0.617, P < .0001) was observed in eyes with ICL implantation. CONCLUSIONS The changes in central vaulting, endothelial cell density, and crystalline lens thickness are more prominent during the first year after ICL implantation, tending to be relatively stable afterwards. The anterior inflammation during the early postoperative period synchronizes with the sharp progression of crystalline lens changes within the first year.
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Almutairi MS, Altoaimi BH, Bradley A. Accommodation and pupil behaviour of binocularly viewing early presbyopes. Ophthalmic Physiol Opt 2017; 37:128-140. [DOI: 10.1111/opo.12356] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/04/2017] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Arthur Bradley
- School of Optometry; Indiana University; Bloomington USA
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Martinez-Enriquez E, Pérez-Merino P, Velasco-Ocana M, Marcos S. OCT-based full crystalline lens shape change during accommodation in vivo. BIOMEDICAL OPTICS EXPRESS 2017; 8:918-933. [PMID: 28270993 PMCID: PMC5330589 DOI: 10.1364/boe.8.000918] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/15/2016] [Accepted: 12/27/2016] [Indexed: 05/22/2023]
Abstract
The full shape of the accommodating crystalline lens was estimated using custom three-dimensional (3-D) spectral OCT and image processing algorithms. Automatic segmentation and distortion correction were used to construct 3-D models of the lens region visible through the pupil. The lens peripheral region was estimated with a trained and validated parametric model. Nineteen young eyes were measured at 0-6 D accommodative demands in 1.5 D steps. Lens volume, surface area, diameter, and equatorial plane position were automatically quantified. Lens diameter & surface area correlated negatively and equatorial plane position positively with accommodation response. Lens volume remained constant and surface area decreased with accommodation, indicating that the lens material is incompressible and the capsular bag elastic.
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Park JS, Park BG, Choi BJ, Lee JS. Long Term Corneal Endothelial Cell Density Loss after Iris-fixed Phakic Intraocular Lens Implantation. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2017. [DOI: 10.3341/jkos.2017.58.4.473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | - Byung Gun Park
- Department of Ophthalmology, Pusan National University School of Medicine, Yangsan, Korea
| | | | - Jong Soo Lee
- Department of Ophthalmology, Pusan National University School of Medicine, Yangsan, Korea
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Abstract
PURPOSE To quantify changes in ocular dimensions associated with age, refractive error, and accommodative response, in vivo, in 30- to 50-year-old human subjects. METHODS The right eyes of 91 adults were examined using ultrasonography, phakometry, keratometry, pachymetry, interferometry, anterior segment optical coherence tomography, and high-resolution magnetic resonance imaging. Accommodation was measured subjectively with a push-up test and objectively using open-field autorefraction. Regression analyses were used to assess differences in ocular parameters with age, refractive error, and accommodation. RESULTS With age, crystalline lens thickness increased (0.03 mm/yr), anterior lens curvature steepened (0.11 mm/yr), anterior chamber depth decreased (0.02 mm/yr), and lens equivalent refractive index decreased (0.001/yr) (all p < 0.01). With increasing myopia, there were significant increases in axial length (0.37 mm/D), vitreous chamber depth (0.34 mm/D), vitreous chamber height (0.09 mm/D), and ciliary muscle ring diameter (0.10 mm/D) (all p < 0.05). Increasing myopia was also associated with steepening of both the cornea (0.16 mm/D) and anterior lens surface (0.011 mm/D) (both p < 0.04). With accommodation, the ciliary muscle ring diameter decreased (0.08 mm/D) and the muscle thinned posteriorly (0.008 mm/D), allowing the lens to shorten equatorially (0.07 mm/D) and thicken axially (0.06 mm/D) (all p < 0.03). CONCLUSIONS Refractive error is significantly correlated with not only the axial dimensions but also the anterior equatorial dimension of the adult eye. Further testing and development of accommodating intraocular lenses should account for differences in patients' preoperative refractive error.
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Laughton DS, Coldrick BJ, Sheppard AL, Davies LN. A program to analyse optical coherence tomography images of the ciliary muscle. Cont Lens Anterior Eye 2015; 38:402-8. [DOI: 10.1016/j.clae.2015.05.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/08/2015] [Accepted: 05/13/2015] [Indexed: 11/28/2022]
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Laughton DS, Sheppard AL, Davies LN. A longitudinal study of accommodative changes in biometry during incipient presbyopia. Ophthalmic Physiol Opt 2015; 36:33-42. [DOI: 10.1111/opo.12242] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/07/2015] [Indexed: 11/26/2022]
Affiliation(s)
- Deborah S. Laughton
- Ophthalmic Research Group Life & Health Sciences Aston University Birmingham UK
| | - Amy L. Sheppard
- Ophthalmic Research Group Life & Health Sciences Aston University Birmingham UK
| | - Leon N. Davies
- Ophthalmic Research Group Life & Health Sciences Aston University Birmingham UK
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Lee H, Kang DSY, Ha BJ, Choi M, Kim EK, Seo KY, Kim TI. Effect of Accommodation on Vaulting and Movement of Posterior Chamber Phakic Lenses in Eyes With Implantable Collamer Lenses. Am J Ophthalmol 2015; 160:710-6.e1. [PMID: 26189089 DOI: 10.1016/j.ajo.2015.07.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 07/09/2015] [Accepted: 07/10/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate and compare vaulting and movement changes during accommodation in eyes with the V4c and V4 implantable collamer lenses (ICL). DESIGN Comparative, observational case series. METHODS The medical records of 35 eyes (18 patients) with the V4 ICL and 51 eyes (26 patients) with the V4c ICL were retrospectively examined and included in analyses. Anterior chamber depth (ACD), posterior corneal surface-to-ICL distance (endo-ICL distance), pupil size, and postoperative vaulting were evaluated using the Visante anterior chamber optical coherence tomography system. Images were taken during the nonaccommodative and accommodative states 3 months after ICL implantation. Refractive error, keratometry values, axial length, intraocular pressure, and central corneal thickness were evaluated at 3 months postoperatively. RESULTS ICL vaulting did not significantly change during accommodation in eyes with either the V4 or V4c ICL (P = .532 for V4 ICL and P = .415 for V4c ICL). However, significant reductions in ACD, endo-ICL distance, and pupil size were observed during accommodation in both groups. In eyes with a V4 ICL, the change in [Δ] ACD was 0.2 ± 0.1 mm (P < .001), Δendo-ICL distance was 0.2 ± 0.1 mm (P < .001), and Δpupil size was 0.5 ± 0.9 mm (P = .021). For eyes with the V4c ICL, ΔACD was 0.2 ± 0.2 mm (P < .001), Δendo-ICL distance was 0.2 ± 0.2 mm (P < .001), and Δpupil size was 0.8 ± 1.2 mm (P < .001). The mean reductions of each parameter were not statistically different between eyes with the V4 ICL and the V4c ICL. CONCLUSIONS Contrary to the light stimulation response, accommodation does not significantly affect ICL vaulting differently in eyes with either the V4 or V4C ICLs.
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Ramasubramanian V, Glasser A. Objective measurement of accommodative biometric changes using ultrasound biomicroscopy. J Cataract Refract Surg 2015; 41:511-26. [PMID: 25804579 DOI: 10.1016/j.jcrs.2014.08.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 08/06/2014] [Accepted: 08/08/2014] [Indexed: 12/01/2022]
Abstract
PURPOSE To demonstrate that ultrasound biomicroscopy (UBM) can be used for objective quantitative measurements of anterior segment accommodative changes. SETTING College of Optometry, University of Houston, Houston, Texas, USA. DESIGN Prospective cross-sectional study. METHODS Anterior segment biometric changes in response to 0 to 6.0 diopters (D) of accommodative stimuli in 1.0 D steps were measured in eyes of human subjects aged 21 to 36 years. Imaging was performed in the left eye using a 35 MHz UBM (Vumax) and an A-scan ultrasound (A-5500) while the right eye viewed the accommodative stimuli. An automated Matlab image-analysis program was developed to measure the biometry parameters from the UBM images. RESULTS The UBM-measured accommodative changes in anterior chamber depth (ACD), lens thickness, anterior lens radius of curvature, posterior lens radius of curvature, and anterior segment length were statistically significantly linearly correlated with accommodative stimulus demands. Standard deviations of the UBM-measured parameters were independent of the accommodative stimulus demands (ACD: 0.0176 mm; lens thickness: 0.0294 mm; anterior lens radius of curvature: 0.3350 mm; posterior lens radius of curvature: 0.1580 mm; and anterior segment length: 0.0340 mm). The mean difference between the A-scan and UBM measurements was -0.070 mm for ACD and 0.166 mm for lens thickness. CONCLUSIONS Accommodating phakic eyes imaged using UBM allowed visualization of the accommodative response, and automated image analysis of the UBM images allowed reliable, objective, quantitative measurements of the accommodative intraocular biometric changes. FINANCIAL DISCLOSURE Neither author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
| | - Adrian Glasser
- From the College of Optometry, University of Houston, Houston, Texas, USA.
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Fu T, Song YW, Chen ZQ, He JW, Qiao K, Sun XF, Zhang H, Wang JM. Ocular biometry in the adult population in rural central China: a population-based, cross-sectional study. Int J Ophthalmol 2015; 8:812-7. [PMID: 26309884 DOI: 10.3980/j.issn.2222-3959.2015.04.30] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/21/2015] [Indexed: 11/02/2022] Open
Abstract
AIM To describe the distribution and determinants of ocular biometric parameters and to ascertain the relative importance of these determinants in a large population of adults in rural central China. METHODS A population-based, cross-sectional study performed in rural central China included 1721 participants aged 40 or more years. Ocular biometrical parameters including axial length (AL), anterior chamber depth (ACD), radius of corneal curvature (K) and horizontal corneal diameter [white-to-white (WTW) distance] were measured using non-contact partial coherence interferometry [intraocular lens (IOL)-Master]. RESULTS Ocular biometric data on 1721 participants with a average age of 57.0±8.7y were analyzed at last. The general mean AL, ACD, mean corneal curvature radius (MCR), WTW were 22.80±1.12, 2.96±0.36, 7.56±0.26 and 11.75±0.40 mm, respectively. The mean values of each parameter in 40 to 49, 50 to 59, 60 to 69, and 70 to 91 years age groups were as follows: AL, 22.77±0.87, 22.76±1.06, 22.89±1.41, 22.92±0.80 mm; ACD, 3.10±0.32, 2.98±0.34, 2.86±0.36, 2.77±0.35 mm; MCR, 7.58±0.25, 7.54±0.26, 7.55±0.26, 7.49±0.28 mm; WTW, 11.79±0.38, 11.75±0.40, 11.72±0.41, 11.67±0.41 mm. The AL, ACD, MCR and WTW were correlated with age and the AL was correlated with height and weight. CONCLUSION Our findings can serve as an important normative reference for multiple purposes and may help to improve the quality of rural eye care.
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Affiliation(s)
- Ting Fu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Yin-Wei Song
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Zhi-Qi Chen
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Jun-Wen He
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Kun Qiao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Xu-Fang Sun
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Hong Zhang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
| | - Jun-Ming Wang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, China
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Optical Coherence Tomography Reveals New Insights into the Accommodation Mechanism. J Ophthalmol 2015; 2015:510459. [PMID: 26236498 PMCID: PMC4506922 DOI: 10.1155/2015/510459] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 06/08/2015] [Accepted: 06/09/2015] [Indexed: 11/18/2022] Open
Abstract
Purpose. To evaluate the movement of the anterior and posterior lens poles during naturally stimulated accommodation in children using anterior segment optical coherence tomography (OCT). Methods. This is a prospective, observational, noncomparative case series including 18 eyes of nine children. Analysis of the anterior segment in the accommodated and unaccommodated state (with cycloplegia) was done using anterior segment OCT. The main outcome measures were the position of the anterior and posterior lens poles (in relation to the cornea) and lens thickness (LT). Results. A Statistically significant forward movement of the anterior lens pole and backward movement of the posterior lens pole with an increase in LT were found during accommodation (P < 0.001). There was no significant difference between the degree of movement of the anterior lens pole and the posterior lens pole during accommodation (P = 0.944). Conclusions. Anterior segment OCT provides a rapid noncontact method for studying accommodation in children. The backward movement of the posterior lens pole during accommodation nearly equals the forward movement of its anterior pole. These data minimize the theoretical hydraulic effect of the vitreous during accommodation, adding more support to the capsular theory of Helmholtz.
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Neri A, Ruggeri M, Protti A, Leaci R, Gandolfi SA, Macaluso C. Dynamic imaging of accommodation by swept-source anterior segment optical coherence tomography. J Cataract Refract Surg 2015; 41:501-10. [PMID: 25704218 DOI: 10.1016/j.jcrs.2014.09.034] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Revised: 08/05/2014] [Accepted: 09/08/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE To study the accommodation process in normal eyes using a commercially available clinical system based on swept-source anterior segment optical coherence tomography (AS-OCT). SETTING Ophthalmology Department, University of Parma, Italy. DESIGN Evaluation of diagnostic technology. METHODS Right eyes were analyzed using swept-source AS-OCT (Casia SS-1000). The optical vergence of the internal coaxial fixation target was adjusted during imaging to obtain monocular accommodation stimuli with different amplitudes (0, 3.0, 6.0, and 9.0 diopters [D]). Overlapping of real and conjugate OCT images enabled imaging of all the anterior segment optical surfaces in a single frame. Central corneal thickness (CCT), anterior chamber depth (ACD), and lens thickness were extracted from the OCT scans acquired at different static accommodation stimulus amplitudes. The crystalline lens was analyzed dynamically during accommodation and disaccommodation by acquiring sequential OCT images of the anterior segment at a rate of 8 frames per second. The lens thickness was extracted from the temporal sequence of OCT images and plotted as a function of time. RESULTS The study analyzed 14 eyes of 14 subjects aged 18 to 46 years. During accommodation, the decrease in the ACD was statistically significant (P < .05), as were the increase in the lens thickness (P < .001) and the slight movement forward of the lens central point (P < .01). The CCT and anterior chamber width measurements did not change statistically significantly during accommodation. The lens thickness at 0 D was positively correlated with age (P < .01). CONCLUSION High-resolution real-time imaging and biometry of the accommodating anterior segment can be effectively performed using a commercially available swept-source AS-OCT clinical device. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Alberto Neri
- Ophthalmology Department (Neri, Protti, Leaci, Gandolfi, Macaluso), Dipartimento di Scienze Biomediche, Biotecnologiche e Traslazionali, University of Parma, Parma, Italy; the Ophthalmic Biophysics Center (Ruggeri), Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA.
| | - Marco Ruggeri
- Ophthalmology Department (Neri, Protti, Leaci, Gandolfi, Macaluso), Dipartimento di Scienze Biomediche, Biotecnologiche e Traslazionali, University of Parma, Parma, Italy; the Ophthalmic Biophysics Center (Ruggeri), Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Alessandra Protti
- Ophthalmology Department (Neri, Protti, Leaci, Gandolfi, Macaluso), Dipartimento di Scienze Biomediche, Biotecnologiche e Traslazionali, University of Parma, Parma, Italy; the Ophthalmic Biophysics Center (Ruggeri), Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Rosachiara Leaci
- Ophthalmology Department (Neri, Protti, Leaci, Gandolfi, Macaluso), Dipartimento di Scienze Biomediche, Biotecnologiche e Traslazionali, University of Parma, Parma, Italy; the Ophthalmic Biophysics Center (Ruggeri), Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Stefano A Gandolfi
- Ophthalmology Department (Neri, Protti, Leaci, Gandolfi, Macaluso), Dipartimento di Scienze Biomediche, Biotecnologiche e Traslazionali, University of Parma, Parma, Italy; the Ophthalmic Biophysics Center (Ruggeri), Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Claudio Macaluso
- Ophthalmology Department (Neri, Protti, Leaci, Gandolfi, Macaluso), Dipartimento di Scienze Biomediche, Biotecnologiche e Traslazionali, University of Parma, Parma, Italy; the Ophthalmic Biophysics Center (Ruggeri), Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
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