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2.
Cont Lens Anterior Eye ; 46(2): 101822, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36804937

RESUMO

INTRODUCTION: Contact lens (CL) practice is an ever-changing field with clinical knowledge, techniques and equipment continuously evolving. These new developments are backed with clinical trials and research to ensure that practitioners feel confident that there is an evidence base to support these advances. Evidence-based practice is now a crucial part of CL practice, and its importance also filters down to CL education. For example, lectures are one of the most popular tools for an educator but, is standing at the front of a lecture theatre full of students a more effective way of teaching than providing the same material for students to read by themselves? What evidence exists specific to CL education? METHOD: An expert panel of educators completed a comprehensive literature review of current evidence of teaching methods in CL training, or if not available then what can be learnt from other health care professional training that could be potentially applicable to CL education. RESULTS: Due to the amount of evidence available in the overall subject area relating to healthcare education, the initial plan of compiling evidence into one narrative review paper was discarded in favour of producing two linked papers. Here, the first paper details definitions of terminology, and also teaching methods. The second paper focuses on assessment and specific clinical training required to attain CL practice competency. In this first paper, no direct evidence of the spreading and benefit of new education strategies evidence such as flipped classrooms, spaced learning, test-enhanced learning, group work, CBL, PBL, TBL, and reflective practice in CL education was found. The only technique that was widely used in the CL field was case reports and the group discussion of them. Nevertheless, the authors found a consensus of opinion from other disciplines that are transferable to CL teaching and could help students meet the intended learning outcomes. CONCLUSION: There is a small amount of evidence supporting CL education, but most of this seems to be related to the practical element of the training. However, there is a lot of evidence in the field of healthcare education from related disciplines which provides additional but important learning tools that may be effectively implemented in CL education.


Assuntos
Pessoal de Saúde , Estudantes , Humanos , Ensino
3.
Cont Lens Anterior Eye ; 46(2): 101821, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36805277

RESUMO

INTRODUCTION: Evidence based practice is now an important part of healthcare education. The aim of this narrative literature review was to determine what evidence exists on the efficacy of commonly used teaching and learning and assessment methods in the realm of contact lens skills education (CLE) in order to provide insights into best practice. A summary of the global regulation and provision of postgraduate learning and continuing professional development in CLE is included. METHOD: An expert panel of educators was recruited and completed a literature review of current evidence of teaching and learning and assessment methods in healthcare training, with an emphasis on health care, general optometry and CLE. RESULTS: No direct evidence of benefit of teaching and learning and assessment methods in CLE were found. There was evidence for the benefit of some teaching and learning and assessment methods in other disciplines that could be transferable to CLE and could help students meet the intended learning outcomes. There was evidence that the following teaching and learning methods helped health-care and general optometry students meet the intended learning outcomes; clinical teaching and learning, flipped classrooms, clinical skills videos and clerkships. For assessment these methods were; essays, case presentations, objective structured clinical examinations, self-assessment and formative assessment. There was no evidence that the following teaching and learning methods helped health-care and general optometry students meet the intended learning outcomes; journal clubs and case discussions. Nor was any evidence found for the following assessment methods; multiple-choice questions, oral examinations, objective structured practical examinations, holistic assessment, and summative assessment. CONCLUSION: Investigation into the efficacy of common teaching and learning and assessment methods in CLE are required and would be beneficial for the entire community of contact lens educators, and other disciplines that wish to adapt this approach of evidence-based teaching.


Assuntos
Competência Clínica , Aprendizagem , Humanos , Estudantes , Exame Físico , Ensino
4.
Eye (Lond) ; 37(2): 297-302, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-35058600

RESUMO

BACKGROUND: Neovascular age-related macular degeneration (nAMD) is a leading cause of blind registrations in the elderly. Unfortunately, it is difficult to detect the early stage of the disease, when treatment is more likely to be successful. Subjects with very early disease are likely to have abnormal macular function, even in the pre-symptomatic stage. In this study, colour vision was evaluated to establish if subjects at high risk of developing nAMD can be identified, thus allowing earlier diagnosis and possible treatment. METHODS: Colour contrast sensitivity (CCS) was evaluated over time in the fellow unaffected eye of subjects with unilateral nAMD. Participants were divided into Group 1 (182 participants) or Group 2 (15 participants) according to whether nAMD did not or did develop in the study period respectively and the two groups were compared. RESULTS: CCS was increased (i.e. worse colour vision) compared with the age-matched reference range in a high proportion of fellow eyes in both Groups 1 and 2. Global mean CCS values did not show statistically significant differences between the two groups. However, there was a statistically significant difference between mean Group 1 CCS values and the last CCS value prior to nAMD diagnosis from Group 2 subjects. CONCLUSION: This study shows that in patients with unilateral nAMD, colour vision is frequently abnormal in the fellow unaffected eye. Abnormal CCS does not predict the development of nAMD within the 12 month period of the study and therefore it is not a viable screening tool for this pathology.


Assuntos
Neovascularização de Coroide , Degeneração Macular , Neovascularização Retiniana , Degeneração Macular Exsudativa , Humanos , Idoso , Cor , Sensibilidades de Contraste , Tomografia de Coerência Óptica , Olho , Neovascularização de Coroide/diagnóstico , Degeneração Macular/diagnóstico , Degeneração Macular Exsudativa/diagnóstico
5.
Eur J Ophthalmol ; 30(6): 1487-1494, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31411062

RESUMO

PURPOSE: To generate the first published reference database of colour contrast sensitivity in eyes at high risk of neovascular age-related macular degeneration and to explore this important feature in quality of vision. BACKGROUND: Quality of vision depends on many factors. Changes in chromatic contrast sensitivity remain largely unexplored in eyes at high risk of neovascular age-related macular degeneration; they may however not only be relevant for quality of life but also an early indicator of the onset of the disease, so it is important to have a means to evaluate any variation in colour contrast sensitivity, especially in view of the likely increase in neovascular age-related macular degeneration as the population ages. METHODS: This prospective longitudinal study evaluated colour contrast sensitivity along the protan and tritan colour axes in 145 eyes at high risk of neovascular age-related macular degeneration. RESULTS: Colour contrast sensitivity showed statistically significant correlations with age and visual acuity, but not gender nor laterality (i.e. whether the right or left eye was being tested). There was significant variability among individuals, especially for the tritan axis, with some subjects well within normal limits for age and others with very poor colour contrast sensitivity. CONCLUSION: This study has generated the first published colour contrast sensitivity reference database for eyes at high risk of neovascular age-related macular degeneration. It has also shown a high inter-individual variability of colour contrast sensitivity in eyes at high risk of neovascular age-related macular degeneration, but the significance of this is unclear. Further work is required to establish if eyes with high colour contrast sensitivity thresholds (i.e. poor colour vision) have a higher risk of developing neovascular age-related macular degeneration over time, and this is the subject of ongoing work.


Assuntos
Visão de Cores/fisiologia , Sensibilidades de Contraste/fisiologia , Acuidade Visual , Degeneração Macular Exsudativa/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Macula Lutea/patologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Microscopia com Lâmpada de Fenda , Degeneração Macular Exsudativa/diagnóstico
6.
Doc Ophthalmol ; 132(2): 123-35, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26988845

RESUMO

BACKGROUND: Previous studies have demonstrated an increase in macular pigment optical density (MPOD) with lutein (L)-based supplementation in healthy eyes. However, not all studies have assessed whether this increase in MPOD is associated with changes to other measures of retinal function such as the multifocal ERG (mfERG). Some studies also fail to report dietary levels of L and zeaxanthin (Z). Because of the associations between increased levels of L and Z, and reduced risk of AMD, this study was designed to assess the effects of L-based supplementation on mfERG amplitudes and latencies in healthy eyes. METHODS: Multifocal ERG amplitudes, visual acuity, contrast sensitivity, MPOD and dietary levels of L and Z were assessed in this longitudinal, randomized clinical trial. Fifty-two healthy eyes from 52 participants were randomly allocated to receive a L-based supplement (treated group), or no supplement (non-treated group). RESULTS: There were 25 subjects aged 18-77 (mean age ± SD; 48 ± 17) in the treated group and 27 subjects aged 21-69 (mean age ± SD; 43 ± 16) in the non-treated group. All participants attended for three visits: visit one at baseline, visit two at 20 weeks and visit three at 40 weeks. A statistically significant increase in MPOD (F = 17.0, p ≤ 0.001) and shortening of mfERG ring 2 P1 latency (F = 3.69, p = 0.04) was seen in the treated group. CONCLUSIONS: Although the results were not clinically significant, the reported trend for improvement in MPOD and mfERG outcomes warrants further investigation.


Assuntos
Luteína/administração & dosagem , Pigmento Macular/metabolismo , Retina/fisiologia , Zeaxantinas/administração & dosagem , Adolescente , Adulto , Sensibilidades de Contraste/fisiologia , Suplementos Nutricionais , Eletrorretinografia , Feminino , Seguimentos , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Acuidade Visual/fisiologia , Adulto Jovem
7.
J Agric Food Chem ; 63(44): 9677-82, 2015 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-26477753

RESUMO

Lutein and zeaxanthin are carotenoids that are selectively taken up into the macula of the eye, where they are thought to protect against the development of age-related macular degeneration. They are obtained from dietary sources, with the highest concentrations found in dark green leafy vegetables, such as kale and spinach. In this Review, compositional variations due to variety/cultivar, stage of maturity, climate or season, farming practice, storage, and processing effects are highlighted. Only data from studies which report on lutein and zeaxanthin content in foods are reported. The main focus is kale; however, other predominantly xanthophyll containing vegetables such as spinach and broccoli are included. A small amount of data about exotic fruits is also referenced for comparison. The qualitative and quantitative composition of carotenoids in fruits and vegetables is known to vary with multiple factors. In kale, lutein and zeaxanthin levels are affected by pre-harvest effects such as maturity, climate, and farming practice. Further research is needed to determine the post-harvest processing and storage effects of lutein and zeaxanthin in kale; this will enable precise suggestions for increasing retinal levels of these nutrients.


Assuntos
Brassica/química , Luteína/análise , Extratos Vegetais/análise , Verduras/química , Zeaxantinas/análise , Animais , Brassica/crescimento & desenvolvimento , Humanos , Luteína/metabolismo , Degeneração Macular/metabolismo , Verduras/crescimento & desenvolvimento , Verduras/metabolismo , Zeaxantinas/metabolismo
8.
Cont Lens Anterior Eye ; 38(1): 15-20, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25223499

RESUMO

BACKGROUND: Optometric practices offer contact lenses as cash sale items or as part of monthly payment plans. With the contact lens market becoming increasingly competitive, patients are opting to purchase lenses from supermarkets and Internet suppliers. Monthly payment plans are often implemented to improve loyalty. This study aimed to compare behavioural loyalty between monthly payment plan members and non-members. METHODS: BBR Optometry Ltd offers a monthly payment plan (Eyelife™) to their contact lens wearers. A retrospective audit of 38 Eyelife™ members (mean±SD: 42.7±15.0 years) and 30 non-members (mean±SD: 40.8±16.7 years) was conducted. Revenue and profits generated, service uptake and product sales between the two groups were compared over a fixed period of 18 months. RESULTS: Eyelife™ members generated significantly higher professional fee revenue (P<0.001), £153.96 compared to £83.50, and profits (P<0.001). Eyelife™ members had a higher uptake of eye examinations (P<0.001). The 2 groups demonstrated no significant difference in spectacle sales by volume (P=0.790) or value (P=0.369). There were also no significant differences in contact lens revenue (P=0.337), although Eyelife™ members did receive a discount. The Eyelife™ group incurred higher contact lens costs (P=0.037), due to a greater volume of contact lens purchases, 986 units compared to 582. CONCLUSIONS: Monthly payment plans improve loyalty among contact lens wearers, particularly service uptake and volume of lens purchases. Additionally the greater professional fees generated, render monthly payment plans an attractive business model and practice builder.


Assuntos
Participação da Comunidade , Lentes de Contato de Uso Prolongado/economia , Equipamentos Descartáveis/economia , Modelos Econômicos , Optometria/economia , Satisfação do Paciente , Adulto , Idoso , Custos e Análise de Custo , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
9.
Schizophr Bull ; 40 Suppl 4: S233-45, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24936084

RESUMO

Much of the research on visual hallucinations (VHs) has been conducted in the context of eye disease and neurodegenerative conditions, but little is known about these phenomena in psychiatric and nonclinical populations. The purpose of this article is to bring together current knowledge regarding VHs in the psychosis phenotype and contrast this data with the literature drawn from neurodegenerative disorders and eye disease. The evidence challenges the traditional views that VHs are atypical or uncommon in psychosis. The weighted mean for VHs is 27% in schizophrenia, 15% in affective psychosis, and 7.3% in the general community. VHs are linked to a more severe psychopathological profile and less favorable outcome in psychosis and neurodegenerative conditions. VHs typically co-occur with auditory hallucinations, suggesting a common etiological cause. VHs in psychosis are also remarkably complex, negative in content, and are interpreted to have personal relevance. The cognitive mechanisms of VHs in psychosis have rarely been investigated, but existing studies point to source-monitoring deficits and distortions in top-down mechanisms, although evidence for visual processing deficits, which feature strongly in the organic literature, is lacking. Brain imaging studies point to the activation of visual cortex during hallucinations on a background of structural and connectivity changes within wider brain networks. The relationship between VHs in psychosis, eye disease, and neurodegeneration remains unclear, although the pattern of similarities and differences described in this review suggests that comparative studies may have potentially important clinical and theoretical implications.


Assuntos
Transtornos Psicóticos Afetivos/psicologia , Alucinações/psicologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Córtex Visual/fisiopatologia , Transtornos Psicóticos Afetivos/fisiopatologia , Encéfalo/fisiopatologia , Oftalmopatias/fisiopatologia , Alucinações/fisiopatologia , Alucinações/terapia , Humanos , Doenças Neurodegenerativas/fisiopatologia , Índice de Gravidade de Doença
10.
Graefes Arch Clin Exp Ophthalmol ; 252(5): 699-713, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24652235

RESUMO

PURPOSE: Alcohol consumption is inversely correlated with the incidence of cardiovascular disease. It is thought that red wine is specifically responsible for these cardiovascular benefits, due to its ability to reduce vascular inflammation, facilitate vasorelaxation, and inhibit angiogenesis. This is because of its high polyphenolic content. Resveratrol is the main biologically active polyphenol within red wine. Owing to its vascular-enhancing properties, resveratrol may be effective in the microcirculation of the eye, thereby helping prevent ocular diseases such as age-related macular degeneration, diabetic retinopathy, and glaucoma. Such conditions are accountable for worldwide prevalence of visual loss. METHOD: A review of the relevant literature was conducted on the ScienceDirect, Web of Science, and PubMed databases. Key words used to carry out the searches included 'red wine', 'polyphenols', 'resveratrol', 'eye' and 'ocular'. Articles relating to the effects of resveratrol on the eye were reviewed. RESULTS: The protective effects of resveratrol within the eye are extensive. It has been demonstrated to have anti-oxidant, anti-apoptotic, anti-tumourogenic, anti-inflammatory, anti-angiogenic and vasorelaxant properties. There are potential benefits of resveratrol supplementation across a wide range of ocular diseases. The molecular mechanisms underlying these protective actions are diverse. CONCLUSION: Evidence suggests that resveratrol may have potential in the treatment of several ocular diseases. However, while there are many studies indicating plausible biological mechanisms using animal models and in-vitro retinal cells there is a paucity of human research. The evidence base for the use of resveratrol in the management of ocular diseases needs to be increased before recommendations can be made for the use of resveratrol as an ocular supplement.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Oftalmopatias/prevenção & controle , Estilbenos/farmacologia , Vasodilatadores/farmacologia , Vinho , Animais , Humanos , Resveratrol , Estilbenos/química
11.
Curr Eye Res ; 39(8): 775-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24559406

RESUMO

PURPOSE: The purpose of this study was to determine whether stereoacuity can be used as an indicator of prism adaptation. In particular, we wanted to know whether the time required for stereoacuity to return to the initial level after viewing through a prism can be used to determine the degree of adaptation. MATERIALS AND METHODS: Eighteen subjects participated in this study. Stereoacuity and dissociated phoria were determined using the TNO stereotest and the Maddox rod, respectively. Prism vergences were measured using a prism bar. For each participant, prism power equivalent to the blur point of base-in (BI) and base-out (BO) fusional vergence at 40 cm was divided and placed in front of both eyes. At 0, 3, 6, 9 and 12 min after prism introduction, the stereoacuity was measured, and at 0 and 12 min, the heterophoria was measured. RESULTS: The repeated measures ANOVA showed a significant difference between the mean stereoacuity for BI and BO prisms at the different measurement times (p < 0.05). For BO prism, the initial value was different between 0 and 3 min after the prism introduction, whereas for BI prism, a difference in stereoacuity was found between the pre-prism value and the value at 0, 3 and 6 min. The size of the heterophoria with BO and BI prisms was different from 0 to 12 min (p < 0.05). CONCLUSION: The time required for stereoacuity to return to baseline level was more than 3 min for BO, and more than 6 min for BI prism. In addition, the time required to return to baseline values was not similar for the stereoacuity and heterophoria. The recovery of stereoacuity is slower when adapting to divergence, as when looking from near to far. This implies that stereopsis responds faster to near targets than to distant one, and may precede complete phoria adaptation.


Assuntos
Adaptação Ocular/fisiologia , Óculos , Estrabismo/fisiopatologia , Visão Binocular/fisiologia , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa , Estrabismo/terapia , Acuidade Visual , Adulto Jovem
12.
Curr Eye Res ; 39(4): 411-5, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24040775

RESUMO

PURPOSE: Although significant amounts of vertical misalignment could have a noticeable effect on visual performance, there is no conclusive evidence about the effect of very small amount of vertical disparity on stereopsis and binocular vision. Hence, the aim of this study was to investigate the effects of induced vertical disparity on local and global stereopsis at near. MATERIALS AND METHODS: Ninety participants wearing best-corrected refraction had local and global stereopsis tested with 0.5 and 1.0 prism diopter (Δ) vertical prism in front of their dominant and non-dominant eye in turn. This was compared to local and global stereopsis in the same subjects without vertical prism. Data were analyzed in SPSS.17 software using the independent samples T and the repeated measures ANOVA tests. RESULTS: Induced vertical disparity decreases local and global stereopsis. This reduction is greater when vertical disparity is induced in front of the non-dominant eye and affects global more than local stereopsis. Repeated measures ANOVA showed differences in the mean stereopsis between the different measured states for local and global values. Local stereopsis thresholds were reduced by 10 s of arc or less on average with 1.0Δ of induced vertical prism in front of either eye. However, global stereopsis thresholds were reduced by over 100 s of arc by the same 1.0Δ of induced vertical prism. CONCLUSION: Induced vertical disparity affects global stereopsis thresholds by an order of magnitude (or a factor of 10) more than local stereopsis. Hence, using a test that measures global stereopsis such as the TNO is more sensitive to vertical misalignment than a test such as the Stereofly that measures local stereopsis.


Assuntos
Percepção de Profundidade/fisiologia , Disparidade Visual , Visão Binocular/fisiologia , Feminino , Humanos , Masculino , Testes Visuais , Acuidade Visual , Adulto Jovem
13.
Clin Exp Optom ; 97(2): 160-3, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24024877

RESUMO

BACKGROUND: The aim was to evaluate the validity and repeatability of the auto-refraction function of the Nidek OPD-Scan III (Nidek Technologies, Gamagori, Japan) compared with non-cycloplegic subjective refraction. The Nidek OPD-Scan III is a new aberrometer/corneal topographer workstation based on the skiascopy principle. It combines a wavefront aberrometer, topographer, autorefractor, auto keratometer and pupillometer/pupillographer. METHODS: Objective refraction results obtained using the Nidek OPD-Scan III were compared with non-cycloplegic subjective refraction for 108 eyes of 54 participants (29 female) with a mean age of 23.7 ± 9.5 years. Intra-session and inter-session variability were assessed on 14 subjects (28 eyes). RESULTS: The Nidek OPD-Scan III gave slightly more negative readings than results obtained by subjective refraction (Nidek mean difference -0.19 ± 0.36 DS, p < 0.01 for sphere; -0.19 ± 0.35 DS, p < 0.01 for mean spherical equivalent; -0.002 ± 0.23 DC, p = 0.91 for cylinder; -0.06 ± 0.38 DC, p = 0.30 for J0 and -0.36 ± 0.31 DC for J45, p = 0.29). Auto-refractor results for 74 per cent of spherical readings and 60 per cent of cylindrical powers were within ± 0.25 of subjective refraction. There was high intra-session and inter-session repeatability for all parameters; 90 per cent of inter-session repeatability results were within 0.25 D. CONCLUSION: The Nidek OPD-Scan III gives valid and repeatable measures of objective refraction when compared with non-cycloplegic subjective refraction.


Assuntos
Técnicas de Diagnóstico Oftalmológico/instrumentação , Erros de Refração/diagnóstico , Adulto , Feminino , Humanos , Masculino , Refração Ocular , Reprodutibilidade dos Testes , Acuidade Visual
14.
Cont Lens Anterior Eye ; 37(2): 106-10, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24075240

RESUMO

PURPOSE: To study the effects of ocular lubricants on higher order aberrations in normal and self-diagnosed dry eyes. METHODS: Unpreserved hypromellose drops, Tears Again™ liposome spray and a combination of both were administered to the right eye of 24 normal and 24 dry eye subjects following classification according to a 5 point questionnaire. Total ocular higher order aberrations, coma, spherical aberration and Strehl ratios for higher order aberrations were measured using the Nidek OPD-Scan III (Nidek Technologies, Gamagori, Japan) at baseline, immediately after application and after 60 min. The aberration data were analyzed over a 5mm natural pupil using Zernike polynomials. Each intervention was assessed on a separate day and comfort levels were recorded before and after application. Corneal staining was assessed and product preference recorded after the final measurement for each intervention. RESULTS: Hypromellose drops caused an increase in total higher order aberrations (p=<0.01 in normal and dry eyes) and a reduction in Strehl ratio (normal eyes: p=<0.01, dry eyes p=0.01) immediately after instillation. There were no significant differences between normal and self-diagnosed dry eyes for response to intervention and no improvement in visual quality or reduction in higher order aberrations after 60 min. Differences in comfort levels failed to reach statistical significance. CONCLUSION: Combining treatments does not offer any benefit over individual treatments in self-diagnosed dry eyes and no individual intervention reached statistical significance. Symptomatic subjects with dry eye and no corneal staining reported an improvement in comfort after using lubricants.


Assuntos
Síndromes do Olho Seco/diagnóstico , Síndromes do Olho Seco/tratamento farmacológico , Lubrificantes/administração & dosagem , Soluções Oftálmicas/administração & dosagem , Erros de Refração/diagnóstico , Erros de Refração/tratamento farmacológico , Agentes Molhantes/administração & dosagem , Síndromes do Olho Seco/complicações , Feminino , Humanos , Masculino , Projetos Piloto , Valores de Referência , Erros de Refração/etiologia , Resultado do Tratamento , Adulto Jovem
15.
Invest Ophthalmol Vis Sci ; 54(4): 2711-9, 2013 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-23471890

RESUMO

PURPOSE: To assess the range of macular pigment optical density (MPOD) in a healthy group of young adults of South Asian origin; to investigate whether any dietary factors or personal characteristics were related to intersubject variations in MPOD; and to compare the mean MPOD of the South Asian group with the mean MPOD of a white group. METHODS: Heterochromatic flicker photometry was used to measure the macular pigment (MP) levels of 169 healthy volunteers, of which 117 were Asian and 52 were white. In addition, the Asian participants completed a questionnaire pertaining to the various physical, ocular, lifestyle, dietary, and environmental factors that may be associated with MPOD or AMD. RESULTS: The mean MPOD of the Asian subjects was 0.43 ± 0.14. The male participants had a higher mean MPOD than the females (0.47 ± 0.13 vs. 0.41 ± 0.14, P < 0.01). Possible associations also emerged between MPOD and form of refractive correction, and iris color. No MPOD associations were found for the other variables examined in the questionnaire. The mean MPOD of the white subject group was 0.33 ± 0.13, which was significantly lower than the Asian group (P < 0.0005). CONCLUSIONS: This study adds to the currently limited information on MPOD in South Asians, and while a comparison between Asians and Whites was not the main focus here, highly significant differences between these two ethnicities were revealed. This provokes the possibility that South Asian individuals could have a lower risk for AMD, and it warrants further study.


Assuntos
Povo Asiático/etnologia , Luteína/metabolismo , Macula Lutea/metabolismo , Pigmentos da Retina/metabolismo , População Branca/etnologia , Xantofilas/metabolismo , Adolescente , Adulto , Densitometria , Meio Ambiente , Comportamento Alimentar , Feminino , Humanos , Estilo de Vida , Degeneração Macular/metabolismo , Masculino , Fotometria/instrumentação , Fotometria/métodos , Inquéritos e Questionários , Adulto Jovem , Zeaxantinas
16.
Graefes Arch Clin Exp Ophthalmol ; 251(3): 871-80, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22899455

RESUMO

BACKGROUND: Heterochromatic flicker photometry (HFP) is a psychophysical technique used to measure macular pigment optical density (MPOD). We used the MPS 9000 (MPS) HFP device. Our aim was to determine if the repeatability of the MPS could be improved to make it more suitable for monitoring MPOD over time. METHODS: Intra-session repeatability was assessed in 25 participants (aged 20-50 years). The resulting data was explored in detail, e.g., by examining the effect of removal and adjustment of data with less than optimal quality parameters. A protocol was developed for improved overall reliability, which was then tested in terms of inter-session repeatability in a separate group of 27 participants (aged 19-52 years). RESULTS: Removal and adjustment of data reduced the intra-session coefficient of repeatability (CR) by 0.04, on average, and the mean individual standard deviation by 0.004. Raw data observation offered further insight into ways of improving repeatability. The proposed protocol resulted in an inter-session CR of 0.08. CONCLUSIONS: Removal and adjustment of less than optimal data improved repeatability, and is therefore recommended. To further improve repeatability, in brief we propose that each patient perform each part of the test twice, and a third time where necessary (described in detail by the protocol). Doing so will make the MPS more useful in research and clinical settings.


Assuntos
Técnicas de Diagnóstico Oftalmológico/normas , Luteína/metabolismo , Fotometria/instrumentação , Retina/metabolismo , Pigmentos da Retina/metabolismo , Xantofilas/metabolismo , Adulto , Densitometria , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Valores de Referência , Reprodutibilidade dos Testes , Adulto Jovem , Zeaxantinas
17.
Drug Discov Today ; 18(5-6): 290-7, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23092895

RESUMO

Ocular barriers and the poor water solubility of drug candidates present a number of problems for the development of ocular drug delivery systems. Recently, the emergence of lipid-based nanocarriers has provided a viable means of enhancing the bioavailability of ophthalmic formulations. A number of these formulations have been found to be clinically active and several others are currently undergoing clinical trials. In this review, the advantages of lipid-based nanocarriers as non-invasive topical ocular drug delivery systems are presented. Many systems, including emulsions, liposomes, cubosomes, niosomes and other lipid-based nanocarriers, are reviewed.


Assuntos
Portadores de Fármacos/administração & dosagem , Nanopartículas/administração & dosagem , Soluções Oftálmicas/administração & dosagem , Administração Oftálmica , Animais , Portadores de Fármacos/química , Humanos , Lipídeos/administração & dosagem , Lipídeos/química , Nanopartículas/química , Soluções Oftálmicas/química
18.
Br J Nutr ; 109(11): 2008-14, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23084077

RESUMO

Lutein and zeaxanthin are lipid-soluble antioxidants found within the macula region of the retina. Links have been suggested between increased levels of these carotenoids and reduced risk for age-related macular disease (ARMD). Therefore, the effect of lutein-based supplementation on retinal and visual function in people with early stages of ARMD (age-related maculopathy, ARM) was assessed using multifocal electroretinography (mfERG), contrast sensitivity and distance visual acuity. A total of fourteen participants were randomly allocated to either receive a lutein-based oral supplement (treated group) or no supplement (non-treated group). There were eight participants aged between 56 and 81 years (65·50 (SD 9·27) years) in the treated group and six participants aged between 61 and 83 years (69·67 (SD 7·52) years) in the non-treated group. Sample sizes provided 80% power at the 5% significance level. Participants attended for three visits (0, 20 and 40 weeks). At 60 weeks, the treated group attended a fourth visit following 20 weeks of supplement withdrawal. No changes were seen between the treated and non-treated groups during supplementation. Although not clinically significant, mfERG ring 3 N2 latency (P=0·041) and ring 4 P1 latency (P=0·016) increased, and a trend for reduction of mfERG amplitudes was observed in rings 1, 3 and 4 on supplement withdrawal. The statistically significant increase in mfERG latencies and the trend for reduced mfERG amplitudes on withdrawal are encouraging and may suggest a potentially beneficial effect of lutein-based supplementation in ARM-affected eyes.


Assuntos
Antioxidantes/administração & dosagem , Luteína/administração & dosagem , Degeneração Macular/terapia , Retina/fisiologia , Idoso , Idoso de 80 Anos ou mais , Antioxidantes/química , Suplementos Nutricionais , Eletrorretinografia , Feminino , Humanos , Luteína/química , Masculino , Pessoa de Meia-Idade , Acuidade Visual/fisiologia
19.
Surv Ophthalmol ; 57(4): 293-316, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22726587

RESUMO

Dry eye is a common yet complex condition. Intrinsic and extrinsic factors can cause dysfunction of the lids, lacrimal glands, meibomian glands, ocular surface cells, or neural network. These problems would ultimately be expressed at the tear film-ocular surface interface. The manifestations of these problems are experienced as symptoms such as grittiness, discomfort, burning sensation, hyperemia, and secondary epiphora in some cases. Accurate investigation of dry eye is crucial to correct management of the condition. Techniques can be classed according to their investigation of tear production, tear stability, and surface damage (including histological tests). The application, validity, reliability, compatibility, protocols, and indications for these are important. The use of a diagnostic algorithm may lead to more accurate diagnosis and management. The lack of correlation between signs and symptoms seems to favor tear film osmolarity, an objective biomarker, as the best current clue to correct diagnosis.


Assuntos
Técnicas de Diagnóstico Oftalmológico , Síndromes do Olho Seco/diagnóstico , Algoritmos , Humanos , Concentração Osmolar , Lágrimas/química , Lágrimas/fisiologia
20.
Clin Exp Optom ; 95(5): 510-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22372735

RESUMO

BACKGROUND: As light-emitting diodes become more common as the light source for low vision aids, the effect of illumination colour temperature on magnifier reading performance was investigated. METHODS: Reading ability (maximum reading speed, critical print size, threshold near visual acuity) using Radner charts and subjective preference was assessed for 107 participants with visual impairment using three stand magnifiers with light emitting diode illumination colour temperatures of 2,700 K, 4,500 K and 6,000 K. The results were compared with distance visual acuity, prescribed magnification, age and the primary cause of visual impairment. RESULTS: Reading speed, critical print size and near visual acuity were unaffected by illumination colour temperature (p > 0.05). Reading metrics decreased with worsening acuity and higher levels of prescribed magnification but acuity was unaffected by age. Each colour temperature was preferred and disliked by a similar number of patients and was unrelated to distance visual acuity, prescribed magnification and age (p > 0.05). Patients had better near acuity (p = 0.002), critical print size (p = 0.034) and maximum reading speed (p < 0.001), and the improvement in near from distance acuity was greater (p = 0.004) with their preferred rather than least-liked colour temperature illumination. CONCLUSION: A range of colour temperature illuminations should be offered to all visually impaired individuals prescribed with an optical magnifier for near tasks to optimise subjective and objective benefits.


Assuntos
Leitura , Baixa Visão/reabilitação , Adulto , Idoso , Idoso de 80 Anos ou mais , Cor , Feminino , Humanos , Luz , Masculino , Pessoa de Meia-Idade , Temperatura , Acuidade Visual
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