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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

Dye assisted macular epiretinal membrane surgery

Kwok, Kwan-ho, Alvin. January 2004 (has links)
Thesis (M. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.
2

Intravitreal versus sub-tenon triamcinolone acetonide for refactory diffuse diabetic macular oedema.

Zaborowski, Anthony Grant. January 2008 (has links)
Purpose: To compare the safety and efficacy of intravitreal (IVT) and sub-Tenon (ST) triamcinolone acetonide for the treatment of refractory diffuse diabetic macular oedema. Method: 29 eyes of 22 patients with long-standing, diffuse diabetic macular oedema refractory to argon laser treatment were randomly assigned to a single 4mg injection of IVT triamcinolone acetonide or a 40mg sub-Tenon injection. Patients were subsequently monitored for six to nine months. Outcome measures were visual acuity, intraocular pressure, macular thickness on optical coherence tomography and adverse effects. Results: There was no significant improvement in visual acuity in either group. A transient decrease in macular thickness was found in the IVT group but not in the ST group. There were no significant adverse effects apart from a mild to moderate intra-ocular pressure rise found more frequently in the IVT group. Conclusion: IVT and ST triamcinolone acetonide injections for refractory diffuse diabetic macular oedema appear relatively safe and well-tolerated. IVT injection produces a significant temporary decrease in macular thickness in patients with long-standing diffuse diabetic macular oedema while ST injection does not. Neither intervention was shown to significantly improve visual acuity in this group of patients.
3

Intravitreal versus sub-tenon triamcinolone acetonide for refactory diffuse diabetic macular oedema / #c by Anthony Grant Zaborowski.

Zaborowski, Anthony Grant. Unknown Date (has links)
Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2008. / Full text also available online. Scroll down for electronic link.
4

Dye assisted macular epiretinal membrane surgery

Kwok, Kwan-ho, Alvin., 郭坤豪. January 2004 (has links)
published_or_final_version / abstract / Medicine / Master / Doctor of Medicine
5

Dopamine related signaling pathways on generation of projection pattern at the Mouse chiasm. / CUHK electronic theses & dissertations collection

January 2013 (has links)
Chen, Tingting. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 100-109). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
6

Langzeitergebnisse der Ranibizumabtherapie der altersabhängigen feuchten Makuladegeneration / Long-term results of ranibizumab treatment for wet age-related macular degeneration

Weindl, Katharina January 2019 (has links) (PDF)
Hintergrund In einer retrospektiven Studie in der Augenklinik Würzburg wurde die Ranibizumabtherapie bei Patienten mit altersabhängiger Makuladegeneration (AMD) im klinischen Alltag ausgewertet. Methoden Patientenakten von Patienten mit AMD, die im Jahr 2007 mit der Ranibizumabtherapie begannen, wurden untersucht. Daten wurden bis zum Ende der Behandlung und/oder Nachbeobachtung bis 2009 gesammelt. Der primäre Endpunkt war das Verhältnis der Patienten, die weniger als 15 Buchstaben (bzw. 0,3 logMAR Einheiten) an Visus verloren zwischen Beginn und nach 12 Monaten. Ergebnisse 375 Patienten wurden einbezogen, nur 298 Patienten beendeten die Untersuchung nach einem Jahr. Nach 12 Monaten verloren 72% der Patienten weniger als 15 Buchstaben. Die Sehschärfe verbesserte sich bis 12 Wochen nach der ersten Injektion und verschlechterte sich danach wieder. Patienten mit mehr als 3 Injektionen profitierten mehr als Patienten mit weniger Injektionen. Durchschnittlich wurden 4,25 Injektionen innerhalb eines Jahres gegeben. Der durchschnittliche Rückgang der Netzhautdicke betrug 50 µm. Schlussfolgerung Intravitreale Injektionen von Ranibizumab in der Augenklinik Würzburg führten zu einer Visusverbesserung. Der Visusgewinn konnte nach 3 Monaten nicht gehalten werden. Bessere Reinjektionskriterien, mehr OCT Untersuchungen und besseres Nachsorgemanagement sollten entwickelt werden. / Background Real-life ranibizumab therapy used in patients with wet age related macular degeneration (AMD) was assessed in a retrospective study in Augenklinik Würzburg Methods Medical records of patients with AMD, who started ranibizumab treatment in 2007, were evaluated. Data were collected until the end of treatment and/or monitoring until 2009. The primary end point was the proportion of patients losing fewer than 15 letters (0,3 logMAR units) from baseline visual acuity at 12 months. Results 375 patients were included, only 298 patients finished one-year examination. At 12 months 72% of the patients lost fewer than 15 letters. Visual acuity improved until 12 weeks after first injection and was not maintained afterwards. Patients with more than 3 Injections profited more than patients with less injections. In average, there were 4,25 injections given in one year. The average decrease in retinal thickness was 50µm. Conclusions Intravitreal administration of ranibizumab in Augenklinik Würzburg improved vision acuity. The vision gain was not maintained after 3 months. Criteria for reinjection, more oct examinations and better control management must be developed.
7

Comparação da densidade óptica de pigmento macular em pacientes diabéticos e indivíduos normais: Avaliação dos principais métodos e associação com a idade / Comparison of macular pigment optical density in diabetic and normal patients: assessment of key methods and association with age

Lima, Veronica Franco de Castro [UNIFESP] January 2014 (has links) (PDF)
Made available in DSpace on 2015-12-06T23:46:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2014 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Objetivos: Comparar os valores de densidade optica de pigmento macular (MPOD) obtidos atraves dos metodos de fotometria de flicker heterocromatico (HFP) e autofluorescencia (AF) em um grupo de pacientes normais; comparar os valores de MPOD em pacientes diabeticos e nao-diabeticos, investigar a relacao entre esses valores e os niveis sericos de hemoglobina glicosilada e perfil lipidico; e, finalmente, investigar a relacao entre a idade e a distribuicao dos valores de MPOD ao redor da fovea em pacientes normais. Metodos: No primeiro estudo, 10 pacientes (20 olhos) normais (sem doencas oculares ou sistemicas) foram incluidos e testados para MPOD atraves dos metodos de HFP e AF. O metodo de AF utiliza dois comprimentos de onda diferentes para a aquisicao das imagens atraves de um oftalmoscopio de varredura a laser confocal modificado (Heidelberg Retina Angiograph, HRA, Heidelberg Engineering, Inc., Heidelberg, Alemanha). Os valores para as duas tecnicas foram obtidos em 4 excentricidades diferentes ao redor do centro da fovea (0,25, 0,5, 1 e 1,75°). Cada olho foi testado tres vezes para cada um dos metodos, e a analise estatistica foi realizada atraves de regressao linear e teste t pareado. Em um segundo estudo, 43 pacientes (43 olhos) diabeticos tipo 2 e normais foram incluidos prospectivamente e alocados em 3 grupos: grupo 1 (controle; n=14), grupo 2 (diabeticos sem sinais de retinopatia; n=17) e grupo 3 (diabeticos com retinopatia nao proliferativa leve; n=12). Todos os pacientes foram submetidos a exame oftalmologico completo e foram coletadas informacoes sistemicas e oculares, incluindo o uso de suplementos vitaminicos contendo carotenoides. A avaliacao da MPOD foi realizada atraves do HRA. Os valores obtidos em 2 excentricidades ao redor do centro da fovea (0,5 e 2°) foram comparados entre os grupos atraves da analise de variancia. Os niveis sericos de hemoglobina glicosilada e lipideos (HDL, LDL, colesterol total e triglicerides) foram correlacionados com os niveis da MPOD para cada grupo atraves de regressao linear. Finalmente, em um terceiro estudo, os valores da MPOD de 30 pacientes (30 olhos) normais foram obtidos atraves do HRA em 3 excentricidades retinianas (0,5, 1 e 2°) e correlacionados com a idade atraves de regressao linear. Resultados: Para a comparacao entre as tecnicas, os valores obtidos pela HFP foram consistente e significativamente inferiores aos valores obtidos pelo HRA (p<0,001) em todas as excentricidades retinianas testadas. Houve uma correlacao significativa entre os valores obtidos pelos dois metodos em quase todos os locais testados, sendo que a correlacao mais forte foi observada no ponto mais afastado da fovea (1,75°) (r=0,73). Em relacao a comparacao entre diabeticos e normais, a media dos valores da MPOD obtidos a 2° do centro da fovea variou significativamente para os tres grupos [grupo 1 (0,29 ± 0,07 DU), grupo 2 (0,22 ± 0,09 DU) e grupo 3 (0,14 ± 0,05 DU), p<0,001]. Alem disso, observou-se uma correlacao inversa e significativa entre os niveis de hemoglobina glicosilada e os valores medios da MPOD a 2° para todos os pacientes (r=-0,63, p<0,001). Nao foram encontradas correlacoes significativas com niveis de lipideos sericos, duracao do diabetes ou idade. Os pacientes incluidos para a analise de correlacao com a idade apresentaram 23 a 77 anos (idade media ± DP = 48,6 ± 16,4 anos). Diferencas significativas para os valores medios de MPOD obtidos a 0,5, 1 e 2° do centro da fovea foram encontradas (0,49 ± 0,12 DU; 0,37 ± 0,11 DU; 0,13 ± 0,05 DU, respectivamente, p<0,05). Os valores da MPOD a 0,5 e 1° e a idade mostraram uma correlacao significativa (p&#8804;0,02), ja os valores da MPOD a 2° nao apresentaram correlacao com a idade (p=0,06). Conclusoes: Os valores da MPOD obtidos atraves do HRA mostraram correlacao significativa com os valores obtidos pelo metodo padrao de HPF, porem foram consistentemente mais elevados em todas as excentricidades retinianas testadas. Estes resultados sugerem que o metodo pode ser usado com seguranca em pacientes incapazes de realizar o teste de HPF, o que e essencial para uma aplicacao clinica mais ampla da analise de pigmento macular. Pacientes diabeticos tipo 2 com e sem retinopatia apresentaram niveis reduzidos da MPOD quando comparados aos pacientes nao-diabeticos. Alem disso, observou-se uma correlacao inversa e significativa entre os niveis de hemoglobina glicosilada e esses valores quando todos os pacientes foram analisados. Finalmente, os valores da MPOD obtidos em uma populacao normal foram mais elevados proximo ao centro da fovea. Esses valores apresentaram pico entre 45-50 anos de idade, seguido por uma reducao gradual apos 60 anos de idade / BV UNIFESP: Teses e dissertações
8

Analyse des facteurs cliniques et structurels associés à l'acuité visuelle post-opératoire des trous maculaires ayant subi une vitrectomie

Lachance, Alexandre 18 October 2022 (has links)
Le trou maculaire (TM) est un défaut dans la rétine au niveau de la zone centrale de la macula (fovéa). Typiquement, les patients atteints de cette pathologie auront une diminution de leur acuité visuelle (AV) et de la métamorphopsie. Le traitement pour ces patients consistera en une vitrectomie par la pars plana (VPP) dans laquelle le vitré est retiré et remplacé par une tamponnade (SF6, C3F8, air ou huile de silicone). Après cette chirurgie, le succès chirurgical, soit de fermeture anatomique du TM, est très élevé. Toutefois, plus récemment, on s'aperçoit que malgré un taux de fermeture anatomique élevé, les résultats visuels après l'intervention chirurgicale ne sont pas aussi importants, d'où la nécessité d'identifier les facteurs pronostiques liés à la VPP dans les TM qui ont fermé chirurgicalement et de tenter de prédire les résultats visuels suivant la VPP. En ce qui concerne les TM qui n'ont pas fermé lors d'une première VPP, il est intéressant d'évaluer les résultats fonctionnels et anatomiques à la suite d'une VPP de reprise. Nos travaux ont démontré que les yeux avec une durée du TM plus courte, une taille du TM plus petite et une AV préopératoire plus élevée ont obtenu de meilleurs résultats visuels après une première chirurgie réussie. Nous avons par la suite produit un modèle hybride basé sur des données cliniques et des tomographies par cohérence optique haute définition (HD-OCT) préopératoires de TM, et ce, à l'aide de l'intelligence artificielle, afin de tenter de mieux prédire les résultats visuels. Les modèles basés sur les données cliniques ou les HD-OCT ont obtenu de bonnes performances discriminantes individuellement. Toutefois, la combinaison des deux modèles dans un modèle hybride n'a pas significativement amélioré les performances. Enfin, les TM qui subissaient une VPP de révision (non-fermeture chirurgicale à la première VPP) montraient une fermeture anatomique dans 85% des cas et avaient une amélioration de l'AV au fil du temps. / Idiopathic full thickness macular hole (MH) is a defect of all layers of the fovea. Typically, patients with this condition will experiment decreased visual acuity (VA) and metamorphopsia. Treatment for these patients will consist in a pars plana vitrectomy in which the vitreous is removed and replaced by a tamponade (SF6, C3F8, air or silicone oil). After this surgery, the surgical success, or anatomical closure of the MH, is very high. However, more recently, it has been noticed that despite a high anatomical closure rate, the visual results after the surgery are not quite as important, hence the need to identify the prognostic factors related to vitrectomy in patients with closed MH and to predict visual results following vitrectomy. For MH that did not close during the primary vitrectomy, it is interesting to assess the functional and anatomical results following a revision vitrectomy. Our works provided that eyes with shorter MH duration, smaller MH size and higher preoperative VA achieved better visual outcomes after successful MH surgery. We then produced a hybrid model based on clinical data and preoperative MH high-definition optical coherence tomography (HD-OCT), using artificial intelligence to try to better predict visual results. Both the clinical data and HD-OCT models had good discriminative performances. Combining both into a hybrid model did not significantly improve performance. Finally, MH that underwent revision vitrectomy (nonsurgical closure at primary vitrectomy) showed anatomical closure in 85% of cases and had VA improvement over the time.
9

Analyse des facteurs cliniques et structurels associés à l'acuité visuelle post-opératoire des trous maculaires ayant subi une vitrectomie

Lachance, Alexandre 12 November 2023 (has links)
Le trou maculaire (TM) est un défaut dans la rétine au niveau de la zone centrale de la macula (fovéa). Typiquement, les patients atteints de cette pathologie auront une diminution de leur acuité visuelle (AV) et de la métamorphopsie. Le traitement pour ces patients consistera en une vitrectomie par la pars plana (VPP) dans laquelle le vitré est retiré et remplacé par une tamponnade (SF6, C3F8, air ou huile de silicone). Après cette chirurgie, le succès chirurgical, soit de fermeture anatomique du TM, est très élevé. Toutefois, plus récemment, on s'aperçoit que malgré un taux de fermeture anatomique élevé, les résultats visuels après l'intervention chirurgicale ne sont pas aussi importants, d'où la nécessité d'identifier les facteurs pronostiques liés à la VPP dans les TM qui ont fermé chirurgicalement et de tenter de prédire les résultats visuels suivant la VPP. En ce qui concerne les TM qui n'ont pas fermé lors d'une première VPP, il est intéressant d'évaluer les résultats fonctionnels et anatomiques à la suite d'une VPP de reprise. Nos travaux ont démontré que les yeux avec une durée du TM plus courte, une taille du TM plus petite et une AV préopératoire plus élevée ont obtenu de meilleurs résultats visuels après une première chirurgie réussie. Nous avons par la suite produit un modèle hybride basé sur des données cliniques et des tomographies par cohérence optique haute définition (HD-OCT) préopératoires de TM, et ce, à l'aide de l'intelligence artificielle, afin de tenter de mieux prédire les résultats visuels. Les modèles basés sur les données cliniques ou les HD-OCT ont obtenu de bonnes performances discriminantes individuellement. Toutefois, la combinaison des deux modèles dans un modèle hybride n'a pas significativement amélioré les performances. Enfin, les TM qui subissaient une VPP de révision (non-fermeture chirurgicale à la première VPP) montraient une fermeture anatomique dans 85% des cas et avaient une amélioration de l'AV au fil du temps. / Idiopathic full thickness macular hole (MH) is a defect of all layers of the fovea. Typically, patients with this condition will experiment decreased visual acuity (VA) and metamorphopsia. Treatment for these patients will consist in a pars plana vitrectomy in which the vitreous is removed and replaced by a tamponade (SF6, C3F8, air or silicone oil). After this surgery, the surgical success, or anatomical closure of the MH, is very high. However, more recently, it has been noticed that despite a high anatomical closure rate, the visual results after the surgery are not quite as important, hence the need to identify the prognostic factors related to vitrectomy in patients with closed MH and to predict visual results following vitrectomy. For MH that did not close during the primary vitrectomy, it is interesting to assess the functional and anatomical results following a revision vitrectomy. Our works provided that eyes with shorter MH duration, smaller MH size and higher preoperative VA achieved better visual outcomes after successful MH surgery. We then produced a hybrid model based on clinical data and preoperative MH high-definition optical coherence tomography (HD-OCT), using artificial intelligence to try to better predict visual results. Both the clinical data and HD-OCT models had good discriminative performances. Combining both into a hybrid model did not significantly improve performance. Finally, MH that underwent revision vitrectomy (nonsurgical closure at primary vitrectomy) showed anatomical closure in 85% of cases and had VA improvement over the time.
10

Retinal internal limiting membrane removal in macular hole surgery. / CUHK electronic theses & dissertations collection

January 2003 (has links)
However, this is by no means the limit. More knowledge on macular hole is needed. Continuous research in Hong Kong and other scientific communities are indispensable. A multicentre, multi-surgeon study should be contemplated and carried out prior to the generalization or application of this technique to all patients. / Over the last few years, we have collected essential clinical and laboratory data on indocyanine green (ICG) assisted internal limiting membrane (ILM) peeling in macular hole surgery in Hong Kong. With the intraoperative use of a small volume and low concentration of ICG, we have shown the usefulness and safety of this technique in improving the surgical outcomes, both antomically and functionally, in patients with macular hole of idiopathic type or in severely myopic eyes. Our randomized controlled trial demonstrated higher anatomical closure rate and better visual outcome with ICG assisted ILM peeling compared with no ILM peeling in primary idiopathic macular hole surgery. Our case-control study also demonstrated that ICG assisted ILM removal in macular hole surgery of severely myopic eyes gives promising anatomical closure rate and visual outcome comparable to emmetropic ones. / Kwok Kwan-ho. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (M.D.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 201-214). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.

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