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Manuel TJ, Bancel T, Tiennot T, Didier M, Santin M, Daniel M, Attali D, Tanter M, Lehéricy S, Pyatigorskaya N, Aubry JF. Ultra-short time-echo based ray tracing for transcranial focused ultrasound aberration correction in human calvaria. Phys Med Biol 2024. [PMID: 38776944 DOI: 10.1088/1361-6560/ad4f44] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
OBJECTIVE Magnetic resonance guided transcranial focused ultrasound holds great promises for treating neurological disorders. This technique relies on skull aberration correction which requires computed tomography (CT) scans of the skull of the patients. Recently, ultra-short time-echo (UTE) magnetic resonance (MR) sequences have unleashed the MRI potential to reveal internal bone structures. In this study, we measure the efficacy of transcranial aberration correction using UTE images.
Approach. We compare the efficacy of transcranial aberration correction using UTE scans to CT based correction on four skulls and two targets using a clinical device (Exablate Neuro, Insightec, Israel). We also evaluate the performance of a custom ray tracing algorithm using both UTE and CT estimates of acoustic properties and compare these against the performance of the manufacturer's proprietary aberration correction software.
Main results. UTE estimated skull maps in Hounsfield units (HU) had a mean absolute error of 242 ± 20 HU (n=4). The UTE skull maps were sufficiently accurate to improve pressure at the target (no correction: 0.44 ± 0.10, UTE correction: 0.79 ± 0.05, manufacturer CT: 0.80 ± 0.05), pressure confinement ratios (no correction: 0.45 ± 0.10, UTE correction: 0.80 ± 0.05, manufacturer CT: 0.81 ± 0.05), and targeting error (no correction: 1.06 ± 0.42 mm, UTE correction 0.30 ± 0.23 mm, manufacturer CT: 0.32 ± 0.22) (n=8 for all values). When using CT, our ray tracing algorithm performed slightly better than UTE based correction with pressure at the target (UTE: 0.79 ± 0.05, CT: 0.84 ± 0.04), pressure confinement ratios (UTE: 0.80 ± 0.05, CT: 0.84 ± 0.04), and targeting error (UTE: 0.30 ± 0.23 mm, CT: 0.17 ± 0.15).
Significance. These 3D transcranial measurements suggest that UTE sequences could replace CT scans in the case of MR guided focused ultrasound with minimal reduction in performance which will avoid ionizing radiation exposure to the patients and reduce procedure time and cost.
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Affiliation(s)
| | - Thomas Bancel
- INSERM, 8 rue de la Croix Jarry, Paris, Île-de-France, 75013, FRANCE
| | - Thomas Tiennot
- INSERM, 8 rue de la Croix Jarry, Paris, Île-de-France, 75013, FRANCE
| | - Mélanie Didier
- INSERM, 8 rue de la Croix Jarry, Paris, Île-de-France, 75013, FRANCE
| | - Mathieu Santin
- INSERM, 8 rue de la Croix Jarry, Paris, Île-de-France, 75013, FRANCE
| | - Maxime Daniel
- ESPCI, 10 rue Vauquelin, Paris, Île-de-France, 75005, FRANCE
| | - David Attali
- Psychiatrie et Neurosciences, GHU Paris, 1 Rue Cabanis, Paris, 75014, FRANCE
| | - Mickael Tanter
- ESPCI, 10 rue Vauquelin, Paris, Île-de-France, 75005, FRANCE
| | - Stéphane Lehéricy
- INSERM, 8 rue de la Croix Jarry, Paris, Île-de-France, 75013, FRANCE
| | | | - Jean-Francois Aubry
- Institut Langevin, ESPCI, 10 rue Vauquelin, Paris, Île-de-France, 75005, FRANCE
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García-Tomás B, Marín-Sánchez JM, García-Elskamp C, Alcon-Ruiz E, Montesinos-López L, García Martínez-Lozano B. Clinical Outcomes of a Monofocal, Optimized, Aspheric, Hydrophobic Acrylic Intraocular Lens Implant. Clin Ophthalmol 2023; 17:3215-3224. [PMID: 37915319 PMCID: PMC10617528 DOI: 10.2147/opth.s434378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 10/02/2023] [Indexed: 11/03/2023] Open
Abstract
Purpose To evaluate the refractive and visual outcomes of eyes implanted with monofocal, optimized, aspheric, hydrophobic acrylic intraocular lenses (IOL) following cataract surgery. Methods The study assessed 55 eyes implanted with CT LUCIA® 621P IOLs (Carl Zeiss Meditec AG, Jena, Germany) at 3-months postsurgery. The main outcome measures were refractive error, monocular corrected distance visual acuity (CDVA), monocular uncorrected distance visual acuity (UDVA), photopic and mesopic contrast sensitivity, and wavefront aberrations. Patients were asked to complete the Catquest-9SF questionnaire. Results At 3 months, the cumulative Snellen visual acuity was 20/20 in 94.55% of eyes and 20/25 or better in 100%. The difference between the UDVA and CDVA was either the same (70.91%) or better (29.09%) in all eyes. The mean Snellen decimal UDVA and DCVA were 1.07 ± 0.15 and 1.13 ± 0.11, respectively. The safety and efficacy indexes were 1.48 and 1.40, respectively. 47.27% of eyes showed a spherical equivalent ±0.13 D, with 92.73% of the eyes were within ±0.50 D and all eyes were within ±1.00 D. The mean spherical equivalent was -0.03 ± 0.30 D and the mean refractive cylinder -0.36 ± 0.34 D. The log photopic and mesopic contrast sensitivity functions were good and similar for all spatial frequencies. All patients reported being either fairly satisfied (score 3) or very satisfied (score 4) with their vision (mean = 3.64 ± 0.49). No intra- and postoperative complications were reported during the 3 months of follow-up. Conclusion The current study demonstrates that excellent visual and refractive outcomes, as well as patient satisfaction, can be achieved after cataract surgery with optimized, aspheric CT LUCIA 621P monofocal IOLs.
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Panicker S, Chengizkhan G, Gor R, Ramachandran I, Ramalingam S. Exploring the Relationship between Fusion Genes and MicroRNAs in Cancer. Cells 2023; 12:2467. [PMID: 37887311 PMCID: PMC10605240 DOI: 10.3390/cells12202467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/05/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023] Open
Abstract
Fusion genes are key cancer driver genes that can be used as potential drug targets in precision therapies, and they can also serve as accurate diagnostic and prognostic biomarkers. The fusion genes can cause microRNA (miRNA/miR) aberrations in many types of cancer. Nevertheless, whether fusion genes incite miRNA aberrations as one of their many critical oncogenic functionalities for driving carcinogenesis needs further investigation. Recent discoveries of miRNA genes that are present within the regions of genomic rearrangements that initiate fusion gene-based intronic miRNA dysregulation have brought the fusion genes into the limelight and revealed their unexplored potential in the field of cancer biology. Fusion gene-based 'promoter-switch' event aberrantly activate the miRNA-related upstream regulatory signals, while fusion-based coding region alterations disrupt the original miRNA coding loci. Fusion genes can potentially regulate the miRNA aberrations regardless of the protein-coding capability of the resultant fusion transcript. Studies on out-of-frame fusion and nonrecurrent fusion genes that cause miRNA dysregulation have attracted the attention of researchers on fusion genes from an oncological perspective and therefore could have potential implications in cancer therapies. This review will provide insights into the role of fusion genes and miRNAs, and their possible interrelationships in cancer.
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Affiliation(s)
- Saurav Panicker
- Department of Genetic Engineering, School of Bio-Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu 603203, Tamil Nadu, India; (S.P.); (R.G.)
| | - Gautham Chengizkhan
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600113, Tamil Nadu, India;
| | - Ravi Gor
- Department of Genetic Engineering, School of Bio-Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu 603203, Tamil Nadu, India; (S.P.); (R.G.)
| | - Ilangovan Ramachandran
- Department of Endocrinology, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai 600113, Tamil Nadu, India;
| | - Satish Ramalingam
- Department of Genetic Engineering, School of Bio-Engineering, SRM Institute of Science and Technology, Kattankulathur, Chengalpattu 603203, Tamil Nadu, India; (S.P.); (R.G.)
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English CM, Kitzhaber ZB, Sanim KRI, Vitzilaios N, Hodgson ME, Richardson TL, Myrick ML. Filter Fluorometer Calibration Without the Fluorometer. Appl Spectrosc 2023; 77:1053-1063. [PMID: 37350765 DOI: 10.1177/00037028231181593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
We recently described a lightweight, low-power, waterproof filter fluorometer using a 180° backscatter geometry for chlorophyll-a (chl-a) detection. Before it was constructed it was modeled to ensure it would have satisfactory performance. This manuscript repeats the modeling process that allows the calibration slope and detection limit for a fluorescent analyte in water to be estimated from system component performance and conventional spectrofluorometry alone. These values are validated by comparison to the experimental result of calibration from the completed instrument. Our model yields a calibration slope of 8.22 mV-L/µg for dissolved chl-a, consistent with the experimentally measured slope of 8.21 mV-L/µg. The detection limit modeled from this slope and an estimate of the baseline noise of the instrument was 0.15 µg/L chl-a, while the measured detection limit using real blank samples was 0.18 µg/L, in 0.1 s differential measurements.
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Affiliation(s)
- Caitlyn M English
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Zechariah B Kitzhaber
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
| | - Kazi Ragib I Sanim
- Department of Mechanical Engineering, University of South Carolina, Columbia, SC, USA
| | - Nikolaos Vitzilaios
- Department of Mechanical Engineering, University of South Carolina, Columbia, SC, USA
| | - Michael E Hodgson
- Department of Geography, University of South Carolina, Columbia, SC, USA
| | - Tammi L Richardson
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Michael L Myrick
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, USA
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Sah RP, Meyer D, Jaskulski M, Rickert M, Cheng X, Brennan N, Kollbaum PS. Impact of zone geometry on the introduction of myopic defocus in young adult eyes wearing multi-zone lenses. Ophthalmic Physiol Opt 2023; 43:1110-1124. [PMID: 37326329 DOI: 10.1111/opo.13182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/22/2023] [Accepted: 05/29/2023] [Indexed: 06/17/2023]
Abstract
PURPOSE Multizone contact lenses control myopia progression by proposed introduction of myopic defocus. This project investigated how much of the pupil area and how many dioptres of myopic defocus are introduced by different lens zone geometries with near- and off-axis viewing. METHODS Ten young myopic adults (18-25 years) binocularly wore four soft contact lenses including a single vision (SV), concentric-ring dual-focus (DF), centre-distance multifocal (MF) and a RingBoost™ (RB) multi-zone design containing a combination of coaxial and non-coaxial zones. A modified aberrometer captured aberrations and pupil sizes at four target vergences between -0.25 and -4.00 D (on-axis) and across the central ±30° of the horizontal retina (off-axis). Defocus was quantified as the difference between the measured refractive state and the target vergence within each zone of a multi-zone design within the pupil and compared with that of equivalent zone areas of the SV lens. The percentage of the pupil containing myopic defocused light for each lens was calculated. RESULTS Defocus within the distance correction zones of multi-zone lenses was similar to that of the SV lens. When viewing on-axis at -0.25 D target vergence, on average 11% of the pupil was myopic with SV, whereas 62%, 84% and 50% of the pupil was myopic for the DF, MF and RB designs, respectively. At -4.00 D target vergence, all lenses exhibited a systematic decrease in the percentage of pupil area having myopic defocus (SV: 3%; DF: 18%; MF: 5% and RB: 26%). The off-axis proportions were similar across multi-zone lenses; however, multi-zone lenses retained approximately 1.25-3.0× more myopic defocus than the SV lens. CONCLUSIONS Subjects accommodated using the distance-correction zones of multi-zone lenses. Multi-zone contact lenses introduced significant myopic defocus on-axis and across the central ±30° retina. However, the magnitude and proportion of defocus were influenced by zone geometry, add power and pupil size.
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Affiliation(s)
- Raman Prasad Sah
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Dawn Meyer
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Matt Jaskulski
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Martin Rickert
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Xu Cheng
- Johnson & Johnson Vision Care Inc., Jacksonville, Florida, USA
| | - Noel Brennan
- Johnson & Johnson Vision Care Inc., Jacksonville, Florida, USA
| | - Pete S Kollbaum
- School of Optometry, Indiana University, Bloomington, Indiana, USA
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Smadja D, Krauthammer M, Wajnsztajn D, Abulafia A, Zadok D, Lavy I. Differences in retinal images quality between normal and subclinical keratoconus and its association to posterior corneal asymmetry. Eur J Ophthalmol 2023:11206721231166559. [PMID: 37013367 DOI: 10.1177/11206721231166559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
PURPOSE To compare retinal image quality in subclinical keratoconus and normal eyes using a double-pass aberrometer and to correlate it with posterior surface deformation. METHODS Sixty normal corneas were compared to 20 subclinical keratoconus (SKC) corneas. Retinal image quality was assessed using a double-pass system in all the eyes. The objective scatter index (OSI) modulation transfer function (MTF) cutoff, Strehl ratio (SR), and Predicted Visual Acuity (PVA) values at 100%, 20%, and 9% were calculated and compared between the groups. Posterior corneal asymmetry was measured using a combined Placido Dual Scheimpflug Analyzer, and correlations were tested with all optical quality parameters. RESULTS Significant decrease in optical quality parameters was observed in SKC eyes compared with that in normal eyes. Subclinical KC eyes expressed greater scattering (OSI = 0.66 ± 0.36 vs 0.47 ± 0.26) and reduced contrast images (MTF and SR) than normal eyes, with 38.82 ± 9.4 and 0.22 ± 0.04, and 44.35 ± 7.1 and 0.24 ± 0.04, respectively. The reduction in the image contrast parameters (MTF and SR) was strongly correlated to the level of posterior corneal asymmetry in SKC. The greater the posterior asymmetry, the more affected was the image contrast, with r = -0.63 and -0.59, respectively for MTF and SR. CONCLUSION Retinal image quality was significantly more affected in eyes with subclinical keratoconus than in normal eyes. The reduction in optical quality observed in subclinical keratoconus was strongly associated with the increased asymmetry of the posterior cornea.
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Affiliation(s)
- David Smadja
- Department of Ophthalmology, 58884Hadassah Medical Center, Jerusalem, Israel
- Ein Tal Hadassah Laser Institute, Tel Aviv, Israel
| | - Mark Krauthammer
- Ein Tal Hadassah Laser Institute, Tel Aviv, Israel
- Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Denise Wajnsztajn
- Department of Ophthalmology, 58884Hadassah Medical Center, Jerusalem, Israel
- Ein Tal Hadassah Laser Institute, Tel Aviv, Israel
| | - Adi Abulafia
- Department of Ophthalmology, 26743Shaare Zedek Medical Center, Jerusalem, Israel
| | - David Zadok
- Department of Ophthalmology, 26743Shaare Zedek Medical Center, Jerusalem, Israel
| | - Itay Lavy
- Department of Ophthalmology, 58884Hadassah Medical Center, Jerusalem, Israel
- Ein Tal Hadassah Laser Institute, Tel Aviv, Israel
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Parilla M, Quesada AE, Medeiros LJ, Thakral B. An update on genetic aberrations in T-cell neoplasms. Pathology 2023; 55:287-301. [PMID: 36801152 DOI: 10.1016/j.pathol.2022.12.350] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 12/17/2022] [Accepted: 12/26/2022] [Indexed: 01/20/2023]
Abstract
T-cell neoplasms are a highly heterogeneous group of leukaemias and lymphomas that represent 10-15% of all lymphoid neoplasms. Traditionally, our understanding of T-cell leukaemias and lymphomas has lagged behind that of B-cell neoplasms, in part due to their rarity. However, recent advances in our understanding of T-cell differentiation, based on gene expression and mutation profiling and other high throughput methods, have better elucidated the pathogenetic mechanisms of T-cell leukaemias and lymphomas. In this review, we provide an overview of many of the molecular abnormalities that occur in various types of T-cell leukaemia and lymphoma. Much of this knowledge has been used to refine diagnostic criteria that has been included in the fifth edition of the World Health Organization. This knowledge is also being used to improve prognostication and identify novel therapeutic targets, and we expect this progress will continue, eventually resulting in improved outcomes for patients with T-cell leukaemias and lymphomas.
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Gomes J, Sapkota K, Franco S. Central and Peripheral Ocular High-Order Aberrations and Their Relationship with Accommodation and Refractive Error: A Review. Vision (Basel) 2023; 7:vision7010019. [PMID: 36977299 PMCID: PMC10054659 DOI: 10.3390/vision7010019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/17/2023] [Accepted: 02/28/2023] [Indexed: 03/30/2023] Open
Abstract
High-order aberrations (HOAs) are optical defects that degrade the image quality. They change with factors such as pupil diameter, age, and accommodation. The changes in optical aberrations during accommodation are mainly due to lens shape and position changes. Primary spherical aberration (Z(4.0)) is closely related to accommodation and some studies suggested that it plays an important role in the control of accommodation. Furthermore, central and peripheral HOAs vary with refractive error and seem to influence eye growth and the onset and progression of myopia. The variations of central and peripheral HOAs during accommodation also appear to be different depending on the refractive error. Central and peripheral high-order aberrations are closely related to accommodation and influence the accuracy of the accommodative response and the progression of refractive errors, especially myopia.
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Affiliation(s)
- Jessica Gomes
- Centre of Physics, University of Minho, 4710-057 Braga, Portugal
| | - Kishor Sapkota
- Centre of Physics, University of Minho, 4710-057 Braga, Portugal
| | - Sandra Franco
- Centre of Physics, University of Minho, 4710-057 Braga, Portugal
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Zheleznyak L. Peripheral optical anisotropy in refractive error groups. Ophthalmic Physiol Opt 2023; 43:435-444. [PMID: 36751123 DOI: 10.1111/opo.13104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 01/20/2023] [Accepted: 01/25/2023] [Indexed: 02/09/2023]
Abstract
INTRODUCTION This study investigated differences in peripheral image quality with refractive error. Peripheral blur orientation is determined by the interaction of optical aberrations (such as oblique astigmatism) and retinal shape. By providing the eye with an optical signal for determining the sign of defocus, peripheral blur anisotropy may play a role in mechanisms of accommodation, emmetropisation and optical myopia control interventions. This study investigated peripheral through-focus optical anisotropy and image quality and how it varies with the eye's refractive error. METHODS Previously published Zernike coefficients across retinal eccentricity (0, 10, 20 and 30° horizontal nasal visual field) were used to compute the through-focus modulation transfer function (MTF) for a 4 mm pupil. Image quality was defined as the volume under the MTF, and blur anisotropy was defined as the ratio of the horizontal to vertical meridians of the MTF (HVRatio). RESULTS Across the horizontal nasal visual field (at 10, 20 and 30°), the peak image quality for emmetropes was within 0.3 D of the retina, as opposed to myopes whose best focus was behind the retina (-0.1, 0.4 and 1.5 D, respectively), while for hyperopes it lay in front of the retina (-0.5, -0.6 and -0.6 D). At 0.0 D (i.e., on the retina), emmetropes and hyperopes both exhibited horizontally elongated blur, whereas myopes had vertically elongated blur (HVRatio = 0.3, 0.7 and 2.8, respectively, at 30° eccentricity). CONCLUSIONS Blur in the peripheral retina is dominated by the so-called "odd-error" blur signals, primarily due to oblique astigmatism. The orientation of peripheral blur (horizontal or vertical) provides the eye with an optical cue for the sign of defocus. All subject groups had anisotropic blur in the nasal visual field; myopes exhibited vertically elongated blur, perpendicular to the blur orientation of emmetropes and hyperopes.
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Avetisov SE, Averich VV, Novikov IA, Erichev VP, Kosova DV, Siplivy VI. [The effect of keratoconus-associated refractive errors on the results of tomographic methods of studying the posterior structures of the eye]. Vestn Oftalmol 2023; 139:27-35. [PMID: 37942594 DOI: 10.17116/oftalma202313905127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
PURPOSE The study assesses the potential influence of refractive errors in keratoconus (KC) on the results of tomographic methods of studying the structures of the posterior eye segment. MATERIAL AND METHODS The study included 30 patients with bilateral stabilized KC of stages I-IV in classification by M. Amsler. Spherical and cylindrical components of refractions were determined using automatic refractometry, keratometry measurements - based on scanning keratotopography with Scheimpflug analyzer. Aberrometry was performed to evaluate corneal wave front according to the following parameters: root mean square for lower order aberrations (RMS LOA), root mean square for higher order aberrations (RMS HOA), vertical trefoil, vertical coma, horizontal coma and spherical aberrations. Optical coherence tomography (OCT) and laser confocal scanning ophthalmoscopy (HRT 3) data was used in morphometric analysis of the optic nerve head and peripapillary retina. The following morphometric parameters were analyzed: optic nerve head (ONH) area, optic disc cup area, optic disc cup volume, ratio of optic disc cup area to ONH area, neuroretinal rim area, neuroretinal rim volume, peripapillary retinal nerve fiber layer (RNFL) thickness. All studies were performed first without correction, and 30 minutes after installing customized scleral hard contact lenses (SHCL). RESULTS Compensation of the refractive errors characteristic for KC was achieved as expected with contact correction. OCT revealed a general trend for reduction in the area and volume of the optic disc cupping, ratio of area to volume of the optic disc cupping, as well as an increase in other parameters. As such, with correction the values for area and volume of the neuroretinal rim according to OCT were 2.2 and 13%, HRT 3 - 18 and 51.6%; comparable increase in mean RNFL thickness - 2.8 and 28.5%, respectively (p<0.001). According to HRT 3 data, the area and volume of optic disc cupping statistically significantly decreased (by 21 and 28%, respectively), while OCT showed statistically significant decrease only in cupping area (by 5.7%). The ratio of cupping to ONH area decreased by 6.6 and 23% relative to the initial data obtained with OCT and HRT 3, respectively. Significant decrease in ONH area amid SHCL correction was observed only with HRT 3. The revealed changes in morphometric parameters were analyzed using the fundamental principles of physiological optics. Changes in interference pattern and, consequently, morphometric parameters of structures of the eye fundus in KC are of multifactorial nature, and are mostly associated with refractive and wave artefacts occurring when the rays pass through the irregular corneal surface and cannot be optically compensated by the device. The use of SHCL as means for making the optic system relatively regular can significantly decrease the artefacts in morphometric measurements. CONCLUSION The results obtained in this study demonstrate the practicality of tomographic examination in KC with contact correction. The optimal choice is custom-fit SHCL, which along with proper correction of refractive errors also ensures stable position of the lens on the cornea. In standard examination specialists should take into account the «false» decrease in parameters of the peripapillary retinal nerve fiber layer and increase in ONH cupping.
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Affiliation(s)
- S E Avetisov
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - V V Averich
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
| | - I A Novikov
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
| | - V P Erichev
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
| | - D V Kosova
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
| | - V I Siplivy
- I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
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Majedy M, Das NK, Johansson J, Saager RB. Influence of optical aberrations on depth-specific spatial frequency domain techniques. J Biomed Opt 2022; 27:116003. [PMID: 36358008 PMCID: PMC9646941 DOI: 10.1117/1.jbo.27.11.116003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
SIGNIFICANCE Spatial frequency domain imaging (SFDI) and spatial frequency domain spectroscopy (SFDS) are emerging tools to non-invasively assess tissues. However, the presence of aberrations can complicate processing and interpretation. AIM This study develops a method to characterize optical aberrations when performing SFDI/S measurements. Additionally, we propose a post-processing method to compensate for these aberrations and recover arbitrary subsurface optical properties. APPROACH Using a custom SFDS system, we extract absorption and scattering coefficients from a reference phantom at 0 to 15 mm distances from the ideal focus. In post-processing, we characterize aberrations in terms of errors in absorption and scattering relative to the expected in-focus values. We subsequently evaluate a compensation approach in multi-distance measurements of phantoms with different optical properties and in multi-layer phantom constructs to mimic subsurface targets. RESULTS Characterizing depth-specific aberrations revealed a strong power law such as wavelength dependence from ∼40 to ∼10 % error in both scattering and absorption. When applying the compensation method, scattering remained within 1.3% (root-mean-square) of the ideal values, independent of depth or top layer thickness, and absorption remained within 3.8%. CONCLUSIONS We have developed a protocol that allows for instrument-specific characterization and compensation for the effects of defocus and chromatic aberrations on spatial frequency domain measurements.
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Affiliation(s)
- Motasam Majedy
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Nandan K. Das
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Johannes Johansson
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
| | - Rolf B. Saager
- Linköping University, Department of Biomedical Engineering, Linköping, Sweden
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Arora R, Gupta I, Sahu J, Vishwanath S, Gupta P, Jain P. Corneal aberrations, densitometry on scheimpflug imaging, and visual acuity after deep anterior lamellar keratoplasty. Eur J Ophthalmol 2022; 33:11206721221128863. [PMID: 36172635 DOI: 10.1177/11206721221128863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
PURPOSE To evaluate visual acuity, corneal aberrations, and densitometry post deep anterior lamellar keratoplasty (DALK). METHODS Twenty-five eyes of 25 patients who underwent DALK for corneal stromal diseases with normal endothelium were enrolled in a prospective interventional study. Evaluation for corneal aberrations and densitometry postoperatively was performed using Scheimpflug imaging at 6 months. Anterior Segment Optical Coherence Tomography (ASOCT) was done for host-graft morphology. Correlation analysis of postoperative best-corrected visual acuity with corneal aberrations and corneal densitometry (CD) was performed. RESULTS Big bubble deep anterior lamellar keratoplasty (BB-DALK) was successful in 18 patients, while 7 eyes underwent manual dissection due to failed BB (Big Bubble) technique. The mean BSCVA was 1.35 ± 0.46 logMAR units pre-operatively which improved to 0.36 ± 0.19 logMAR units post DALK at 6 months (P < 0.001). The mean Root Mean Square (RMS) (μm) of the magnitude of total corneal aberrations, HOA and LOA from central 6mm zone of cornea were 14.6 ± 9.2, 4.7 ± 2.9, and 13.8 ± 8.8, respectively. The mean anterior (120μm), central and posterior corneal (60μm) densitometry in 0-2mm zone were 25.8 ± 7.7 GSU, 18.7 ± 4.16 GSU and 10.09 ± 3.9 GSU respectively. A statistically significant correlation of postoperative residual stromal bed thickness, total corneal HOA, LOA, total corneal aberrations, HOA front and posterior corneal densitometry (0-2mm zone) with postoperative BSCVA was found. CONCLUSION Though there is a significant improvement in BSCVA after DALK, the quality of vision in terms of aberrometry and densitometry is suboptimal, especially in cases undergoing manual DALK compared to those undergoing big bubble formation.
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Affiliation(s)
- Ritu Arora
- Department of Ophthalmology (76300Guru Nanak Eye Centre), Maulana Azad Medical College, New Delhi, India
| | - Isha Gupta
- Department of Ophthalmology (76300Guru Nanak Eye Centre), Maulana Azad Medical College, New Delhi, India
| | - Jigyasa Sahu
- Department of Ophthalmology (76300Guru Nanak Eye Centre), Maulana Azad Medical College, New Delhi, India
| | - Shweta Vishwanath
- Department of Ophthalmology (76300Guru Nanak Eye Centre), Maulana Azad Medical College, New Delhi, India
| | - Palak Gupta
- Department of Ophthalmology (76300Guru Nanak Eye Centre), Maulana Azad Medical College, New Delhi, India
| | - Parul Jain
- Department of Ophthalmology (76300Guru Nanak Eye Centre), Maulana Azad Medical College, New Delhi, India
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13
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Kaur M, Xu M, Wang L. Cyto-Genotoxic Effect Causing Potential of Polystyrene Micro-Plastics in Terrestrial Plants. Nanomaterials (Basel) 2022; 12:2024. [PMID: 35745363 DOI: 10.3390/nano12122024] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 12/03/2022]
Abstract
The polystyrene micro-plastics (Ps-MPs) is one of the leading pollutants found in both aquatic and terrestrial ecosystems. While most of the studies on the morphology and cyto-toxicity of MPs have been based on aquatic organisms, their effects on terrestrial plants are still scarcely known. The present study was an attempt to measure the effect of different sizes (80, 100, 200, 500, 1000, 2000, 4000, and 8000 nm) and concentrations (100 and 400 mg/L) of Ps-MPs on the root length and chromosomes of root tip cells of Allium cepa using A. cepa root chromosomal aberration assay. Large size Ps-MPs (4000 and 8000 nm) showed the highest reduction in A. cepa root length; however, the differences were not significant (at p ≤ 0.05), with respect to negative control (Milli-Q water). The mitotic index showed both significant size- and concentration-dependent decreases, being the lowest (12.06%) in 100 nm at 100 mg/L concentration, with respect to the control (25.05%). The chromosomal abnormality index (CAI) and nuclear abnormality index (NAI) showed significant decreases, with respect to negative control. In addition, the induction of micro-nucleated cells was also observed in Allium root tip cells, when treated with MPs of all sizes, which can predict direct DNA damage to the plant cells. Hence, we conclude that most of the MP sizes caused cyto-toxic and nuclear damage by adversely impacting the spindle formation and induction of micro-nucleated cells in Allium cepa root tip cells. To the best of our knowledge, this is the first study that showed the effect of considerable size range of Ps-MP sizes on the root length and cell division in plants.
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14
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Zhou K, Wu Z, Zhang T, Li F, Iqbal A, Sivanandam S. Active Aberration Correction with Adaptive Coefficient SPGD Algorithm for Laser Scanning Confocal Microscope. Sensors (Basel) 2022; 22:3755. [PMID: 35632164 PMCID: PMC9147356 DOI: 10.3390/s22103755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
A laser scanning confocal microscope (LSCM) is an effective scientific instrument for studying sub-micron structures, and it has been widely used in the field of biological detection. However, the illumination depth of LSCMs is limited due to the optical aberrations introduced by living biological tissue, which acts as an optical medium with a non-uniform refractive index, resulting in a significant dispersion of the focus of LSCM illumination light and, hence, a loss in the resolution of the image. In this study, to minimize the effect of optical aberrations, an image-based adaptive optics technology using an optimized stochastic parallel gradient descent (SPGD) algorithm with an adaptive coefficient is applied to the optical path of an LSCM system. The effectiveness of the proposed aberration correction approach is experimentally evaluated in the LSCM system. The results illustrate that the proposed adaptive optics system with an adaptive coefficient SPGD algorithm can effectively reduce the interference caused by aberrations during depth imaging.
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Affiliation(s)
- Kunhua Zhou
- Department of Precision Mechanical Engineering, Shanghai University, Shanghai 200444, China; (K.Z.); (T.Z.)
| | - Zhizheng Wu
- Department of Precision Mechanical Engineering, Shanghai University, Shanghai 200444, China; (K.Z.); (T.Z.)
| | - Tianyu Zhang
- Department of Precision Mechanical Engineering, Shanghai University, Shanghai 200444, China; (K.Z.); (T.Z.)
| | - Feng Li
- School of Optical-Electrical and Computer Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;
| | - Azhar Iqbal
- Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4, Canada; (A.I.); (S.S.)
| | - Suresh Sivanandam
- Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4, Canada; (A.I.); (S.S.)
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15
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Morales A, Horstrand P, Guerra R, Leon R, Ortega S, Díaz M, Melián JM, López S, López JF, Callico GM, Martel E, Sarmiento R. Laboratory Hyperspectral Image Acquisition System Setup and Validation. Sensors (Basel) 2022; 22:2159. [PMID: 35336337 DOI: 10.3390/s22062159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/04/2022] [Accepted: 03/09/2022] [Indexed: 12/04/2022]
Abstract
Hyperspectral Imaging (HSI) techniques have demonstrated potential to provide useful information in a broad set of applications in different domains, from precision agriculture to environmental science. A first step in the preparation of the algorithms to be employed outdoors starts at a laboratory level, capturing a high amount of samples to be analysed and processed in order to extract the necessary information about the spectral characteristics of the studied samples in the most precise way. In this article, a custom-made scanning system for hyperspectral image acquisition is described. Commercially available components have been carefully selected in order to be integrated into a flexible infrastructure able to obtain data from any Generic Interface for Cameras (GenICam) compliant devices using the gigabyte Ethernet interface. The entire setup has been tested using the Specim FX hyperspectral series (FX10 and FX17) and a Graphical User Interface (GUI) has been developed in order to control the individual components and visualise data. Morphological analysis, spectral response and optical aberration of these pushbroom-type hyperspectral cameras have been evaluated prior to the validation of the whole system with different plastic samples for which spectral signatures are extracted and compared with well-known spectral libraries.
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16
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Hastings GD, Applegate RA, Schill AW, Hu C, Coates DR, Marsack JD. Clinical applications of personalising the neural components of visual image quality metrics for individual eyes. Ophthalmic Physiol Opt 2022; 42:272-282. [PMID: 34981848 PMCID: PMC8833140 DOI: 10.1111/opo.12937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 01/13/2023]
Abstract
PURPOSE Eyecare is evolving increasingly personalised corrections and increasingly personalised evaluations of corrections on-eye. This report describes individualising optical and neural components of the VSX (visual Strehl) metric and evaluates personalisation using two clinical applications. (1) Better understanding visual experience: While VSX tracks visual performance in typical eyes, non-individualised metrics underestimated visual performance in highly aberrated eyes - could this be understood by personalising metrics? (2) Metric-optimised objective spherocylindrical refractions in typical and atypical eyes have used neural weighting functions of typical eyes - will personalisation affect the outcome in clinical 0.25D steps? METHODS Orientation-specific neural contrast sensitivity was measured in four typical myopic and astigmatic eyes and six eyes with keratoconus. Wavefront error was measured in all eyes while uncorrected and when the keratoconic eyes wore wavefront-guided scleral lenses. Total experiment duration was 24-28 h per subject. Two versions of VSX were calculated for each application: one weighted ocular optics with measured neural contrast sensitivity data from that eye, another weighted optics with a representative neural function of typical eyes. Wavefront-guided corrections were evaluated using the two metric values. Spherocylindrical corrections that optimised each metric were identified. RESULTS Metric values for keratoconic eyes improved by a mean factor of 1.99 (~0.3 log units) when personalised. Applying this factor to a larger sample of eyes from a previous keratoconus study reconciled dissonances between the percentage of eyes reaching normative best-corrected metric levels and the percentages of eyes reaching normative levels of visual acuity and contrast sensitivity. Spherocylindrical corrections that optimised both versions of VSX were clinically equivalent (mean ± SD Euclidean dioptric difference 0.13 ± 0.18 D). CONCLUSIONS Personalising visual image quality metrics is beneficial when actual metric values are used (evaluating ophthalmic corrections on-eye against norms) and when fine increments in visual quality are imparted (wavefront-guided corrections). However, partially individualised metrics appear adequate when metrics relatively rank spherocylindrical corrections in 0.25 D steps.
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Affiliation(s)
- Gareth D Hastings
- College of Optometry, University of Houston, Houston, Texas, USA,Center for Innovation in Vision and Optics, School of Optometry, University of California, Berkeley, California, USA
| | | | | | - Chuan Hu
- College of Optometry, University of Houston, Houston, Texas, USA
| | - Daniel R Coates
- College of Optometry, University of Houston, Houston, Texas, USA
| | - Jason D Marsack
- College of Optometry, University of Houston, Houston, Texas, USA
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17
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Kamal S, Hailstone RK. SEM Nano: An Electron Wave Optical Simulation for the Scanning Electron Microscope. Microsc Microanal 2022; 28:1-13. [PMID: 35190009 DOI: 10.1017/s1431927622000198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The simulation program “SEM Nano” is introduced to explain and visualize probe formation in field-emission scanning electron microscopes (SEMs). The program offers an easy and intuitive graphical user interface (GUI) to provide input in terms of understandable SEM parameters and visualization of the output. The simulations are based on wave optics treatment of the electron beam in the SEM column. Based on input parameters provided by the user, the spatial intensity distribution of electrons is calculated at the specimen by incorporating the effects of diffraction, aberrations, coherence, and noise. Given the specimen structure signal (So), the program has the capability to produce an image of the specimen using the electron probe intensity distribution. Finally, a feature is provided to reconstruct the electron probe intensity from the noisy image using a Wiener filter-based deconvolution.
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Affiliation(s)
- Surya Kamal
- NanoImaging Lab, Chester F. Carlson Center for Imaging Science, Rochester Institute of Technology, Rochester, NY14623, USA
| | - Richard K Hailstone
- NanoImaging Lab, Chester F. Carlson Center for Imaging Science, Rochester Institute of Technology, Rochester, NY14623, USA
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18
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Zhang M, Li X, Hu Q. Analysis on the correlation between long-term refractive regression and visual quality after FS-LASIK. Curr Eye Res 2022; 47:824-831. [PMID: 35179405 DOI: 10.1080/02713683.2022.2035402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To record the long-term visual quality after FS-LASIK and analyze the effect of long-term refractive regression after corneal laser surgery on the visual quality. METHODS 78 patients (153 eyes), who had undergone FS-LASIK more than 5 years before and had undergone follow-ups between November 2020 and March 2021. We collected data on the patients' age of surgery, postoperative period, and preoperative diopters (corrected to LogMAR 0.0 by mydriatic optometry). We obtained the measurements of ARC, PRC, THP by Pentacam, and extracted values for UCVA(LogMAR), CTRmsTotal, CTRmsHO, RmsTotal, RmsHO, MTFTotal, MTFHO, PSFTotal, PSFHO, Coma-T, Coma-CT, SA-T, SA-CT, Trefoil-T, and Trefoil-CT measured with OPD Scan III. We allocated the patients into emmetropia group (SE≤ -0.5D) 40 patients (78 eyes) and regression group (SE>-0.5D) 38 patients (75eyes) based on their postoperative diopters. RESULTS The values for postoperative periods, preoperative diopters, CTRmsTotal, CTRmsHO, and RmsTotal, Coma-CT, CTSA-CT in the emmetropia group were significantly lower than those in the regression group. The age of surgery, UCVA, MTFTotaL, MTFHO, PSFTotal, and CTPSF values in the emmetropia group were significantly higher than those in the regression group. The ARC, PRC, THP, RmsHO, Coma-T, SA-T, Trefoil-T and Trefoil-CT values were similar in both groups. There was no significant difference in preoperative sphere, spherical equivalent and BCVA between the two groups. There were significant differences in postoperative parameters at 1y, 3yrs and 5yrs. The postoperative diopter value was significantly correlated with age of surgery, postoperative period, THP, MTFTotal, PSFTotal, Coma-T, and SA-CT. CONCLUSION After FS-LASIK, young patients with relatively thin cornea are susceptible to refractive regression. With the extension of postoperative period, refractive regression may aggravate. There was no significant correlation between postoperative refractive regression and higher order aberrations.
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Affiliation(s)
- Mingyue Zhang
- Ophthalmology Department, Civil Aviation Medical Center, Beijing, China
| | - Xin Li
- Ophthalmology Department, Civil Aviation Medical Center, Beijing, China
| | - Qingjun Hu
- Ophthalmology Department, Civil Aviation Medical Center, Beijing, China
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19
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Sah RP, Jaskulski M, Kollbaum PS. Modelling the refractive and imaging impact of multi-zone lenses utilised for myopia control in children's eyes. Ophthalmic Physiol Opt 2022; 42:571-585. [PMID: 35170789 PMCID: PMC9544677 DOI: 10.1111/opo.12959] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 11/27/2022]
Abstract
PURPOSE To develop an optical model of a child's eye to reveal the impact of target distance and accommodative behaviour on retinal image quality when fitted with multi-zone lenses. METHODS Pupil size, aberration levels and accommodative lag were adjusted for models viewing stimuli at 400, 100, 33 and 20 cm. Distributions of defocus across the pupil and simulated retinal images were obtained. An equivalent 16-point letter was imaged at near viewing distances, while a 0.00 logMAR (6/6) letter was imaged at 400 cm. Multi-zone lenses included those clinically utilised for myopia control (e.g., dual-focus, multi-segmented and aspherical optics). RESULTS Viewing distance adjustments to model spherical aberration (SA) and pupil radius resulted in a model eye with wider defocus distributions at closer viewing distances, especially at 20 cm. The increasing negative SA at near reduced the effective add power of dual-focus lenses, reducing the amount of myopic defocus introduced by the centre-distance, 2-zone design. The negative SA at near largely compensated for the high positive SA introduced by the aspheric lens, removing most myopic defocus when viewing at near. A 0.50 D accommodative lag had little impact on the legibility of typical text (16-point) at the closer viewing distances. CONCLUSIONS All four multi-zone lenses successfully generated myopic defocus at greater viewing distances, but two failed to introduce significant amounts of myopic defocus at the nearest viewing distance due to the combined effects of pupil miosis and negative SA. Typical 16-point type is easily legible at near even in presence of the multi-zone optics of lenses utilised for myopia control and accommodative lag.
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Affiliation(s)
- Raman Prasad Sah
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Matt Jaskulski
- School of Optometry, Indiana University, Bloomington, Indiana, USA
| | - Pete S Kollbaum
- School of Optometry, Indiana University, Bloomington, Indiana, USA
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20
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Ding C, Chen Y, Li X, Huang Y, Chen H, Bao J. The associations of accommodation and aberrations in myopia control with orthokeratology. Ophthalmic Physiol Opt 2021; 42:327-334. [PMID: 34866209 PMCID: PMC9300108 DOI: 10.1111/opo.12930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 10/20/2021] [Accepted: 10/23/2021] [Indexed: 11/29/2022]
Abstract
Purpose This study aimed to investigate the effect of orthokeratology (OK) on accommodative function and aberrations, to explore the correlations between them and determine what role they play in myopia control. Methods In this prospective case‐controlled study, 61 children were divided into an OK (n = 30) and a single‐vision spectacles (SVS) (n = 31) group. Accommodation and ocular wavefront aberrations in the OK group were measured at baseline and after 1, 3, 6, 9 and 12 months of OK wear, and again at 1 month after stopping OK (13th month). The same procedure was performed in the SVS group at baseline and at 3, 6 and 12 months. Axial length (AL), accommodative lag area and aberrations including spherical aberration (SA), coma and total higher‐order aberrations (HOAs) were analysed. Results During OK wear, the accommodative lag area at each visit was lower than the baseline level (all p < 0.01); all aberrations at each visit were higher than pre‐treatment (all p < 0.001). After 1 month of OK treatment, changes in accommodative lag area and SA did not show significant correlation (p = 0.16), but after OK cessation these changes were correlated (p = 0.01). In the OK group, multivariate regression analysis showed changes in accommodative lag area were associated with AL progression in the first 6 months but not in the 1‐year analysis. For the SVS group, there were no significant changes in the accommodative lag area or any aberrations during the study period. Conclusions Increased HOAs and improved accommodative accuracy were observed during OK treatment, but began to regress after the cessation of OK. A significant positive correlation between improved accommodative accuracy and slowed axial elongation was only observed during the first 6 months of treatment.
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Affiliation(s)
- Chenglu Ding
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Yunyun Chen
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Xue Li
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Yingying Huang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Hao Chen
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,National Clinical Research Center for Ocular Diseases, Wenzhou, China
| | - Jinhua Bao
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, China.,National Clinical Research Center for Ocular Diseases, Wenzhou, China
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21
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Neroev VV, Tarutta EP, Khanjian AT, Harutyunyan SG, Markosian GA, Khodzhabekyan NV. [Optical aberrations of the eyes with various degrees of myopia]. Vestn Oftalmol 2021; 137:14-21. [PMID: 34726853 DOI: 10.17116/oftalma202113705114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose - to comparatively analyze the wavefront aberrations and biometric parameters of the eyes with various degrees of myopia. MATERIAL AND METHODS The study included 134 eyes of 67 patients with mild, moderate and high myopia aged 7-28 (mean age 19.3±1.5 years). The following biometric parameters were examined: anterior chamber depth (ACD), lens thickness (LT), axial length (AL), as well as corneal and total aberrations. The parameters were studied on the Galilei G6 system (Ziemer Ophthalmic Systems AG, Switzerland) and the OPD-Scan III aberrometer (Nidek, Japan). Spherical aberration (SA) was estimated as the sum of Z4+Z8+Z12. RESULTS As the refraction increased, the root mean square higher-order aberrations (RMS HOA) also increased significantly: from 0.24±0.02 μm in mild myopia to 0.45±0.03 μm in high myopia, and in eyes with AL of ≥27.0 mm - to 0.57±0.02 μm (p=0.01). An increase in vertical tilt, vertical coma and vertical trefoil were also observed. Total SA was positive and increased in eyes with moderate myopia compared to those with low myopia (from 0.02±0.01 μm to 0.06±0.02 μm, p=0.02), which coincided with changes in the internal optics of the eye: an increase in ACD and a decrease in LT. At the same time, no differences in corneal aberrations were observed among patients with low and moderate myopia. A significant decrease of SA occurred in high myopia (from 0.06 μm in low myopia to 0.015±0.02 μm in high myopia). The average value of SA was 0.005±0.01 μm in eyes with AL of ≥27.0 mm and appeared to be negative in 40% of cases. The average value of corneal SA was negative (-0.002±0.01μm) in eyes with AL of ≥27.0 mm. This group had predominantly patients with congenital myopia. CONCLUSION An increase of total positive SA in patients with moderate myopia compared to those with low myopia is associated with changes in the internal optics of the eye (ACD, LT). Significant increase of higher-order aberrations and decrease of SA with the transition to negative values was observed in patients with high axial myopia.
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Affiliation(s)
- V V Neroev
- Helmholtz National Medical Research Center of Eye Disease, Moscow, Russia
| | - E P Tarutta
- Helmholtz National Medical Research Center of Eye Disease, Moscow, Russia
| | - A T Khanjian
- Helmholtz National Medical Research Center of Eye Disease, Moscow, Russia
| | - S G Harutyunyan
- Helmholtz National Medical Research Center of Eye Disease, Moscow, Russia
| | - G A Markosian
- Helmholtz National Medical Research Center of Eye Disease, Moscow, Russia
| | - N V Khodzhabekyan
- Helmholtz National Medical Research Center of Eye Disease, Moscow, Russia
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22
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Averich VV, Avetisov SE, Voronin GV. [Results of optical coherence tomography of the retina and optic nerve in keratoconus]. Vestn Oftalmol 2021; 137:275-280. [PMID: 34669338 DOI: 10.17116/oftalma2021137052275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The article reviews the results of optical coherence tomography (OCT) of the retina and optic nerve in patients with keratoconus (KC). This research direction is premised by the possibility that changes in the retina and optic nerve are associated with KC, as well as the potential influence of significant changes in axial eye length, disorders of corneal refraction and increased level of aberrations on the quality of visualization of these ocular structures. Results of the conducted studies were conflicting, but in all they indicated a possibility of OCT findings to be altered in KC patients. Therefore, the question of changing the parameters for OCT of the retina and optic nerve requires further investigation. The main problem that needs solving with evidence based medical research can be phrased as follows: are the changes in OCT findings observed in KC patients the consequence of changes in the retina and optic nerve associated with this disorder, or potential effect of aberrations and irregular astigmatism on the quality of visualization of the studied structures?
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Affiliation(s)
- V V Averich
- Research Institute of Eye Diseases, Moscow, Russia
| | - S E Avetisov
- Research Institute of Eye Diseases, Moscow, Russia.,Sechenov First Moscow State Medical University, Moscow, Russia
| | - G V Voronin
- Research Institute of Eye Diseases, Moscow, Russia.,Sechenov First Moscow State Medical University, Moscow, Russia
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23
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Holečková B, Schwarzbacherová V, Galdíková M, Koleničová S, Halušková J, Staničová J, Verebová V, Jutková A. Chromosomal Aberrations in Cattle. Genes (Basel) 2021; 12:1330. [PMID: 34573313 PMCID: PMC8468509 DOI: 10.3390/genes12091330] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 02/04/2023] Open
Abstract
Chromosomal aberrations and their mechanisms have been studied for many years in livestock. In cattle, chromosomal abnormalities are often associated with serious reproduction-related problems, such as infertility of carriers and early mortality of embryos. In the present work, we review the mechanisms and consequences of the most important bovine chromosomal aberrations: Robertsonian translocations and reciprocal translocations. We also discuss the application of bovine cell cultures in genotoxicity studies.
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Affiliation(s)
- Beáta Holečková
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.S.); (M.G.); (S.K.); (J.H.); (A.J.)
| | - Viera Schwarzbacherová
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.S.); (M.G.); (S.K.); (J.H.); (A.J.)
| | - Martina Galdíková
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.S.); (M.G.); (S.K.); (J.H.); (A.J.)
| | - Simona Koleničová
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.S.); (M.G.); (S.K.); (J.H.); (A.J.)
| | - Jana Halušková
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.S.); (M.G.); (S.K.); (J.H.); (A.J.)
| | - Jana Staničová
- First Faculty of Medicine, Charles University in Prague, Salmovská 1, 121 08 Prague, Czech Republic;
- Department of Chemistry, Biochemistry and Biophysics, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia;
| | - Valéria Verebová
- Department of Chemistry, Biochemistry and Biophysics, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia;
| | - Annamária Jutková
- Department of Biology and Physiology, University of Veterinary Medicine and Pharmacy, Komenského 73, 041 81 Košice, Slovakia; (V.S.); (M.G.); (S.K.); (J.H.); (A.J.)
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Iftimie S, Răduţă AM, Dragoman D. Characterization of Monochromatic Aberrated Metalenses in Terms of Intensity-Based Moments. Nanomaterials (Basel) 2021; 11:1805. [PMID: 34361191 DOI: 10.3390/nano11071805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/08/2021] [Accepted: 07/09/2021] [Indexed: 12/12/2022]
Abstract
Consistent with wave-optics simulations of metasurfaces, aberrations of metalenses should also be described in terms of wave optics and not ray tracing. In this respect, we have shown, through extensive numerical simulations, that intensity-based moments and the associated parameters defined in terms of them (average position, spatial extent, skewness and kurtosis) adequately capture changes in beam shapes induced by aberrations of a metalens with a hyperbolic phase profile. We have studied axial illumination, in which phase-discretization induced aberrations exist, as well as non-axial illumination, when coma could also appear. Our results allow the identification of the parameters most prone to induce changes in the beam shape for metalenses that impart on an incident electromagnetic field a step-like approximation of an ideal phase profile.
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Kim SJ, Kim C, Kim Y, Jeong J, Choi S, Han W, Kim J, Lee B. Dielectric Metalens: Properties and Three-Dimensional Imaging Applications. Sensors (Basel) 2021; 21:s21134584. [PMID: 34283117 PMCID: PMC8272126 DOI: 10.3390/s21134584] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/01/2021] [Accepted: 07/02/2021] [Indexed: 02/05/2023]
Abstract
Recently, optical dielectric metasurfaces, ultrathin optical skins with densely arranged dielectric nanoantennas, have arisen as next-generation technologies with merits for miniaturization and functional improvement of conventional optical components. In particular, dielectric metalenses capable of optical focusing and imaging have attracted enormous attention from academic and industrial communities of optics. They can offer cutting-edge lensing functions owing to arbitrary wavefront encoding, polarization tunability, high efficiency, large diffraction angle, strong dispersion, and novel ultracompact integration methods. Based on the properties, dielectric metalenses have been applied to numerous three-dimensional imaging applications including wearable augmented or virtual reality displays with depth information, and optical sensing of three-dimensional position of object and various light properties. In this paper, we introduce the properties of optical dielectric metalenses, and review the working principles and recent advances in three-dimensional imaging applications based on them. The authors envision that the dielectric metalens and metasurface technologies could make breakthroughs for a wide range of compact optical systems for three-dimensional display and sensing.
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Affiliation(s)
- Sun-Je Kim
- Department of Physics, Myongji University, Myongjiro 116, Namdong, Cheoin-gu, Yongin 17058, Korea; (S.C.); (W.H.); (J.K.)
- Correspondence:
| | - Changhyun Kim
- Inter-University Semiconductor Research Center, School of Electrical and Computer Engineering, Seoul National University, Gwanak-Gu Gwanakro 1, Seoul 08826, Korea; (C.K.); (Y.K.); (B.L.)
| | - Youngjin Kim
- Inter-University Semiconductor Research Center, School of Electrical and Computer Engineering, Seoul National University, Gwanak-Gu Gwanakro 1, Seoul 08826, Korea; (C.K.); (Y.K.); (B.L.)
| | - Jinsoo Jeong
- Hologram Research Center, Korea Electronics Technology Institute, 8 Floor, 11, World cup buk-ro 54-gil, Mapo-gu, Seoul 13488, Korea;
| | - Seokho Choi
- Department of Physics, Myongji University, Myongjiro 116, Namdong, Cheoin-gu, Yongin 17058, Korea; (S.C.); (W.H.); (J.K.)
| | - Woojun Han
- Department of Physics, Myongji University, Myongjiro 116, Namdong, Cheoin-gu, Yongin 17058, Korea; (S.C.); (W.H.); (J.K.)
| | - Jaisoon Kim
- Department of Physics, Myongji University, Myongjiro 116, Namdong, Cheoin-gu, Yongin 17058, Korea; (S.C.); (W.H.); (J.K.)
| | - Byoungho Lee
- Inter-University Semiconductor Research Center, School of Electrical and Computer Engineering, Seoul National University, Gwanak-Gu Gwanakro 1, Seoul 08826, Korea; (C.K.); (Y.K.); (B.L.)
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Sanchez Del Rio M, Goldberg KA, Yashchuk VV, Lacey I, Padmore HA. Simulations of applications using diaboloid mirrors. J Synchrotron Radiat 2021; 28:1041-1049. [PMID: 34212867 DOI: 10.1107/s160057752100401x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 04/14/2021] [Indexed: 06/13/2023]
Abstract
The diaboloid is a reflecting surface that converts a spherical wave to a cylindrical wave. This complex surface may find application in new Advanced Light Source bending-magnet beamlines or in other beamlines that now use toroidal optics for astigmatic focusing. Here, the numerical implementation of diaboloid mirrors is described, and the benefit of this mirror in beamlines exploiting diffraction-limited storage rings is studied by ray tracing. The use of diaboloids becomes especially interesting for the new low-emittance storage rings because the reduction of aberration becomes essential for such small sources. The validity of the toroidal and other mirror surfaces approximating the diaboloid, and the effect of the mirror magnification, are discussed.
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Affiliation(s)
| | | | | | - Ian Lacey
- Advanced Light Source, LBNL, Berkeley, CA, USA
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Zarokosta M, Foutsitzi A, Mpartziotas I, Manthas A, Tsiaoussis J, Mariolis-Sapsakos T. Anomalous anatomic trajectory of the superior thyroid artery encountered during thyroidectomy. A rare case report. J Surg Case Rep 2021; 2021:rjab030. [PMID: 33927847 PMCID: PMC8068421 DOI: 10.1093/jscr/rjab030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 01/21/2021] [Indexed: 11/12/2022] Open
Abstract
Superior thyroid artery (STA), which is one of the primary arteries supplying to the thyroid gland, constitutes a severe consideration of both surgeons and interventional radiologists. Knowledge of the origin, the trajectory, the branching patterns and the anatomic aberrations of STA are of paramount clinical significance, due to its proximity to the external branch of the superior laryngeal nerve and the potentiality of accidental hemorrhage. The present manuscript reports for the first time the anomalous trajectory of the left STA, coursing superficially, through the left sternothyroid muscle and underlines the clinical significance of such aberrations.
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Affiliation(s)
- Maria Zarokosta
- University Department of Surgery, General and Oncologic Hospital of Kifissia "Agii Anargiri", Athens, Greece.,Anatomy and Histology Laboratory, Nursing School, National and Kapodistrian University of Athens, Athens, Greece
| | - Aikaterini Foutsitzi
- University Department of Surgery, General and Oncologic Hospital of Kifissia "Agii Anargiri", Athens, Greece.,Anatomy and Histology Laboratory, Nursing School, National and Kapodistrian University of Athens, Athens, Greece
| | - Iraklis Mpartziotas
- University Department of Surgery, General and Oncologic Hospital of Kifissia "Agii Anargiri", Athens, Greece.,Anatomy and Histology Laboratory, Nursing School, National and Kapodistrian University of Athens, Athens, Greece
| | - Alexandros Manthas
- University Department of Surgery, General and Oncologic Hospital of Kifissia "Agii Anargiri", Athens, Greece.,Anatomy and Histology Laboratory, Nursing School, National and Kapodistrian University of Athens, Athens, Greece
| | - John Tsiaoussis
- Department of Anatomy, Faculty of Medicine, University of Crete, Heraklion, Greece
| | - Theodoros Mariolis-Sapsakos
- University Department of Surgery, General and Oncologic Hospital of Kifissia "Agii Anargiri", Athens, Greece.,Anatomy and Histology Laboratory, Nursing School, National and Kapodistrian University of Athens, Athens, Greece
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Kumar M, Shetty R, Lalgudi VG, Khamar P, Vincent SJ, Atchison DA. The effect of scleral lenses on vision, refraction and aberrations in post-LASIK ectasia, keratoconus and pellucid marginal degeneration. Ophthalmic Physiol Opt 2021; 41:664-672. [PMID: 33769593 DOI: 10.1111/opo.12802] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 01/21/2021] [Indexed: 12/28/2022]
Abstract
PURPOSE To quantify the effect of a single scleral lens design on visual acuity and ocular higher-order aberrations in eyes with post-LASIK ectasia, keratoconus and pellucid marginal degeneration (PMD) that could not achieve satisfactory vision with spectacles or soft contact lenses. METHODS Forty-six eyes of 28 participants fitted with diagnostic scleral lenses (KeraCare) were analysed, including 19, 15 and 12 eyes with post-LASIK ectasia, keratoconus and PMD, respectively. Corrected distance visual acuity (CDVA) and ocular aberrations were measured prior to lens wear and during lens wear after 60 min of settling. An i-Trace aberrometer was used to determine aberrations over a 4.5 mm diameter pupil. RESULTS Before lens wear, the median (95% confidence interval) values across all groups were: CDVA 0.30 (0.30, 0.40) logMAR, spherical equivalent refraction -2.75 (-5.25, -2.12) D, cylindrical refraction 3.75 (2.50, 5.00) D, higher-order-root-mean-square error (HO-RMS) 0.90 (0.64, 1.03) μm and vertical coma co-efficient C(3,-1) -0.32 (-0.42, -0.12) μm. RMS coma of 0.52 (0.40, 0.74) μm was higher for the keratoconus group than for the other groups (p < 0.05). During lens wear, values improved considerably across all groups: CDVA 0.0 (0.0, 0.00) logMAR, spherical equivalent refraction -0.50 (-0.75, +0.50) D, cylindrical refraction 0.50 (0.00, 0.50) D, HO-RMS 0.32 (0.26, 0.42) μm and C(3,-1) +0.12 (+0.02, +0.19) μm (all p < 0.001 compared to pre-lens wear). While reduced significantly, RMS coma remained higher in the keratoconus group at 0.35 (0.31, 0.52) μm than in the post-LASIK ectasia and PMD groups at 0.17 (0.12, 0.21) μm and 0.07 (0.02, 0.46) μm, respectively (p < 0.05). CONCLUSIONS The KeraCare scleral contact lens reduced ocular aberrations and improved visual acuity in patients with post-LASIK ectasia, keratoconus and PMD. The sign of vertical coma changed in keratoconus and PMD.
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Affiliation(s)
| | | | | | | | - Stephen J Vincent
- Centre for Vision and Eye Research, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - David A Atchison
- Centre for Vision and Eye Research, School of Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia
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Goldberg KA, Wojdyla A, Bryant D. Binary Amplitude Reflection Gratings for X-ray Shearing and Hartmann Wavefront Sensors. Sensors (Basel) 2021; 21:s21020536. [PMID: 33451025 PMCID: PMC7828504 DOI: 10.3390/s21020536] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 11/26/2022]
Abstract
New, high-coherent-flux X-ray beamlines at synchrotron and free-electron laser light sources rely on wavefront sensors to achieve and maintain optimal alignment under dynamic operating conditions. This includes feedback to adaptive X-ray optics. We describe the design and modeling of a new class of binary-amplitude reflective gratings for shearing interferometry and Hartmann wavefront sensing. Compact arrays of deeply etched gratings illuminated at glancing incidence can withstand higher power densities than transmission membranes and can be designed to operate across a broad range of photon energies with a fixed grating-to-detector distance. Coherent wave-propagation is used to study the energy bandwidth of individual elements in an array and to set the design parameters. We observe that shearing operates well over a ±10% bandwidth, while Hartmann can be extended to ±30% or more, in our configuration. We apply this methodology to the design of a wavefront sensor for a soft X-ray beamline operating from 230 eV to 1400 eV and model shearing and Hartmann tests in the presence of varying wavefront aberration types and magnitudes.
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Jark W. On obtaining high spectral resolution in extreme ultraviolet/soft X-ray monochromators operating off-plane diffraction in a divergent incident beam. J Synchrotron Radiat 2020; 27:1499-1509. [PMID: 33147175 DOI: 10.1107/s1600577520011194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 08/15/2020] [Indexed: 06/11/2023]
Abstract
When the trajectory of an incident beam is oriented parallel to the grooves of a periodic grating structure the radiation beam is diffracted off-plane orthogonal to the plane of incidence. The diffraction efficiency in this condition is very high and in a grating with a sawtooth profile it can approach the reflection coefficient for a simple mirror, when the diffraction order of interest follows the direction for specular reflection at the flat part of the steps. When this concept is used in a plane grating in a monochromator for synchrotron radiation sources, the incident beam is almost always collimated in order to minimize any deterioration of the beam properties due to aberrations, which will be introduced in the diffraction process when an uncollimated beam is used. These aberrations are very severe when the groove density is constant. It will be shown that the effect of these aberrations can be corrected after the diffraction by the use of astigmatic focusing. The latter can be provided by a crossed mirror pair with different focal lengths in the corresponding orthogonal directions. Then a monochromator based on this concept can provide source size limited spectral resolution in an uncollimated incident beam. This is identical to the spectral resolution that can be provided by the same grating when operated at the same position in a collimated incident beam. The source size limited spectral resolution in this case corresponds to a high spectral resolving power of better than ΔE/E = 10 000 for photon energies around 300 eV in the soft X-ray range.
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Affiliation(s)
- Werner Jark
- Elettra - Sincrotrone Trieste SCpA, SS 14 - km 163.5 in AREA Science Park, Basovizza, Trieste 34149, Italy
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31
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Aliev AGD, Aliev AAG, Nurudinov MM. [Clinical significance of aberrations of the ocular optical system in glaucoma surgery and the capabilities of minimizing them]. Vestn Oftalmol 2020; 136:20-25. [PMID: 32366065 DOI: 10.17116/oftalma202013602120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Despite the achievements of modern pharmacology and laser surgery, traditional glaucoma surgery remains the main method of reducing intraocular pressure (IOP). After successful glaucoma surgery, some of the patients are observed to have a decrease in visual functions not associated with progression of the glaucomatous process. This phenomenon is explained by the effect glaucoma surgery can have on eye refraction; detailed understanding of such changes would significantly speed up functional rehabilitation of these patients. PURPOSE To study the time course of clinical manifestations of aberrations of the ocular optical system in the surgical treatment of glaucoma and to assess the effectiveness of the method used to minimize them. MATERIAL AND METHODS The study included 32 patients (32 eyes), aged from 52 to 73 years. The patients were divided into 2 groups. Patients of the first group (20 eyes) were treated with standard non-penetrating deep sclerectomy (NPDS). In the second group (12 eyes), patients underwent a modified NPDS according to an original method proposed by us. All patients were examined before and monitored after the surgery including precision visometry and corneal topography. RESULTS A significant change in the studied parameters was observed in the first group in the early postoperative period (3rd day) - the average value of corneal astigmatism increased from 0.83±0.12 D to 2.86±0.07 D, while in the second group it increased from 0.86±0.20 D to 1.36±0.12 D. CONCLUSION Non-penetrating deep sclerectomy according to the modified method proposed by us helps achieve higher functional results in the early postoperative period due to the reduction of induced changes in eye refraction.
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Affiliation(s)
- A-G D Aliev
- Dagestan Center of Eye Microsurgery, Kaspiysk, Russia
| | - A A-G Aliev
- Dagestan Center of Eye Microsurgery, Kaspiysk, Russia
| | - M M Nurudinov
- Dagestan Center of Eye Microsurgery, Kaspiysk, Russia
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Lloret T, Navarro-Fuster V, Ramírez MG, Morales-Vidal M, Beléndez A, Pascual I. Aberration-Based Quality Metrics in Holographic Lenses. Polymers (Basel) 2020; 12:E993. [PMID: 32344566 PMCID: PMC7240593 DOI: 10.3390/polym12040993] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 11/16/2022] Open
Abstract
Aberrations and the image quality of holographic lenses were evaluated by a Hartmann-Shack (HS) wavefront sensor. Two lenses, one recorded with a symmetrical configuration and the other with an asymmetrical one, were stored in a photopolymer called Biophotopol. Each was reconstructed with two different wavelengths, 473 nm and 633 nm. Different metrics were applied to determine and quantify the aberration of the lenses (Zernike coefficients, Seidel coefficients, Marechal tolerances, root-mean-square (RMS), peak to valley, critical fraction of the pupil), and the quality of the image they provided (Strehl ratio, entropy, cutoff frequency, modulation transfer function (MTF), and area under the MTF). Good agreement between the metrics related to optical quality was obtained. The negative asymmetric holographic lenses had less aberration than the positive symmetric ones.
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Affiliation(s)
- Tomás Lloret
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain; (T.L.); (M.G.R.); (A.B.)
| | - Víctor Navarro-Fuster
- Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain;
| | - Manuel G. Ramírez
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain; (T.L.); (M.G.R.); (A.B.)
- Instituto Universitario de Física Aplicada a las Ciencias y las Tecnologías, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain;
| | - Marta Morales-Vidal
- Instituto Universitario de Física Aplicada a las Ciencias y las Tecnologías, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain;
| | - Augusto Beléndez
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain; (T.L.); (M.G.R.); (A.B.)
- Departamento de Física, Ingeniería de Sistemas y Teoría de la Señal, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain;
| | - Inmaculada Pascual
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain; (T.L.); (M.G.R.); (A.B.)
- Instituto Universitario de Física Aplicada a las Ciencias y las Tecnologías, Universidad de Alicante, Carretera San Vicente del Raspeig s/n, 03690 San Vicente del Raspeig, Spain;
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Durairaj K, Roy B, Chandrasekaran N, Krishnan SP, Mukherjee A. Silver nanorods induced oxidative stress and chromosomal aberrations in the Allium cepa model. IET Nanobiotechnol 2020; 14:161-166. [PMID: 32433034 PMCID: PMC8675964 DOI: 10.1049/iet-nbt.2019.0224] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 09/22/2019] [Accepted: 11/20/2019] [Indexed: 10/26/2023] Open
Abstract
The production of different size and shape silver nanoparticles (AgNPs) has increased considerably in recent years due to several commercial and biological applications. Here, rod-shaped AgNPs (SNRs) were prepared using the microwave-assisted method and characterised by ultraviolet-visible spectroscopy, and transmission electron microscopy analysis. The present study aims to investigate the cyto-genotoxic effect of various concentrations (5, 10, and 15 µM) of SNRs using Allium cepa model. As a result, concentration-dependent cyto-genotoxic effect of SNRs was observed through a decrease in the mitotic index, and an increase in the chromosomal aberrations such as chromosome break, disturbed metaphase, and anaphase bridge. To check the impact of Ag+ ions, 15 µM silver nitrate (AgNO3) was prepared and tested in all the assays. Furthermore, cell viability and different reactive oxygen species assays were performed to test the cytotoxicity evaluation of SNRs. The authors found that in all the tested assays, SNRs at high concentrations (15 µM) and AgNO3 (15 µM) were observed to cause maximal damage to the roots. Therefore, the current study implies that the cytotoxicity and genotoxicity of SNRs were dependent on the concentration of SNRs.
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Affiliation(s)
- Karthiga Durairaj
- Centre for Nanobiotechnology, Vellore Institute of Technology, Vellore, India
| | - Barsha Roy
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, India
| | | | | | - Amitava Mukherjee
- Centre for Nanobiotechnology, Vellore Institute of Technology, Vellore, India.
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Marcos S, Benedí-García C, Aissati S, Gonzalez-Ramos AM, Lago CM, Radhkrishnan A, Romero M, Vedhakrishnan S, Sawides L, Vinas M. VioBio lab adaptive optics: technology and applications by women vision scientists. Ophthalmic Physiol Opt 2020; 40:75-87. [PMID: 32147855 DOI: 10.1111/opo.12677] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 01/27/2020] [Indexed: 11/29/2022]
Abstract
PURPOSE Adaptive Optics allows measurement and manipulation of the optical aberrations of the eye. We review two Adaptive Optics set-ups implemented at the Visual Optics and Biophotonics Laboratory, and present examples of their use in better understanding of the role of optical aberrations on visual perception, in normal and treated eyes. RECENT FINDINGS Two systems (AOI and AOII) are described that measure ocular aberrations with a Hartmann-Shack wavefront sensor, which operates in closed-loop with an electromagnetic deformable mirror, and visual stimuli are projected in a visual display for psychophysical measurements. AOI operates in infrared radiation (IR) light. AOII is provided with a supercontiniuum laser source (IR and visible wavelengths), additional elements for simulation (spatial light modulator, temporal multiplexing with optotunable lenses, phase plates, cuvette for intraocular lenses-IOLs), and a double-pass retinal camera. We review several studies undertaken with these AO systems, including the evaluation of the visual benefits of AO correction, vision with simulated multifocal IOLs (MIOLs), optical aberrations in pseudophakic eyes, chromatic aberrations and their visual impact, and neural adaptation to ocular aberrations. SUMMARY Monochromatic and chromatic aberrations have been measured in normal and treated eyes. AO systems have allowed understanding the visual benefit of correcting aberrations in normal eyes and the adaptation of the visual system to the eye's native aberrations. Ocular corrections such as intraocular and contact lenses modify the wave aberrations. AO systems allow simulating vision with these corrections before they are implanted/fitted in the eye, or even before they are manufactured, revealing great potential for industry and the clinical practice. This review paper is part of a special issue of Ophthalmic & Physiological Optics on women in visual optics, and is co-authored by all women scientists of the research team.
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Affiliation(s)
- Susana Marcos
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Clara Benedí-García
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Sara Aissati
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Ana M Gonzalez-Ramos
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Carmen M Lago
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Aiswaryah Radhkrishnan
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Mercedes Romero
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Shrilekha Vedhakrishnan
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Lucie Sawides
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
| | - Maria Vinas
- Visual Optics and Biophotonics Lab, Instituto de Optica "Daza de Valdés" (IO-CSIC), Consejo Superior de Investigaciones Científicas, Serrano, Madrid, Spain
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Zivanov J, Nakane T, Scheres SHW. Estimation of high-order aberrations and anisotropic magnification from cryo-EM data sets in RELION-3.1. IUCrJ 2020; 7:253-267. [PMID: 32148853 PMCID: PMC7055373 DOI: 10.1107/s2052252520000081] [Citation(s) in RCA: 407] [Impact Index Per Article: 101.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/06/2020] [Indexed: 05/21/2023]
Abstract
Methods are presented that detect three types of aberrations in single-particle cryo-EM data sets: symmetrical and antisymmetrical optical aberrations and magnification anisotropy. Because these methods only depend on the availability of a preliminary 3D reconstruction from the data, they can be used to correct for these aberrations for any given cryo-EM data set, a posteriori. Using five publicly available data sets, it is shown that considering these aberrations improves the resolution of the 3D reconstruction when these effects are present. The methods are implemented in version 3.1 of the open-source software package RELION.
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Affiliation(s)
- Jasenko Zivanov
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, England
- Biozentrum, University of Basel, Switzerland
| | - Takanori Nakane
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, England
| | - Sjors H. W. Scheres
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 0QH, England
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Almutairi MS, Altoaimi BH, Bradley A. Impact of monovision on dynamic accommodation of early presbyopes. Ophthalmic Physiol Opt 2019; 40:47-59. [PMID: 31879995 DOI: 10.1111/opo.12660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/24/2019] [Accepted: 11/29/2019] [Indexed: 01/13/2023]
Abstract
PURPOSE To examine the impact of monovision on dynamic changes in accommodation, pupil responses, spherical aberration and resultant image quality in early presbyopes. METHODS Refractive state, pupil size and spherical aberration levels were monitored in nine early presbyopes who exhibited some accommodation (40-50 years, mean = 42 ± 2.37 years) using a Shack-Hartmann aberrometer as a binocularly viewed stimulus stepped closer (from 2 m to 40 cm), or farther (from 40 cm to 2 m). Comparison data from two fully presbyopic (i.e. non-accommodating) subjects (ages 46 and 61 years) and two young adults (ages 26 and 29 years) were also collected. Each subject was fit with four different refractive strategies: (1) both eyes corrected for 2 m, (2) both eyes corrected for 40 cm, (3) monovision with the measured right eye corrected for 2 m and, (4) monovision with the right eye corrected for 40 cm. Monochromatic image quality was quantified using the AreaMTF metric. RESULTS When fit with monovision, the largest number of early presbyopes produce an accommodative response dominated by the right eye correction (distance or near) as the stimulus is abruptly changed from the retinal conjugate plane of one eye to that of the other eye. However, the accommodative responses in some early presbyopes were always dominated by the distance corrected eye, the near corrected eye, or by convergence. When the stimulus approached, the near corrected eye experienced high image quality only if there was no accommodative response. However, reduced image quality was observed if an accommodative response was initiated. Neither accommodation nor pupil response latencies were longer with monovision corrections compared with bilateral distance corrections (p > 0.05). In the early presbyopes, spherical aberration was reduced during near viewing, but primarily due to pupil miosis and not lens shape changes. CONCLUSION As the stimulus was abruptly changed from the retinal conjugate plane of the distance corrected eye to that of the near corrected eye, most early presbyopes fit with monovision accommodated, which resulted in a decline, not an increase in image quality in the near corrected eye. These results reveal a non-optimal accommodative strategy in early presbyopes fit with monovision.
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Affiliation(s)
- Meznah S Almutairi
- Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.,School of Optometry, Indiana University, Bloomington, USA
| | - Basal H Altoaimi
- Department of Optometry, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Arthur Bradley
- School of Optometry, Indiana University, Bloomington, USA
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Kayhan B, Coskunseven E, Sahin O, Pallikaris I. The effects of implantable collamer lens implantation on higher order aberrations. Int J Ophthalmol 2019; 12:1848-1852. [PMID: 31850167 DOI: 10.18240/ijo.2019.12.05] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 04/30/2019] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the changes in higher order aberrations (HOAs) after implantable collamer lens (ICL; Staar Surgical, Nidau, Switzerland) implantation. METHODS Totally 30 eyes of 18 patients with myopia were included in this study with an average age of 25.77y (min: 21, max: 40). Refraction, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), HOAs (entire, corneal and internal) were evaluated preoperatively and three months postoperatively. Ocular aberrations were measured by using iTrace (Tracey Technology, Houston, Texas, USA). SPSS (IBM Corp. Released 2013. IBM SPSS Statistics for Windows, Version 22.0. Armonk, NY: IBM Corp) was used for the statistical analysis and the interpretation of the data. P values of less than 0.05 were considered statistically significant. RESULTS The preoperative mean spherical power was -9.01 D (min: -5.00, max: -13.00) and the mean cylindrical error was -2.40 D (min: -0.50, max: -4.75). The postoperative mean residual spherical power was -0.73 D (min: -0.20, max: -1.75) and the mean cylindrical error was -0.89 D (min: -0.18, max: -2.09). Analyses were made on root mean square (RMS) values of total HOAs (tHOAs), spherical aberration, coma and trefoil as entire, corneal and internal components. The differences in entire tHOAs and in internal tHOAs were significant. There was no significant change found in spherical aberrations. The differences in entire coma and in internal coma were significant. There was no significant change found in corneal coma. With respect to trefoil, the only significant difference was in internal trefoil. CONCLUSION The ICL implantation corrects the refractive error successfully and changes entire and internal HOAs of the eye.
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Affiliation(s)
- Belma Kayhan
- Dunyagoz Hospital Group, Istanbul 34337, Turkey.,Department of Ophthalmology, Sultan Abdulhamid Han Training and Research Hospital, the University of Saglik Bilimleri, Istanbul 34668, Turkey
| | | | - Onurcan Sahin
- Dunyagoz Hospital Group, Istanbul 34337, Turkey.,Institute of Vision and Optics, University of Crete, Heraklion 70013, Greece
| | - Ioannis Pallikaris
- Dunyagoz Hospital Group, Istanbul 34337, Turkey.,Institute of Vision and Optics, University of Crete, Heraklion 70013, Greece
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Omar IAN, Zein HA. Accelerated Epithelium-Off Corneal Collagen Cross-Linking For Keratoconus: 12-Month Results. Clin Ophthalmol 2019; 13:2385-2394. [PMID: 31824132 PMCID: PMC6900281 DOI: 10.2147/opth.s232118] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 10/22/2019] [Indexed: 11/23/2022] Open
Abstract
Purpose The main aim of the study was to report visual, refractive, topographic, and aberrometric results of accelerated CXL in patients with keratoconus who were followed for 12 months and to highlight the important parameters that can be used in follow-up. Settings It was a prospective interventional non-randomized case series study, in which 40 keratoconus eyes of 40 patients were studied in the period between April 2016 and July 2018. Methods All eyes were examined preoperatively and post-accelerated CXL to evaluate visual acuity, refractive state, keratometric values, keratoconus indices, and corneal higher order aberrations (HOAs). Results The mean age of the studied patients was 28.4 ± 8.6 years (18-37years). One year after cross-linking, 11.6% of the eyes gained two lines of the UCVA, 26.4% of the eyes gained one line, 49.8% showed no change, 7.1% lost one line, and 5.1% lost two lines. Postoperative BCVA showed 13.7% of the eyes gained at least two lines, 32.5% gained one line, 49.9% had no change, and 3.9% lost one line. The keratometric values changed significantly after CXL; K1 decreased by a mean of 0.41D, K2 by 0.62D while Kmax by 1.57 D. The significant changes in keratoconus indices were in index of vertical asymmetry (IVA), index of surface variance (ISV), and keratoconus index (KI). Vertical coma, spherical aberrations, and trefoil decreased significantly at 12 months compared to baseline values (p = 0.04, 0.017, 0.025, respectively). Conclusion Keratoconus indices especially ISV, IVA, and KI along with HOAsparticularly vertical coma, spherical aberrations, and trefoil can add value beside keratometric readings in the follow-up of eyes treated with accelerated CXL.
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Affiliation(s)
| | - Hosny Ahmed Zein
- Ophthalmology Department, Faculty of Medicine, Minia University, El-Minya, Egypt
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Martínez‐Roda JA, García‐Guerra CE, Diaz‐Doutón F, Pujol J, Salvador A, Vilaseca M. Quantification of forward scattering based on the analysis of double-pass images in the frequency domain. Acta Ophthalmol 2019; 97:e1019-e1026. [PMID: 31050166 PMCID: PMC6849746 DOI: 10.1111/aos.14122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 03/28/2019] [Indexed: 11/26/2022]
Abstract
Purpose To assess forward intraocular scattering by means of a new parameter (Frequency Scatter Index, FSI3) based on the analysing double‐pass retinal images in the frequency domain, which minimizes the impact of aberrations on the results. Methods A prospective observational study was carried out in the Department of Ophthalmology, Hospital Universitari Mútua de Terrassa (Spain) on a group of 19 patients diagnosed with nuclear cataracts of various LOCSIII grades and a control group (CG) with nine healthy eyes. We recorded double‐pass retinal images with a custom set‐up based on a high‐sensitivity digital camera. The FSI3 was then computed using spatial frequencies below three cycles per degree. A preliminary validation of the FSI3 was performed on an artificial eye and two eyes of volunteers with and without commercial diffusers, and under defocus. Results The FSI3 was hardly affected by defocus values up to 2.50 D. The mean (and standard deviation) FSI3 values were as follows: for the CG, 1.19 (0.21); and for LOCSIII grades nuclear opacity 1, 2 and 3, 1.30 (0.12), 1.62 (0.21) and 1.85 (0.21), respectively. Eyes with cataracts showed FSI3 values significantly different than healthy eyes (p = 0.001). A good correlation (ρ = 0.861, p < 0.001) was found between the FSI3 and objective scatter index provided by a commercial instrument. Conclusion Since aberrations have little impact on the FSI3, the light scatter assessment becomes less dependent on the patient's refractive error compensation and the presence of higher‐order aberrations. The FSI3 can further the clinical and scientific understanding of forward intraocular scattering.
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Affiliation(s)
- Joan A. Martínez‐Roda
- Centre for Sensors, Instruments and Systems Development (CD6) Universitat Politècnica de Catalunya (UPC) Terrassa Spain
| | - Carlos E. García‐Guerra
- Centre for Sensors, Instruments and Systems Development (CD6) Universitat Politècnica de Catalunya (UPC) Terrassa Spain
| | - Fernando Diaz‐Doutón
- Centre for Sensors, Instruments and Systems Development (CD6) Universitat Politècnica de Catalunya (UPC) Terrassa Spain
| | - Jaume Pujol
- Centre for Sensors, Instruments and Systems Development (CD6) Universitat Politècnica de Catalunya (UPC) Terrassa Spain
| | - Antoni Salvador
- Ophthalmology Service Hospital Universitari Mútua de Terrassa Terrassa Spain
| | - Meritxell Vilaseca
- Centre for Sensors, Instruments and Systems Development (CD6) Universitat Politècnica de Catalunya (UPC) Terrassa Spain
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Chandapura R, Salomão MQ, Ambrósio R, Swarup R, Shetty R, Sinha Roy A. Bowman's topography for improved detection of early ectasia. J Biophotonics 2019; 12:e201900126. [PMID: 31152630 DOI: 10.1002/jbio.201900126] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 04/08/2019] [Accepted: 05/31/2019] [Indexed: 06/09/2023]
Abstract
The aim of this study was to evaluate whether OCT topography of the Bowman's layer and artificial intelligence (AI) can result in better diagnosis of forme fruste (FFKC) and clinical keratoconus (KC). Normal (n = 221), FFKC (n = 72) and KC (n = 116) corneas were included. Some of the FFKC and KC patients had the fellow eye (VAE-NT) with normal topography (n = 30). The Scheimpflug and OCT scans of the cornea were analyzed. The curvature and surface aberrations (ray tracing) of the anterior corneal surface [air-epithelium (A-E) interface in OCT] and epithelium-Bowman's layer (E-B) interface (in OCT only) were calculated. Four random forest models were constructed: (1) Scheimpflug only; (2) OCT A-E only; (3) OCT E-B only; (4) OCT A-E and E-B combined. For normal eyes, both Scheimpflug and OCT (A-E and E-B combined) performed equally in identifying these eyes (P = .23). However, OCT A-E and E-B showed that most VAE-NT eyes were topographically similar to normal eyes and did not warrant a separate classification based on topography alone. For identifying FFKC eyes, OCT A-E and E-B combined performed significantly better than Scheimpflug (P = .006). For KC eyes, both Scheimpflug and OCT performed equally (P = 1.0). Thus, OCT Topography of Bowman's layer significantly improved the detection of FFKC eyes.
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Affiliation(s)
- Rachana Chandapura
- Imaging, Biomechanics and Mathematical Modeling Solutions, Narayana Nethralaya Foundation, Bangalore, India
| | - Marcella Q Salomão
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanical Study Group, Rio de Janeiro, Brazil
- Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
| | - Renato Ambrósio
- Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
- Rio de Janeiro Corneal Tomography and Biomechanical Study Group, Rio de Janeiro, Brazil
- Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
| | - Rishi Swarup
- Department of Cornea and Refractive Surgery, Swarup Eye Center, Hyderabad, India
| | - Rohit Shetty
- Department of Cornea and Refractive Surgery, Narayana Nethralaya Eye Hospital, Bangalore, India
| | - Abhijit Sinha Roy
- Imaging, Biomechanics and Mathematical Modeling Solutions, Narayana Nethralaya Foundation, Bangalore, India
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Li C, Zhang J, Yin X, Li J, Cao Y, Lu P. Distribution and related factors of corneal regularity and posterior corneal astigmatism in cataract patients. Clin Ophthalmol 2019; 13:1341-1352. [PMID: 31440022 PMCID: PMC6664321 DOI: 10.2147/opth.s212946] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 06/23/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose To study the distribution of posterior corneal astigmatism (PCA) and its influencing factors in Chinese patients before cataract surgery. Patients and methods A retrospective study was conducted in the First Affiliated Hospital of Soochow University, Suzhou, China. In all, this study enrolled 121 eligible eyes of 121 cataract patients. The astigmatism, aberrations and Q value of anterior, posterior and total cornea and anterior segment parameters (ACD, CCT, WTW, ATA) were measured by the Sirius System, and AL was measured by Lenstar LS 900. Cataract was diagnosed using slit-lamp examination. Results The mean age of patients was 67.44±10.66 years old. Mean PCA was 0.31±0.17 (range 0.05–1.09) D and 85.9% eyes had PCA values <0.5 D. With-the-rule (WTR) astigmatism predominated the anterior cornea astigmatism (ACA) (48.8%) and total corneal astigmatism (TCA) (61.2%), while against-the-rule (ATR) astigmatism predominated posterior (86.0%). Significant positive correlation was found between the astigmatic power vector (APV) of ACA and PCA (Pearson correlation=0.318, P<0.001); TCA and PCA (Pearson correlation=0.204, P=0.025); keratometric astigmatism and PCA (Pearson correlation=0.356, P<0.001); this study also found a positive correlation between primary spherical aberration (Z4°) of the total cornea and PCA (Pearson correlation=0.266, P=0.003); primary spherical aberration (Z4°) of the corneal front surface and PCA (Pearson correlation=0.260, P=0.004); total corneal aberrations (Total cornea root mean square [RMS]) and PCA (Pearson correlation=0.327, P<0.001); total corneal higher-order
aberrations (Total HOA RMS) (Pearson correlation=0.232, P=0.011); total corneal lower-order aberrations (Total LOA RMS) (Pearson correlation=0.250, P=0.006). A positive linear correlation between Q value of corneal front surface and PCA, either 6 mm pupil diameter (Pearson correlation=0.264, P=0.003) or 8 mm pupil diameter (Pearson correlation=0.184, P=0.043) was found in this study. Conclusion Corneal aberration, Q value (front surface specifically) was essential that we need to take into consideration when we conduct PCA and intraocular
lens measurement in clinics.
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Affiliation(s)
- Chen Li
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Jiaju Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Xue Yin
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Jianqing Li
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Yihong Cao
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
| | - Peirong Lu
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, People's Republic of China
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Del Águila-Carrasco AJ, Kruger PB, Lara F, López-Gil N. Aberrations and accommodation. Clin Exp Optom 2019; 103:95-103. [PMID: 31284325 DOI: 10.1111/cxo.12938] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 12/26/2022] Open
Abstract
Modern methods of measuring the refractive state of the eye include wavefront sensors which make it possible to monitor both static and dynamic changes of the ocular wavefront while the eye observes a target positioned at different distances away from the eye. In addition to monitoring the ocular aberrations, wavefront refraction methods allow measurement of the accommodative response while viewing with the eye's habitual chromatic and monochromatic aberrations present, with these aberrations removed, and with specific aberrations added or removed. A large number of experiments describing the effects of accommodation on aberrations and vice versa are reviewed, pointing out the implications for fundamental questions related to the mechanism of accommodation.
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Affiliation(s)
| | - Philip B Kruger
- College of Optometry, The State University of New York, New York, NY, USA
| | - Francisco Lara
- Vision Science Research Group (CiViUM), Instituto Universitario de Investigación en Envejecimiento (IUIE), University of Murcia, Murcia, Spain
| | - Norberto López-Gil
- Vision Science Research Group (CiViUM), Instituto Universitario de Investigación en Envejecimiento (IUIE), University of Murcia, Murcia, Spain
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Dhallu SK, Sheppard AL, Drew T, Mihashi T, Zapata-Díaz JF, Radhakrishnan H, Iskander DR, Wolffsohn JS. Factors Influencing Pseudo-Accommodation-The Difference between Subjectively Reported Range of Clear Focus and Objectively Measured Accommodation Range. Vision (Basel) 2019; 3:E34. [PMID: 31735835 DOI: 10.3390/vision3030034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 06/06/2019] [Accepted: 06/20/2019] [Indexed: 02/07/2023] Open
Abstract
The key determinants of the range of clear focus in pre-presbyopes and their relative contributions to the difference between subjective range of focus and objective accommodation assessments have not been previously quantified. Fifty participants (aged 33.0 ± 6.4 years) underwent simultaneous monocular subjective (visual acuity measured with an electronic test-chart) and objective (dynamic accommodation measured with an Aston open-field aberrometer) defocus curve testing for lenses between +2.00 to −10.00 DS in +0.50 DS steps in a randomized order. Pupil diameter and ocular aberrations (converted to visual metrics normalized for pupil size) at each level of blur were measured. The difference between objective range over which the power of the crystalline lens changes and the subjective range of clear focus was quantified and the results modelled using pupil size, refractive error, tolerance to blur, and ocular aberrations. The subjective range of clear focus was principally accounted for by age (46.4%) and pupil size (19.3%). The objectively assessed accommodative range was also principally accounted for by age (27.6%) and pupil size (15.4%). Over one-quarter (26.0%) of the difference between objective accommodation and subjective range of clear focus was accounted for by age (14.0%) and spherical aberration at maximum accommodation (12.0%). There was no significant change in the objective accommodative response (F = 1.426, p = 0.229) or pupil size (F = 0.799, p = 0.554) of participants for levels of defocus above their amplitude of accommodation. Pre-presbyopes benefit from an increased subjective range of clear vision beyond their objective accommodation due in part to neural factors, resulting in a measured depth-of-focus of, on average, 1.0 D.
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Hoshing A, Samant M, Bhosale S, Naik AM. Comparison of higher order aberrations in amblyopic and non-amblyopic eyes in pediatric patients with anisometropic amblyopia. Indian J Ophthalmol 2019; 67:1025-1029. [PMID: 31238401 PMCID: PMC6611289 DOI: 10.4103/ijo.ijo_1625_18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Purpose: To compare the ocular higher order aberrations (HOAs) for the physiologic pupil size in amblyopic and non-amblyopic eyes of patients with anisometropic amblyopia in pediatric age group. Methods: Children between 5 and 15 years age having treatment naïve anisometropic amblyopia; after a detailed examination by a pediatric ophthalmologist; underwent assessment of wavefront aberrations for both amblyopic and non-amblyopic eyes at their physiologic pupil sizes using i-Trace ray tracing wavefront aberrometer. The axial lengths were also measured using IOL Master 500. The RMS values of the total ocular higher order aberrations (HOAs) and those arising from internal and corneal components of the two eyes were tabulated and compared to look for differences. Comparison of total ocular aberrations for pre-determined refractive error groups was also done for amblyopic and non-amblyopic eyes separately. Results: Eighty-eight eyes of 44 subjects were included for analysis. Mean pupil size was comparable in between amblyopic and non-amblyopic eyes (3.98 mm vs. 4.07 mm, P = 0.346). The mean axial lengths of the two eyes were comparable (amblyopic eyes 23.13 mm vs. non-amblyopic eyes 22.88 mm, P = 0.419). Significant differences in total HOAs and those arising from the internal optics (except spherical aberrations) of the eye were noted between the two eyes. There were no differences in the corneal HOAs. The total HOAs were comparable amongst the various refractive error groups for amblyopic and non-amblyopic eyes individually. Conclusion: There are significant differences in ocular HOAs between amblyopic and non-amblyopic eyes in children with anisometropic amblyopia.
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Affiliation(s)
- Abhishek Hoshing
- Department of Pediatric Ophthalmology and Strabismus, Laxmi Eye Institute, Uran Road, Panvel, Maharashtra, India
| | - Monica Samant
- Department of Pediatric Ophthalmology and Strabismus, Laxmi Eye Institute, Uran Road, Panvel, Maharashtra, India
| | - Seema Bhosale
- Department of Pediatric Ophthalmology and Strabismus, Laxmi Eye Institute, Uran Road, Panvel, Maharashtra, India
| | - Anaya M Naik
- Department of Pediatric Ophthalmology and Strabismus, Laxmi Eye Institute, Uran Road, Panvel, Maharashtra, India
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Abstract
Ophthalmic lens design concerns the control of spectacle lens aberrations which occur when the eye rotates away from the optical centre of the lens. The most significant aberrations are oblique astigmatism and mean oblique error (power error). A brief review of these aberrations is given, explaining how the lens designer can control them using just the bending of the lens, and what results can be achieved using simple spherical and toroidal surfaces. Before 1985, aspherical surfaces were used only for post-cataract spectacle lenses and high-power magnifiers. Today, aspherical surfaces are used by all major lens manufacturers to produce thinner, lighter and more attractive best-form lenses in the normal power range. Aspherical surfaces are employed because the surface itself is astigmatic and the surface astigmatism is used to combat aberrational astigmatism due to oblique incidence. The various types of aspherical surface and how the surface astigmatism arises is described, before considering how this feature is used to produce flatter, thinner lenses. In the case of astigmatic prescriptions, the surface requires different asphericities along its principal meridians and the geometry of these atoroidal surfaces is also described. The advent of free-form manufacturing techniques requires the lens designer to convert the surface description to the (x,y,z) co-ordinates needed to generate the surface. Examples of how these co-ordinates can be obtained from the equation to the surface are given for toroidal and aspherical surfaces. In the case of free-form progressive surfaces, the pre-determined z-co-ordinates must be added to the z-co-ordinates of the prescription surface to obtain the final free-form surface. In the case of optimised prescription surfaces, on-board software will analyse the result by ray tracing to obtain the final z-co-ordinates.
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Affiliation(s)
- Mohammed Jalie
- Department of Biomedical Science, Ulster University, Coleraine, Northern Ireland, UK
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Thibos LN. Calculation of the geometrical point-spread function from wavefront aberrations. Ophthalmic Physiol Opt 2019; 39:232-244. [PMID: 31172533 DOI: 10.1111/opo.12619] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 04/10/2019] [Indexed: 01/30/2023]
Abstract
PURPOSE This report uses the principles of geometrical optics to compute the optical point-spread function (PSF) from the wavefront error function. METHOD Step 1 uses Prentice's rule to determine the spatial form of the PSF established by tracing a field of rays from the eye's exit pupil to the retina. Ray vergence is related to the slope of the wavefront error function, which enables the mapping of light rays to produce a retinal 'spot diagram'. Step 2 completes the PSF by assigning an irradiance value to each ray in the spot diagram. RESULTS AND CONCLUSIONS Spot irradiance is inversely proportional to the Gaussian curvature (i.e. the product of principal curvatures) of each local region of wavefront error surface centered on the corresponding ray. The Gaussian curvature, in turn, may be computed as the determinant of the vergence error matrix associated with each point on the wavefront error surface. Elements of the vergence error matrix consist of sums and differences of the local power vector components M, J0 and J45 . This method is shown to be equivalent to published derivations of the geometric PSF using the Jacobian of the ray mapping function and equivalent also to the Hessian of the wavefront error function. Examples are presented for the familiar cases of spherical and astigmatic blur as well as for higher order aberrations and the formation of caustics in the retinal image.
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Affiliation(s)
- Larry N Thibos
- School of Optometry, Indiana University, Bloomington, USA
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Neroev VV, Tarutta EP, Harutyunyan SG, Khandzhyan AT, Khodzhabekyan NV, Proskurina OV. [Wavefront and accommodation parameters under different conditions of correction in myopia and hyperopia]. Vestn Oftalmol 2018; 134:15-20. [PMID: 30499534 DOI: 10.17116/oftalma201813405115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE To compare the wavefront and accommodation parameters without correction and in soft contact lenses (SCL) in natural and cycloplegic conditions in eyes with myopia and hyperopia. MATERIAL AND METHODS A total of 142 myopic (mean -5.6±1.4 D) and 48 hyperopic (mean +3.5±1.1 D) eyes were examined in 95 patients aged 5-32 years (mean age 16.9±0.9 years) to compare the wavefront aberrations without correction and with different SCL before and after cycloplegia (two drops of cyclopentolate hydrochloride 1%). The device was set up for 4 mm zone for both narrow and wide pupils. To compare the accommodation parameters under different correction conditions, 85 patients aged 8-23 years (mean age 14.9±0.6 years) with average myopia of (-)5.27±1.4D (123 eyes) and average hyperopia of +3.53±1.2 D (46 eyes) were chosen from the study group. Among the measured parameters are objective accommodative response (OAR), relative accommodation reserves (RAR), pseudoaccumulation amplitude (PA), higher-order aberrations: RMSHOAs, 6-9 Trefoil, 7-8 Coma, spherical aberration (SA). RESULTS In myopic eyes with SCL Coma 7 decreases, Coma 8 increases with transition to positive values, and Trefoil 9 increases. In hyperopic eyes, trefoil 6 decreases, Coma 7-8 go negative. In myopic or hyperopic eyes with SCL, SA goes from positive to negative. In both myopia and hyperopia, accommodation and PA rates are higher in SCL than in glasses. CONCLUSION SCL change certain wavefront parameters for myopia and hyperopia in different ways. The accommodation parameters in SCL are elevated in both myopia and hyperopia. The negative spherical aberration induced by contact lenses improves the accommodative response. The revealed features should be considered in the development of correction methods that target refractogenesis.
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Affiliation(s)
- V V Neroev
- Helmholtz Moscow Research Institute of Eye Diseases, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062
| | - E P Tarutta
- Helmholtz Moscow Research Institute of Eye Diseases, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062
| | - S G Harutyunyan
- Helmholtz Moscow Research Institute of Eye Diseases, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062
| | - A T Khandzhyan
- Helmholtz Moscow Research Institute of Eye Diseases, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062
| | - N V Khodzhabekyan
- Helmholtz Moscow Research Institute of Eye Diseases, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062
| | - O V Proskurina
- Helmholtz Moscow Research Institute of Eye Diseases, 14/19 Sadovaya-Chernogryazskaya St., Moscow, Russian Federation, 105062
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Yousif MO, Said AMA. Contralateral eye study of refractive, topographic and aberrometric outcomes after femtosecond assisted MyoRing implantation and DALK for management of keratoconus. Int J Ophthalmol 2018; 11:1621-1630. [PMID: 30364157 DOI: 10.18240/ijo.2018.10.08] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Accepted: 07/12/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To evaluate the efficacy of femtosecond laser assisted MyoRing intrastromal corneal implant and deep anterior lamellar keratoplasty (DALK) for management of moderate to advanced keratoconus regarding the degree of changes in visual acuity, refraction, corneal asphericity and aberrations. METHODS A prospective non comparative interventional case study was conducted in Ophthalmology Department, Ain Shams University Hospital in the period from January 2015 to February 2017. The study included 30 eyes of moderate to advanced keratoconus. MyoRing was implanted in one eye (Group I) and DALK operation was performed in the contralateral eye of the same patient (Group II). Preoperative and 6mo post-operative uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), corneal and refractive astigmatisms, keratometry and Q-value using topography images were acquired. Quality of vision was assessed in all eyes including total corneal, anterior corneal high order aberrations analysis at 5 mm pupil size and the Strehl ratio of point spread function (PSF) as an objective measure of glare. RESULTS Mean postoperative UCVA, CDVA, SE, refractive astigmatism, keratometry readings and asphericity were statistically improved compared to preoperative parameters in both groups (P<0.05). Significant reduction of all corneal aberrations following both techniques (P<0.05) was achieved except mean trefoil and mean PSF in Group I (P>0.05). Postoperative corneal aberrations were significantly lower in Group II compared to Group I. A statistically significant negative correlation was found in Group I between the mean change in CDVA (logMAR) and the mean preoperative and mean postoperative total corneal aberrations root mean square (RMS; r=-0.78, P=0.04). Also a statistically significant negative correlation was found between mean preoperative coma RMS and mean post PSF (r=-0.86, P=0.01). In Group II, there was a statistically significant positive correlation between mean change in CDVA (logMAR) and mean change in Kmax (r=0.87, P=0.01) and between mean change in refractive cylinder and mean postoperative PSF (r=0.76, P=0.05). CONCLUSION Femtosecond laser assisted MyoRing and DALK are effective in improving visual acuities, refraction, corneal asphericity and aberrations. MyoRing reduced spherical error more than the corneal cylinder. Post operative homogenous corneal surface and good image quality were achieved following both techniques compared to the preoperative state. However, DALK results in better image quality and lower corneal aberrations.
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Affiliation(s)
- Mohamed Omar Yousif
- Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo 11736, Egypt
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Wada G, Vincent M, Lee M. Inner Leaf Gel of Aloe striata Induces Adhesion-Reducing Morphological Hyphal Aberrations. J Fungi (Basel) 2018; 4:jof4010023. [PMID: 29419783 PMCID: PMC5872326 DOI: 10.3390/jof4010023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/03/2018] [Accepted: 02/06/2018] [Indexed: 11/30/2022] Open
Abstract
Fungi, particularly molds that are cosmopolitan in soils, are frequent etiologic agents of opportunistic mycoses. Members of the Fusarium solani and Fusarium oxysporum species complexes are the most commonly implicated etiologic agents of opportunistic fusarial infections in mammals, while Paecilomyces variotii is one of the most frequently encountered Paecilomyces species in human infections. Prevention and treatment of these mycoses are problematic because available antimycotics are limited and often have toxic side effects. Popular folk medicines, such as the inner leaf gel from Aloe spp., offer potential sources for novel antimycotic compounds. To screen for antifungal properties of Aloe striata, we treated conidia of three strains each of F. solani, F. oxysporum, and P. variotii with homogenized and filtered inner leaf gel. Exposure to gel homogenates caused minimal inhibition of conidial germination in tested strains. However, it significantly increased the frequency of hyphal aberrations characterized by increased hyphal diameters that resulted in intervals of non-parallel cell walls. Non-parallel cell walls ostensibly reduce total hyphal surface area available for adhesion. We found a significant decrease in the ability of aberrated P. variotii hyphae to remain adhered to microscope slides after repeated washing with reverse osmosis water. Our results suggest that treatment with A. striata contributes to a decrease in the adhesion frequency of tested P. variotii strains.
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Affiliation(s)
- Gloria Wada
- Department of Microbiology, Miami University, Oxford, OH 45056, USA.
| | - Michael Vincent
- Department of Biology, Miami University, Oxford, OH 45056, USA.
| | - Marcia Lee
- Department of Microbiology, Miami University, Oxford, OH 45056, USA.
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Chandapura RS, Shetty R, Shroff R, Shilpy N, Francis M, Sinha Roy A. OCT layered tomography of the cornea provides new insights on remodeling after photorefractive keratectomy. J Biophotonics 2018; 11:e201700027. [PMID: 28700139 DOI: 10.1002/jbio.201700027] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 05/25/2017] [Accepted: 05/25/2017] [Indexed: 06/07/2023]
Abstract
OCT (optical coherence tomography) of corneal layers was generated to analyze the remodeling of the epithelium and stroma after photorefractive keratectomy (PRK). Myopic PRK was performed in 15 patients. One eye underwent manual scraping of epithelium while the other was treated with Epi clear. Epi clear allowed a gentler removal of the epithelium compared to manual scraping. Scheimpflug (Pentacam, OCULUS Optikgerate Gmbh, Wetzlar, Germany) and OCT (RTVue, Optovue Inc., Fremont, California, USA) scans of the cornea were performed before and after PRK (3 months). The OCT scanner and Pentacam acquired 8 and 25 radial 2-D scans of the cornea, respectively. The results showed similar topographic changes on the anterior corneal surface between Scheimpflug and OCT imaging. The curvature of the underlying anterior surface of the stroma after PRK was similar to the anterior corneal surface (air-epithelium interface), when measured with OCT. Aberrometric changes were mostly similar between Scheimpflug and OCT. However, Scheimpflug imaging reported greater changes in spherical aberration and corneal higher order aberrations than OCT after PRK. This is the first study to quantify the curvatures of the stromal layers with OCT after PRK. New insights were gained, which could be useful for refinement of surgical ablation algorithms, refractive procedures and detection of ectasia.
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Affiliation(s)
- Rachana S Chandapura
- Imaging, Biomechanics and Mathematical Modeling Solutions, Narayana Nethralaya Foundation, Bangalore, India
| | - Rohit Shetty
- Division of Cornea and Refractive Surgery, Narayana Nethralaya Foundation, Bangalore, India
| | - Rushad Shroff
- Division of Cornea and Refractive Surgery, Narayana Nethralaya Foundation, Bangalore, India
| | - Neha Shilpy
- Division of Cornea and Refractive Surgery, Narayana Nethralaya Foundation, Bangalore, India
| | - Mathew Francis
- Imaging, Biomechanics and Mathematical Modeling Solutions, Narayana Nethralaya Foundation, Bangalore, India
| | - Abhijit Sinha Roy
- Imaging, Biomechanics and Mathematical Modeling Solutions, Narayana Nethralaya Foundation, Bangalore, India
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