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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

Surgical outcomes of recurrent macular hole

Sharifzadeh, Arya 08 April 2016 (has links)
Idiopathic macular hole is a disease of the eye with unknown cause, but a pathology that, over the course of several decades of investigation by clinicians and researchers alike, has become readily treatable with surgical intervention at a very high rate of successful repair. The current study presents a retrospective case series exploring surgical outcomes for treatment of recurrent macular holes. The study additionally provides a window into the past, present, and future of macular holes across all clinical considerations, and importantly performs a supplementary statistical meta analysis of reoperation success rates in the relevant field of published data- the first of its kind. The introductory background of the present study establishes a natural history of idiopathic macular holes in clinical discovery, classification, and management. The study's case series data specifically focuses on the phenomenon of macular hole recurrence, offering surgical outcome measures of patients undergoing primary and secondary repair operations in a single-center, single-surgeon design. The findings of the retrospective series support the hypothesis that macular hole reoperation does achieve successful anatomical closure in a majority of cases. A meta analysis performed on the current field of published clinical research pertaining to recurrent macular holes established cumulative success rates across a variety of surgical conditions. The present study's findings were then compared to the corresponding measures across the landscape of recurrent macular hole literature, to help inform a niche of clinical research that continues to be an area of investigation and discovery. In presenting a cohesive, synthesized narrative of recurrent macular holes, the study provides a foundation wherein ongoing collaborative efforts in the field can continue to build upon a blueprint currently set in place, and work towards finding a cause behind an otherwise idiopathic disease.
2

Regulation of tissue oxygen levels in the ocular lens

McNulty, Richard. January 2004 (has links)
Thesis (Ph.D.)--University of Wollongong, 2004. / Typescript. Includes bibliographical references: leaf 171-192.
3

Anatomiska och funktionella resultat efter behandling av vitreomakulär traktion/adhesion (VMA/VMT) med vitrektomi eller ocriplasmin (Jetrea®)

Dukay, Maria January 2021 (has links)
Background: Vitrectomy is a well-accomplished method for treatment of vitreomacular traction. In 2013, a new approach for treating symptomatic vitreomacular traction was presented, ocriplasmin (Jetrea®), that could perform enzymatic vitreolysis. In this study ocriplasmin was studied to compare the treatment results with the standard method vitrectomy. Aim: The purpose of this study was to compare vitrectomy to ocriplasmin-injection for treatment of vitreomacular traction performed between 2013 and 2016. Materials and methods: The medical records of 16 patients were reviewed. Eight of them were treated with ocriplasmin and the other eight underwent vitrectomy due to vitreomacular traction. All patients who received ocriplasmin at the clinic were included, and vitrectomy-patients were matched to these according to sex, age and visual acuity. Preoperative and postoperative symptoms, visual acuity and optical coherence tomography findings were analyzed. Results: Vitreomacular traction resolved in every eye treated with vitrectomy compared to four of eight eyes treated with ocriplasmin. With one exception, every patient´s visual acuity in the vitrectomy group improved, with a mean value of +0,223 Snellen. Three of eight patients in the ocriplasmin group had improved visual acuity, while three worsened and two remained the same. Visual acuity in this group altered with a mean value of +0,071 Snellen. Conclusions: Enzymatic vitreolysis is a good idea, but according to our and other international studies, it only achieves good results in half of the cases, while vitrectomy almost always succeeds. Although vitrectomy can lead to certain complications, for example cataract, it is a well functioning and relatively moderate surgical procedure and its complications can be managed.
4

Vitreous cytokine profile after phaco-emulsification and posterior segment chamber lens placement

Begum, Shimul 08 April 2016 (has links)
The purpose of this study was to quantify the effects of phacoemulsification and posterior segment chamber lens placement on vitreous inflammatory and neovascular growth factors. More specifically, the effect of immediately preceding cataract surgery was compared to a history of cataract surgery. This study involved a retrospective review and analysis of vitreous samples from a total of twenty seven patients separated into three groups. Group 1, seven patients who underwent a pars plana vitrectomy with macular surgery, group 2, fourteen patients who underwent a combined cataracts and pars plana vitrectomy procedure and group 3, six patients with a history of cataract surgery who underwent a pars plana vitrectomy. The twenty seven patients were picked from a pool of 100 patients who all received pars plana vitrectomy at Beth Israel Deaconess Medical Center with surgeon Dr. Jorge Arroyo. Exclusion factors included active ocular pathologies such as vitreous hemorrhage and retinal detachment. Undiluted vitreous samples from each group were taken before beginning the pars plana vitrectomy. The vitreous samples were analyzed for concentrations of fourteen specific vitreous cytokines and neovascular growth factors including but not limited to TNF Alpha; and SCD40L. These fourteen cytokines and growth factors were chosen through a literature review on the post-surgery ocular inflammatory response. Statistical analysis was done on the average means of the cytokine levels for each group using SPSS 20 for windows. A comparison of means analysis found no significant difference in the means of the fourteen cytokines for group 1 and group 2. A second comparison of means with a pooled control group of both group 1 and group 2 patients versus group 3 was also run. In this analysis, only SCD40L or soluble CD40 ligand was shown to have a significant difference between groups. SCD40L levels were significantly higher (significance level of .038) in group 3, the history of cataract group with a mean of (9.50±4.76) than in the control group with a mean of (5.50±3.35). The findings of this study indicate that the protein SCD40L may play an important role in mediating the inflammatory response seen post cataract surgery and may be useful as a target for novel therapies against the inflammatory response.
5

Surgical outcomes of pars plana vitrectomy with and without internal limiting membrane peeling for symptomatic vitreomacular traction

Stern, Adam 12 July 2017 (has links)
PURPOSE: To study the long-term anatomic and visual outcomes after pars plana vitrectomy (PPV) with and without internal limiting membrane (ILM) peeling in patients with symptomatic vitreomacular traction (VMT). This study assesses the frequency of complications, changes in visual acuity, and changes in anatomical central macular thickness after macular surgery. METHODS: This retrospective, single-site, single-surgeon study reviewed 40 medical records (45 eyes) of patients at the Beth Israel Deaconess Medical Center requiring PPV with ILM peeling (n=27) or without ILM peeling (n=18) for VMT between the years of 2003 and 2016. Successful surgery was defined as the relief of anatomical traction, and the absence of a second surgery, or any post-operative complications (n=42). Visual acuity was documented for each eye prior to surgery and post surgery. RESULTS: All 27 (100%) eyes that had ILM peeling had successfully resolved macular traction following a single surgery, and 15 of the 18 (83.3%) eyes without ILM peel were successful. None of 27 (0%) eyes that had ILM peeling required a second surgery, nor did they have complications. 3 of the 18 (16.7%) eyes without ILM peeling required a second surgery. Best corrected visual acuity (BCVA, logMAR) improved significantly in both groups: BCVA improved from 0.59 ± 0.29 preoperatively to 0.37 ± 0.25 postoperatively in eyes receiving ILM peeling and from 0.77 ± 0.37 to 0.53 ± 0.37 in eyes with PPV only. Mean change in CMT pre-operatively to post-operatively was found to be greater in eyes with PPV alone, but this difference was not statistically significant. CONCLUSIONS: Our case series shows that PPV with ILM peeling for VMT relieved macular traction better than PPV alone, although there was no significant difference in visual acuity outcomes or central macular thickness between the two groups. Further research is required to validate these findings. / 2019-07-11T00:00:00Z
6

Comparison of two vitrectomy systems (25g vs. 20g) /

Holland, Rita M. January 1900 (has links)
Thesis (M.A.)--Northern Kentucky University, 2008. / Made available through ProQuest. Publication number: AAT 1450346. ProQuest document ID: 1490080981. Includes bibliographical references (p. 36-40)
7

Anatomic outcomes after retinal detachment surgery in patients with retinal detachment associated with choroidal detachment

Barrett, Jake Adams 03 July 2018 (has links)
PURPOSE: To investigate relationships between preoperative and intraoperative characteristics with outcome variables in patients suffering from primary rhegmatogenous retinal detachment (RRD) or traction retinal detachment (TRD) complicated by serous choroidal detachment (CD). Choroidal detachment is a rare complication of retinal detachment and the current literature cites generally poor visual outcome variables. By investigating a retrospective case series, we hope to elucidate new relationships and embolden existing ones so that future physicians can make more educated decisions regarding the care for these complicated patients. METHODS: A retrospective case series analyzed 18 patient’s medical records (18 eyes) who had been diagnosed and surgically treated for RRD or TRD associated with a CD at the Longwood Medical Eye Center at Beth Israel Deaconess Medical Center. Patients with RDCD who had undergone 23-gauge pars plana vitrectomy with silicone oil tamponade were selected. Exclusionary criteria included ocular complications such as phthisis bulbi and open globe trauma. Patients experienced a variety of surgical procedures including by not limited to relaxing retinotomy (n=12 eyes), choroidal drainage (n=10 eyes), endoscopy-assisted PPV (n=10 eyes), and ERM peeling (n=8 eyes). Primary outcome variables tabulated were primary and final anatomic success, defined as successful reattachment of the retina to the underlying choroid, and final visual acuity. RESULTS: The mean age of the sample group was 69 with 8 patients (44%) diagnosed with preoperative hypotony (IOP <= 6 mmHg). A total of 12 patients were pseudophakic (67%). With a mean follow-up of 21.6 months, patients exhibited expected visual outcomes with 6 patients (33%) improving visual acuity and 7 patients (39%) decreasing visual acuity. Final anatomic success was seen in 17 cases (94%). A significant correlation was found between decreased number of previous surgeries and better visual outcomes (change in BCVA). Another significant relationship correlates choroidal drainage with worse visual outcomes (change in BCVA). Finally, patients who received ERM peeling had better rates of primary anatomic success. CONCLUSION: The advanced age of the sample lends itself to increased risk for cataracts and thus pseudophakia. In addition, high rates of diabetes and macular degeneration follow. The pathophysiology of RDCD in relation to the risk factors of hypotony and macular holes is possibly based on the Starling forces and favorable fluid transudation into the suprachoroidal space. Although the outcomes of this study were similar to previous literature, the visual outcomes are still poor at best. Reducing the number of previous, invasive, ocular surgeries was seen to be correlated with better visual outcomes. In addition, performing ERM peels is seen to be correlated with improved rates of primary anatomic success. More research is required on the etiology of the disease process and a case-controlled longitudinal study may be helpful in determining more relationships with outcome variables.
8

Bilateral endogenous ophthalmitis due to Candida glabrata after complicated bariatric surgery

Pizango, O., Tejeda, E., Buendia, M., Lujana, S. 24 March 2015 (has links)
orionpizango@gmail.com / Case report: A 43-year-old female presented with decreased visual acuity in the right eye.“Snowball-like” retinal lesions were found in both eyes on examination. Due to a lackof improvement with intravitreal antifungal empirical treatment, vitreous culture wasperformed and Candida glabrata was isolated. The patient then received intravitreal ampho-tericin B, as well as systemic treatment with caspofungin and amphotericin B lipid complex.Discussion: Endogenous fungal endophthalmitis is a sight-threatening condition. There arefew reports of C. glabrata endogenous endophthalmitis. Treatment regimens for Candidaendophthalmitis include combinations of systemic and/or intravitreal antifungals, as wellas vitrectomy.
9

Avaliação de um novo índice prognóstico para a cirurgia do buraco macular idiopático / Evaluation of a new prognostic index for the idiopatic macular hole surgery

Negretto, Alan Diego 28 March 2008 (has links)
Objetivo: A partir das medidas anatômicas isoladas (altura, diâmetro externo e interno) do BMI construir um novo índice prognóstico para a cirurgia de correção do Buraco Macular Idiopático (IPBM). Tipo de estudo: intervencional, série de casos. Pacientes e Métodos: Estudo realizado no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo e no Instituto Suel Abujamra, São Paulo-SP, entre outubro de 2005 e outubro de 2007. Foram incluídos 36 olhos de 36 pacientes com BMI, que foram avaliados segundo as medidas apresentadas ao exame de TCO (Stratus - Zeiss, versão 4.01) antes da cirurgia do BMI. Utilizando o compasso do TCO, obteve-se a medida dos maiores diâmetros externo e interno e da altura dos BMI. Por meio dessas medidas, foi criado o IPBM. Após vitrectomia posterior com retirada de Membrana Limitante Interna (MLI), sem utilização de corantes, os pacientes foram acompanhados por seis meses. Após a cirurgia, os pacientes foram avaliados no primeiro e sétimo dias, duas semanas, um, três e seis meses. Ao final do seguimento, o IBPM e outras variáveis (sexo, idade, raça, estádio do BMI pela classificação biomicroscópica de Gass, tempo decorrido desde a piora da acuidade visual informada pelo paciente e a acuidade visual pré-operatória), foram correlacionadas com o resultado anatômico e a acuidade visual pós-operatória. Resultados: Vinte e nove (80,6%) dos 36 olhos com BMI obtiveram fechamento anatômico ao final de seis meses de acompanhamento (8,86 ± 4,23 meses). Dezenove (52,7%) dos BMI eram do estádio IV de Gass, com tempo de duração maior que um ano em 21 pacientes (58,3%). A AV LogMAR corrigida pré-operatória média foi de 1,10 (0,60 a 1,62) e a pós-operatória média foi de 0,69 (0,0 a 1,60). A média de melhora da AV foi de 3,94 linhas. Em relação ao fechamento anatômico, não houve significância em relação ao tempo de história da doença entre os grupos aberto (grupo 1) e fechado (grupo 2) (Teste t-Student, p=0,072). O diâmetro da base interna foi maior no grupo 1 em relação ao grupo 2 (Teste t-Student, p=0,007). Na análise do índice IPBM, houve diferença significativa entre o grupo 1 (média 0,49) e o grupo 2 (média 0,91). (Teste t-Student, p< 0,001) A análise de regressão logística apontou que BMIs com IPBM maior que 0,53 apresentam chance de fechamento anatômico 9,6 vezes maior (Odds Ratio= 9,6, p = 0,018). Pacientes com IPBM > 0,53 apresentaram AV pós-operatória ao final do sexto mês significativamente melhor do que pacientes com IPBM < 0,53 (Mann-Whitney, p=0,005). O ganho percentual da AV foi de 41,93% nos pacientes com IBPM>0,53, quando comparado com os 7,14% do grupo com IPBM <0,53 (p=0,002). No que diz respeito à AV final LogMAR, todas as variáveis estudadas anteriormente foram submetidas ao teste de correlação de Pearson. Observou-se que o IPBM tem uma correlação negativa significante com a AV, e foi selecionado juntamente com a AV pré-operatória através de regressão linear como os melhores preditores de AV final (p<0,001 e p=0,005, respectivamente). O modelo aponta que 58,4% da AV pós-operatória está sendo explicada pelo IPBM e AV pré-operatória. Conclusões: Foi construído um novo índice Prognóstico do Buraco Macular Idiopático (IPBM) representado pela razão altura / diâmetro interno do BMI. Verificou-se que o IPBM pode ser utilizado como fator prognóstico de fechamento anatômico do BMI. O IPBM e a AV pré-operatória foram os fatores prognósticos com melhor relação para a AV no sexto mês após o tratamento cirúrgico do BMI. / Purpose: To create a new prognostic index for IMH surgery based on anatomical values of IMH height, external and internal diameters (MHPI). Type of Study: Prospective, interventional, case of series. Patients and Methods: 36 eyes with IMH of 36 patients followed at Hospital das Clinicas, University of São Paulo Medical School (HC-FMUSP) and Suel Abujamra Institute (ISA), São Paulo-SP, between October 2006 and October 2007, were included. IMH OCT measurements were obtained before surgery (Stratus - Zeiss version 4.01) Values of the larger external and internal diameters, and the IMH height were obtained using the OCT compass. The prognostic index of IMH (MHPI) was defined as the index height / internal base. MHPI was defined by using those OCT measurements. Patients underwent pars plana vitrectomy with ILM peeling without dye and were followed by 6 months. Patients were seen at days 1, 7, 14, and months 1, 2, 3, and 6 after surgery. At the end of the follow-up period, MHPI and, other variables (sex, age, ethnic group, stage of IMH following the biomicroscopic classification of Gass, the time of visual loss reported by the patient, and pre surgical visual acuity) were correlated with anatomical results and post-surgical visual acuity. Results: Twenty nine eyes (80.6%) of thirty six patients with IMH had anatomical closure at the end of the six-month follow-up (8.86 ± 4.23 months). Nineteen (52.7%) IMH were stage IV of Gass with more than one year duration in twenty one patients. Pre-surgical medium LogMAR VA was 1.10 (0.60 to 1.62) and post-surgical was 0.69 (0.0 to 1.60). Medium VA improvement was 3.94 lines. The internal base diameter (BINT) was larger in group 1 than in group 2 (t-Student Test, p=0.373). MHPI analisys showed significant difference between group 1 (average 0.49) and group 2 (average 0.91) (t-Student Test, p> 0.001). Logistical regression showed that IMH with MHPI higher than 0.53 present 9.6 times more risk of failure than those with MHPI lower than 0.53 (Mann-Whitney, p=0.005). The percentage gain of VA was 41.93% in patients with MHPI > 0.53, and 7.14% in patients with MHPI lower than 0.53 (p=0.002). In regards to the final LogMAR VA, all studied variables above submitted to Pearson correlation test. MHPI is inversely correlated with VA by linear regression with gradient procedure as best predictor of final VA (p< 0.001 and p= 0.005 respectively). The sample shows that 58.4% of post-surgery VA is being explained by the MHPI and pre-surgery VA. Conclusions: A new prognostic index for IMH surgery was defined as IMH height/internal diameter. We concluded that MHPI may be used as a prognostic factor for IMH anatomical closure after surgical treatment. MHPI and preoperatory VA were the best correlated prognostic factors for 6-month VA.
10

Cataract Formation After Retinal Procedures

Huffman, Ryan Issac 02 January 2007 (has links)
The purpose of this project is to study the risk of cataract development in patients who had undergone pars plana vitrectomy, scleral buckle, or both. A retrospective study was performed of phakic patients who underwent pars plana vitrectomy, scleral buckle, or both at Yale University Eye Center from 1998 to 2005. Mild postoperative cataract, defined as a change in severity of 1+, developed in 32 of 53 (60%) eyes following vitrectomy, 2 of 19 (11%) post scleral buckle, and 14 of 16 (88%) after both. Moderate postoperative cataract, defined as a change in severity of 2+, developed in 14 of 53 (26%) eyes post vitrectomy, 1 of 19 (5%) post scleral buckle, and 11 of 16 (69%) after both procedures. In eyes that underwent vitrectomy, a lens change of at least 2+ occurred in 8% at 3 months, 15% at 6 months, 21% at 12 months, and 26% at 36 months. In eyes status post scleral buckle surgery, one eye (5%) experienced a 2+ change at 36 months. In eyes that underwent both vitrectomy and scleral buckle, a lens change of at least 2+ occurred in 44% at 3 months, 50% at 6 months, 63% at 12 months, and 69% at 36 months. Cataract extraction surgery was performed in 15% of eyes post vitrectomy, 0% post scleral buckling, and 50% after both. The most common type of cataract to develop was nuclear sclerotic, which accounted for 61% of cataracts after vitrectomy, 50% after scleral buckling, and 50% after combined vitrectomy and scleral buckling. Scleral buckling surgery is associated with a low risk of cataract formation. Pars plana vitrectomy and combined vitrectomy and buckle have a higher risk of cataract development.

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