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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Investigation of Tear Film Osmolality as a Clinical Instrument Used in Assessments of the Tear Film and Dry Eye Disease

Dalton, Kristine Nicole January 2009 (has links)
Introduction: Tear film osmolality is a product of the varying concentrations of dissolved solutes (proteins, lipids and mucins) in the tear fluid. Research suggests that a hyperosmotic tear film is a trait common to all forms of dry eye, and it may be the driving force causing the discomfort, ocular surface damage and inflammation found in both evaporative and tear deficient forms of dry eye disease. Tear film osmolality has been proposed to be the “gold standard” diagnostic test for the evaluation of dry eye disease, as a distinct separation between tear film osmolalities in normal and dry-eyed (aqueous deficient or evaporative) populations has become evident. Historically, tear film osmolality could only be measured in a laboratory setting and required a highly skilled technician to use the instrumentation. The recent development of easy-to-use, small volume osmometers has made it possible for tear film osmolality to be measured clinically. As these instruments are quite new, there has been very little research completed with them. Therefore, a series of studies was conducted to investigate the utility of one of these new osmometers – the Advanced Instruments Model 3100 Nanolitre Osmometer. The specific aims of each chapter were: - Chapter 3: To determine if the Advanced Instruments Model 3100 Nanolitre Osmometer was capable of quantitatively measuring tear film osmolality in a normal population, using 0.5μL tear samples. - Chapter 4: Previous studies have shown the Advanced Instruments Model 3100 Nanolitre Osmometer not significantly different from another commercially available osmometer (Wescor Vapor Pressure Osmometer) for the measurement of human tears. This chapter examined the repeatability of the new instrument over multiple measurements on the same sample and over multiple days. - Chapter 5: To determine if tear film osmolality values varied significantly over the course of a normal working day in a population that was primarily free from symptoms of dry eye. - Chapter 6: To investigate the relationships between tear film osmolality and other commonly used clinical tests for dry eye disease. The clinical tests examined included various questionnaires designed to assess patient symptoms (Single Item Dry Eye Questionnaire (SIDEQ), the Ocular Surface Disease Index (OSDI), and the McMonnies Dry Eye Questionnaire (MMDEQ) and a linear analogue comfort scale (LACS)), a non-invasive tear break-up time test (NIBUT), and examination of ocular surface redness and tear ferning (TF). Secondarily to determine if the other clinical tests demonstrated significant diurnal variations over the course of a normal working day. - Chapter 7: To measure tear film osmolality in a population with mild to moderate symptoms of dry eye disease, and to compare this value with the osmolality of a population of age-matched controls without the disease. Secondarily, to investigate the relationship between tear film osmolality and patient comfort in a population with mild to moderate symptoms of dry eye disease. Methods: - Chapter 3: Tears were collected from 40 volunteer participants with a capillary tube. Some participants were non-contact lens wearers (Non-CL), while others wore either soft or rigid contact lenses (CL). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 4: Tears were collected from 10 volunteer participants using two different collection techniques. Collections were repeated on three separate days (6 study visits total); three osmolality measurements per collection were taken using the Advanced Instruments Model 3100 Nanolitre osmometer. - Chapter 5: Tears were collected from 40 volunteer participants in two separate studies (n=80 in total). Tears were collected with a capillary tube three times a day (morning, mid-day and afternoon), on two separate days (6 study visits total). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 6: Clinical tests were administered and tear samples were collected using a capillary tube from 40 volunteer participants. Measurements were taken three times a day (morning, mid-day and afternoon), on two separate days (6 study visits total). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 7: Participants were classified as either having dry eye disease (DE) or not having dry eye disease (NDE) based on a clinical examination that included a case history, phenol red thread test and biomicroscopy (white light and sodium fluorescein assessment). Tear samples were then collected from all participants using a capillary tube and tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. Participants also completed the SIDEQ, the OSDI, and the MMDEQ. Results: - Chapter 3: The mean tear film osmolality of the population was 298.7±11.4mOsm/Kg. CL wear (soft or rigid) did not appear to have a significant effect on tear film osmolality (CL: 298.5±11.2mOsm/Kg vs. Non-CL: 298.9±11.5mOsm/Kg), although this study was not designed to specifically look at the effects of contact lens wear on tear film osmolality. - Chapter 4: There was reasonably good concordance between measurements of tear film osmolality taken with the Advanced Instruments Model 3100 Nanolitre Osmometer (intraclass correlations range from 0.6497 (F= 0.0582) to 0.9550 (F = 0.5893)). Repeatability appeared to be affected by significant changes in ambient humidity (>10% per day). Concordance was similar with both sampling techniques. - Chapter 5: In the first study, no significant diurnal change in tear film osmolality was found (p>0.05), although a significant difference in measurements taken on Day 1 compared to Day 2 was found (p=0.040). When the first and last 10 participants enrolled were compared, the difference between days was present in the first 10 participants, but not in the last 10; it is likely that the investigator underwent a learning process during the period of the study, and that reflex tearing occurred more often in the early portion of the study compared with the latter portion. In the second study, no significant diurnal change in tear film osmolality was found (p>0.05) and no significant difference in measurements taken on Day 1 compared to Day 2 was found (p>0.05). When tear film osmolality was compared with the number of hours participants were awake, no significant correlation was found (r = 0.07044). - Chapter 6: Significant correlations were not found between tear film osmolality and SIDEQ (r = 0.1347), OSDI (r = 0.0331), MMDEQ (r = 0.2727), LACS (r = -0.1622), NIBUT (r = -0.2280), subjectively graded redness (r=-0.2280), or objectively measured redness (r = 0.1233). A weakly significant correlation was found between TF and tear film osmolality (r = 0.3978). None of the clinical measures (LACS, NIBUT, subjective or objective redness or TF) varied significantly over the course of the day. - Chapter 7: Tear film osmolality was higher in both the right (DE = 311.1±12.4mOsm/Kg, NDE = 306.2±11.2mOsm/Kg) and left eyes (DE = 313.2±11.9mOsm/Kg, NDE = 304.0±7.5mOsm/Kg) of participants, but the difference was only statistically significant in the left eye. Tear film osmolality did not correlate significantly with DE patient symptoms using any of the questionnaires (SIDEQ, OSDI, MMDEQ). Conclusions: - Chapter 3: The Advanced Instruments Model 3100 Nanolitre Osmometer appeared to be capable of measuring tear film osmolality in a normal population. Our population mean was slightly lower than what is reported to be normal (305mOsm/Kg), but it still fell within the range of values reported as normal (297 – 318mOsm/Kg). - Chapter 4: The Advanced Instruments Model 3100 Nanolitre Osmometer demonstrated reasonably good repeatability for the measurement of human tear samples. Unfortunately, the instrumentation appeared to be affected by dramatic weather changes. Maintaining the instrument in a humidity controlled environment may resolve this problem. - Chapter 5: Tear film osmolality did not appear to vary significantly over a normal working day. Inducing reflex tearing, perhaps with an unskilled investigator collecting the tears, can be a significant source of error (as demonstrated in the first study). - Chapter 6: Tear film osmolality did not correlate well with other clinical instruments designed to assess either patient symptoms or signs of dry eye disease in a normal population. Tear film osmolality and tear ferning did demonstrate a weakly significant positive correlation. None of the clinical measures assessed demonstrated a significant diurnal variation over the course of a normal working day. - Chapter 7: Tear film osmolality appeared to be higher in participants with mild to moderate symptoms of dry eye when compared with age matched, asymptomatic controls. Tear film osmolality did not correlate well with patient symptoms in a population of mild to moderate severe dry eyed individuals.
2

The Investigation of Tear Film Osmolality as a Clinical Instrument Used in Assessments of the Tear Film and Dry Eye Disease

Dalton, Kristine Nicole January 2009 (has links)
Introduction: Tear film osmolality is a product of the varying concentrations of dissolved solutes (proteins, lipids and mucins) in the tear fluid. Research suggests that a hyperosmotic tear film is a trait common to all forms of dry eye, and it may be the driving force causing the discomfort, ocular surface damage and inflammation found in both evaporative and tear deficient forms of dry eye disease. Tear film osmolality has been proposed to be the “gold standard” diagnostic test for the evaluation of dry eye disease, as a distinct separation between tear film osmolalities in normal and dry-eyed (aqueous deficient or evaporative) populations has become evident. Historically, tear film osmolality could only be measured in a laboratory setting and required a highly skilled technician to use the instrumentation. The recent development of easy-to-use, small volume osmometers has made it possible for tear film osmolality to be measured clinically. As these instruments are quite new, there has been very little research completed with them. Therefore, a series of studies was conducted to investigate the utility of one of these new osmometers – the Advanced Instruments Model 3100 Nanolitre Osmometer. The specific aims of each chapter were: - Chapter 3: To determine if the Advanced Instruments Model 3100 Nanolitre Osmometer was capable of quantitatively measuring tear film osmolality in a normal population, using 0.5μL tear samples. - Chapter 4: Previous studies have shown the Advanced Instruments Model 3100 Nanolitre Osmometer not significantly different from another commercially available osmometer (Wescor Vapor Pressure Osmometer) for the measurement of human tears. This chapter examined the repeatability of the new instrument over multiple measurements on the same sample and over multiple days. - Chapter 5: To determine if tear film osmolality values varied significantly over the course of a normal working day in a population that was primarily free from symptoms of dry eye. - Chapter 6: To investigate the relationships between tear film osmolality and other commonly used clinical tests for dry eye disease. The clinical tests examined included various questionnaires designed to assess patient symptoms (Single Item Dry Eye Questionnaire (SIDEQ), the Ocular Surface Disease Index (OSDI), and the McMonnies Dry Eye Questionnaire (MMDEQ) and a linear analogue comfort scale (LACS)), a non-invasive tear break-up time test (NIBUT), and examination of ocular surface redness and tear ferning (TF). Secondarily to determine if the other clinical tests demonstrated significant diurnal variations over the course of a normal working day. - Chapter 7: To measure tear film osmolality in a population with mild to moderate symptoms of dry eye disease, and to compare this value with the osmolality of a population of age-matched controls without the disease. Secondarily, to investigate the relationship between tear film osmolality and patient comfort in a population with mild to moderate symptoms of dry eye disease. Methods: - Chapter 3: Tears were collected from 40 volunteer participants with a capillary tube. Some participants were non-contact lens wearers (Non-CL), while others wore either soft or rigid contact lenses (CL). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 4: Tears were collected from 10 volunteer participants using two different collection techniques. Collections were repeated on three separate days (6 study visits total); three osmolality measurements per collection were taken using the Advanced Instruments Model 3100 Nanolitre osmometer. - Chapter 5: Tears were collected from 40 volunteer participants in two separate studies (n=80 in total). Tears were collected with a capillary tube three times a day (morning, mid-day and afternoon), on two separate days (6 study visits total). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 6: Clinical tests were administered and tear samples were collected using a capillary tube from 40 volunteer participants. Measurements were taken three times a day (morning, mid-day and afternoon), on two separate days (6 study visits total). Tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. - Chapter 7: Participants were classified as either having dry eye disease (DE) or not having dry eye disease (NDE) based on a clinical examination that included a case history, phenol red thread test and biomicroscopy (white light and sodium fluorescein assessment). Tear samples were then collected from all participants using a capillary tube and tear film osmolality was measured with the Advanced Instruments Model 3100 Nanolitre Osmometer. Participants also completed the SIDEQ, the OSDI, and the MMDEQ. Results: - Chapter 3: The mean tear film osmolality of the population was 298.7±11.4mOsm/Kg. CL wear (soft or rigid) did not appear to have a significant effect on tear film osmolality (CL: 298.5±11.2mOsm/Kg vs. Non-CL: 298.9±11.5mOsm/Kg), although this study was not designed to specifically look at the effects of contact lens wear on tear film osmolality. - Chapter 4: There was reasonably good concordance between measurements of tear film osmolality taken with the Advanced Instruments Model 3100 Nanolitre Osmometer (intraclass correlations range from 0.6497 (F= 0.0582) to 0.9550 (F = 0.5893)). Repeatability appeared to be affected by significant changes in ambient humidity (>10% per day). Concordance was similar with both sampling techniques. - Chapter 5: In the first study, no significant diurnal change in tear film osmolality was found (p>0.05), although a significant difference in measurements taken on Day 1 compared to Day 2 was found (p=0.040). When the first and last 10 participants enrolled were compared, the difference between days was present in the first 10 participants, but not in the last 10; it is likely that the investigator underwent a learning process during the period of the study, and that reflex tearing occurred more often in the early portion of the study compared with the latter portion. In the second study, no significant diurnal change in tear film osmolality was found (p>0.05) and no significant difference in measurements taken on Day 1 compared to Day 2 was found (p>0.05). When tear film osmolality was compared with the number of hours participants were awake, no significant correlation was found (r = 0.07044). - Chapter 6: Significant correlations were not found between tear film osmolality and SIDEQ (r = 0.1347), OSDI (r = 0.0331), MMDEQ (r = 0.2727), LACS (r = -0.1622), NIBUT (r = -0.2280), subjectively graded redness (r=-0.2280), or objectively measured redness (r = 0.1233). A weakly significant correlation was found between TF and tear film osmolality (r = 0.3978). None of the clinical measures (LACS, NIBUT, subjective or objective redness or TF) varied significantly over the course of the day. - Chapter 7: Tear film osmolality was higher in both the right (DE = 311.1±12.4mOsm/Kg, NDE = 306.2±11.2mOsm/Kg) and left eyes (DE = 313.2±11.9mOsm/Kg, NDE = 304.0±7.5mOsm/Kg) of participants, but the difference was only statistically significant in the left eye. Tear film osmolality did not correlate significantly with DE patient symptoms using any of the questionnaires (SIDEQ, OSDI, MMDEQ). Conclusions: - Chapter 3: The Advanced Instruments Model 3100 Nanolitre Osmometer appeared to be capable of measuring tear film osmolality in a normal population. Our population mean was slightly lower than what is reported to be normal (305mOsm/Kg), but it still fell within the range of values reported as normal (297 – 318mOsm/Kg). - Chapter 4: The Advanced Instruments Model 3100 Nanolitre Osmometer demonstrated reasonably good repeatability for the measurement of human tear samples. Unfortunately, the instrumentation appeared to be affected by dramatic weather changes. Maintaining the instrument in a humidity controlled environment may resolve this problem. - Chapter 5: Tear film osmolality did not appear to vary significantly over a normal working day. Inducing reflex tearing, perhaps with an unskilled investigator collecting the tears, can be a significant source of error (as demonstrated in the first study). - Chapter 6: Tear film osmolality did not correlate well with other clinical instruments designed to assess either patient symptoms or signs of dry eye disease in a normal population. Tear film osmolality and tear ferning did demonstrate a weakly significant positive correlation. None of the clinical measures assessed demonstrated a significant diurnal variation over the course of a normal working day. - Chapter 7: Tear film osmolality appeared to be higher in participants with mild to moderate symptoms of dry eye when compared with age matched, asymptomatic controls. Tear film osmolality did not correlate well with patient symptoms in a population of mild to moderate severe dry eyed individuals.
3

Preactivated Thiomer Mucoadhesive Micelles for Anterior Ophthalmic Drug Delivery

Goostrey, Taylor January 2021 (has links)
Effective delivery of drugs to the anterior segment of the eye is notoriously inefficient due to the anatomical barriers in place. Topical administration is the most common method of drug delivery to the anterior segment. When applied to the ocular surface, topical solutions encounter barriers such as lacrimal drainage, rapid tear turnover, and reflex blinking which result in < 5% of instilled therapeutic reaching the intended tissue. One potential method to evade some of these anatomical barriers and improve the delivery of therapeutics is the use of mucoadhesive nanoparticles. These materials are designed to encapsulate a relevant ocular therapeutic and provide a means of maintaining the vehicle on the ocular surface by adhering to the mucin layer of the tear film. To this end, the work presented herein describes the design, characterization, and testing of a novel mucoadhesive polymeric nano-micelle ocular drug delivery system. The base polymer used was selected from a system that has been previously used in the Sheardown Lab. It was composed of poly(D,L-lactide)-block-poly(methacrylic acid-co-3-(acrylamido)phenylboronic acid) (PLA-b-P(MAA-co-3-AAPBA); LMP-20). The formulation was modified to replace the 3-AAPBA monomer, which contains phenyl boronic acid as the mucoadhesive component, with a preactivated thiol monomer (pyridyl disulfide ethyl methacrylate; PDSMA) to generate a novel polymer (LMS-20) to investigate the potential for drug incorporation and mucoadhesion. Modifications of the polymer were made with small thiol molecules cysteamine (Cys; LMC-20), glutathione (GSH; LMG-20), and N-acetyl cysteine (NAC; LMA-20) with a goal of reducing cytotoxicity associated with the 2-pyridinethione leaving group. Synthesis of the PDSMA monomer, LMS-20 and LMP-20 polymers, and modified polymers LMC-20, LMG-20, and LMA-20 were confirmed by 1H NMR. LMA-20 was chosen for further examination as it contained the most relevant thiol modification for ocular applications and was capable of nanoprecipitation to form aqueous micelles with previously developed methods. Micelles were formed from LMA-20 and LMP-20, with spherical morphology as confirmed by TEM. Effective diameters of 64 ± 5 nm and 72 ± 3 nm are reported for LMA-20 and LMP-20, respectively, as confirmed by DLS. Critical micelle concentration for LMA-20 of 217 mg/L was found via a pyrene fluorescence study, significantly lower than the concentration of intended application. LMA-20 and LMP-20 are predicted to be mucoadhesive based on results of zeta-potential studies. However, oscillatory rheology studies were inconclusive based on a negative rheological synergism. LMA-20 micelles loaded with 0.16% (w/w) Cyclosporine-A were able to provide sustained release of drug up to 3 days in vitro. These results suggest the possible future use of these preactivated thiomer-based materials for the delivery of therapeutics to the anterior segment. / Thesis / Master of Applied Science (MASc)
4

Resultados funcionais da ressecção supramáxima do levantador da pálpebra superior em pacientes com blefaroptose congênita / Functional results in supramaximal levator resection for congenital ptosis

Mendonça, Ana Karina Téles Silveira de 28 May 2015 (has links)
O tratamento cirúrgico da blefaroptose congênita é controverso e, embora a ressecção supramáxima do levantador palpebral tenha sido advogada por alguns autores como eficaz em diminuir a assimetria palpebral, existe o risco de que a cirurgia possa estar associada à restrição dos movimentos palpebrais e à ocorrência de olho seco. Com o objetivo de quantificar os movimentos palpebrais nos pacientes submetidos à cirurgia e avaliar a eventual relação entre supostas alterações funcionais dos movimentos palpebrais e a ocorrência de complicações relacionadas à superfície ocular, foram caracterizadas, mediante a utilização da técnica magnetic search coil, as amplitudes e as velocidades dos movimentos do piscar e dos sacádicos palpebrais dos olhos operados de dezoito pacientes e, em seguida, foram comparadas com as amplitudes e velocidades obtidas para os olhos contralaterais não operados dos mesmos pacientes e também com as obtidas para os olhos dos pacientes do grupo controle, não operados. Também foram avaliados os resultados cosméticos nos pacientes operados e a ocorrência de complicações relacionadas à superfície ocular entre os olhos operados e os controles, não operados. A cirurgia acarretou aumento da distância margem-reflexo da pálpebra superior e diminuição da assimetria palpebral, logrando bom resultado estético. Porém, tanto a amplitude quanto a velocidade, seja das piscadelas, ou dos movimentos sacádicos palpebrais dos olhos operados, foram inferiores às dos controles e a cirurgia esteve relacionada com maior risco de ocorrência de olho seco. Por esse motivo, os autores advogam que a ressecção supramáxima do levantador da pálpebra superior permanece uma opção eficaz para o tratamento da ptose palpebral congênita, mas contraindicam a sua utilização em pacientes com ausência do reflexo de Bell ou outras alterações prévias documentadas ou predisponentes à ceratoconjuntivite seca. / Surgical treatment of congenital blepharoptosis remains controversial and, although supramaximal resection of the levator palpebrae superioris has been advocated as effective in reducing eyelid asymmetry, there is a risk that the surgery may be associated with restriction of eyelid movements and the occurrence of dry eye. In order to quantify eyelid movements in patients undergoing surgery and to assess the possible relationship between the alleged functional changes of eyelid movements and the occurrence of complications related to the ocular surface, we measured by magnetic search coil technique the amplitude and the maximal descent speed of blinks and lid saccades in eighteen patients who undergone surgery and in ten patients of the control group, with no eyelid diseases. We compared the amplitude and speed of the operated eyes with that of the non-operated eyes. We also evaluate the cosmetic results in operated patients and the occurrence of dry eye between operated and non-operated eyes. The surgery resulted in increased upper lid margin-reflex distance and consequent decreased eyelid asymmetry, achieving good aesthetic result. However, both amplitude and speed of eyelid movements in operated eyes were lower than those for the control eyes and the surgery was associated with increased risk of dry eye. For this reason, the authors advocate that supramaximal levator resection of the levator palpebrae superioris remains an effective option for the treatment of congenital blepharoptosis, but contraindicate its use in patients with absence of Bell\'s reflex or with previous ocular surface diseases.
5

Assessment of dry eyes using ocular surface thermography

Tan, Li Li January 2017 (has links)
Assessment and diagnosis of dry eye disease (DED) is a challenging task. The conventional ways of diagnosing DED are problematic due to their invasiveness, poor test reliability and significant test duration. Previously, ocular surface thermography has been shown to be able to detect early inflammation and dry eye. However, its diagnostic ability and ocular temperature metrics that can best diagnose DED are not clear. The objectives of this thesis were manyfold. First, the prevalence of dry eye in Singapore population was investigated as a helpful basis for the rest of the project. A cross-sectional dry eye survey was carried out using McMonnies dry eye questionnaire. Members of the public were interviewed at 46 (out of 62) selected mass rapid transit stations in Singapore and its vicinity. 1004 questionnaires were collected from participants aged 15 - 83 years and various ethnicity. Prevalence of symptomatic dry eye (SDE) was found to be 12.3% (about 0.5 million Singaporeans). Risk factors associated with SDE were found to be age, gender, ethnicity, hypertension and contact lens wear. Smoking was not associated with SDE.The main part of this thesis sought to evaluate the efficacy of ocular thermography in diagnosing DED. A new infrared detector (NEC Thermo Tracer TH 9260) with relatively high resolution was used. Inter-image, inter-occasion and inter-examiner repeatability was first studied on 21 healthy and 15 DED subjects. Ocular surface marking and ocular surface temperature (OST) acquisition was performed with a novel 'diamond' method using a custom-designed OST analysis V2 software. Ten out of the twelve tested OST indices were shown to be highly repeatable for three studied time points: 0 s, 5 s and 10 s. They were temperatures of the geometric center of the cornea (GCC), mean temperature (MOST) of the region of interest (ROI), maximum (MaxT) and minimum (MinT) temperatures of the ROI, extreme temporal (T1) and nasal conjunctiva (T4), mid temporal (CT) and nasal conjunctiva (CN) and temporal (LT) and nasal limbal (LN). Another 62 DED and 63 age- and sex-matched controls were then recruited and the ten static and dynamic OST indices were evaluated. Static measures were study of absolute OST at t = 0 s, 5 s and 10 s after eye opening. Dynamic measures were study of mean change and net change in OST over 10 s of sustained eye opening. Static measures on eight OST indices (GCC, MOST, MinT, MaxT, T4, CT, LT and LN) at t = 0 s, 5 s and 10 s and dynamic measures on two OST indices (T4 at 3 s onward and MaxT at 5 s onward) were found to be valuable in detecting DED. The temperature metrics (static and dynamic) were identified for further investigation. Thereafter, the diagnostic ability of the temperature metrics were evaluated singly and as combinations in terms of their area under the curve (AUC), Youden index and discrimination power. Receiver operating characteristic curves were plotted for each metric. Best detectors for DED were found to be the T4 temperature metrics: particularly T4-5 and T4-10 (i.e. absolute temperature of the extreme nasal conjunctiva at 5 s and 10 s). Values of T4-5 of < 34.8 °C were found to give sensitivity and specificity of 87.1% and 50.8% respectively and values of T4-10 of < 34.6 °C were found to give sensitivity and specificity of 77.6% and 61.9% respectively. The two temperature metrics had highest Youden index as compared to other metrics and were shown to be useful in view of AUC > 70% but of limited performance in view of their discrimination power. Nevertheless, measuring T4-5 and T4-10 was found to be comparable to other conventional methods for DED. T4-10 was better than T4-5 in view of higher AUC and Youden index. None of the tested dynamic metrics was good detector for DED and combining metrics were not able to increase the diagnostic ability. The last part of this thesis was to validate the effectiveness of some common conventional dry eye tests, to study their correlation with T4 temperature metrics and derive the best composite/combined tests for DED. Sixty two DED patients and 82 controls were studied. The conventional clinical tests examined were: symptom evaluation using McMonnies dry eye questionnaire (Mscore) and symptom count (Scount), fluorescein break-up time (FBUT) and corneal epithelial staining (CES), non-invasive break-up time (NIBUT) and tear meniscus height (TMH). Mscore and Scount was the best detectors for DED, followed by FBUT and CES. Discordance between signs and symptoms for DED was further confirmed. Combining CES with T4-10 (series) can be future objective tests for DED. Further research is warranted, particularly to (1) validate the ability of T4-10 as a stand-alone test for DED and (2) work out an algorithm and validate the diagnostic ability of the recommended combined test (CES and T4-10) using newly recruited subjects.
6

Resultados funcionais da ressecção supramáxima do levantador da pálpebra superior em pacientes com blefaroptose congênita / Functional results in supramaximal levator resection for congenital ptosis

Ana Karina Téles Silveira de Mendonça 28 May 2015 (has links)
O tratamento cirúrgico da blefaroptose congênita é controverso e, embora a ressecção supramáxima do levantador palpebral tenha sido advogada por alguns autores como eficaz em diminuir a assimetria palpebral, existe o risco de que a cirurgia possa estar associada à restrição dos movimentos palpebrais e à ocorrência de olho seco. Com o objetivo de quantificar os movimentos palpebrais nos pacientes submetidos à cirurgia e avaliar a eventual relação entre supostas alterações funcionais dos movimentos palpebrais e a ocorrência de complicações relacionadas à superfície ocular, foram caracterizadas, mediante a utilização da técnica magnetic search coil, as amplitudes e as velocidades dos movimentos do piscar e dos sacádicos palpebrais dos olhos operados de dezoito pacientes e, em seguida, foram comparadas com as amplitudes e velocidades obtidas para os olhos contralaterais não operados dos mesmos pacientes e também com as obtidas para os olhos dos pacientes do grupo controle, não operados. Também foram avaliados os resultados cosméticos nos pacientes operados e a ocorrência de complicações relacionadas à superfície ocular entre os olhos operados e os controles, não operados. A cirurgia acarretou aumento da distância margem-reflexo da pálpebra superior e diminuição da assimetria palpebral, logrando bom resultado estético. Porém, tanto a amplitude quanto a velocidade, seja das piscadelas, ou dos movimentos sacádicos palpebrais dos olhos operados, foram inferiores às dos controles e a cirurgia esteve relacionada com maior risco de ocorrência de olho seco. Por esse motivo, os autores advogam que a ressecção supramáxima do levantador da pálpebra superior permanece uma opção eficaz para o tratamento da ptose palpebral congênita, mas contraindicam a sua utilização em pacientes com ausência do reflexo de Bell ou outras alterações prévias documentadas ou predisponentes à ceratoconjuntivite seca. / Surgical treatment of congenital blepharoptosis remains controversial and, although supramaximal resection of the levator palpebrae superioris has been advocated as effective in reducing eyelid asymmetry, there is a risk that the surgery may be associated with restriction of eyelid movements and the occurrence of dry eye. In order to quantify eyelid movements in patients undergoing surgery and to assess the possible relationship between the alleged functional changes of eyelid movements and the occurrence of complications related to the ocular surface, we measured by magnetic search coil technique the amplitude and the maximal descent speed of blinks and lid saccades in eighteen patients who undergone surgery and in ten patients of the control group, with no eyelid diseases. We compared the amplitude and speed of the operated eyes with that of the non-operated eyes. We also evaluate the cosmetic results in operated patients and the occurrence of dry eye between operated and non-operated eyes. The surgery resulted in increased upper lid margin-reflex distance and consequent decreased eyelid asymmetry, achieving good aesthetic result. However, both amplitude and speed of eyelid movements in operated eyes were lower than those for the control eyes and the surgery was associated with increased risk of dry eye. For this reason, the authors advocate that supramaximal levator resection of the levator palpebrae superioris remains an effective option for the treatment of congenital blepharoptosis, but contraindicate its use in patients with absence of Bell\'s reflex or with previous ocular surface diseases.
7

Cigarettröknings påverkan på torra ögon

Le, Anna, Karlsson, Ebba January 2021 (has links)
Syftet med studien var att genom en litteraturstudie undersöka cigarettröknings påverkan på torra ögon och ögats främre delar. Har cigarettrökning en negativ inverkan på parametrarna för torra ögon? Litteraturstudien genomfördes utifrån sökningar via Web of Science och Pubmed på tidigare kliniska studier och vetenskapliga publikationer. Sökningarna utfördes mellan 2021-03-18 och 2021-03-26. För att specificera sökresultaten skulle artiklarna finnas i fulltext och vara publicerade från år 2016-2021. Sökorden som tillämpades var ”dry eye and smoking” och ”dry eye + smoking”. Studier med färre än 50 deltagare och litteraturstudier/reviews exkluderades. De fem mest relevanta artiklarna utifrån sökresultaten valdes ut för att ingå i studien. Totalt deltog 2692 personer i studierna. Mängden cigarettrökning varierade mellan studierna. Frågeformulären som utfördes var Ocular Surface Disease Index (OSDI) och Mcmonnies Dry Eye Questionnaire (MDEQ), dessa visade en statistisk signifikant skillnad på symptompoäng mellan rökare och icke-rökare i två av fem studier. Det sågs en statistisk signifikant skillnad i Tear Break Up Time (TBUT) mellan testgrupperna i tre av fem studier. Studien visar att cigarettrökning påverkar torra ögon, torra ögonsymptom, ögats främre delar och meibomska körtlarna negativt. Dock ses stora variationer i vad som påverkas inom olika grupper, vilket gör det svårt att fastställa exakt vilken påverkan cigarettrökning har på torra ögon. Fler studier med fler deltagare, ett bestämt antal cigaretter per dag under en bestämd period samt tydliga riktlinjer för utvärdering av DED behövs för att fastställa cigarettröknings påverkan på torra ögon.
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Tear Lipid Layer Thickness and Symptoms in Patients with Dry Eye Disease following the use of Emollient versus Non-Emollient Artificial Tears

Weisenberger, Kimberly R. 08 October 2020 (has links)
No description available.
9

Comparison of the Ocular Surface in Adult and Pediatric Contact Lens Wearers

Bickle, Katherine Margaret 18 August 2022 (has links)
No description available.
10

Korrelation mellan fenolröd tråd och Schirmers tårtest : En litteraturstudie

Olsson, Malin, Sjösvärd, Richard January 2020 (has links)
Syfte: Att genom en litteraturstudie jämföra Schirmers tårtest (STT) och fenolröd tråd (PRTT), för att se hur god korrelation det är mellan de två testerna vid diagnostisering av torra ögon. Metod: Analysera och jämföra studier med hjälp av olika artiklar. Dessa artiklar har hittats genom sökning i databasen Google scholar med sökfraserna schirmer´s test versus phenol red thread och tear test correlations. Fem relevanta artiklar valdes ut för närmare granskning. Resultat: Det har framkommit varierande resultat angående huruvida det finns en god korrelation mellan Schirmers tårtest och fenolröd tråd. Slutsats: Efter att ha tittat närmare på de fem studierna så kan man konstatera att det behövs ytterligare studier av testerna Schirmers tårtest och fenolröd tråd, dessutom behövs det gemensamma gränser för vad som är torra ögon. När det gäller korrelationen mellan Schirmers tårtest och fenolröd tråd så är det svårt att ta ställning till det eftersom alla studier har olika urvalskriterier. / Objective: This literature review is a comparison of the Schirmer's tear test (STT) and the Phenol Red Thread Test (PRTT). The aim of the review is to find out if there was a good correlation between the two tests regarding diagnosing dry eye disease. Method: Analyze and compare studies using different articles. These articles were found by searching the Google Scholar. The search phrases were Schirmer´s test versus phenol red thread and tear test correlations. Five relevant articles were selected for further review. Results: There have been varying results regarding whether there is a good correlation between Schirmer's tear test and Phenol Red Thread. Conclusion: After a closer look at the five studies, it can be concluded that further studies of the Schirmer's tear test and Phenol Red Thread are required, in addition, there is a need of common cutoffs for diagnosing dry eye disease. It is hard to find a correlation between Schirmer's tear test and Phenol Red Thread, since all studies use different criteria for inclusion.

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