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1.
Ann Rheum Dis ; 80(3): 339-348, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33168545

RESUMEN

OBJECTIVES: To evaluate efficacy and safety of abatacept in adults with active primary Sjögren's syndrome (pSS) in a phase III, randomised, double-blind, placebo-controlled trial. METHODS: Eligible patients (moderate-to-severe pSS [2016 ACR/European League Against Rheumatism (EULAR) criteria], EULAR Sjögren's Syndrome Disease Activity Index [ESSDAI] ≥5, anti-SS-related antigen A/anti-Ro antibody positive) received weekly subcutaneous abatacept 125 mg or placebo for 169 days followed by an open-label extension to day 365. Primary endpoint was mean change from baseline in ESSDAI at day 169. Key secondary endpoints were mean change from baseline in EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) and stimulated whole salivary flow (SWSF) at day 169. Other secondary clinical endpoints included glandular functions and patient-reported outcomes. Selected biomarkers and immune cell phenotypes were examined. Safety was monitored. RESULTS: Of 187 patients randomised, 168 completed double-blind period and 165 continued into open-label period. Mean (SD) baseline ESSDAI and ESSPRI total scores were 9.4 (4.3) and 6.5 (2.0), respectively. Statistical significance was not reached for primary (ESSDAI -3.2 abatacept vs -3.7 placebo, p=0.442) or key secondary endpoints (ESSPRI, p=0.337; SWSF, p=0.584). No clinical benefit of abatacept over placebo at day 169 was seen with other clinical and PRO endpoints. Relative to baseline, abatacept was associated with significant differences vs placebo in some disease-relevant biomarkers (including IgG, IgA, IgM-rheumatoid factor) and pathogenic cell subpopulations (post hoc analyses). No new safety signals were identified. CONCLUSIONS: Abatacept treatment did not result in significant clinical efficacy compared with placebo in patients with moderate-to-severe pSS, despite evidence of biological activity.


Asunto(s)
Síndrome de Sjögren , Abatacept/uso terapéutico , Humanos , Medición de Resultados Informados por el Paciente , Índice de Severidad de la Enfermedad , Síndrome de Sjögren/complicaciones , Síndrome de Sjögren/tratamiento farmacológico , Resultado del Tratamiento
2.
Clin Ophthalmol ; 17: 757-767, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36915716

RESUMEN

Purpose: Validation of the novel Lexitas modified NEI scale for use in assessment of corneal fluorescein staining. Patients and Methods: A series of 18 illustrations and 14 clinical photographs depicting varying severity levels of corneal fluorescein staining were assessed by 3 independent examiners. Regions of the cornea were graded for staining severity based on 3 different grading scales: the original NEI staining scale (density-based scoring; 0-3 scale), a structured version of the NEI scale (dot-count scoring; 0-3 scale), and the Lexitas modified NEI staining scale (0-4 scale with half-point increments). Kappa statistics (simple and weighted) were computed to determine intra-examiner image grading repeatability for each examiner over 2 separate assessments. Inter-examiner assessment reliability utilized the scores from the first read of each examiner, and pairs of examiners to compute kappa statistics. Results: Data was analyzed from the scores provided by the examiners from each gradable corneal region on 32 images (18 illustrations and 14 photographs) for a total of 154 corneal regions across the 3 grading scales for each validation run. The mean intra-examiner simple/weighted kappa values using the NEI density, NEI dot count, and the Lexitas modified NEI staining scales were 0.67/0.72, 0.91/0.94, 0.80/0.92 for the graded illustrations, and 0.83/0.88, 0.76/0.85, 0.77/0.88 for the graded photographs, respectively. The mean inter-examiner simple/weighted kappa values using the NEI density, NEI dot count, and the Lexitas modified NEI staining scales were 0.59/0.65, 0.86/0.90, and 0.78/0.91 for the graded illustrations, and 0.80/0.88, 0.84/0.89, 0.69/0.88 for the graded photographs, respectively. Conclusion: The expanded scale of the Lexitas modified NEI staining scale demonstrated a high degree of reliability and repeatability of grading assessments within and across individual examiners, comparing favorably with the original NEI staining scale. A future investigation into the in-office utility of the Lexitas modified NEI staining scale is warranted.

3.
Ophthalmology ; 119(7): 1328-35, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22525048

RESUMEN

OBJECTIVE: To evaluate safety and efficacy of topical ophthalmic tofacitinib (CP-690,550), a novel Janus kinase inhibitor, in treating dry eye disease (DED). DESIGN: A phase 1/2 prospective, randomized, double-masked, multicenter, vehicle- and comparator-controlled trial (NCT00784719). PARTICIPANTS: Patients (n = 327) 18 years of age and older with a DED diagnosis for 6 months or more. METHODS: Tofacitinib (0.0003% twice daily, n = 46; 0.001% in both eyes twice daily, n = 47; 0.003% twice daily, n = 48; 0.005% twice daily, n = 48; 0.005% once daily, n = 44) results were compared with those of groups receiving active treatment cyclosporine ophthalmic emulsion 0.05% twice daily (n = 47) and vehicle twice daily (n = 47). Safety and efficacy evaluations were performed at baseline and throughout the 8-week study. MAIN OUTCOME MEASURES: Schirmer wetting, corneal staining, tear film break-up time, conjunctival staining, Ocular Comfort Index (OCI), and Ocular Surface Disease Index (OSDI). RESULTS: All tofacitinib doses were well tolerated, exhibiting better patient-reported ocular tolerability than cyclosporine. For the proportion of patients achieving 10 mm or more Schirmer wetting (without anesthesia) at week 8 (primary end point), greater response rates were observed in the tofacitinib 0.001% twice daily (27.3%), 0.005% twice daily (25.5%), and 0.005% once daily (26.1%) groups versus vehicle (20.0%); however, the differences were not statistically significant. Mean increase in Schirmer wetting (without anesthesia) from baseline was statistically significant (P<0.2, 2-sided) for all tofacitinib doses (1.7-3.1 mm), cyclosporine (3.9 mm), and vehicle (1.4 mm). For corneal staining (total score), significant improvement (reduction) from baseline was observed for all tofacitinib doses (-0.9 to -1.9) and vehicle (-2.0), but not for cyclosporine. The proportion of patients with complete corneal clearing (CCC; 100%) at week 8 was greatest with tofacitinib 0.005% once daily (15.9%) versus vehicle (6.7%). Symptom scores (OCI, OSDI) at week 8 showed significant improvements from baseline for all tofacitinib groups, and tofacitinib demonstrated greater improvements than cyclosporine. The tofacitinib 0.005% once daily group showed significant improvements in both a sign (Schirmer wetting without anesthesia) and symptom (OSDI environmental triggers subscale) versus vehicle and also demonstrated the highest response rate for CCC (16.7%) at week 8. CONCLUSIONS: This phase 1/2 study of tofacitinib demonstrated a trend for improving both signs and symptoms of dry eye. All doses of tofacitinib exhibited a reasonable safety profile and were well tolerated by patients with DED.


Asunto(s)
Síndromes de Ojo Seco/tratamiento farmacológico , Janus Quinasa 3/antagonistas & inhibidores , Pirimidinas/administración & dosificación , Pirroles/administración & dosificación , Ciclosporina/administración & dosificación , Método Doble Ciego , Síndromes de Ojo Seco/metabolismo , Síndromes de Ojo Seco/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Soluciones Oftálmicas , Piperidinas , Estudios Prospectivos , Pirimidinas/efectos adversos , Pirroles/efectos adversos , Encuestas y Cuestionarios , Lágrimas/química , Lágrimas/fisiología , Resultado del Tratamiento
4.
Ophthalmology ; 119(10 Suppl): S1-12, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23034341

RESUMEN

Ocular surface disorder--and dry eye, in particular--is a leading reason for visits to eye care professionals. It has been generally accepted that meibomian gland dysfunction (MGD) is a leading cause of evaporative dry eye, as well as being associated with aqueous-deficient dry eye. Yet, researchers and clinicians have lacked a global consensus on the definition of MGD, its epidemiology, pathophysiology, and management. Various systemic diseases and medications have been associated with the progression of both dry eye and MGD, as have several ocular disorders beyond those directly affecting the surface. It is in the best interest of patients for clinicians to be able to better identify and diagnose MGD, differentiating it from other ocular surface disorders, and to recognize the effects of MGD on the ocular surface, and thus initiate appropriate therapy. This CME activity provides expert insight into the Tear Film and Ocular Surface Society's International Workshop on MGD consensus report, offering practical application of its findings to better manage MGD patient care, particularly for those patients facing or undergoing ocular surgery.


Asunto(s)
Síndromes de Ojo Seco/diagnóstico , Enfermedades de los Párpados/diagnóstico , Enfermedades del Aparato Lagrimal/diagnóstico , Glándulas Tarsales/patología , Adulto , Ciclosporina/administración & dosificación , Síndromes de Ojo Seco/metabolismo , Enfermedades de los Párpados/clasificación , Enfermedades de los Párpados/metabolismo , Femenino , Humanos , Queratomileusis por Láser In Situ , Enfermedades del Aparato Lagrimal/metabolismo , Masculino , Persona de Mediana Edad , Soluciones Oftálmicas/administración & dosificación , Lágrimas/metabolismo , Agudeza Visual
5.
Exp Eye Res ; 100: 32-9, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22564968

RESUMEN

Protein-meibum and terpenoids-meibum lipid interactions could be important in the etiology of meibomian gland dysfunction (MGD) and dry eye symptoms. In the current model studies, attenuated total reflectance (ATR) infrared (IR) spectroscopy was used to determine if the terpenoid ß-carotene and the major proteins in tears and meibum affect the hydrocarbon chain conformation and carbonyl environment of wax, an abundant component of meibum. The main finding of these studies is that mucin binding to wax disordered slightly the conformation of the hydrocarbon chains of wax and caused the wax carbonyls to become hydrogen bonded or experience a more hydrophilic environment. Lysozyme and lactoglobulin, two proteins shown to bind to monolayers of meibum, did not have such an effect. Keratin and ß-carotene did not affect the fluidity (viscosity) or environment of the carbonyl moieties of wax. Based on these results, tetraterpenoids are not likely to influence the structure of meibum in the meibomian glands. In addition, these findings suggest that it is unlikely that keratin blocks meibomian glands by causing the meibum to become more viscous. Among the tear fluid proteins studied, mucin is the most likely to influence the conformation and carbonyl environment of meibum at the tear film surface.


Asunto(s)
Proteínas del Ojo/química , Ácidos Grasos Insaturados/química , Queratinas/química , Mucinas/química , Espectroscopía Infrarroja por Transformada de Fourier , beta Caroteno/química , Síndromes de Ojo Seco/metabolismo , Enfermedades de los Párpados/metabolismo , Humanos , Lactoglobulinas/química , Glándulas Tarsales/química , Muramidasa/química , Conformación Proteica , Viscosidad
6.
Cornea ; 40(5): 564-570, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32826644

RESUMEN

PURPOSE: The safety of KPI-121 0.25%, an ophthalmic nanoparticle suspension of loteprednol etabonate, was evaluated in subjects with dry eye disease (DED) in one phase 2 and three phase 3 randomized trials of similar design. METHODS: Adults with DED received KPI-121 0.25% or vehicle drops 4 times daily (QID) for ≥2 weeks; 1430 subjects received KPI-121 0.25% and 1438 subjects received vehicle drops. Main safety assessments were adverse events (AEs) and intraocular pressure (IOP). As a common side effect associated with the use of ocular corticosteroids is elevated IOP, subjects with a history of or current diagnosis of glaucoma were excluded. RESULTS: Instillation site pain was the most common AE, reported by 5.2% of subjects in the KPI-121 0.25% group and 4.4% of subjects in the vehicle group; other AEs were reported by ≤0.8% of subjects in the KPI-121 group. IOP elevations, a side effect associated with the use of ophthalmic corticosteroids, were observed with low incidence: 0.6% and 0.2% of subjects in the KPI-121 and vehicle groups, respectively. An IOP elevation was defined as an increase from baseline of >5 mm Hg that resulted in an IOP of ≥21 mm Hg in either eye during use of the study product. CONCLUSIONS: KPI-121 ophthalmic suspension 0.25% seemed to be safe and well tolerated when dosed QID for 2 to 4 weeks in those DED subjects included in the 4 trials.


Asunto(s)
Antialérgicos/administración & dosificación , Síndromes de Ojo Seco/tratamiento farmacológico , Etabonato de Loteprednol/administración & dosificación , Administración Oftálmica , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antialérgicos/efectos adversos , Método Doble Ciego , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/diagnóstico , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Dolor Ocular/inducido químicamente , Femenino , Humanos , Presión Intraocular/efectos de los fármacos , Etabonato de Loteprednol/efectos adversos , Masculino , Persona de Mediana Edad , Nanopartículas , Soluciones Oftálmicas , Suspensiones , Tonometría Ocular , Agudeza Visual/efectos de los fármacos , Adulto Joven
7.
Exp Eye Res ; 91(2): 246-56, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20546726

RESUMEN

Changes in the phase transition temperatures and conformation of human meibum lipid with age and meibomian gland dysfunction have been quantified but with analysis of less than 1% of the infrared spectral range. The remaining 99% of the spectral range was analyzed with principal component analysis (PCA) and confirms our previous studies and reveal further insights into changes that occur in meibum with age and disease. Infrared spectra of meibum from 41 patients diagnosed with meibomian gland dysfunction (Md) and 32 normal donors (Mn) were measured. Principal component analysis (PCA) was used to quantify the variance among the spectra and meibum protein was quantified using the infrared carbonyl and amide I and II bands. A training set of spectra was used to discriminate between Mn and Md with an accuracy of 93%. This shows that certain spectral regions (eigenvectors) contain compositional and structural information about the changes that occur with the principal component (variable), meibomian gland dysfunction. The spectral features of the major eigenvector indicate that Md contains more protein and relatively less CH(3) and cis = CH band intensity compared to Mn. The amount of protein was confirmed from relative infrared band intensities. Our study supports the idea that compositional differences result in meibum that is less fluid and more viscous with meibomian gland dysfunction so that less lipid flows out of the meibomian gland orifice as observed clinically. This study also demonstrates the power of the combination of infrared spectroscopy and PCA as a diagnostic tool that discriminates between Mn and Md.


Asunto(s)
Enfermedades de los Párpados/metabolismo , Metabolismo de los Lípidos , Lípidos/química , Glándulas Tarsales/metabolismo , Análisis de Componente Principal/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedades de los Párpados/diagnóstico , Femenino , Análisis de Fourier , Humanos , Masculino , Glándulas Tarsales/patología , Persona de Mediana Edad , Espectrofotometría Infrarroja , Adulto Joven
8.
Ocul Surf ; 8(1): 29-39, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20105405

RESUMEN

The orbital manifestations of ophthalmic Graves' disease have been appreciated since the first description of the disease many years ago. The effects of ophthalmic Graves' disease on the ocular surface, although some of the most bothersome and potentially damaging features of the disease, are often not as well appreciated. This review identifies and summarizes the manifestations of ocular surface disease attendant to ophthalmic Graves' disease and provides recommendations for clinical evaluation and management options to control the ocular surface problems.


Asunto(s)
Oftalmopatías/etiología , Enfermedades de la Tiroides/complicaciones , Conjuntiva/patología , Córnea/patología , Oftalmopatías/diagnóstico , Humanos , Esclerótica/patología
9.
Ophthalmic Res ; 44(1): 34-42, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20160464

RESUMEN

Both lipids and mucins contribute to the stability of the tear film and lipids may inhibit tears from evaporating. Younger people have lower lipid viscosity, higher lipid volume, and a lower rate of tear evaporation. Since age-related changes in human meibum composition and conformation have never been investigated, as a basis for the study of lipid-associated changes with meibomian gland dysfunction, we used the power of infrared spectroscopy to characterize hydrocarbon chain conformation and packing in meibum from humans without dry eye symptoms in relation to age and sex. Meibum from normal human donors ranging in age from 3 to 88 years was studied. Meibum phase transitions were quantified by fitting them to a 4-parameter 2-state sigmoidal equation. Human meibum order and phase transition temperatures decrease with age and this trend may be attributed to lipid compositional changes. If meibum has the same thermodynamic properties on the surface of the tears as it does on the lid margin, a decrease in lipid-lipid interaction strength with increasing age could decrease the stability of tears since lipid-lipid interactions on the tear surface must be broken for the tear film to break up. This study also serves as a foundation to examine meibum conformational differences in meibum from people with meibomian gland dysfunction.


Asunto(s)
Envejecimiento/fisiología , Metabolismo de los Lípidos , Lípidos/química , Glándulas Tarsales/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Femenino , Humanos , Hidrocarburos/química , Masculino , Persona de Mediana Edad , Transición de Fase , Distribución por Sexo , Espectroscopía Infrarroja por Transformada de Fourier , Lágrimas/química
10.
Eye Contact Lens ; 36(5): 249-53, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20724853

RESUMEN

OBJECTIVE: To recount the historic evaluation of meibomian gland dysfunction (MGD) and describe new techniques to monitor disease and therapy. METHODS: A review of the literature regarding the description of MGD and the role of abnormalities of meibomian gland secretion in health and disease. RESULTS: Meibomian gland dysfunction is a common clinical condition and is a major cause of evaporative dry eye with associated discomfort, visual disturbance, and contact lens intolerance. Despite the early description of the anatomy and physiology of the meibomian gland, recognition of the importance of the MGD and particularly therapeutic options to treat it has been limited. CONCLUSIONS: Improved methods of spectroscopic and chemical analysis of the meibomian gland secretion in health and disease are providing a better understanding of the physical and chemical abnormalities of the meibomian gland secretions and are allowing better evaluation of medical therapies.


Asunto(s)
Técnicas de Diagnóstico Oftalmológico/tendencias , Enfermedades de los Párpados/historia , Enfermedades de los Párpados/terapia , Glándulas Tarsales , Oftalmología/historia , Oftalmología/tendencias , Animales , Enfermedades de los Párpados/complicaciones , Enfermedades de los Párpados/diagnóstico , Historia del Siglo XVII , Historia del Siglo XX , Historia del Siglo XXI , Historia Antigua , Humanos , Glándulas Tarsales/anatomía & histología , Glándulas Tarsales/fisiología , Oftalmología/métodos
11.
Am J Ophthalmol ; 211: 15-21, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31811861

RESUMEN

PURPOSE: This study sought to identify factors contributing to the inadequacies of systematic reviews and meta-analyses (SRMAs) published in the ophthalmology literature. DESIGN: Perspective. METHODS: Review and synthesis of selective literature, with interpretation and perspective. RESULTS: Although recommendations for the design, conduct, assessment of quality, and risk of bias of systematic reviews have been widely available, some recent publications illustrate a serious potential failing in this domain: inclusion of refuted science, lack of citation of post-publication correspondence and failure to use ≥1 alternative search strategy. CONCLUSIONS: Examples of inadequacies of peer review in medical literature and perpetuation of erroneous science by unfiltered inclusion in subsequent systematic reviews have been identified, and the problem can be traced to authors, peer reviewers, and editors of journals. This perspective identifies and analyzes several possible causes of the problem and recommends some specific corrective actions to improve the quality and accuracy of such reviews.


Asunto(s)
Adhesión a Directriz/normas , Guías como Asunto/normas , Metaanálisis como Asunto , Oftalmología/normas , Publicaciones Periódicas como Asunto/normas , Proyectos de Investigación/normas , Revisiones Sistemáticas como Asunto , Recolección de Datos , Humanos , Sesgo de Publicación , Informe de Investigación/normas
12.
Exp Eye Res ; 88(3): 334-8, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18619437

RESUMEN

Dry eye syndrome is a collection of common disorders of multifactorial etiology. Although the epidemiology of dry eye has been well studied, reports of genetic patterns that might influence susceptibility to dry eye are few. We reported that the frequency of non-Sjögren's aqueous-deficient dry eye patients expressing only the MUC1/A splice variant of the mucin MUC1 may be lower than that of a normal control group [Imbert, Y., Darling, D.S., Jumblatt, M.M., Foulks, G.N., Couzin, E.G., Steele, P.S., Young, W.W., Jr., 2006. MUC1 splice variants in human ocular surface tissues: possible differences between dry eye patients and normal controls. Exp. Eye Res. 83, 493-501]. Also, He et al. [He, Y., Li, X., Bao, Y., Sun, J., Liu, J., 2006. The correlation of polymorphism of estrogen receptor gene to dry eye syndrome in postmenopausal women. Yan. Ke. Xue. Bao. 22, 233-236] reported a difference between Chinese dry eye and control groups in the frequency of a polymorphism in estrogen receptor alpha (ERalpha). In the present study we determined the statistical significance and generality of these observations and tested if the MUC1 splice variant difference between subject groups reflected a difference in the MUC1 variable number of tandem repeat (VNTR) size class. There was a perfect correlation between the MUC1/A or MUC1/B splice variant pattern and the SNP genotype frequency of the SNP (rs4072037) controlling that splicing event. In contrast, western and Southern blotting indicated that MUC1 VNTR size class corresponded to the MUC1 SNP genotype in only 80% of cases. We determined the status of the MUC1 SNP in normal and dry eye populations all of whom were female Caucasians. The MUC1 SNP genotype frequency of the normal control group was statistically different from both the non-Sjögren's aqueous-deficient dry eye group with ocular surface staining (P=0.017) and the evaporative dry eye group (P=0.015). We also tested SNP rs2234693 to analyze the polymorphism in the ERalpha gene and found no significant difference in the SNP genotype frequency between the control group and either of the dry eye subtypes. Thus, among Caucasians there is no evidence for an association of the ERalpha gene polymorphism with dry eye syndrome as previously described in a Chinese population. In conclusion, the etiologies of evaporative dry eye and non-Sjögren's aqueous-deficient dry eye are known to be different. However, our results suggest that both of these subtypes of dry eye disease may share a common mechanism or factor related to MUC1 genotypic differences that affects susceptibility to ocular surface damage. This altered susceptibility may not be related to the MUC1 VNTR size class. Therefore, mechanisms influencing protection of the ocular surface against inflammation and damage in different types of dry eye disease warrant further investigation particularly in relation to MUC1 genotype.


Asunto(s)
Síndromes de Ojo Seco/genética , Receptor alfa de Estrógeno/genética , Mucina-1/genética , Polimorfismo de Nucleótido Simple , Anciano , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Persona de Mediana Edad , Repeticiones de Minisatélite , Isoformas de Proteínas
13.
Eye Contact Lens ; 35(1): 32-7, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19125046

RESUMEN

OBJECTIVES: With increasing age and in patients affected with dry-eye symptoms, the human tear film becomes more unstable and exhibits shorter tear break-up times. We examined whether the inclusion of proteins and lipids to water affected the evaporation rates measured in vitro and could account for the lower rates reported previously from in vivo measurements. The impact of temperature, air flow, and humidity on the evaporation rate of tears was measured in vitro. METHODS: Lipid-protein interactions were measured using fluorescence spectroscopy and in vitro rates of evaporation were performed gravimetrically. RESULTS: Human reflex tears evaporated at a rate similar to that of water. A temperature increase from 25 degrees C to 34 degrees C caused a threefold increase in the evaporation rates of tears in still air. Further increases were observed under a current of dry air. Wax, mucin, lysozyme, or beta-lactoglobulin did not influence significantly the rates of evaporation measured in vitro. In contrast, lipid layered on the surface resulted in a 23% decrease in the rates. CONCLUSIONS: Environmental factors affect evaporation rates significantly and should be carefully controlled when performing in vivo measurements. The presence of a lipid layer lowers evaporation rates. The significantly lower rates of evaporation of tears measured in vivo suggest that with the lipid layer intact, the high reserve capacity of the lacrimal gland to provide both unstimulated and stimulated tear flow is more than enough to compensate for evaporative loss. However, with dry eye, increased rates of evaporation and decreased lacrimal tear flow could result in decreased break-up times.


Asunto(s)
Lágrimas/química , Aire , Proteínas del Ojo/farmacología , Humanos , Humedad , Hidrocarburos/farmacología , Técnicas In Vitro , Lactoglobulinas/farmacología , Lípidos/farmacología , Masculino , Persona de Mediana Edad , Mucinas/farmacología , Muramidasa/farmacología , Espectrometría de Fluorescencia , Temperatura , Volatilización/efectos de los fármacos , Ceras/farmacología
14.
Invest Ophthalmol Vis Sci ; 60(6): 2286-2293, 2019 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-31112994

RESUMEN

Purpose: Relationships between tear film lipid (TFL) layer composition, structure, and function could provide insight into the etiology of dry eye. The molar ratio of cholesteryl ester (CE)/wax ester (WE) was measured in meibum from normal donors (Mn) and compared with meibum from donors with meibomian gland dysfunction (MMGD). Methods: CE/WE was measured using nuclear magnetic resonance spectroscopy. Results: CE/WE was distributed into two populations with 81% distributed near 0.55 and 19% near 0.3. CE/WE were higher in donors 13 to 19 years old compared with donors 1 to 12 years old and 20 to 88 years old. CE/WE for MMGD was 30% lower, 0.34 ± 0.04, compared with Mn, 0.49 ± 0.04. There were no sex differences in CE/WE. There were no significant racial differences between the CE/WE ratios for Asians and Caucasians. The CE/WE ratio was higher for blacks and lower for Hispanics compared to Caucasians. Due to the small number sampled, confirmation of the later racial results is needed. The packing of CE and WE in the TFL layer was proposed. Conclusions: Although MMGD contains much less CE than Mn, factors other than the CE content, such as the levels of saturation and/or proteins, may be responsible for the higher order of MMGD. In addition to saturation, CE could contribute to the increase in order of Mn between 0 and 20 years of age. Observed changes in the meibum content of CE alone is not likely to influence tear film stability.


Asunto(s)
Blefaritis/metabolismo , Ésteres del Colesterol/metabolismo , Síndromes de Ojo Seco/metabolismo , Glándulas Tarsales/metabolismo , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Lípidos/análisis , Masculino , Lágrimas/metabolismo , Adulto Joven
15.
Drugs Aging ; 25(2): 105-18, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18257598

RESUMEN

Dry eye disease is a common and increasingly prevalent condition particularly associated with advancing age and postmenopausal women. Epidemiological studies identify prevalence rates ranging from 7% in the US to 33% in the Asian population. Research increasingly identifies risk factors of increasing age, female sex, smoking, use of video display terminals and use of certain medications as well as environmental stresses as aggravating factors for the disease. Basic and clinical investigations provide cumulative evidence of hyperosmolarity of the tear film and ocular surface/lacrimal gland inflammation as pathogenic features of dry eye disease. A decline in systemic and local levels of sex hormones is associated with advancing age and advancing disease. Pharmacological therapeutic interventions include enhanced lubricants and anti-inflammatory drugs such as topical corticosteroids and ciclosporin (cyclosporine A). Secretagogues and hormonal supplementation are potential future therapies. The increased understanding of the contributing and pathogenetic factors responsible for dry eye provides a rationale for multiple therapeutic options for this multi-factorial disease. In the elderly patient it is important to recognize the physical and cognitive limitations that will influence the selection of appropriate topical medication.


Asunto(s)
Antiinflamatorios/uso terapéutico , Síndromes de Ojo Seco/tratamiento farmacológico , Lubrificación , Anciano , Antiinflamatorios/farmacología , Ciclosporina/farmacología , Ciclosporina/uso terapéutico , Síndromes de Ojo Seco/diagnóstico , Síndromes de Ojo Seco/epidemiología , Síndromes de Ojo Seco/fisiopatología , Ácidos Grasos Esenciales/farmacología , Ácidos Grasos Esenciales/uso terapéutico , Glucocorticoides/farmacología , Glucocorticoides/uso terapéutico , Humanos , Inflamación/tratamiento farmacológico , Inflamación/etiología , Soluciones Oftálmicas , Suero
19.
Surv Ophthalmol ; 52(4): 369-74, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17574063

RESUMEN

Dry eye, also known as keratoconjunctivitis sicca, can be due either to insufficient tear production or excessive tear evaporation, both resulting in tear hyperosmolarity that leads to symptoms of discomfort and ocular damage. Additionally, the severity of dry eye symptoms appears to be correlated to lipid layer thickness. It is now generally recognized that increased evaporation due to a compromised lipid layer is one of the most common etiologies for hyperosmolarity of the tear film. Thus, therapies targeted at replenishing or stabilizing the lipid layer are key to the treatment of dry eye, either as monotherapy or in conjunction with therapies designed to enhance aqueous production.


Asunto(s)
Síndromes de Ojo Seco/metabolismo , Metabolismo de los Lípidos , Lágrimas/metabolismo , Progresión de la Enfermedad , Humanos , Concentración Osmolar , Índice de Severidad de la Enfermedad , Propiedades de Superficie
20.
Chem Phys Lipids ; 147(2): 87-102, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17482588

RESUMEN

Infrared and fluorescence spectroscopies were applied to characterize the molecular conformational/structure and dynamics of human meibum (ML) and tear lipids (SSL). ML lipids contained more CC and CH3 moieties than SSL. SSL contained OH groups that were not apparent in the spectra of ML. The CO stretching band observed in the infrared spectra of SSL and ML revealed that the CO groups are not involved in hydrogen bonds. Bands due to the polar moieties CO and PO2- did not change significantly with increasing temperature, suggesting that they may not play an appreciable thermodynamic role in the lipid hydrocarbon chain phase transition. Components in tears bind to SSL and exclude water at the water-lipid boundary where the polar headgroups of phospholipids are located. If similar interactions occur in vivo at the tear film lipid-aqueous interface, they would reduce the rate of evaporation. The results provide a foundation for future studies to assess possible differences with age and sex in tears from normal and dry eye subjects.


Asunto(s)
Lípidos/química , Lágrimas/química , Carbono/química , Centrifugación , Humanos , Hidrocarburos/química , Hidroxilación , Peso Molecular , Oxígeno/química , Fosfatos/química , Fósforo/química , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Agua/química
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