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Kleinbeck S, Wolkoff P. Exposure limits for indoor volatile substances concerning the general population: The role of population-based differences in sensory irritation of the eyes and airways for assessment factors. Arch Toxicol 2024; 98:617-662. [PMID: 38243103 PMCID: PMC10861400 DOI: 10.1007/s00204-023-03642-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/16/2023] [Indexed: 01/21/2024]
Abstract
Assessment factors (AFs) are essential in the derivation of occupational exposure limits (OELs) and indoor air quality guidelines. The factors shall accommodate differences in sensitivity between subgroups, i.e., workers, healthy and sick people, and occupational exposure versus life-long exposure for the general population. Derivation of AFs itself is based on empirical knowledge from human and animal exposure studies with immanent uncertainty in the empirical evidence due to knowledge gaps and experimental reliability. Sensory irritation in the eyes and airways constitute about 30-40% of OELs and is an abundant symptom in non-industrial buildings characterizing the indoor air quality and general health. Intraspecies differences between subgroups of the general population should be quantified for the proposal of more 'empirical' based AFs. In this review, we focus on sensitivity differences in sensory irritation about gender, age, health status, and vulnerability in people, based solely on human exposure studies. Females are more sensitive to sensory irritation than males for few volatile substances. Older people appear less sensitive than younger ones. However, impaired defense mechanisms may increase vulnerability in the long term. Empirical evidence of sensory irritation in children is rare and limited to children down to the age of six years. Studies of the nervous system in children compared to adults suggest a higher sensitivity in children; however, some defense mechanisms are more efficient in children than in adults. Usually, exposure studies are performed with healthy subjects. Exposure studies with sick people are not representative due to the deselection of subjects with moderate or severe eye or airway diseases, which likely underestimates the sensitivity of the group of people with diseases. Psychological characterization like personality factors shows that concentrations of volatile substances far below their sensory irritation thresholds may influence the sensitivity, in part biased by odor perception. Thus, the protection of people with extreme personality traits is not feasible by an AF and other mitigation strategies are required. The available empirical evidence comprising age, lifestyle, and health supports an AF of not greater than up to 2 for sensory irritation. Further, general AFs are discouraged for derivation, rather substance-specific derivation of AFs is recommended based on the risk assessment of empirical data, deposition in the airways depending on the substance's water solubility and compensating for knowledge and experimental gaps. Modeling of sensory irritation would be a better 'empirical' starting point for derivation of AFs for children, older, and sick people, as human exposure studies are not possible (due to ethical reasons) or not generalizable (due to self-selection). Dedicated AFs may be derived for environments where dry air, high room temperature, and visually demanding tasks aggravate the eyes or airways than for places in which the workload is balanced, while indoor playgrounds might need other AFs due to physical workload and affected groups of the general population.
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Affiliation(s)
- Stefan Kleinbeck
- Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
| | - Peder Wolkoff
- National Research Centre for the Working Environment, Copenhagen, Denmark
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Chidi-Egboka NC, Jalbert I, Wagner P, Golebiowski B. Blinking and normal ocular surface in school-aged children and the effects of age and screen time. Br J Ophthalmol 2023; 107:1613-1620. [PMID: 36002237 DOI: 10.1136/bjo-2022-321645] [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: 04/13/2022] [Accepted: 08/09/2022] [Indexed: 11/03/2022]
Abstract
PURPOSE Baseline ocular surface characteristics in children require investigation. This study characterised blinking and relationships with ocular symptoms, tear film and digital device use. METHODS 45 children aged 6-15 years (56% female) participated in a cross-sectional study. Ocular surface symptoms (Instant Ocular Symptoms Survey, Dry Eye Questionnaire 5, Symptoms Assessment in Dry Eye, Ocular Surface Disease Index, Ocular Comfort Index and Numerical Rating Scale) and clinical indices (lipid layer thickness, tear secretion and stability, meibomian gland) were assessed. Blink rate and interblink interval were measured in situ using a wearable eye-tracking headset (Pupil Labs GmbH, Germany). Associations between blinking, ocular surface, age, and digital device use (bivariate and partial correlations) and between automated and manually counted blink rate (Bland & Altman) were examined. RESULTS Mean blink rate and interblink interval were 20.5±10.5 blinks/min and 2.9±1.9 s during conversation. There was no difference between automated and manual blink rate (p=0.78) and no relationship between blinking and digital device use, age or sex. Mean group symptoms were within normal range and not associated with clinical measurements including blinking. Greater tear volume was associated with a faster blink rate (r=0.46, p=0.001) and shorter interblink interval (r=-0.36, p=0.02). Older age was associated with improved tear volume (r=0.37, p=0.01) and stability (r=0.38, p=0.01). CONCLUSIONS Blinking characterised in situ was not impacted by age or habitual digital device use. A faster blink rate was associated with greater tear volume but not symptoms. Improved tear function was found with age suggesting that the ocular surface continues to develop through childhood.
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Affiliation(s)
- Ngozi Charity Chidi-Egboka
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Isabelle Jalbert
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Peter Wagner
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia
| | - Blanka Golebiowski
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia
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Chidi-Egboka NC, Jalbert I, Chen J, Briggs NE, Golebiowski B. Blink Rate Measured In Situ Decreases While Reading From Printed Text or Digital Devices, Regardless of Task Duration, Difficulty, or Viewing Distance. Invest Ophthalmol Vis Sci 2023; 64:14. [PMID: 36763349 PMCID: PMC9927758 DOI: 10.1167/iovs.64.2.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Purpose To compare blinking measured in situ during various tasks and examine relationships with ocular surface symptoms. The day-to-day repeatability of the blink rate and interblink interval was assessed. Methods Twenty-four students (28.6 ± 6.3 years; 8 male and 16 female) completed six reading tasks (printed text, laptop, TV, smartphone, smartphone at 50% brightness, smartphone with complex text), and two nonreading tasks (conversation, walking) in a randomized cross-over study. Ocular surface symptoms and clinical signs were assessed. The blink rate and interblink interval were measured using a wearable eye tracking headset. Blink parameters were compared across tasks and time (linear mixed model and post hoc comparisons with Bonferroni correction). Associations between blinking, symptoms, ocular surface, and clinical signs were assessed (Spearman's correlation). The smartphone reading task was completed twice to determine the coefficient of repeatability. Results The blink rate was lower (mean 10.7 ± 9.7 blinks/min) and the interblink interval longer (mean 9.6 ± 8.7 seconds) during all reading tasks compared with conversation (mean 32.4 ± 12.4 blinks/min; 1.5 ± 0.6 seconds) and walking (mean 31.3 ± 15.5 blinks/min; 1.9 ± 1.3s) (P < 0.001). There were no significant differences in blink parameters between any of the reading tasks or between conversation and walking. Changes in blinking occurred within 1 minute of starting the task. No associations were evident between blink rate or interblink interval and ocular surface symptoms or signs. The coefficient of repeatability was ±12.4 blinks/min for blink rate and ±18.8 seconds for interblink interval. Conclusions Spontaneous blinking can be measured reliably in situ. The blink rate was decreased and the interblink interval increased during reading compared with conversation and walking. Changes in blinking were immediate, sustained, and not associated with ocular surface symptoms or signs.
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Affiliation(s)
- Ngozi Charity Chidi-Egboka
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW, Australia
| | - Isabelle Jalbert
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW, Australia
| | - Jiaying Chen
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW, Australia
| | - Nancy E. Briggs
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW, Australia,Mark Wainwright Analytical Centre, UNSW Sydney, Sydney, NSW, Australia
| | - Blanka Golebiowski
- School of Optometry and Vision Science, Faculty of Medicine and Health, UNSW Sydney, Sydney, NSW, Australia
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Prolonged Computer Use by Office Workers Induces Ocular Symptoms Associated With Tear Film Alterations and Overexpression of Mucin 5 AC and Catalase. J Occup Environ Med 2023; 65:34-38. [PMID: 35914288 DOI: 10.1097/jom.0000000000002653] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE The aim of the study was to evaluate office workers for symptoms of computer vision syndrome (CVS) and alterations in the tear film relate to the hours of daily computer use. METHODS Sixty-seven volunteers were divided into 2 groups: 2 to 6 and 7 to 12 hours of daily computer use. Computer vision syndrome symptoms, tear film stability by tear film break-up time test, and composition of mucin 5 AC, catalase, and IL-6 was assessed by relative gene expression of conjunctival impression cytology samples were examined. RESULTS All participants exhibited moderate symptoms of CVS, whereas 90% showed reduced tear film stability. For the 7- to 12-hour (vs 2- to 6-hour) group, these effects were more pronounced and overexpression of mucin 5 AC and catalase was detected. CONCLUSIONS Prolonged computer use induced an overexpression of mucin 5 AC and catalase and instability of the tear film, associated with ocular symptoms.
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Abstract
The 2017 consensus report of the Asia Dry Eye Society (ADES) on the definition and diagnosis of dry eyes described dry eye disease as "Dry eye is a multifactorial disease characterized by unstable tear film causing a variety of symptoms and/or visual impairment, potentially accompanied by ocular surface damage." The report emphasized the instability of tear film and the importance of visual dysfunction in association with dry eyes, highlighting the importance of the evaluation of tear film stability. This report also discussed the concept of tear film-oriented therapy, which stemmed from the definition, and which is centered on provision of insufficient components in each tear film layer and ocular surface epithelium. The current ADES report proposes a simple classification of dry eyes based on the concept of tear film-oriented diagnosis and suggests that there are three types of dry eye: aqueous-deficient, decreased wettability, and increased evaporation. It is suggested that these three types respectively coincide with the problems of each layer: aqueous, membrane-associated mucins, and lipid/secretory mucin. Although each component cannot be quantitatively evaluated with the current technology, a practical diagnosis based on the patterns of fluorescein breakup is recommended. The Asia Dry Eye Society classification report suggests that for a practical use of the definition, diagnostic criteria and classification system should be integrated and be simple to use. The classification system proposed by ADES is a straightforward tool and simple to use, only through use of fluorescein, which is available even to non-dry eye specialists, and which is believed to contribute to an effective diagnosis and treatment of dry eyes.
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Elhusseiny AM, Khalil AA, El Sheikh RH, Bakr MA, Eissa MG, El Sayed YM. New approaches for diagnosis of dry eye disease. Int J Ophthalmol 2019; 12:1618-1628. [PMID: 31637199 DOI: 10.18240/ijo.2019.10.15] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 08/12/2019] [Indexed: 12/31/2022] Open
Abstract
We reviewed the literature for different diagnostic approaches for dry eye disease (DED) including the most recent advances, contradictions and promising diagnostic tools and technique. We performed a broad literature search for articles discussing different methods for diagnosis of DED including assessment of tear osmolarity, tear film stability, ocular biomarkers and others. Articles indexed in PubMed and google scholar were included. With the growing cosmetic industry, environmental pollution, and booming of digital screens, DED is becoming more prevalent. Its multifactorial etiology renders the diagnosis challenging and invites the emergence of new diagnostic tools and tests. Diagnostic tools can be classified, based on the parameter they measure, into tear film osmolarity, functional visual acuity, tear volume, tear turnover, tear film stability, tear film composition, ocular biomarkers and others. Although numerous methods exist, the most accurate diagnosis can be reached through combining the results of more than one test. Many reported tests have shown potential as diagnostic/screening tools, however, require more research to prove their diagnostic power, alone or in combination. Future research should focus on identifying and measuring parameters that are the most specific to DED diagnosis.
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Affiliation(s)
- Abdelrahman M Elhusseiny
- Department of Ophthalmology, Kasr Al Ainy School of medicine, Cairo University, Dokki 12611, Egypt.,Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 900 NW 17 Street, Miami, FL 33136, USA
| | - Ali A Khalil
- Faculty of Medicine, American University of Beirut, Beirut 2341, Lebanon
| | - Reem H El Sheikh
- Department of Ophthalmology, Kasr Al Ainy School of medicine, Cairo University, Dokki 12611, Egypt
| | - Mohammad A Bakr
- Department of Ophthalmology, Kasr Al Ainy School of medicine, Cairo University, Dokki 12611, Egypt
| | - Mohamed Gaber Eissa
- Department of Ophthalmology, Kasr Al Ainy School of medicine, Cairo University, Dokki 12611, Egypt
| | - Yasmine M El Sayed
- Department of Ophthalmology, Kasr Al Ainy School of medicine, Cairo University, Dokki 12611, Egypt
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Yokoi N, Georgiev GA. Tear Film-Oriented Diagnosis and Tear Film-Oriented Therapy for Dry Eye Based on Tear Film Dynamics. Invest Ophthalmol Vis Sci 2019; 59:DES13-DES22. [PMID: 30481801 DOI: 10.1167/iovs.17-23700] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In December 2010 and January 2012, 3% diquafosol sodium ophthalmic solution and 2% rebamipide ophthalmic suspension, respectively, appeared first in Japan as prescription drugs for the treatment of dry eye (DE). Since then, not only the diagnosis and treatment but also the understanding of the pathophysiology of DE have greatly advanced, and a new concept of layer-by-layer diagnosis and treatment for DE, respectively termed "tear-film-oriented diagnosis" (TFOD) and "tear-film-oriented therapy" (TFOT) was born. This new concept is currently in the process of expanding from Japan to other Asian countries. TFOD is the method used for the differential diagnosis of DE, which includes aqueous-deficiency DE (ADDE), decreased wettability DE (DWDE), and increased evaporation DE (IEDE), through the dynamics of tear film (TF) and breakup patterns (BUPs) after the eye is opened. BUPs and/or each diagnosed DE subtype are/is able to distinguish the insufficient components of the ocular surface that are responsible for each BUP in a layer-by-layer fashion. Aqueous fluid, membrane-associated mucins (especially MUC16), and the lipid layer and/or secretory mucins must be insufficient in ADDE, DWDE, and IEDE, respectively, and this allows for a layer-by-layer treatment to be proposed for each BUP via the supplementation of the insufficient components, using the topical therapy currently available. In Japan, TF breakup is regarded as a visible core mechanism for DE, and an abnormal breakup time (i.e., ≤5 seconds) and symptoms are currently used for the diagnosis of DE. Therefore, TFOD and TFOT could be an ideal and practical pathway for clinicians to manage DE.
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Affiliation(s)
- Norihiko Yokoi
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Georgi As Georgiev
- Department of Optics and Spectroscopy, Faculty of Physics, St. Kliment Ohridski University of Sofia, Sofia, Bulgaria
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Mudgil P, Borchman D, Ramasubramanian A. Insights into Tear Film Stability from Babies and Young Adults: A Study of Human Meibum Lipid Conformation and Rheology. Int J Mol Sci 2018; 19:ijms19113502. [PMID: 30405031 PMCID: PMC6275043 DOI: 10.3390/ijms19113502] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/31/2018] [Accepted: 11/02/2018] [Indexed: 11/22/2022] Open
Abstract
Babies have the most stable tears and people with dry eye have the least stable tears. Meibum may contribute to tear film stability, so in this study, the hydrocarbon chain conformation and rheology of meibum from babies was studied for the first time. Infrared spectroscopy was used to measure lipid phase transitions. Rheology was measured using Langmuir film technology. Meibum from 25 donors 1 to 13 years old was compared with meibum from 18 donors 13 to 25 years old. The phase transition temperature and lipid order (stiffness) increased with increasing age from 1 to 25 years. The increase in meibum lipid order from 1 to 25 years of age may contribute to the instability of the tear film with age and contribute to films with a higher reciprocal compressibility modulus that are not as compressible and not as viscoelastic. Changes in the lipid phase transition parameters of meibum lipid with dry eye are an exacerbation of the changes observed with age. The lower reciprocal compressibility moduli of meibum films from children and babies compared with meibum from adults reiterates higher stability in their films which spread better, resist deformation, and facilitates their ability to be quickly restored after blinking.
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Affiliation(s)
- Poonam Mudgil
- School of Medicine, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia.
| | - Douglas Borchman
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Aparna Ramasubramanian
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
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9
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Inaba T, Tanaka Y, Tamaki S, Ito T, Ntambi JM, Tsubota K. Compensatory increases in tear volume and mucin levels associated with meibomian gland dysfunction caused by stearoyl-CoA desaturase-1 deficiency. Sci Rep 2018; 8:3358. [PMID: 29463801 PMCID: PMC5820245 DOI: 10.1038/s41598-018-21542-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 02/06/2018] [Indexed: 12/25/2022] Open
Abstract
The stearoyl-CoA desaturase (SCD) family of enzymes catalyzes monounsaturated fatty acid synthesis by inserting a cis double bond at the Δ9 position of saturated fatty acids. Disruption of these enzymes has been reported to induce a severe dry skin phenotype. Since lipid abnormalities in the meibomian glands have been associated with dry eye, we analyzed selected eye tissues contributing to tear volume and composition in genetically SCD-1-deficient mice (SCD-1 KO), including the lacrimal glands and conjunctiva. Previous histopathological analysis had revealed atrophy and loss of meibomian glands; taken together with the increased goblet cell and MUC5AC expression in the conjunctiva reported here, these findings suggest that the tear volume and mucin levels secreted are enhanced in the absence of lipid secretion as a compensatory mechanism. The expression of lipid metabolism genes in lacrimal glands was decreased in SCD1 KO mice. Thus, these results provide new pathophysiological mechanisms to pursue with regard to meibomian gland dysfunction. In addition, lack of SCD-1 causes a compensatory increase in the tear volume and mucin levels associated with changes in expression of lipid metabolism genes. These results may be useful as a new concept for dry eye treatment strategies.
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Affiliation(s)
- Takaaki Inaba
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yasuhisa Tanaka
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Shusaku Tamaki
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Tomotaka Ito
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - James M Ntambi
- Departments of Biochemistry and of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
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Sledge S, Henry C, Borchman D, Yappert MC, Bhola R, Ramasubramanian A, Blackburn R, Austin J, Massey K, Sayied S, Williams A, Georgiev G, Schikler KN. Human Meibum Age, Lipid-Lipid Interactions and Lipid Saturation in Meibum from Infants. Int J Mol Sci 2017; 18:ijms18091862. [PMID: 28846660 PMCID: PMC5618511 DOI: 10.3390/ijms18091862] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 07/25/2017] [Accepted: 08/17/2017] [Indexed: 01/21/2023] Open
Abstract
Tear stability decreases with increasing age and the same signs of instability are exacerbated with dry eye. Meibum lipid compositional changes with age provide insights into the biomolecules responsible for tear film instability. Meibum was collected from 69 normal donors ranging in age from 0.6 to 68 years of age. Infrared spectroscopy was used to measure meibum lipid phase transition parameters. Nuclear magnetic resonance spectroscopy was used to measure lipid saturation. Increasing human meibum lipid hydrocarbon chain unsaturation with age was related to a decrease in hydrocarbon chain order, cooperativity, and in the phase transition temperature. The change in these parameters was most dramatic between 1 and 20 years of age. Meibum was catalytically saturated to determine the effect of saturation on meibum lipid phase transition parameters. Hydrocarbon chain saturation was directly related to lipid order, phase transition temperature, cooperativity, changes in enthalpy and entropy, and could account for the changes in the lipid phase transition parameters observed with age. Unsaturation could contribute to decreased tear film stability with age.
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Affiliation(s)
- Samiyyah Sledge
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Collin Henry
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Douglas Borchman
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Marta C Yappert
- Department of Chemistry, University of Louisville, Louisville, KY 40292, USA.
| | - Rahul Bhola
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
- Division of Ophthalmology, Children's Hospital of Orange County, Orange, CA 92868, USA.
| | - Aparna Ramasubramanian
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Ryan Blackburn
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Jonathan Austin
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Kayla Massey
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Shanzeh Sayied
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Aliza Williams
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USA.
| | - Georgi Georgiev
- Model Membranes Lab, Department of Biochemistry, Faculty of Biology, St. Kliment Ohridski University of Sofia, Sofia 1164, Bulgaria.
| | - Kenneth N Schikler
- Department of Pediatrics, University of Louisville, Louisville, KY 40202, USA.
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Choi KE, Song JS, Kang B, Eom Y, Kim HM. Immediate Effect of 3% Diquafosol Ophthalmic Solution on Tear MUC5AC Concentration and Corneal Wetting Ability in Normal and Experimental Keratoconjunctivitis Sicca Rat Models. Curr Eye Res 2016; 42:666-671. [PMID: 27791390 DOI: 10.1080/02713683.2016.1233986] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE To evaluate the immediate effect of 3% diquafosol ophthalmic solution on tear MUC5AC concentration, periodic acid-Schiff (PAS)-positive goblet cells, and tear film stability in normal and keratoconjunctivitis sicca (KCS) rat models. METHODS Rats were divided into normal and KCS groups. 3% of diquafosol solution was instilled into the right eye and normal saline into the left eye in both groups. To determine the peak time of tear MUC5AC concentration, tears were collected after 3% diquafosol instillation every 5 min up to 20 min. The tear film stability and the numbers of PAS-positive goblet cells were compared in both models. RESULTS After diquafosol instillation, tear MUC5AC concentration increased steadily for 15 min, at which point the MUC5AC concentration reached its peak. In both normal and KCS groups, the MUC5AC concentration at 15 min was higher after instillation of 3% diquafosol solution (17.77 ± 2.09 ng/ml in the normal group, 9.65 ± 3.51 ng/ml in the KCS group) than that after saline instillation (13.74 ± 2.87 ng/ml in the normal group, 8.19 ± 3.99 ng/ml in the KCS group) (p = 0.018 for both). The corneal wetting ability was significantly longer after instillation of 3% diquafosol solution compared with that after instillation of normal saline in the normal group (p = 0.018). The percentage of PAS-positive goblet cells after the instillation of 3% diquafosol solution was significantly lower than that after instillation of normal saline in both models (p = 0.018 for both). CONCLUSIONS Diquafosol ophthalmic solution was effective in stimulating mucin secretion in both normal and KCS rat models, and the peak time of tear MUC5AC concentration was 15 min after diquafosol instillation. The increased tear MUC5AC concentration was accompanied by improved tear film stability and a decreased percentage of PAS-positive goblet cells.
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Affiliation(s)
- Kwang-Eon Choi
- a Department of Ophthalmology, Guro Hospital , Korea University College of Medicine , Seoul , South Korea
| | - Jong-Suk Song
- a Department of Ophthalmology, Guro Hospital , Korea University College of Medicine , Seoul , South Korea
| | - Boram Kang
- a Department of Ophthalmology, Guro Hospital , Korea University College of Medicine , Seoul , South Korea
| | - Youngsub Eom
- b Department of Ophthalmology, Ansan Hospital , Korea University College of Medicine , Gyeonggi , South Korea
| | - Hyo-Myung Kim
- c Department of Ophthalmology , Anam Hospital, Korea University College of Medicine , Seoul , South Korea
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12
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Mantelli F, Moretti C, Macchi I, Massaro-Giordano G, Cozzupoli GM, Lambiase A, Bonini S. Effects of Sex Hormones on Ocular Surface Epithelia: Lessons Learned From Polycystic Ovary Syndrome. J Cell Physiol 2015; 231:971-5. [PMID: 26491950 DOI: 10.1002/jcp.25221] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 10/20/2015] [Indexed: 11/08/2022]
Abstract
Polycystic ovary syndrome (PCOS) is the most common endocrine abnormality in women of reproductive age. Although its clinical consequences have been known for a long time to extend beyond the reproductive system, with type-2 diabetes and obesity being the most common, the involvement of the ocular surface in PCOS has been described only more recently. The ocular surface is a morphofunctional unit comprising eyelid margin, tear film, cornea, and conjunctiva. Increasing evidence indicates that these structures are under a sex hormone control and relevant diseases such as ocular allergy and dry eye are often caused by alterations in circulating or local steroid hormones levels. Novel treatments targeting sex hormone receptors on ocular surface epithelial cells are also being developed. In this review we aim to describe the current knowledge on the effects of sex hormones at the ocular surface, with a special focus on the effects of androgen imbalance in PCOS.
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Affiliation(s)
- Flavio Mantelli
- Department of Biology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania
| | - Costanzo Moretti
- Department of Endocrinology, Tor Vergata University of Rome, Rome, Italy
| | - Ilaria Macchi
- Department of Ophthalmology, Campus Bio-Medico University of Rome, Rome, Italy
| | | | | | | | - Stefano Bonini
- Department of Ophthalmology, Campus Bio-Medico University of Rome, Rome, Italy
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13
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Descroix E, Charavel M, Świątkowski W, Graff C. Spontaneous eye-blinking rate from pre-term to six-months. COGENT PSYCHOLOGY 2015. [DOI: 10.1080/23311908.2015.1091062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- Emmanuel Descroix
- Université Pierre Mendès France, Grenoble Alpes University, Grenoble, France
- CNRS UMR5105, Laboratoire de Psychologie et Neurocognition, Grenoble, France
- Psychology Department, Centre de Biologie du Comportement, 1251, avenue centrale, BP 47X, 38400 Grenoble Cedex 9, France
| | - Marie Charavel
- Université Pierre Mendès France, Grenoble Alpes University, Grenoble, France
- Laboratoire Inter-universitaire de Psychologie LIP/PC2S EA4105, Université Pierre Mendès France, Grenoble Alpes University, Grenoble, France
| | | | - Christian Graff
- Université Pierre Mendès France, Grenoble Alpes University, Grenoble, France
- CNRS UMR5105, Laboratoire de Psychologie et Neurocognition, Grenoble, France
- Psychology Department, Centre de Biologie du Comportement, 1251, avenue centrale, BP 47X, 38400 Grenoble Cedex 9, France
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Xiao W, Xu GT, Zhang J, Zhang J, Zhang Y, Ye W. FTY720 ameliorates Dry Eye Disease in NOD mice: Involvement of leukocytes inhibition and goblet cells regeneration in ocular surface tissue. Exp Eye Res 2015; 138:145-52. [PMID: 26187517 DOI: 10.1016/j.exer.2015.06.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2015] [Revised: 06/06/2015] [Accepted: 06/24/2015] [Indexed: 10/23/2022]
Abstract
UNLABELLED FTY720 is a promising drug in attenuating multiple sclerosis, prolonging survival of organ allograft, and many other protective effects. Its mechanism of action is considered to be mediated by the internalization of sphingosine 1-phosphate receptors (S1PRs). In the current study, we investigated the efficacy of FTY720 in Non-Obese Diabetic (NOD) mice, serving as a model of Dry Eye Disease (DED). NOD mice were divided into six study groups, i.e., FTY720-treated groups with 3 concentrations of FTY720 (0.05%, 0.005%, and 0.001%), 0.05% Cyclosporin A (CsA) treated group, normal saline treated group, and no treatment control group. FTY720 was reconstituted with normal saline and prepared as eye drop. The stability and production of tear film was measured by Tear Break up Time test (TBUT) and phenol red cotton thread test (PRCTT), respectively. Tear fluid washings were collected and assessed by ELISA. Cytokines were detected in lacrimal glands by RT-PCR. Inflammation in conjunctiva was assessed by immunohistochemistry, goblet cells and conjunctival epithelia were examined and evaluated by impression cytology. Our results indicated that FTY720 had a significantly therapeutic effect in NOD mice. After FTY720 intervention, TBUT and PRCTT data were greatly improved (p < 0.01), the interleukin 1β (IL-1β) level was markedly decreased in tear fluid washings compared to control and normal saline groups after 2 weeks ( CONTROL 1.06 ± 0.12, Normal saline:0.97 ± 0.09 pg/ml, CsA:0.22 ± 0.02 pg/ml, 0.001% FTY720:0.23 ± 0.02 pg/ml, 0.005% FTY720:0.14 ± 0.03 pg/ml, 0.05% FTY720: 0.18 ± 0.03 pg/ml. CsA group and 3 FTY720 groups VS. control group and normal saline groups: p < 0.01). Proinflammatory factors were greatly decreased in lacrimal glands (p < 0.01). Leukocytes were identified and markedly decreased in conujnctiva (p < 0.01), inflammatory reaction of DED was greatly relieved. More importantly, the goblet cells were largely restored and ocular surface lesions were significantly ameliorated (p < 0.01). Thus, we observed FTY720 alleviated DED in NOD mice by inhibiting leukocytes, the function of ocular surface tissue in NOD mice was partially restored via inhibiting ocular surface inflammation and increasing the density of goblet cells and conjunctival epithelia. FTY720 may offer a novel strategy for the treatment of inflammatory disorders in the ocular surface.
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Affiliation(s)
- Weibao Xiao
- Department of Ophthalmology, Huashan Hospital Affiliated to Fudan University, 12 Middle Wulumuqi Road, Buiding 3, Room 802, Shanghai 200040, China
| | - Guo-Tong Xu
- Tongji Eye Institute and Department of Regenerative Medicine, Tongji University School of Medicine, 1239 Siping Road, Medical School Building, Room 521, Shanghai 200092, China
| | - Jingfa Zhang
- Tongji Eye Institute and Department of Regenerative Medicine, Tongji University School of Medicine, 1239 Siping Road, Medical School Building, Room 521, Shanghai 200092, China
| | - Jiaying Zhang
- Department of Ophthalmology, Huashan Hospital Affiliated to Fudan University, 12 Middle Wulumuqi Road, Buiding 3, Room 802, Shanghai 200040, China
| | - Yu Zhang
- Department of Ophthalmology, Huashan Hospital Affiliated to Fudan University, 12 Middle Wulumuqi Road, Buiding 3, Room 802, Shanghai 200040, China
| | - Wen Ye
- Department of Ophthalmology, Huashan Hospital Affiliated to Fudan University, 12 Middle Wulumuqi Road, Buiding 3, Room 802, Shanghai 200040, China.
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Mantelli F, Massaro-Giordano M, Macchi I, Lambiase A, Bonini S. The cellular mechanisms of dry eye: from pathogenesis to treatment. J Cell Physiol 2014; 228:2253-6. [PMID: 23696296 DOI: 10.1002/jcp.24398] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Accepted: 05/02/2013] [Indexed: 12/28/2022]
Abstract
Dry eye is a complex disease characterized by changes in the ocular surface epithelia related to reduced quality and/or quantity of tears, inflammatory reaction, and impairment of ocular surface sensitivity. It has recently been proposed that increased tear osmolarity represents a main trigger to the altered cellular mechanisms leading to epithelial damage in dry eye. However, dry eye pathogenesis is multifactorial, with cytotoxic inflammatory mediators, altered lacrimal gland secretion and nerve function, squamous metaplasia of the conjunctival epithelium and decrease of goblet cells density, all playing a role in a detrimental loop that perpetuates and worsens damage to the corneal and conjunctival epithelia. Current topical treatments for dry eye patients include the use of lubricants and anti-inflammatory drugs. However, lubricants only improve symptoms temporarily, and chronic use of topical steroids is associated to severe ocular side effects such as cataract and glaucoma. The deeper understanding of the cellular mechanisms that are altered in dry eye is opening novel perspectives for patients and physicians, who are seeking treatments capable not only of improving symptoms but also of restoring the homeostasis of the ocular surface. In this review, we will focus on novel anti-inflammatory agents and on nerve growth factor, a neurotrophin that is altered in dry eye and has been suggested as a main player in the neuroimmune cross-talk of the ocular surface as well as in the stimulation of corneal sensitivity, epithelial proliferation and differentiation, and stimulation of mucin production by goblet cells. J. Cell. Physiol. 228: 2253-2256, 2013. © 2013 Wiley Periodicals, Inc.
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Mudgil P, Borchman D, Yappert MC, Duran D, Cox GW, Smith RJ, Bhola R, Dennis GR, Whitehall JS. Lipid order, saturation and surface property relationships: A study of human meibum saturation. Exp Eye Res 2013; 116:79-85. [DOI: 10.1016/j.exer.2013.08.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 08/08/2013] [Accepted: 08/15/2013] [Indexed: 12/01/2022]
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17
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You J, Hodge C, Wen L, McAvoy JW, Madigan MC, Sutton G. Using soybean trypsin inhibitor as an external loading control for Western blot analysis of tear proteins: application to corneal disease. Exp Eye Res 2012; 99:55-62. [PMID: 22498032 DOI: 10.1016/j.exer.2012.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/06/2012] [Accepted: 03/24/2012] [Indexed: 01/26/2023]
Affiliation(s)
- Jingjing You
- Save Sight Institute, Discipline of Ophthalmology, University of Sydney, GPO Box 4337, Sydney NSW 2001, Australia.
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Borchman D, Foulks GN, Yappert MC, Milliner SE. Changes in human meibum lipid composition with age using nuclear magnetic resonance spectroscopy. Invest Ophthalmol Vis Sci 2012; 53:475-82. [PMID: 22169100 DOI: 10.1167/iovs.11-8341] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Human tear film stability decreases with increasing age. In this study, the changes in meibum composition were measured in search of markers of tear film instability. METHODS (1)H NMR nuclear magnetic resonance (NMR) spectra of 43 normal donors aged 1 to 88 years were acquired. RESULTS Compared with meibum from adolescents and adults, meibum from infants and children contains less CH(3) and C═C groups and an increased aldehyde-to-lipid hydroperoxide ratio. CONCLUSIONS It is reasonable that tear film stability is higher in infants than in adults. Their meibum contains less CH(3) and C═C groups and higher levels of protein, and as a result, the lipid is more ordered because of the tighter and stronger lipid-lipid interactions. For water to evaporate, it must first pass through the tight lipid-lipid barrier. For tears to break up, lipid-lipid interactions must be broken. It is reasonable that because the lipid-lipid interactions are stronger in infants' and children's tears compared with those of adolescents and adults, the tear film in the younger groups is more stable and provides a better barrier to evaporation than does the tear film of adults. Lipid saturation could be the critical feature in meibum that stabilizes tears in infants.
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Affiliation(s)
- Douglas Borchman
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, USA.
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Shrestha RK, Borchman D, Foulks GN, Yappert MC, Milliner SE. Analysis of the composition of lipid in human meibum from normal infants, children, adolescents, adults, and adults with meibomian gland dysfunction using ¹H-NMR spectroscopy. Invest Ophthalmol Vis Sci 2011; 52:7350-8. [PMID: 21849420 DOI: 10.1167/iovs.11-7391] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study represents a first step toward the evaluation of possible compositional differences in meibum from normal donors (Mn) and donors with meibomian gland dysfunction (Md) by (1)H-NMR spectroscopy. The results highlight the applicability of (1)H-NMR spectroscopy for the quantitative analysis of waxes, cholesteryl esters, and glycerides in meibum lipid (ML). METHODS Meibum was obtained from 41 normal donors and 51 donors with meibomian gland dysfunction (MGD). (1)H-NMR spectroscopy was used to quantify the amount of waxes, glycerides, and cholesteryl esters in human meibum. RESULTS The relative amount of cholesteryl esters in Mn increased with age and was 40% (P < 0.05) lower in Md. Interestingly, the relative levels of cholesteryl esters in infant meibum were comparable to those in Md. The relative amounts of glycerides were not affected significantly by age or MGD. CONCLUSIONS The changes in cholesteryl ester could be used as a molecular marker for MGD and could potentially be applied to follow the efficacy of drug therapy in the treatment of MGD. The similarity of the levels of cholesteryl esters in infant meibum and Md suggests that the relative amounts of these meibum components alone are unlikely to be responsible for the increased stability of the infant tear film and decreased stability of the tear film with MGD. This study reveals the complexity of human MLs and the changes that occur with age and disease. Understanding the factors that lead to such variations is of utmost relevance in the design of effective therapies.
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Affiliation(s)
- Rashmi K Shrestha
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, USA
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Abstract
Spontaneous blinking is essential for maintaining a healthy ocular surface and clarity of vision. The spontaneous blink rate (SBR) is believed to reflect a complex interaction between peripheral influences mediated by the eye surface and the central dopaminergic activity. The SBR is thus extremely variable and dependent on a variety of psychological and medical conditions. Many different methods have been employed to measure the SBR and the upper eyelid kinematics during a blink movement. Each has its own merits and drawbacks, and the choice of a specific method should be tailored to the specific needs of the investigation. Although the sequence of muscle events that leads to a blink has been fully described, knowledge about the neural control of spontaneous blinking activity is not complete. The tear film is dynamically modified between blinks, and abnormalities of the blink rate have an obvious influence on the ocular surface.
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Affiliation(s)
- Antonio A V Cruz
- Department of Ophthalmology, School of Medicine of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
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Abstract
PURPOSE To investigate infant tear film secretion and protein profile, and to compare major tear proteins, such as immunoglobulin A, lactoferrin, and lysozyme, with those of adult controls. METHODS Tears were collected, with a cellulose rod, from 40 healthy infants (19 female infants and 21 male infants, gestational duration: 39.71 ± 1.27 weeks) within 48 hours of birth and 22 adults (10 female infants and 12 male infants, mean age: 24.95 ± 3.63 years). A second collection was obtained from 14 of the infants (8 female infants and 6 male infants, postnatal age: 7.76 ± 6.14 weeks). The tear volume was measured, and protein in the samples was analyzed by Bradford assay and gel electrophoresis. RESULTS Median tear volume (interquartile range) was 0.5 μL (0.6-2 μL) for newborn infants, 2.5 μL (1.4-7.75 μL) for these infants at an older age, and 6 μL (2.73-12.75 μL) in adults (P < 0.001, Kruskall-Wallis test). Immunoglobulin A concentration was significantly lower in newborns (P < 0.001, analysis of variance). Lipocalin was present in 36% of the newborn tear samples, whereas serum albumin was found in 86%. Mean protein concentration (μg/μL ± SD) was 10.95 ± 5.51 in the newborns, 12.93 ± 3.99 in the older infants, and 13.04 ± 3.46 in the adults (P > 0.5, analysis of variance). CONCLUSIONS This is the first study reporting an investigation of unstimulated infant tears, using a noninvasive collection method. Tear protein content demonstrated that the infant tear film is different to that in adults.
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Abstract
PURPOSE The purpose of this work was to investigate whether individual differences in eye surface area are related to the rate of spontaneous eye blinking (SB) in young infants. Rate of SB was also compared with the rate of gaze shifts. METHODS Forty-four 4-month-old infants were observed under controlled conditions for 4 to 6 min. SB, eye surface area, gaze shifts, and various background variables were measured. RESULTS Individual differences in the rate of SB and in eye surface area were wide. Neither the eye surface area nor the rate of gaze shifting was related to the rate of SB in young infants. However, when SB do occur, they are more likely to coincide with a shift in gaze than immediately precede or follow a shift in gaze. CONCLUSIONS Eye surface area does not explain individual differences in the rate of SB in infancy. This and other recent work suggests that central factors may play a more prominent role in the mechanisms of SB early in human development than previously reported and that the mechanisms regulating the rate of SB seem to be developmentally continuous with those of adults. To the extent that the rate and timing of SB reflects developing neurological systems, SB may be useful clinically.
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Bacher LF, Allen KJ. Sensitivity of the rate of spontaneous eye blinking to type of stimuli in young infants. Dev Psychobiol 2009; 51:186-97. [PMID: 19062172 DOI: 10.1002/dev.20357] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although progress has been made toward understanding the mechanisms of spontaneous eye blinking (SB), few reports focus on the ontogeny of SB. The purpose of the present work was to investigate SB in infants by attempting to manipulate SB and examine potential correlates of SB. Fifty-two infants were observed in a quiet baseline condition then presented with either moving stimuli or a social stimulus. SB, eye movement, body movement and various background variables were measured. Results demonstrate that SB can be manipulated and that SB rate is differentially sensitive to the type of stimulus presented. Eye and body movements did not systematically relate to the rate of SB. Implications for mechanisms of SB regulation are discussed.
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Affiliation(s)
- Leigh F Bacher
- Department of Psychology, State University of New York at Oswego, 455 Mahar Hall, Oswego, NY 13126, USA.
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Wojtowicz JC, Butovich IA, McCulley JP. Historical Brief on Composition of Human Meibum Lipids. Ocul Surf 2009; 7:145-53. [DOI: 10.1016/s1542-0124(12)70309-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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