1
|
Fukuoka H, Gali HE, Bu JJ, Sella R, Afshari NA. Ultraviolet light exposure and its penetrance through the eye in a porcine model. Int J Ophthalmol 2023; 16:172-177. [PMID: 36816219 PMCID: PMC9922635 DOI: 10.18240/ijo.2023.02.02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 12/14/2022] [Indexed: 02/05/2023] Open
Abstract
AIM To determine the amount of ultraviolet (UV) light irradiance that various layers of the eye receive as sunlight passes through the eye, and to investigate the protective benefits of UV light-blocking contact lenses. METHODS Twenty-four porcine eyes were prepared in one of three ways: isolated cornea, cornea and lens together, or whole eye preparation. UV light irradiance was measured with a UV-A/B light meter before and after the eye preparations were placed over the meter to measure UV light penetration in each eye structure. In the whole eye preparation, a hole was placed in the fovea to measure light as it passed through the vitreous. Subsequently, UV-protective contact lenses were placed over the structures, and UV light penetrance was measured. Measurements of UV light exposure were taken outdoors at various locations and times. RESULTS Cornea absorbed 63.56% of UV light that reached the eye. Cornea and lens absorbed 99.34% of UV light. Whole eye absorbed 99.77% of UV light. When UV-protective contact lenses were placed, absorption was 98.90%, 99.55%, and 99.87%, respectively. UV light exposure was dependent on directionality and time of day, and was greatest in areas of high albedo that reflect significant amounts of light, such as a beach. CONCLUSION Cornea absorbs the majority of UV light that reaches the eye in this model. UV-protective contact lenses reduce UV exposure to the eye. Locations with high albedo expose the eye to higher levels of UV light.
Collapse
|
2
|
Extracellular Vesicles in Corneal Fibrosis/Scarring. Int J Mol Sci 2022; 23:ijms23115921. [PMID: 35682600 PMCID: PMC9180085 DOI: 10.3390/ijms23115921] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 11/24/2022] Open
Abstract
Communication between cells and the microenvironment is a complex, yet crucial, element in the development and progression of varied physiological and pathological processes. Accumulating evidence in different disease models highlights roles of extracellular vesicles (EVs), either in modulating cell signaling paracrine mechanism(s) or harnessing their therapeutic moiety. Of interest, the human cornea functions as a refractive and transparent barrier that protects the intraocular elements from the external environment. Corneal trauma at the ocular surface may lead to diminished corneal clarity and detrimental effects on visual acuity. The aberrant activation of corneal stromal cells, which leads to myofibroblast differentiation and a disorganized extracellular matrix is a central biological process that may result in corneal fibrosis/scarring. In recent years, understanding the pathological and therapeutic EV mechanism(s) of action in the context of corneal biology has been a topic of increasing interest. In this review, we describe the clinical relevance of corneal fibrosis/scarring and how corneal stromal cells contribute to wound repair and their generation of the stromal haze. Furthermore, we will delve into EV characterization, their subtypes, and the pathological and therapeutic roles they play in corneal scarring/fibrosis.
Collapse
|
3
|
On the Relationship between Corneal Biomechanics, Macrostructure, and Optical Properties. J Imaging 2021; 7:jimaging7120280. [PMID: 34940747 PMCID: PMC8706034 DOI: 10.3390/jimaging7120280] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 11/16/2022] Open
Abstract
Optical properties of the cornea are responsible for correct vision; the ultrastructure allows optical transparency, and the biomechanical properties govern the shape, elasticity, or stiffness of the cornea, affecting ocular integrity and intraocular pressure. Therefore, the optical aberrations, corneal transparency, structure, and biomechanics play a fundamental role in the optical quality of human vision, ocular health, and refractive surgery outcomes. However, the inter-relationships of those properties are not yet reported at a macroscopic scale within the hierarchical structure of the cornea. This work explores the relationships between the biomechanics, structure, and optical properties (corneal aberrations and optical density) at a macro-structural level of the cornea through dual Placido–Scheimpflug imaging and air-puff tonometry systems in a healthy young adult population. Results showed correlation between optical transparency, corneal macrostructure, and biomechanics, whereas corneal aberrations and in particular spherical terms remained independent. A compensation mechanism for the spherical aberration is proposed through corneal shape and biomechanics.
Collapse
|
4
|
Factors influencing haze formation and corneal flattening, and the impact of haze on visual acuity after conventional collagen cross-linking: a 12-month retrospective study. BMC Ophthalmol 2021; 21:306. [PMID: 34425775 PMCID: PMC8381497 DOI: 10.1186/s12886-021-02066-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/10/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Our aim was to determine associations of pachymetry, keratometry, and their changes with haze formation and corneal flattening after collagen cross-linking, and to analyse the relationship between postoperative haze and visual outcome. METHODS Retrospective analysis was performed on 47 eyes of 47 patients with keratoconus using the Pentacam HR Scheimpflug camera before and 1, 3, 6 and 12 months after cross-linking. Corneal backscattered light values in grey scale unit were recorded in the anterior, center and posterior corneal layers and in four concentric rings. Surface area- and thickness-corrected grey scale unit values were assessed with an additional calculation. Friedman test with post hoc Wilcoxon signed-rank test was used to analyse changes in visual acuity, pachymetry, keratometry and densitometry. Spearman's rank correlation test was used to detect correlations of haze formation and corneal flattening with pachymetry, keratometry and their postoperative change. Generalized estimating equations analysis was used to investigate the influence of densitometry values on postoperative visual acuity after controlling for the effect of preoperative keratometry. RESULTS One year after treatment, significant flattening was observed in maximum and mean keratometry readings (p < 0.001). Significantly increased densitometry values were observed in three central rings compared to baseline (post hoc p < 0.0125). According to receiver operating characteristic curve, densitometry value of the anterior layer of 0-2 mm ring was the most characteristic parameter of densitometry changes after cross-linking (area under the curve = 0.936). Changes in haze significantly correlated with preoperative maximum keratometry (R = 0.303, p = 0.038) and with the changes in maximum keratometry (R = -0.412, p = 0.004). Changes in maximum keratometry correlated with preoperative maximum keratometry (R = -0.302, p = 0.038). Postoperative haze had a significant impact on uncorrected and best corrected distance visual acuity (β coefficient = 0.006, p = 0.041 and β coefficient = 0.003, p = 0.039, respectively). CONCLUSIONS Our findings indicate that in more advanced keratoconus more significant corneal flattening effect parallel with haze formation can be observed after cross-linking. Despite significant reduction of keratometry, postoperative corneal haze may limit final visual acuity.
Collapse
|
5
|
Choi MK, Le MT, Cho HS, Lee J, Jeon H, Cha SY, Na M, Chun T, Kim JH, Song H, Park C. Transgenic Mice Overexpressing PG1 Display Corneal Opacity and Severe Inflammation in the Eye. Int J Mol Sci 2021; 22:1586. [PMID: 33557346 PMCID: PMC7915784 DOI: 10.3390/ijms22041586] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 12/13/2022] Open
Abstract
Antimicrobial peptides (AMPs) are of interest as alternatives to antibiotics or immunomodulators. We generated and characterized the phenotypes of transgenic mice overexpressing protegrin 1 (PG1), a potent porcine cathelicidin. No obvious differences were observed between PG1 transgenic and wild-type mice in terms of growth, development, general behaviour, and the major immune cell population. However, PG1 transgenic mice intranasally infected with Staphylococcus aureus resulted in a reduction in microscopic pulmonary injury, improved clearance of bacteria, and lower proinflammatory cytokine secretion, compared to those of wild-type mice. On the other hand, approximately 25% of PG1 transgenic mice (n = 54/215) showed corneal opacity and developed inflammation in the eye, resulting ultimately in phthisis bulbi. Immunohistochemical analyses revealed that PG1 and its activator, neutrophil elastase, localized to the basal cells of the cornea and glands in eyelids, respectively. In addition, apoptosis indicated by a Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL)-positive signal was detected from flat cells of the cornea. Our study suggests that the expression regulation or localization of AMPs such as PG1 is important to prevent their adverse effects. However, our results also showed that the cytotoxic effects of PG1 on cells could be tolerated in animals, except for the eyes.
Collapse
Affiliation(s)
- Min-Kyeung Choi
- Department of Stem Cell Biology and Regenerative Biology, Konkuk University, Hwayang-dong, Seoul 05029, Korea; (M.-K.C.); (M.T.L.); (H.-S.C.); (J.L.); (H.J.); (J.-H.K.); (H.S.)
| | - Minh Thong Le
- Department of Stem Cell Biology and Regenerative Biology, Konkuk University, Hwayang-dong, Seoul 05029, Korea; (M.-K.C.); (M.T.L.); (H.-S.C.); (J.L.); (H.J.); (J.-H.K.); (H.S.)
| | - Hye-Sun Cho
- Department of Stem Cell Biology and Regenerative Biology, Konkuk University, Hwayang-dong, Seoul 05029, Korea; (M.-K.C.); (M.T.L.); (H.-S.C.); (J.L.); (H.J.); (J.-H.K.); (H.S.)
| | - Juyoung Lee
- Department of Stem Cell Biology and Regenerative Biology, Konkuk University, Hwayang-dong, Seoul 05029, Korea; (M.-K.C.); (M.T.L.); (H.-S.C.); (J.L.); (H.J.); (J.-H.K.); (H.S.)
| | - Hyoim Jeon
- Department of Stem Cell Biology and Regenerative Biology, Konkuk University, Hwayang-dong, Seoul 05029, Korea; (M.-K.C.); (M.T.L.); (H.-S.C.); (J.L.); (H.J.); (J.-H.K.); (H.S.)
| | - Se-Yeoun Cha
- College of Veterinary Medicine, Chonbuk National University, Iksan 54596, Korea;
| | - Manheum Na
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea; (M.N.); (T.C.)
| | - Taehoon Chun
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea; (M.N.); (T.C.)
| | - Jin-Hoi Kim
- Department of Stem Cell Biology and Regenerative Biology, Konkuk University, Hwayang-dong, Seoul 05029, Korea; (M.-K.C.); (M.T.L.); (H.-S.C.); (J.L.); (H.J.); (J.-H.K.); (H.S.)
| | - Hyuk Song
- Department of Stem Cell Biology and Regenerative Biology, Konkuk University, Hwayang-dong, Seoul 05029, Korea; (M.-K.C.); (M.T.L.); (H.-S.C.); (J.L.); (H.J.); (J.-H.K.); (H.S.)
| | - Chankyu Park
- Department of Stem Cell Biology and Regenerative Biology, Konkuk University, Hwayang-dong, Seoul 05029, Korea; (M.-K.C.); (M.T.L.); (H.-S.C.); (J.L.); (H.J.); (J.-H.K.); (H.S.)
| |
Collapse
|
6
|
Peterson JC, Arrieta E, Ruggeri M, Silgado JD, Mintz KJ, Weisson EH, Leblanc RM, Kochevar I, Manns F, Parel JM. Detection of singlet oxygen luminescence for experimental corneal rose bengal photodynamic antimicrobial therapy. BIOMEDICAL OPTICS EXPRESS 2021; 12:272-287. [PMID: 33520385 PMCID: PMC7818961 DOI: 10.1364/boe.405601] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 10/19/2020] [Accepted: 10/25/2020] [Indexed: 05/03/2023]
Abstract
Rose bengal photodynamic antimicrobial therapy (RB-PDAT) treats corneal infection by activating rose bengal (RB) with green light to produce singlet oxygen (1O2). Singlet oxygen dosimetry can help optimize treatment parameters. We present a 1O2 dosimeter for detection of 1O2 generated during experimental RB-PDAT. The system uses a 520 nm laser and an InGaAs photoreceiver with bandpass filters to detect 1O2 luminescence during irradiation. The system was validated in RB solutions and ex vivo in human donor eyes. The results demonstrate the feasibility of 1O2 dosimetry in an experimental model of RB-PDAT in the cornea.
Collapse
Affiliation(s)
- Jeffrey C Peterson
- Ophthalmic Biophysics Center, Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Ave, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami, 1251 Memorial Dr, Coral Gables, FL 33146, USA
- Miller School of Medicine, University of Miami, 1600 NW 10th Ave #1140, Miami, FL 33136, USA
| | - Esdras Arrieta
- Ophthalmic Biophysics Center, Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Ave, Miami, FL 33136, USA
| | - Marco Ruggeri
- Ophthalmic Biophysics Center, Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Ave, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami, 1251 Memorial Dr, Coral Gables, FL 33146, USA
| | - Juan D Silgado
- Ophthalmic Biophysics Center, Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Ave, Miami, FL 33136, USA
| | - Keenan J Mintz
- Department of Chemistry, University of Miami, 1301 Memorial Dr, Coral Gables, FL 33146, USA
| | - Ernesto H Weisson
- Miller School of Medicine, University of Miami, 1600 NW 10th Ave #1140, Miami, FL 33136, USA
| | - Roger M Leblanc
- Department of Chemistry, University of Miami, 1301 Memorial Dr, Coral Gables, FL 33146, USA
| | - Irene Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
| | - Fabrice Manns
- Ophthalmic Biophysics Center, Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Ave, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami, 1251 Memorial Dr, Coral Gables, FL 33146, USA
- Miller School of Medicine, University of Miami, 1600 NW 10th Ave #1140, Miami, FL 33136, USA
| | - Jean-Marie Parel
- Ophthalmic Biophysics Center, Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Ave, Miami, FL 33136, USA
- Department of Biomedical Engineering, University of Miami, 1251 Memorial Dr, Coral Gables, FL 33146, USA
- Anne Bates Leach Eye Center, Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 900 NW 17th St, Miami, FL 33136, USA
| |
Collapse
|
7
|
Age-related changes in visual search: manipulation of colour cues based on cone contrast and opponent modulation space. Sci Rep 2020; 10:21328. [PMID: 33288789 PMCID: PMC7721812 DOI: 10.1038/s41598-020-78303-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 11/16/2020] [Indexed: 11/09/2022] Open
Abstract
Reduced retinal illuminance affects colour perception in older adults, and studies show that they exhibit deficiencies in yellow-blue (YB) discrimination. However, the influence of colour cues on the visual attention in older individuals remains unclarified. Visual attention refers to the cognitive model by which we prioritise regions within the visual space and selectively process information. The present study aimed to explore the effect of colour on visual search performance in older observers. In our experiment, younger observers wearing glasses with a filter that simulated the spectral transmittance of the aging human lens and older observers performed two types of search tasks, feature search (FS) and conjunction search (CS), under three colour conditions: red-green, YB, and luminance. Targets and distractors were designed on the basis of the Derrington–Krauskopf–Lennie colour representation. In FS tasks, reaction times changed according to colour in all groups, especially under the YB condition, regardless of the presence or absence of distractors. In CS tasks with distractors, older participants and younger participants wearing glasses showed slower responses under chromatic conditions than under the achromatic condition. These results provide preliminary evidence that, for older observers, visual search performance may be affected by impairments in chromatic colour discrimination.
Collapse
|
8
|
Experimental Models for Fungal Keratitis: An Overview of Principles and Protocols. Cells 2020; 9:cells9071713. [PMID: 32708830 PMCID: PMC7408389 DOI: 10.3390/cells9071713] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/08/2020] [Accepted: 07/09/2020] [Indexed: 12/21/2022] Open
Abstract
Fungal keratitis is a potentially blinding infection of the cornea that afflicts diverse patient populations worldwide. The development of better treatment options requires a more thorough understanding of both microbial and host determinants of pathology, and a spectrum of experimental models have been developed toward this end. In vivo (animal) models most accurately capture complex pathological outcomes, but protocols may be challenging to implement and vary widely across research groups. In vitro models allow for the molecular dissection of specific host cell–fungal interactions, but they do so without the appropriate environmental/structural context; ex vivo (corneal explant) models provide the benefits of intact corneal tissue, but they do not provide certain pathological features, such as inflammation. In this review, we endeavor to outline the key features of these experimental models as well as describe key technical variations that could impact study design and outcomes.
Collapse
|
9
|
Oral l-Cysteine Supplementation Enhances the Long Term-Effect of Topical Basic Fibroblast Growth Factor (bFGF) in Reducing the Corneal Haze after Photorefractive Keratectomy in Myopic Patients. Pharmaceuticals (Basel) 2020; 13:ph13040067. [PMID: 32326563 PMCID: PMC7243117 DOI: 10.3390/ph13040067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/10/2020] [Accepted: 04/13/2020] [Indexed: 11/28/2022] Open
Abstract
We aimed at evaluating the long-term effects of l-cysteine oral supplementation to basic fibroblast growth factor (bFGF) eye-drops on corneal re-epithelization and transparency in myopic patients subjected to photorefractive keratectomy (PRK). Forty patients subjected to bilateral PRK for myopia were enrolled and randomly divided into two groups receiving an additional therapy together with the standard postoperative treatment consisting in local tobramycin 0.3%, dexamethasone 0.1%, diclofenac 0.1%, and 0.2% hyaluronate. Group 1 included 20 patients (11 males and 9 females; 34.09 ± 8 years of age) receiving only bFGF eye-drops (10 μg/10 μL) four times a day for 7 days starting from the day of surgery; Group 2 included 20 patients (12 males and 8 females; 37.35 ± 11.5 years of age) who were postoperatively administered with topical basic fibroblast growth factor (bFGF; 10 μg/10 μL) four times a day for 7 days plus oral l-cysteine supplementation (500 mg/capsule) once a day for 15 days, starting 7 days before PRK. Patients were followed-up for 12 months. Clinical ophthalmologic parameters were recorded for all the 80 examined eyes. The corneal transparency was evaluated in vivo by slit lamp and confocal microscopy. The data showed that: (a) the corneal haze occurred in a smaller percentage of the patients who were postoperatively administered with topical bFGF plus oral l-cysteine supplementation (Group 2) compared to patients who received only bFGF (Group 1); (b) at 6 months of follow-up, the stromal mean image brightness of the patients belonging to Group 2 was significantly lower than that of the Group 1 (p < 0.03), and, interestingly, the difference was even more evident at 12 month from the treatment (p < 0.001). Moreover, the final mean of the spherical equivalent refraction was −0.06 ± 0.2 D in Group 1 and −0.08 ± 0.3 D in Group 2, whereas the final uncorrected distance visual acuity (UDVA) was equal or superior to 20/25 in 100% of eyes in both Group 1 and 2. Post refractive patients can benefit from the administration of l-cysteine before the surgery and in association with bFGF in the early postoperative period, showing a faster corneal re-epithelization able to prevent corneal haze in the long-term recovery.
Collapse
|
10
|
Nagra M, Patel M, Barbur J. Changes in forward light scatter parameters as a function of refractive error in young adults. Graefes Arch Clin Exp Ophthalmol 2020; 258:925-930. [PMID: 31912219 PMCID: PMC7575508 DOI: 10.1007/s00417-019-04584-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/10/2019] [Accepted: 12/19/2019] [Indexed: 11/04/2022] Open
Abstract
Background/aims Some aspects of visual performance worsen with increasing myopia. Whilst the underlying causes are not always clear, reduction in retinal image quality is often attributed to structural changes in the posterior myopic eye. Forward light scatter, originating principally from the cornea and lens, is known to produce veiling glare which subsequently reduces retinal image contrast. It is therefore of interest to investigate whether forward light scatter varies with refractive error. Methods Thirteen young-adult subjects (18–25 years), with mean spherical errors (MSE ± sd, D) RE, − 1.69 ± 2.02 (range 0.38 to − 4.75); LE, − 1.91 ± 1.94 (range 0.50 to − 4.63) underwent binocular assessment of forward light scatter using the AVOT light scatter test. Five glare annuli, with effective eccentricities ranging from 2 to 10°, were used to estimate parameters, k and n, which define the light scatter function of the eye. These were then used to calculate the area under the light scatter function (k′) and the total volume of light scatter (k″). Results Significant correlation was found between increasing myopia and k′ values (RE, p < 0.05; r = 0.64; LE, p < 0.05, r = 0.66). Neither the ‘volume’ of light scatter (k″), the parameter, n, which controls the angular distribution of light scatter, or the straylight parameter constant, k, were significantly correlated with refractive error (p > 0.05 for both eyes). Axial length was also not correlated with any of the light scatter parameters measured. Conclusion The preliminary data from this study provide evidence that some light scatter parameters may be correlated with refractive error. Further studies are needed to characterize how changes in the anterior media of the eye, and inclusion of a wider range of refractive errors, may affect forward light scatter.
Collapse
Affiliation(s)
- Manbir Nagra
- School of Health and Care Professions, University of Portsmouth, Portsmouth, PO1 2DT, UK.
| | - Mansi Patel
- Applied Vision Research Centre, Division of Optometry and Visual Science, City, University of London, London, EC1V 0HB, UK
| | - John Barbur
- Applied Vision Research Centre, Division of Optometry and Visual Science, City, University of London, London, EC1V 0HB, UK
| |
Collapse
|
11
|
Dias-Teixeira K, Horton X, McKown R, Romano J, Laurie GW. The Lacritin-Syndecan-1-Heparanase Axis in Dry Eye Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1221:747-757. [PMID: 32274735 PMCID: PMC7398572 DOI: 10.1007/978-3-030-34521-1_31] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Homeostasis and visual acuity of the surface of the eye are dependent on tears, a thin film comprising at least 1800 different extracellular proteins and numerous species of lipids through which 80% of entering light is refracted at the air interface. Loss of homeostasis in dry eye disease affects 5-7% of the world's population, yet little is known about key molecular players. Our story began as an unbiased screen for regulators of tearing that led to the discovery of homeostasis-restorative 'lacritin', a tear protein whose active form is selectively deficient in dry eye. Heparanase acts as a novel 'on-switch' for lacritin ligation of syndecan-1 necessary to trigger basal tearing, as well as pertussis toxin-sensitive and FOXO-dependent signaling pathways for healing of inflammation-damaged epithelia and restoring epithelial oxidative phosphorylation by mitochondrial fusion downstream of transiently accelerated autophagy. A phase 2 clinical trial has tested the applicability of this mechanism to the resolution of dry eye disease. Results are not yet available. With lacritin proteoforms detected in cerebral spinal fluid, plasma, and urine, the capacity of the lacritin-syndecan-1-heparanase axis to restore homeostasis might have wide systemic relevance to other organs.
Collapse
Affiliation(s)
| | - Xavier Horton
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Robert McKown
- School of Integrated Sciences, James Madison University, Harrisonburg, VA, USA
| | - Jeffrey Romano
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Gordon W Laurie
- Departments of Cell Biology, Biomedical Engineering and Ophthalmology, University of Virginia, Charlottesville, VA, USA.
| |
Collapse
|
12
|
Khattak A, An-Nakhli F. Incidence and quantification of corneal haze by Pentacam Scheimpflug densitometry following photorefractive keratectomy for myopia in virgin and post corneal transplant eyes with dark irides. Saudi J Ophthalmol 2020; 34:8-12. [PMID: 33542980 PMCID: PMC7849850 DOI: 10.4103/1319-4534.301295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/26/2019] [Accepted: 02/26/2020] [Indexed: 12/03/2022] Open
Abstract
PURPOSE: To assess the incidence and quantification of corneal haze after myopic photorefractive keratectomy in virgin and post corneal transplant eyes with dark irides. METHODS: In this retrospective study at the tertiary eye hospital, the corneal haze was evaluated by slit-lamp and quantified by Pentacam Scheimpflug densitometry after myopic photorefractive keratectomy with mitomycin C in virgin eyes (group I) and post corneal transplant eyes (group II) with dark irides over 12 months. RESULTS: Group I compromised 126eyes from 77patients (35males and 42females) aged 31.31 years (24.11–36.18 years), and group II compromised 44eyes from 33patients (18males and 15females) aged of 32.25 years (26.15–36.66 years). The incidence of corneal haze was 9.5% (95%CI: 5.0%–16%) and 6.8% (95%CI: 1.4–18.7%) in group I and II respectively (P = 0.587). The corneal densitometry was 22.69 ± 8.28GSU preoperatively and 17.98 ± 3.13GSU at 12 months postoperatively (P = 0.010) in group I. The corneal densitometry was 21.86 ± 6.22GSU preoperatively and 21.23 ± 4.29GSU at 12 months postoperatively (P = 0.815) in group II. High corneal maximal densitometry was associated with the thin central corneal thickness (P = 0.027), the presence of haze (P = 0.028), post-keratoplasty (P = 0.004), steep keratometry (P = 0.035). CONCLUSION: The incidence of corneal haze was comparable in virgin and post corneal transplant eyes. The Pentacam Scheimflug densitometry can be helpful in the diagnosis of corneal haze; however, the cutoff values need to be studied further in larger studies.
Collapse
Affiliation(s)
- Ashbala Khattak
- Dhahran Eyes Specialist Hospital, Eastern Province, Saudi Arabia
| | - Fouad An-Nakhli
- Dhahran Eyes Specialist Hospital, Eastern Province, Saudi Arabia
| |
Collapse
|
13
|
Barrett S, Weimer F, Cosmas J. Virtual eye region: development of a realistic model to convey emotion. Heliyon 2019; 5:e02778. [PMID: 31867450 PMCID: PMC6906678 DOI: 10.1016/j.heliyon.2019.e02778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/19/2019] [Accepted: 10/29/2019] [Indexed: 11/25/2022] Open
Abstract
The human eyes and their surrounding features are capable of conveying an array of emotional and social information through expressions. Producing virtual human eyes which are able to communicate these complex mental states continues to be a challenging research topic in computer graphics (CG) as subtle inaccuracies can be the difference between realistic and uncanny. With the recent emergence of virtual customer service agents, the demand for expressive virtual eyes is increasing. One essential question that remains to be answered is: Can virtual human eyes effectively transmit emotion? Through a combination of 3D scanning and manual hand modelling techniques, we developed an efficient pipeline to realise a virtual model of the human eye area that displays real-world characteristics. From this model eye expression renders of the six basic emotions, anger, disgust, fear, happiness, sadness and surprise were generated (Ekman et al., 1969). The perceptual quality of the model was evaluated by showing respondents from two age groups the six eye expressions renders and corresponding real-world photos. Respondents then judged which of the six emotions best described each image. Our findings indicate a clear relationship between the recognition levels for both photographic and virtual stimuli plus a significant level of emotional perception was found for the virtual eye expressions of sadness and anger. This research of human cognition and CG is a starting point for investigating the use of artificial human eye expressions as an effective research tool in the perceptual community.
Collapse
|
14
|
Gros-Otero J, Ketabi S, Cañones-Zafra R, Garcia-Gonzalez M, Parafita-Fernandez A, Villa-Collar C, Casado S, Teus M. Analysis of corneal stromal roughness after iFS 150 kHz and LenSx femtosecond LASIK flap creation in porcine eyes. Graefes Arch Clin Exp Ophthalmol 2019; 257:2665-2670. [PMID: 31650272 DOI: 10.1007/s00417-019-04497-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/20/2019] [Accepted: 09/23/2019] [Indexed: 10/25/2022] Open
Abstract
PURPOSE To describe and compare the stromal bed roughness obtained after laser in situ keratomileusis (LASIK) flap creation using a corneal femtosecond laser platform (iFS 150) and a "dual" femtosecond (FS) laser platform (LenSx). METHODS This ex vivo experimental study was conducted in an animal model using 12 freshly enucleated porcine eyes, six with each femtosecond laser. The standard laser treatment parameters were used for the experiment. After LASIK flap creation, the corneal stromal roughness was assessed using atomic force microscopy (AFM) in contact mode immersed in liquid. In each sample, surface measurements were obtained in 60 regions of six eyes per FS laser in 10 20 × 20-micron areas of the central corneal stroma at 512 × 512-point resolution. The surface roughness was measured and the root-mean-square (RMS) values of the roughness were obtained. RESULTS The mean RMS ± standard deviation values were 430 ± 150 nm for the corneal femtosecond laser platform and 370 ± 100 nm for the dual FS laser platform (P < 0.011). CONCLUSIONS In this experimental study with AFM, we found smoother stromal beds after LASIK flap creation with LenSx compared to iFS 150 kHz. Further studies are needed to understand visual implications of the differences found.
Collapse
Affiliation(s)
- Juan Gros-Otero
- Clínica Rementería, Calle Almagro, 36, 28010, Madrid, Spain. .,Universidad CEU San Pablo, Madrid, Spain.
| | - Samira Ketabi
- Hospital Universitario Príncipe de Asturias, Madrid, Spain
| | | | - Montserrat Garcia-Gonzalez
- Clínica Rementería, Calle Almagro, 36, 28010, Madrid, Spain.,Clínica Novovisión, Madrid, Spain.,Universidad Europea de Madrid, Madrid, Spain
| | | | | | - Santiago Casado
- Facultad de Ciencia e Ingeniería de Alimentos, Universidad Técnica de Ambato, Ambato, Ecuador.,IMDEA Nanociencia, Madrid, Spain
| | - Miguel Teus
- Hospital Universitario Príncipe de Asturias, Madrid, Spain.,Clínica Novovisión, Madrid, Spain
| |
Collapse
|
15
|
Webb JN, Langille E, Hafezi F, Randleman JB, Scarcelli G. Biomechanical Impact of Localized Corneal Cross-linking Beyond the Irradiated Treatment Area. J Refract Surg 2019; 35:253-260. [PMID: 30984983 DOI: 10.3928/1081597x-20190304-01] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 03/04/2019] [Indexed: 12/11/2022]
Abstract
PURPOSE To investigate the stiffening effect of localized corneal cross-linking (L-CXL) within and beyond the irradiated region in three dimensions. METHODS Ten porcine eyes were debrided of epithelium and incrementally soaked with 0.1% riboflavin solution. Using a customized, sharp-edged mask, half of the cornea was blocked while the other half was exposed to blue light (447 nm). The three-dimensional biomechanical properties of each cornea were then measured via Brillouin microscopy. An imaging system was used to quantify the optimal transition zone between cross-linked and non-cross-linked sections of the cornea when considering light propagation and scattering. RESULTS A broad transition zone of 610 µm in width was observed between the fully cross-linked and non-cross-linked sections, indicating the stiffening response extended beyond the irradiated region. Light propagation and the scattering induced by the riboflavin-soaked cornea accounted for a maximum of 25 and 159 ± 3.2 µm, respectively. CONCLUSIONS The stiffening effect of L-CXL extends beyond that of the irradiated area. When considering L-CXL protocols clinically, it will be important to account for increased stiffening in surrounding regions. [J Refract Surg. 2019;35(4):253-260.].
Collapse
|