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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.
161

Die Auswirkungen Ketamin-basierter Narkoseprotokolle auf den intraokularen Druck bei der Katze – eine prospektive randomisierte Blindstudie

McIntosh, Jenny 12 June 2013 (has links) (PDF)
Der Einsatz von Ketamin erfolgt in der Humananästhesie, vor allem aufgrund seiner vielfältigen Nebenwirkungen, nur noch nach strenger Indikation. In der Veterinärmedizin ist Ketamin tierartenübergreifend für die Injektionsnarkose weit verbreitet. Um den bekannten Nebenwirkungen vorzubeugen, wird Ketamin mit verschiedenen anderen Anästhetika kombiniert und stellt so ein sicheres Narkoseverfahren bei Tieren dar. Eine besondere Herausforderung ist die Anästhesie bei ophthalmologischen Patienten unter Berücksich-tigung der Kontrolle des Intraokularen Drucks (IOP). In diesem Zusammenhang gibt es in der Literatur widersprüchliche Angaben zur Auswirkung von Ketamin auf den IOP beim Menschen und verschiedenen Tierarten. Auch für die Auswirkungen von Propofol und der endotrachealen Intubation auf den IOP existieren widersprüchliche Aussagen. In der vorliegenden Arbeit wurde untersucht, ob gängige Ketamin-Kombinationsnarkosen bei der augengesunden Katze einen Einfluss auf den IOP haben. Angeregt durch Berichte in der Literatur wurde zudem untersucht, ob die Applikation von Propofol sowie die endotracheale Intubation den IOP bei der Katze beeinflussen. Methodik: Untersucht wurden 48 adulte, augengesunde Katzen, die dem chirurgischen Patientengut der Klinik für Kleintiere der Universität Leipzig entstammten. Es handelt sich um eine prospektive, randomisierte Blindstudie. Die Patienten wurden vier Untersuchungsgruppen zugeordnet. Zur intramuskulären Narkoseeinleitung erhielten Tiere der KX-Gruppe Ketamin (10 mg/kg) und Xylazin (1 mg/kg), der KXAtr-Gruppe Ketamin (10 mg/kg), Xylazin (1 mg/kg) und Atropin (0,025 mg/kg), der KA-Gruppe Ketamin (20 mg/kg) und Acepromazin (0,5 mg/kg) und der KM-Gruppe Ketamin (10 mg/kg) und Medetomidin (50 g/kg). Bei allen Patienten wurde mittels Tono-Pen® XL zu verschiedenen Zeitpunkten der IOP bestimmt: vor Narkoseeinleitung (Ausgangswert), nach Narkoseeinleitung nach 5, Zusammenfassung 86 10, 15 und 20 Minuten und direkt nach der Intubation sowie final nach Beendigung der Narkose während der Aufwachphase. Einige Tiere erhielten zur Vertiefung der Narkose vor der Intubation Propofol. Im Anschluss erfolgte eine ophthalmologische Untersuchung der Patienten, um eine Augenerkrankung auszuschließen. Ergebnisse: Der mittlere Ausgangs-IOP aller Tiere beträgt 15,8 mmHg. Mit p = 0,756 besteht kein signifikanter Unterschied zwischen den Gruppen. Getrennt nach linken (OS) und rechten (OD) Augen ist der mittlere IOP 15,7 und 15,8 mmHg. Dieser Unterschied ist nicht signifikant (p = 0,442). Daher wird für die Auswertung der Mittelwert aller 6 Datenpunkte pro Tier und Messzeitpunkt zugrunde gelegt. Im Vergleich zum Ausgangswert zeigt die KX-Gruppe keine signifikanten IOP-Änderungen. Die KXAtr-Gruppe und die KM-Gruppe weisen zur Final-Messung einen signifikanten IOP-Abfall um 16 % (p = 0,012) bzw. 17 % (p = 0,021) im Vergleich zum Ausgangswert auf. Die KA-Gruppe zeigt zur 15-Minuten-Messung den stärksten IOP-Abfall mit 21 % Prozent (p = 0,001) gegenüber dem Ausgangswert. Ab der 10-Minuten-Messung bis zur post-Intubations-Messung ist der IOP-Abfall der KA-Gruppe signifikant. Für die Gesamtstichprobe hat die Intubation keinen signifikanten Einfluss auf den IOP (p = 0,063). Die Gabe von Propofol zur Vertiefung der Narkose bei einzelnen Tieren hat ebenfalls keinen signifikanten Einfluss auf den IOP (p = 0,42). Schlussfolgerung: Die verwendeten Ketamin-basierten Narkoseprotokolle bewirken bei der augengesunden Katze keinen signifikanten IOP-Anstieg. Die Gruppen KX, KXAtr und KM gewährleisten für den Zeitraum von 20 Minuten nach Narkoseeinleitung einen relativ stabilen IOP. Trotz des signifikanten IOP-Abfalls in der KA-Gruppe sind sämtliche IOP-Schwankungen aller Gruppen klinisch nicht relevant. Die gemessenen IOP-Werte bewegen sich alle im physiologischen Bereich. Zudem geben die Ergebnisse keinen Hinweis auf eine IOP-Steigerung infolge Propofolgabe und Intubation bei der Katze. / Ketamine is used in human medicine based on strict indications, mainly due to its numerous side effects. In veterinary medicine however Ketamine is commonly used to induce anesthesia intramuscularly throughout all species. To minimize the well known side effects Ketamine is used in combination with several other anesthetics and thus represents a safe anesthetic procedure in animals. Ophthalmological patients are a particular challenge for anesthetists with regard to maintaining the intraocular pressure (IOP). Conflicting data can be found in the literature about the effects of Ketamine on IOP in humans and various animal species. The literature also contains various statements about the effects of Propofol and endotracheal intubation on IOP. In this clinical trial we investigated the effects of commonly used Ketamine-based anesthetic protocols on IOP in cats. Motivated by conflicting statements in the literature the analysis of the effects of Propofol and endotracheal intubation on IOP was included in the study. Methods: This is a prospective, randomized, blinded study. 48 adult cats without ophthalmological abnormalities, recruited from the pool of admitted surgical patients of the Department of Small Animal Medicine of the University of Leipzig were included in the study. The patients were assigned to one of the following four groups and anesthesia was induced intramuscularly. Cats in the KX-group were induced with Ketamine (10 mg/kg) and Xylazine (1 mg/kg). Cats in the KXAtr-group were induced with Ketamine (10 mg/kg), Xylazine (1 mg/kg) and Atropine (0,025 mg/kg). Cats in the KA-group were induced with Ketamine (20 mg/kg) and Acepromazine (0,5 mg/kg). Cats in the KM-group were induced with Ketamine (10 mg/kg) and Medetomidine (50 g/kg). In all patients the IOP was measured three times per eye using the Tono-Pen® XL at particular times: baseline IOP before induction of anesthesia, at 5, 10, 15 and 20 minutes after induction of anesthesia, after intubation and final IOP after completion of surgery. Some cats received a single bolus of Propofol to be able to tolerate endotracheal intubation. After the final IOP-measurement all Zusammenfassung 88 cats were subjected to an ophthalmological examination, including slitlamp biomicroscopy and gonioscopy, in order to exclude patients with ophthalmological pathologies. Results: The mean baseline IOP for all animals is 15,8 mmHg (SD 4,0). There is no significant difference between the four groups (p = 0,756). The mean IOP for the right (OD) and left eyes (OS) of all patients was 15,8 mmHg and 15,7 mmHg, respectively. There is no significant difference between right (OD) and left eyes (OS) (p = 0,442). Therefore all further analyses are based on the mean of all six data points per animal and measuring time. The KX-group shows no significant IOP-change relative to baseline-IOP. The KXAtr and KM-group show a significant decrease in IOP of 16 % and 17 %, respectively, at the final measurement compared with baseline-IOP. The KA-group shows a significant decrease in IOP starting at 10 minutes after induction of anesthesia until the post-intubation measurement. The maximum decrease in IOP in this group is 21 % relative to baseline-IOP 15 minutes after induction of anesthesia. For the total data no significant influence of endotracheal intubation on IOP could be detected (p = 0,063). The application of Propofol in a total of 14 cats has no significant effect on IOP (p = 0,42). Conclusion: The Ketamine-based anesthetic protocols used in this study do not cause a significant increase in IOP in cats without ophthalmological abnormalities. The KX, KXAtr and KM-group ensure a relatively stable IOP for the time period of 20 minutes after induction of anesthesia. Despite the significant IOP-decrease in the KA-group none of the IOP-changes in all groups examined are of clinical relevance. All of the collected IOP-values are within the physiological range for cats. There is no evidence for an increase in IOP caused by endotracheal intubation or the application of Propofol.
162

Evaluation of endothelial cell response to drug for intraocular lens delivery

Doody, Laura January 2011 (has links)
Cataract is one of the leading causes of vision loss worldwide. The rate of cataract surgery has been steadily increasing. Toxic Anterior Segment Syndrome (TASS) is a sterile inflammatory response in the anterior segment of the eye that may occur following cataract surgery. When left untreated, it can lead to permanent vision loss. Corneal endothelial cells are the cells most affected by TASS. These cells are unable to reproduce in vivo and consequently once the density of these cells drops below a certain level, vision is reduced and cannot be reversed. The damage is thought to be mediated by cytokines and endotoxins, primarily through the NF-κΒ pathway. It is hypothesized that anti-inflammatory drug delivery intraocular lenses may help reduce the occurrence of TASS and consequent vision loss. In this research thesis project, an in vitro model was developed as a tool to select drug and delivery material to be used in an anti-TASS ophthalmic biomaterial. In an attempt to find a novel and more effective approach to TASS prevention, dexamethasone, a potent anti-inflammatory steroid drug, was compared to triptolide, a cytokine inhibitor; aprotinin, a general protease inhibitor; and PPM-18, a NF-κΒ inhibitor. To assess the efficacy of these drugs, an in vitro assay using human umbilical vein endothelial cells (HUVEC) and lipopolysaccharide as a stimulant was developed. Cell response to dexamethasone (10 nM), triptolide (3 nM), aprotinin (20 μM) and PPM-18 (10 μM) with or without LPS was characterized by cell viability and flow cytometry analysis of cell activation. Activation was characterized using markers for cell adhesion and activation ICAM-1, PECAM-1, VCAM-1, β1-integrin, CD44 and E-selectin. Following preliminarily testing, the efficacy of dexamethasone (10 nM) and PPM-18 (10 μM) loaded polymer (PDMS) and copolymer (PDMS/pNIPAAm) interpenetrating polymer networks were evaluated over a 4 day release period. The results from soluble drug and LPS (100 ng/mL) testing indicated no decrease in cell viability after 24 h. Dexamethasone, triptolide, aprotinin, and PPM-18 did not reduce the significant ICAM-1 upregulation seen in HUVECs after exposure to LPS for 4 days. PPM-18 in combination with LPS significantly upregulated E-selectin iv and CD44 from unstimulated HUVEC cells. The polymer materials without drug loading did not influence the cell phenotype. However, PPM-18 delivering polymer and copolymer materials significantly upregulated VCAM-1, CD44 when compared to all other treatments. Propidium iodide uptake in HUVEC exposed to PPM-18 drug delivering polymer and copolymer treatments indicated that these treatments caused cell necrosis. None of the drugs, or the drug delivering materials were shown to counteract the upregulation seen from LPS stimulation of HUVEC cells. Future work should focus on validating the in vitro model to more closely replicate the in vivo environment of the anterior segment with the use of primary bovine corneal endothelial cells.
163

Untersuchungen zum Einfluss verschiedener Dosierungsintervalle von Dorzolamid, Dorzolamid-Timolol und Latanoprost auf den Intraokulardruck normotensiver Hunde

Schönfelder, Ralph 01 September 2010 (has links) (PDF)
Ralph Schönfelder Untersuchungen zum Einfluss verschiedener Dosierungsintervalle von Dorzolamid, Dorzolamid-Timolol und Latanoprost auf den Intraokulardruck normotensiver Hunde Klinik für Kleintiere, Veterinärmedizinische Fakultät der Universität Leipzig Eingereicht im März 2010 Bibliografische Angaben: 93 S., 27 Abb., 14 Tab., 224 Lit., Anhang mit 2 Abb., 4 Tab. Schlüsselwörter: Glaukom, Intraokulardruck, Prostaglandine, Karboanhydrasehemmer, Timolol, Hund Das Glaukom beim Hund ist ein Notfall, der eine rasche Senkung des erhöhten Intraokulardruckes verlangt, um dem Verlust der Sehfähigkeit und den auftretenden Schmerzen entgegen zu wirken. Die medikamentöse Behandlung ist dabei ein wichtiger Bestandteil. Das Ziel der vorliegenden Arbeit war es, den Effekt der lokal applizierten Wirkstoffe Dorzolamid, Dorzolamid-Timolol und Latanoprost zur Senkung des Intraokulardruckes bei verschiedenen Dosierungsintervallen zu untersuchen. Für jeden Wirkstoff wurden an vier aufeinander folgenden Tagen tonometrische Messungen des Intraokulardruckes mit dem Tonopen-XL als Kontrolle durchgeführt. Anschließend erfolgte eine Verlaufsuntersuchung, in welcher der Einfluss jedes der drei Wirkstoffe auf den Intraokulardruck bei ein- und zweimal täglicher Applikation jeweils vier Tage lang untersucht wurde. Dabei erfolgten Messungen von Intraokularduck, Pupillendurchmesser und konjunktivaler Irritation beider Augen von zehn Hunden (Beagle) jeweils 8.00; 10.00; 12.00; 16.00; 20.00; 22.00; 24.00; 4.00 Uhr. Bei dreimal täglicher Applikation von Dorzolamid und Dorzolamid-Timolol erfolgten zusätzlich 7.00, 15.00 und 23.00 Uhr Tonometrien. Die einmalige Applikation des Wirkstoffes erfolgte 8.00, die zweimalige Applikation 8.00 und 20.00 Uhr sowie 7.00, 15.00 und 23.00 Uhr die dreimalige Applikation. Für jeden Wirkstoff wurde an Tag fünf, nach Beendigung der Applikationen, die Normalisierung des Intraokulardruckes überprüft. Die Ergebnisse wurden nach Applikationshäufigkeit sowie vergleichend analysiert. Dies erfolgte mittels Friedman-Test für drei und mehr k-verbundene Stichproben als Zwei-Weg Varianzanalyse. Ohne Dorzolamidapplikation betrug der Mittelwert des Intraokulardruckes ± SEM am 91 ersten Tag 12,3 ± 0,5 sowie am zweiten, dritten und vierten Tag 12,5 ± 0,4 mmHg, 11,2 ± 0,4 mmHg und 11,0 ± 0,4 mm Hg. Die einmal tägliche Applikation von Dorzolamid führte mit 7,6 ± 0,4 mm Hg am ersten Tag sowie nachfolgend 8,7 ± 0,3 mmHg, 8,6 ± 0,2 sowie 8,3 ± 0,2 mm Hg zu einer signifikanten Drucksenkung. Die zweimalige Applikation von Dorzolamid wies mit 9,6 ± 0,4 mmHg am ersten Tag sowie 7,4 ± 0,4 mmHg, 6,7 ± 0,3 mmHg und 6,6 ± 0,3 mmHg am zweiten, dritten und vierten Tag, das größte Potential zu einer signifikant stärkeren Absenkung des Intraokulardruckes im Vergleich zu Dorzolamid-Timolol und Latanoprost auf. Nach dreimal täglicher Applikation von Dorzolamid trat mit 8,0 ± 0,2 mmHg am ersten Tag und 7,0 ± 0,3 am zweiten sowie 7,6 ± 0,3 mm Hg am dritten und vierten Tag, eine signifikant stärkere, den Intraokulardruck senkende Wirkung im Vergleich zu Dorzolamid-Timolol ein. Ohne Applikation von Dorzolamid-Timolol lag der Mittelwert des IOD ± SEM vom ersten bis vierten Tag bei 10,6 ± 0,4 mmHg, 11,6 ± 0,5 mm Hg, 11,6 ± 0,6 mmHg und 11,2 ± 0,4 mmHg. Bei einmal täglicher Applikation wurden vom ersten bis vierten Tag folgende Werte mit signifikanter Senkung des IOD bestimmt: 7,6 ± 0,4 mmHg, 7,1 ± 0,3 mmHg, 8,6 ± 0,3 mmHg und 9,6 ± 0,3 mmHg. Bei zweimal täglicher Applikation lag der Mittelwert des IOD bei 9,8 ± 0,5 mmHg, am zweiten bis vierten Tag 8,2 ± 0,4 mmHg, 8,6 ± 0,4 mmHg und 7,3 ± 0,2 mmHg. Die dreimalige Applikation führte zu einem Mittelwert des IOD von 8,1 ± 0,3 mmHg am ersten Tag sowie 8,7 ± 0,3 mmHg, 7,8 ± 0,3 mmHg und 7,3 ± 0,3 mmHg am zweiten bis vierten Tag der Studie. Bei der Untersuchung von Latanoprost lag der Mittelwert des IOD ± SEM ohne Applikation bei 9,9 ± 0,3 mmHg am ersten sowie 10,0 ± 0,3 mmHg, 10,0 ± 0,3 mmHg und 9,8 ± 0,2 mmHg am zweiten bis vierten Tag. Bei einmaliger Applikation lag dieser entsprechend bei 9,8 ± 0,3 mmHg, 8,7 ± 0,2 mmHg, 9,0 ± 0,3 und 10,1 ± 0,4 mmHg Nach zweimaliger Applikation betrug er am ersten Tag 9,9 ± 0,3 mmHg, am zweiten bis vierten Tag 9,3 ± 0,4 mmHg, 8,9 ± 0,4 mmHg sowie 8,9 ± 0,3 mmHg. Der Einfluss alller drei Wirkstoffe auf den mittleren Pupillendurchmesser wurde untersucht. Bei einmal- und zweimal-täglicher Applikation von Latanoprost trat mit einer Differenz im Median von 2,5 bzw. 4,7 im Vergleich ohne Applikation eine ausgeprägte Miosis auf. Schließlich wurde die Wirkung auf die Bindehaut durch Ermittlung des Grades der konjunktivalen Irritation bestimmt. Die Applikation von Latanoprost führte dabei zu deutlichen Reizungen der Konjunktiva bis hin zu verstärkter Hyperämie, in einigen Fällen zu konjunktivalem Ödem sowie vereinzelt zu Juckreiz.
164

Long-term outcome after cataract surgery a longitudinal study /

Lundqvist, Britta, January 2009 (has links)
Diss. (sammanfattning) Umeå : Umeå universitet, 2010. / Härtill 4 uppsatser. Även tryckt utgåva.
165

SKIRTINGŲ DAUGIAŽIDINIŲ INTRAOKULINIŲ LĘŠIŲ IMPLANTACIJA: REGĖJIMO KOKYBĖ IR PACIENTŲ PASITENKINIMO REZULTATAIS SĄSAJOS SU ASMENYBĖS BRUOŽAIS / DIFFERENT MULTIFOCAL INTRAOCULAR LENSES: THE QUALITY OF VISION AND THE LINKS BETWEEN PATIENTS' SATISFACTION WITH THE OUTCOMES AND THEIR PERSONALITY TRAITS

Rudalevičius, Paulius 30 September 2014 (has links)
Lietuvoje pirmą kartą nagrinėjama daugiažidinių intraokulinių lęšių (DIOL) implantacija. Atliktas tyrimas leidžia detaliau vertinti regėjimo funkcijas po DIOL implantacijos. Keturi skirtingi DIOL lyginami pagal tą pačią meto¬diką ir pateikiami ilgos pooperacinės stebėsenos duomenys. Pirmą kartą aprašomos paciento pasitenkinimo po DIOL implantacijos ir Didžiojo penketo asmenybės dimensijų sąsajos. Darbo tikslas - įvertinti regėjimo kokybę ir pacientų pasitenkinimo rezultatais sąsajas su asmenybės bruožais po skirtingų modelių daugiažidinių intraokulinių lęšių implantacijos. Uždaviniai: 1) įvertinti regėjimo aštrumą implantavus skirtingus DIOL modelius; 2) įvertinti kontrastinį jautrumą implantavus skirtingus DIOL mo¬de¬lius; 3) įvertinti paciento poreikį papildomai korekcijai akiniais po DIOL implantacijos; 4) įvertinti pašalinių optinių fenomenų pasireiškimą su DIOL; 5) įvertinti pacientų pasitenkinimo regėjimo rezultatais dažnumą ir sąsajas su asmenybės bruožais po DIOL implantacijos. / In this study, postoperative follow-up data that cover a rather long period after the multifocal intraocular lens (MIOL) implantation are presented. It is the first time that the same methodology was used to compare four different types of MIOL. The influence of personality traits on the visual function has been defined. The aim of the study - to assess the influence of different MIOL on the quality of vision and the links between the satisfaction of patients with the results and their personality traits after the implanting of different MIOL models. The objectives of the study: 1) to compare the visual acuity between different MIOLs models; 2) to compare the contrast sensitivity between different MIOLs models; 3) to establish the need of patients for additional correction with glasses after the implanting of MIOLs; 4) to assess the occurrence of photic phenomena after the implanting of MIOLs; 5) to assess the level of visual function and the influence of personality traits on patients’ satisfaction with the visual function following the MIOL implantation.
166

Evaluation of endothelial cell response to drug for intraocular lens delivery

Doody, Laura January 2011 (has links)
Cataract is one of the leading causes of vision loss worldwide. The rate of cataract surgery has been steadily increasing. Toxic Anterior Segment Syndrome (TASS) is a sterile inflammatory response in the anterior segment of the eye that may occur following cataract surgery. When left untreated, it can lead to permanent vision loss. Corneal endothelial cells are the cells most affected by TASS. These cells are unable to reproduce in vivo and consequently once the density of these cells drops below a certain level, vision is reduced and cannot be reversed. The damage is thought to be mediated by cytokines and endotoxins, primarily through the NF-κΒ pathway. It is hypothesized that anti-inflammatory drug delivery intraocular lenses may help reduce the occurrence of TASS and consequent vision loss. In this research thesis project, an in vitro model was developed as a tool to select drug and delivery material to be used in an anti-TASS ophthalmic biomaterial. In an attempt to find a novel and more effective approach to TASS prevention, dexamethasone, a potent anti-inflammatory steroid drug, was compared to triptolide, a cytokine inhibitor; aprotinin, a general protease inhibitor; and PPM-18, a NF-κΒ inhibitor. To assess the efficacy of these drugs, an in vitro assay using human umbilical vein endothelial cells (HUVEC) and lipopolysaccharide as a stimulant was developed. Cell response to dexamethasone (10 nM), triptolide (3 nM), aprotinin (20 μM) and PPM-18 (10 μM) with or without LPS was characterized by cell viability and flow cytometry analysis of cell activation. Activation was characterized using markers for cell adhesion and activation ICAM-1, PECAM-1, VCAM-1, β1-integrin, CD44 and E-selectin. Following preliminarily testing, the efficacy of dexamethasone (10 nM) and PPM-18 (10 μM) loaded polymer (PDMS) and copolymer (PDMS/pNIPAAm) interpenetrating polymer networks were evaluated over a 4 day release period. The results from soluble drug and LPS (100 ng/mL) testing indicated no decrease in cell viability after 24 h. Dexamethasone, triptolide, aprotinin, and PPM-18 did not reduce the significant ICAM-1 upregulation seen in HUVECs after exposure to LPS for 4 days. PPM-18 in combination with LPS significantly upregulated E-selectin iv and CD44 from unstimulated HUVEC cells. The polymer materials without drug loading did not influence the cell phenotype. However, PPM-18 delivering polymer and copolymer materials significantly upregulated VCAM-1, CD44 when compared to all other treatments. Propidium iodide uptake in HUVEC exposed to PPM-18 drug delivering polymer and copolymer treatments indicated that these treatments caused cell necrosis. None of the drugs, or the drug delivering materials were shown to counteract the upregulation seen from LPS stimulation of HUVEC cells. Future work should focus on validating the in vitro model to more closely replicate the in vivo environment of the anterior segment with the use of primary bovine corneal endothelial cells.
167

Peripheral ocular monochromatic aberrations

Mathur, Ankit January 2009 (has links)
Aberrations affect image quality of the eye away from the line of sight as well as along it. High amounts of lower order aberrations are found in the peripheral visual field and higher order aberrations change away from the centre of the visual field. Peripheral resolution is poorer than that in central vision, but peripheral vision is important for movement and detection tasks (for example driving) which are adversely affected by poor peripheral image quality. Any physiological process or intervention that affects axial image quality will affect peripheral image quality as well. The aim of this study was to investigate the effects of accommodation, myopia, age, and refractive interventions of orthokeratology, laser in situ keratomileusis and intraocular lens implantation on the peripheral aberrations of the eye. This is the first systematic investigation of peripheral aberrations in a variety of subject groups. Peripheral aberrations can be measured either by rotating a measuring instrument relative to the eye or rotating the eye relative to the instrument. I used the latter as it is much easier to do. To rule out effects of eye rotation on peripheral aberrations, I investigated the effects of eye rotation on axial and peripheral cycloplegic refraction using an open field autorefractor. For axial refraction, the subjects fixated at a target straight ahead, while their heads were rotated by ±30º with a compensatory eye rotation to view the target. For peripheral refraction, the subjects rotated their eyes to fixate on targets out to ±34° along the horizontal visual field, followed by measurements in which they rotated their heads such that the eyes stayed in the primary position relative to the head while fixating at the peripheral targets. Oblique viewing did not affect axial or peripheral refraction. Therefore it is not critical, within the range of viewing angles studied, if axial and peripheral refractions are measured with rotation of the eye relative to the instrument or rotation of the instrument relative to the eye. Peripheral aberrations were measured using a commercial Hartmann-Shack aberrometer. A number of hardware and software changes were made. The 1.4 mm range limiting aperture was replaced by a larger aperture (2.5 mm) to ensure all the light from peripheral parts of the pupil reached the instrument detector even when aberrations were high such as those occur in peripheral vision. The power of the super luminescent diode source was increased to improve detection of spots passing through the peripheral pupil. A beam splitter was placed between the subjects and the aberrometer, through which they viewed an array of targets on a wall or projected on a screen in a 6 row x 7 column matrix of points covering a visual field of 42 x 32. In peripheral vision, the pupil of the eye appears elliptical rather than circular; data were analysed off-line using custom software to determine peripheral aberrations. All analyses in the study were conducted for 5.0 mm pupils. Influence of accommodation on peripheral aberrations was investigated in young emmetropic subjects by presenting fixation targets at 25 cm and 3 m (4.0 D and 0.3 D accommodative demands, respectively). Increase in accommodation did not affect the patterns of any aberrations across the field, but there was overall negative shift in spherical aberration across the visual field of 0.10 ± 0.01m. Subsequent studies were conducted with the targets at a 1.2 m distance. Young emmetropes, young myopes and older emmetropes exhibited similar patterns of astigmatism and coma across the visual field. However, the rate of change of coma across the field was higher in young myopes than young emmetropes and was highest in older emmetropes amongst the three groups. Spherical aberration showed an overall decrease in myopes and increase in older emmetropes across the field, as compared to young emmetropes. Orthokeratology, spherical IOL implantation and LASIK altered peripheral higher order aberrations considerably, especially spherical aberration. Spherical IOL implantation resulted in an overall increase in spherical aberration across the field. Orthokeratology and LASIK reversed the direction of change in coma across the field. Orthokeratology corrected peripheral relative hypermetropia through correcting myopia in the central visual field. Theoretical ray tracing demonstrated that changes in aberrations due to orthokeratology and LASIK can be explained by the induced changes in radius of curvature and asphericity of the cornea. This investigation has shown that peripheral aberrations can be measured with reasonable accuracy with eye rotation relative to the instrument. Peripheral aberrations are affected by accommodation, myopia, age, orthokeratology, spherical intraocular lens implantation and laser in situ keratomileusis. These factors affect the magnitudes and patterns of most aberrations considerably (especially coma and spherical aberration) across the studied visual field. The changes in aberrations across the field may influence peripheral detection and motion perception. However, further research is required to investigate how the changes in aberrations influence peripheral detection and motion perception and consequently peripheral vision task performance.
168

Reprodutibilidade do teste de sobrecarga hidrica realizado em diferentes horarios do dia / Reproductility of the water drinking test performde at different times of the day

Medina, Flavio Mac Cord, 1978- 01 December 2009 (has links)
Orientadores: Jose Paulo Cabral de Vasconcellos, Vital Paulino Costa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-12T19:09:11Z (GMT). No. of bitstreams: 1 Medina_FlavioMacCord_M.pdf: 2280525 bytes, checksum: d64f96bf19c317e1e22a704a8562d282 (MD5) Previous issue date: 2009 / Resumo: Objetivo: Avaliar a reprodutibilidade do teste de sobrecarga hídrica (TSH) em diferentes horários em que é realizado, em pacientes com glaucoma primário de ângulo aberto (GPAA) e em indivíduos normais. Métodos: Quinze pacientes com GPAA e 30 indivíduos normais foram submetidos a três TSHs, realizados em diferentes horários do dia (às 7:00, 12:00 e 17:00), em três dias diferentes. Foram comparados os resultados dos testes em pacientes com GPAA e indivíduos normais. Foram analisadas a concordância e a correlação entre os valores de medida basal, pico e variação de pressão intra-ocular (PIO) (pico de PIO - PIO basal) nos testes realizados nos diferentes horários. Apenas as medidas do olho direito foram analisadas. Resultados: Os valores médios de medida basal, pico e variação de PIO foram significativamente maiores nos pacientes glaucomatosos que nos indivíduos normais, em todos os horários (p<0,05). A análise de Bland-Altman apresentou limites de concordância de pico e variação de PIO maiores do que o clinicamente aceitável (> 3 mmHg), apesar de o teste de Pearson demonstrar boa correlação entre os resultados. Conclusões: O TSH apresenta valores de pico e variação de Pio significativamente maiores em pacientes glaucomatosos que em indivíduos normais. Os baixos níveis de concordância entre os TSHs realizados em diferentes horários do dia sugerem uma baixa reprodutibilidade do TSH, que pode limitar sua aplicabilidade para diagnóstico e acompanhamento do glaucoma / Abstract: Purpose: To evaluate the reproducibility of the water drinking test (WDT) performed at different times of the day, in primary open angle glaucoma (POAG) patients and normal individuals. Methods: Fifteen patients with POAG and 30 normal individuals underwent three WDTs at different times of the day (7 AM, 12 PM, and 5 PM) on 3 different days. Test results in POAG patients and normal individuals were compared. Agreement and correlation of intraocular pressure (IOP) baseline levels, peak levels, and IOP change (peak IOP - baseline IOP) on tests performed at different times were evaluated. Only right eye measurements were analyzed. Results: Mean baseline IOP, peak IOP and IOP change were significantly higher in POAG patients than in normal individuals, at all time intervals (p<0.05). The Bland-Altman analysis demonstrated limits of agreement for IOP peak levels and IOP changes larger than the clinically acceptable (> 3 mmHg), even though Pearson's test revealed good correlation among the results. Conclusions: The mean IOP peak and mean IOP change observed during the WDT are significantly higher in POAG patients than in control individuals. Low levels of agreement among WDTs performed at different times of the day suggest a poor reproducibility of WDT, which may limit its applicability for the diagnosis and follow-up of glaucoma / Mestrado / Oftalmologia / Mestre em Ciências Médicas
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Influencia da redução medicamentosa da pressão intra-ocular na medida da espessura da camada de fibras nervosas da retina de olhos hipertensos e glaucomatosos pela polarimetria de varredura a laser / The influence of intraocular pessure reduction with medication on retinal nerve fiber layer thickness measurements obtained with scanning laser polarimetry in glaucomatous and hypertensive eyes

Avelino, Rodrigo Rezende Gomes 27 August 2007 (has links)
Orientador: Vital Paulino Costa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-09T04:54:16Z (GMT). No. of bitstreams: 1 Avelino_RodrigoRezendeGomes_M.pdf: 2930957 bytes, checksum: c66d1b04f0e830ee3e2b0a2e3897981b (MD5) Previous issue date: 2007 / Resumo: Objetivo: Avaliar o efeito da redução da pressão intra-ocular (PIO) obtido com o uso de terapia medicamentosa na espessura da camada de fibras nervosas da retina medida pela Polarimetria de Varredura a Laser (PVL) em pacientes glaucomatosos ou hipertensos oculares. Métodos: Trinta e sete olhos de 37 pacientes foram prospectivamente incluídos no estudo e avaliados com a PVL sem uso de medicação ocular hipotensora e num período entre 15 e 30 dias após a instituição de medicação ocular hipotensora, que resultou em redução da PIO de pelo menos 25%. Os parâmetros medidos pela PVL antes e após a redução da PIO foram comparados com o teste t de Student pareado. Resultados: A PIO média dos 37 pacientes diminuiu significativamente de 26,57 ± 4,23 mmHg para 16,54 ± 2,92 mmHg (p<0,05) após terapia medicamentosa. Não houve diferença estatisticamente significativa entre os valores dos 10 parâmetros do PVL medidos antes e após a administração de medicação ocular hipotensora (p>0,05). Conclusão: A redução da PIO com o uso de medicação ocular hipotensora não altera a medida da espessura da camada de fibras nervosas da retina pela PVL em pacientes com glaucoma ou hipertensão ocular / Abstract: Purpose: To evaluate changes in retinal nerve fiber layer thickness as measured by scanning laser polarimetry (SLP) after the use of medication to reduce intraocular pressure (IOP) in glaucomatous or ocular hypertensive patients. Methods: The authors prospectively enrolled 37 eyes of 37 patients in whom IOP was reduced by more than 25% after the use of medication. The images were obtained before and 15 to 30 days after the introduction of medication. The SLP parameters measured before and after the use of medication were compared using paired Student¿s t Test. Results: The mean IOP was significantly reduced from 26.57 ± 4.23 mmHg to 16.54 ± 2.92 mmHg after the use of medication (p<0.05). None of the 10 SLP analyzed parameters was significantly affected by the reduction of IOP with medication (p>0.05). Conclusion: The retinal nerve fiber layer thickness, as measured by SLP, is not affected by the reduction of IOP with medication in patients with glaucoma or ocular hypertension / Mestrado / Oftalmologia / Mestre em Ciências Médicas
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Estudo da toxicidade do adalimumabe (Humira®) intravítreo para a retina de coelhos / Testing intravitreal toxicity of adalimumab (Humira®) in the rabbit

Roberta Pereira de Almeida Manzano 16 December 2010 (has links)
O adalimumabe (Humira®, Abbott) é um antagonista do Fator de Necrose Tumoral- alpha (TNF-alfa ). É aprovado para o tratamento de artrite reumatoide, espondilite anquilosante, doença de Crohn, psoríase crônica e artrite reumatoide juvenil. É um anticorpo monoclonal que contém apenas sequências humanas de peptídeos contra a molécula do Fator de Necrose Tumoral-alfa. Na literatura, relatos e série de casos sugerem que os antagonistas do Fator de Necrose Tumoral-alfa são úteis no tratamento da inflamação ocular, edema macular cistoide e secundário à uveíte e degeneração macular relacionada à idade. Entretanto, a administração sistêmica do adalimumabe pode gerar efeitos adversos graves. A fim de diminuir esses efeitos adversos e aumentar a concentração da medicação no segmento posterior do olho, uma possível opção é a injeção intravítrea. O objetivo do presente estudo foi avaliar a toxicidade do adalimumabe intravítreo nas diferentes doses para a retina de coelhos por meio de avaliação clínica (biomicroscopia e oftalmoscopia indireta), funcional (eletrorretinograma) e histopatológica (microscopia óptica e eletrônica). Foram utilizados 30 coelhos albinos da raça Nova Zelândia divididos em cinco grupos de seis coelhos. Injeções intravítreas foram realizadas nas seguintes concentrações de adalimumabe: 0,5mg/0,1ml, 1mg/0,1ml, 2,5mg/0,1ml, 5,0mg/0,1ml e 10mg/0,2ml e 0,1ml de solução salina balanceada (BSS) foi injetada nos olhos esquerdos dos grupos 1 e 2 para constituir o grupo controle. Foram realizadas biomicroscopia e fundoscopia e sinais de inflamação, infecção ou toxicidade foram observados durante duas semanas. O eletrorretinograma foi realizado antes do tratamento e após 14 dias da injeção intravítrea. Os animais foram sacrificados, foi feita a enucleação dos olhos, e o tecido para a avaliação histopatológica foi preparado. A injeção intravítrea de adalimumabe (Humira®) nas doses estudadas até 5mg (0,5mg, 1,0mg, 2,5mg, 5mg) não apresentou sinais clínicos, eletrorretinográficos e histopatológicos de toxicidade para a retina de coelhos a curto prazo. No grupo de 10mg, foram observados sinais inflamatórios leves em três dos seis olhos e houve diminuição da amplitude da onda a na resposta fotópica do ERG, não foram observadas alterações na microscopia óptica / Adalimumab is a fully human anti-TNF alpha monoclonal antibody consisting of 100% human sequences developed using phage display technology. It is currently FDA approved for the treatment of rheumatoid arthritis, ankylosing spondylitis, Crohns disease, moderate to severe chronic psoriasis, and juvenile idiopathic arthritis. Anti-TNF alpha drugs may be an effective therapy for cystoid macular edema associated with uveitis. Significant improvements in chronic diabetic macular edema and regression of CNV from AMD have also been documented in small published series after systemic treatment with TNF-alpha antagonists. However the systemic administration of these drugs can have serious side effects. Intravitreous injection would assure delivery of high concentrations of medication at the posterior segment with minimum side effects.The aim of this study was to evaluate the ocular toxicity of escalating doses of intravitreous adalimumab (Humira®) in the rabbit eye. Thirty New Zealand albino rabbits received intravitreous injections of 0.1ml of adalimumab 0.5 mg (6 eyes), 1mg (6 eyes), 2.5mg (6 eyes), 5mg (6 eyes) and 0.2ml was injected in the10mg (6 eyes) group. BSS (0,1ml) was injected in the left eye of the rabbits from the groups 1 and 2 to serve as control group. Slit lamp biomicroscopy, fundoscopy were carried out at baseline, day 7 and 14 following intravitreous injection while electroretinography (ERG) was carried out at baseline and day 14. Animals were euthanized on day 14 and histopathological examination of the eyes was performed. The tested doses of intravitreous adalimumab up to 5mg (0.5mg, 1.0mg, 2.5mg, 5mg) had no associated ocular short-term toxicity in rabbit eyes. The 10mg group showed mild inflammatory reaction in 3 out of 6 eyes and showed decrease in the a wave amplitude in the photopic response, light microscopy was normal

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