This thesis present research work conducted in the field of retina image analysis. More specifically, the work is directed at the application of texture analysis technique for the segmentation of common retinal landmark and for retina image classification. The main challenge in this research is in identifying the suitable texture measurement for retina images. In this research we proposed the used of texture measurement based on Binary Robust Independent Elementary Features (BRIEF). BRIEF measure texture by performing an intensity comparison in a local image patch, thus it is very fast to compute and tolerant to any monotonic increase or decrease of image intensities, which makes the descriptor invariant to illumination. The performance of BRIEF as texture measurement is first shown in an experiment involving texture classification and segmentation using common texture datasets. The result demonstrates good performance from BRIEF in this experiment. BRIEF is next used in two applications of retinal image analysis, namely optic disc segmentation and glaucoma classification. In the former, we proposed the used of pixel classification using BRIEF as textural features and circular template matching to segment the optic disc. In addition, an extension of BRIEF called Rotation Invariant BRIEF (OBRIEF) is later proposed to improve the segmentation result. For glaucoma classification, we described two approaches for glaucoma classification using BRIEF/OBRIEF features. The first is based on determination of cup to disc ratio (CDR) and the second is classification using image features i.e. BRIEF features. Overall, our preliminary results on using BRIEF as texture measurement for retinal image analysis are encouraging and demonstrate that it has the potential to be used in retina image analysis.

Orientador: Wang Binseng / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Campinas / Made available in DSpace on 2018-07-15T11:51:29Z (GMT). No. of bitstreams: 1 Fossey_MarceloAndre_M.pdf: 1942478 bytes, checksum: be673589961b28b0f1ac699750d312aa (MD5) Previous issue date: 1985 / Resumo: Devido às graves implicações sociais do glaucoma, e ao fato dele ser relativamente imperceptível no início, é necessário a avaliação da pressão intra-ocular (PIO) toda vez que se efetua o "check-up"., pois pressões prolongadas acima de 21 mmHg podem causar alteração do campo visual e, se não tratado em tempo, cegueira ao paciente. Atualmente os tonômetros utilizados no Pais são importados, apresentando alto custo, baixa precisao (tonômetro de Goldmann) e pouca confiabilidade (tonômetros eletrônicos). Foi projetado e construido um tonômetro eletrônico, com materiais e componentes facilmente encontráveis no mercado nacional. A PIO é medida por uma ponta de prova, no centro da qual existe um pino rigidamente acoplado a uma cerâmica piezoelétrica, que ao ser deformada pela PIO produz uma tensão elétrica e, ao se detetar eletronicamente a condição de aplanação, é registrado o valor da PIO num display digital. Para aumentar a confiabilidade, o tonômetro foi montado num suporte com o formato de revólver, com dois suportes laterais. Este tonômetro pode ser utilizado com.o paciente na posição vertical ou reclinado, sem o auxílio da lâmpada de fenda. / Abstract: The grave social consequences of glaucoma and the fact its onset is relatively imperceptivable make evaluation of the intraocular pressure (IOP) essential at each Iredical examination. Prolonged IOPs above 21 nmHg may cause alterations in the visual field and, if not treated, blindness in the patient. At the present time, alI tonometers used in Brazil are irnported. 1n general, they present either high cost and low precision (Goldman tonometers) or little reliability (electronic tonometers). An electronic tonometers was designed and built using materiaIs and corrponents available in Brazil. The IOP is measured with a probe at the center of which exists a pin fixed rigidly onto a piezoelectric transducer, whose deforrnation by tpe IOP produces an electric signal. As the cornea is depressed by the probe, the applanation, condition is detected electronically and the value of IOP thus detected is displayed digitally. To provide reliable measurerrents, the tonometer was mounted in front of a pistol-like holder with two supports to be positioned on, the facial banes. The instrument may be used with the patient in any position without the need af a slit lamp. / Mestrado / Mestre em Engenharia Elétrica

Primary angle closure glaucoma (PACG) is a chronic optic neuropathy that results in retinal ganglion cell (RGC) degeneration, cupping of the optic nerve head (ONH) and subsequent loss of vision. In humans, PACG occurs as a result of a plateau iris or more commonly, a pupillary block. Increased Intraocular pressure and reduced axial length are some of the predisposing factors to PACG. The condition occurs in several breeds of dogs and the prognosis for affected animals is typically poor. Unlike PACG in humans, the mechanism of PACG in canines involves the gradual collapse of the ciliary cleft with or without complete collapse of the irido-corneal angle. We have identified and examined several Basset Hound (BH) pedigrees with clinically confirmed PACG that segregates in an autosomal recessive manner. The goal of this proposal is to utilize the Basset Hound PACG model in order to characterize the genetics of PACG. In addition to investigating the underlying genetic mechanisms of PACG, a series of functional studies aimed at improving our understanding of the pathophysiology of PACG, were also performed to investigate the disease. Extensive clinical phenotyping of all pedigree members was conducted by a veterinary ophthalmologist. We performed a genome-wide logistic regression test for association using 37 PACG cases and 41 unaffected controls. Population stratification and cryptic relatedness were assessed using a multidimensional scaling analysis. The expression of two candidate genes within the target tissues of the Basset Hound eye was assessed by immunohistochemistry. SNP-chip genotyping was additionally conducted in 9 affected and 15 unaffected pedigree members. Two-point and multipoint linkage analyses of genome-wide SNP data were performed using Superlink-Online SNP-1.1. Targeted exome capture was performed using the Agilent SureSelect exon kit. A primary fibroblast cell culture was established from the sclera of three PACG, two wild type and two obligatory carrier Bassets. Total RNA extracted from fibroblast cells was assayed using the Affymetrix GeneChip Canine Genome 2.0 Array. The Robust Multichip Average expression summary method was used for background adjustment and normalization. A two class, unpaired, Wilcoxon statistical test was conducted to identify differentially expressed genes. qRT-PCR was performed to validate significantly expressed genes. Furthermore, a primary fibroblast cell culture was established from the skin of a PACG and an obligatory carrier BH. Microscope images and cell counts from all cell cultures were established at various time points. Our findings reveal significant associations at two novel loci: BICF2P31912 in COL1A2 on chromosome 14 with a per-allele odds ratio OR(95% CI) 8.95(1.73-6.51); Pgenome = 3.6 x 10-4 and BICF2P893476 residing in proximity to RAB22A on chromosome 24 with a per-allele odds ratio OR(95% CI) = 12.03(1.78-8.66); Pgenome = 4.9 x 10-4. COL1A2 and RAB22A demonstrated wide-spread localization throughout the eye and were prominently noted in the ciliary body, trabecular meshwork and iris. A 1.82Mbp locus was additionally mapped to chromosome 19 with a maximum LOD score of 3.24. The locus contains 12 Ensemble predicted canine genes and shares synteny to a region on chromosome 2 in the human genome. Using exome-sequencing analysis, a possibly damaging, nonsynonymous variant was found to segregate with PACG in the gene Nebulin (NEB) (g.55885214 A->G, p.2051 K->R), which alters a conserved Lysine. Nebulin, a protein that promotes the contractile function of sarcomeres was found to be prominently expressed in the ciliary muscles of the anterior segment. Primary scleral fibroblast cells derived from PACG animals were found to exhibit severely reduced growth rates when compared to wild type derived cells. Genes with sharply reduced expression levels are of particular interest due to the possible involvement of a loss of- function mutation in PACG. More than 600 genes were found to be significantly under expressed in PACG derived cells. In contrast to unaffected-derived cell, PACG derived cells display significantly altered gene expression patterns for a number of possibly important candidate genes. Furthermore, PACG derived cells display aberrant and reduced motility in PACG versus wild type derived cell cultures. The identification of two genetic associations supports the potential segregation of PACG risk-conferring variants in the Basset Hound. The genetic associations identified may contribute to mechanisms underlying the pathogenesis of PACG, which remain to be elucidated. Moreover, our studies provide the first evidence of a gene directly linked to PACG in the Basset Hound. Our findings may provide insight into the molecular mechanisms that underlie PACG. The phenotypic similarities of disease presentation in dogs and humans may enable the translation of findings made in this study to patients with PACG. The findings of our functional studies suggest that cellular dysfunction is an important aspect in the pathophysiology of PACG in the dog. The identification of genes with significantly altered expression levels may provide insight into the molecular pathways associated with the development of the disease and aid in the identification of the genetic defect underlying PACG.

Bakgrund: Glaukom (grön starr) är en kronisk ögonsjukdom där synnerven skadas och orsakar synfältsdefekter. Sjukdomen drabbar framför allt den äldre befolkningen över 50 års ålder. Asymtomatiskt förlopp gör att sjukdomen är svårt att upptäcka. Orsakerna till sjukdomen är oklara men det finns en rad riskfaktor där bland annat högt ögontryck nämns som den största orsaken. Utan behandling är risken för blindhet oundviklig. Behandling med ögondroppar bromsar sjukdomen genom att hålla det intraokulära trycket i schack. Tidigare studier har visat att följsamheten till behandlingen bland glaukom patienter inte är optimal.   Syfte: Syftet med studien var att identifiera och beskriva faktorer som har påverkan på följsamheten till behandlingen bland patienter med glaukom. Metod: Integrativ litteraturstudie genomfördes och resultatet baseras på 17 vetenskapliga artiklar. Dataanalys genomfördes enligt Whittemore och Knafl (2005). Resultat: Analysen av artiklarna gav till resultat tre kategorier på faktorer som har betydelse för patienters följsamhet vid behandling av glaukom: personliga faktorer, behandlingsrelaterade faktorer och faktorer relaterade till patientkunskap. Slutsats: Studien visade att kunskapsfrågor och faktorer som är relaterade till behandlingen är de områden som behöver lyftas fram och läggas mer fokus på i arbetet med glaukompatienter. Det kan bidra till att rädsla för sjukdomen reduceras, medvetandegöra och egenansvaret för sjukdomen ökar. Åtgärderna kan bidra både till en nöjd patient och ekonomisk vinst för samhället. / Background: Glaucoma eye disease in when the optic nerve is damaged and causes visual field defects. The disease mainly affects the elderly population over the age of 50. Asymptomatic course makes the disease difficult to detect. The causes of the disease are unclear, but there are several risk factors where, among other things, high eye pressure is mentioned as the biggest cause, without treatment, the risk of blindness is inevitable. The treatment with eye drops slows down the disease by keeping the intraocular pressure in check. Previous studies have shown that adherence to treatment among glaucoma patients is not optimal. Aim: The aim of the study was to identify and describe factors that influence the adherence to treatment among patients with glaucoma. Method: Integrative literature study was conducted, and results are based on 17 scientific articles. Data analysis was performed according to Whittemore and Knafl (2005).  Result: Analysis of the articles gave results in three categories of factors that are important for patient’s compliance in the treatment of glaucoma: personal factors, therapy-related factors, factors related to patient knowledge. Conclusion: The study showed that knowledge and factors related to the treatment are the areas that need to be highlighted and more focus placed on the work with glaucoma patients.  It can help reduce the fear of the disease and increase awareness and responsibility for the disease.  The measures can contribute to both a satisfied patient and financial gain for society.

The purpose of this study was to investigate morphological changes in the outflow pathway from Schlemm’s canal (SC) to the intrascleral vessels (ISVs) in POAG eyes through comparisons with age-matched, normal control eyes using light microscopy and morphometric analysis. We hypothesized that there would be a reduction in the size and number of ISVs when SC becomes narrower and collapsed in the eyes with POAG and there would be no reduction in size and number of ISVs when SC is open in eyes with POAG. 11 normal eyes from 10 donors (63-92 years old) without a history of ocular diseases and 10 POAG eyes from 6 donors (67-90 years old) with clinically confirmed diagnoses of POAG were acquired. The eyes were fixed and embedded. The sections of anterior chamber angle (2-3 μm in thickness) were cut, stained with sectioning procedures, and imaged using a light microscope. 36 images from 11 normal eyes and 40 images from 10 glaucomatous eyes were examined and analyzed in this study. Cross-sectional area (CSA), width, height of SC and percentage collapse of SC as well as the number and CSA of ISVs were measured within each quadrant of the eye. Statistical analyses were conducted using one-way ANOVA and Kruskal-Wallis test in the IBM SPSS software. A significant reduction in height, width, and CSA of SC, and a significant increase in percentage of SC collapse were found in 70% of POAG eyes, while open SC was found in 30% of POAG eyes when compared to normal eyes. Decreased sizes and number of ISVs were observed in 70% of POAG eyes with narrower and collapsed SC, but these changes did not reach statistical significance. Decreased sizes of ISVs were observed in 30% of POAG eyes with open SC, although these changes did not reach statistical significance. The results suggested that smaller and collapsed SC was found in 70% of eyes with POAG. Ultimately, the decreased size and number of ISVs found in POAG eyes may be secondary to decreased size and collapse of SC in POAG pathology.

Glaucoma is a group of ocular disorders characterized by optic nerve damage that leads to vision loss and blindness. Damage to retinal ganglion cells (RGCs), particularly through axonal damage due to an increase in intraocular pressure (IOP), is a proposed mechanism behind glaucomatous injury. Other than increased IOP, vascular changes leading to ischemia are another explanation for glaucoma. A state of ischemia leads to a decrease in nutrients supplied to neurons of the retina and creates a hypoxic environment which is linked to cell death in both IOP- and non-IOP-related injury. Injury during glaucoma not only affects RGCs but also has secondary effects that impact the function of other cells in the retina like amacrine cells (ACs). To better understand how RGCs and ACs respond during glaucomatous injury, this study characterized the changes in viability of these cells under hypoxic conditions over time. With the use of a unique immunopanning technique, RGCs and two subpopulations of ACs (CD15+ and CD57+) were isolated from 12-week-old C57BL/6J mice and cultured for 6 to 9 days. After about a week of culturing, the three cell types were placed under either normoxic (n = 5) or hypoxic (n = 6) conditions, and cell viabilities were measured at 1-hour time intervals over 24 hours. RGC and AC isolations based on the immunopanning technique resulted in high yield and viability, confirming the findings of previous optimization studies. In response to hypoxic conditions, RGCs and the two subpopulations of ACs all experienced a decrease in cell viability over the course of 24 hours. Surprisingly, CD57+ cells showed increased susceptibility to injury and death during isolation. However, the remaining CD57+ cells that stayed alive in culture by the start of the time-course experiment were the most resilient to cell death during hypoxia, showing significantly higher cell viability compared with CD15+ and Thy1.2+ cells. The characterization of CD15+, CD57+, and Thy1.2+ cells in response to hypoxia highlights a difference in resilience across neuronal cell types in the retina. Although CD57+ exhibited greater resilience than its counterparts, the mechanism behind neuroprotection among these cells is still unknown and requires further study. / 2024-01-28T00:00:00Z

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第17826号 / 医博第3824号 / 新制||医||999(附属図書館) / 30641 / 京都大学大学院医学研究科医学専攻 / (主査)教授 渡邉 大, 教授 村井 俊哉, 教授 柳田 素子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Matrix metalloproteinases (MMPs) are known to be the mediators of extracellular matrix remodeling. Increased levels of matrix metalloproteinases, particularly MMP-9, have been found in the aqueous humor of patients with glaucoma. However the exact role of MMP-9 in glaucomatous changes is not understood. Previous results from the West-Mays’ lab indicated that MMP-9 deficient (knockout - KO) mice exhibit elevated IOP, in the absence of distinct morphological changes in the anterior chamber. In the current thesis, I investigated whether the elevated IOP in MMP-9KO mice leads to RGC death. Wild type and KO littermates at different age groups: 2-3 months, 3-4 months, 6-8 and 9-12 months were studied. IOP was measured using TonoLab rebound tonometer. My results demonstrated that IOP was significantly increased in MMP-9KO mice compared to control littermates at all ages examined. To investigate if the elevated IOP was due to a difference in central corneal thickness (CCT), CCT measurements were made between WT and KO mice using ultrasound pachymeter. There was no difference in CCT demonstrating that the elevated IOP observed in MMP-9KO mice was not related to changes in corneal thickness. To determine whether the elevated IOP led to RGC death, the animals were sacrificed, eyes were enucleated and retinas (n=4) from both WT and KO animals were dissected and stained with Brn-3a antibody. Additional eyes were harvested from both WT and KO mice for histological and immunofluorescence studies. I found no observable difference in Brn3a+ RGC count between MMP9-WT and KO mice. Furthermore, no difference in retinal morphology, glial reactivity and laminin expression between WT and KO mice was observed. In the future it will be important to investigate whether elevated IOP in the MMP-9KO mice leads to optic nerve axonal loss and further investigate the possibility that the MMP-9KO retina is neuroprotected. / Thesis / Master of Science (MSc)

Th ocular bilateral hypotensive effect after unilateral topical administration of medetomidine and 4 analogs was demonstrated in a dose-response study (0.5%-2%) in NZW rabbits (bilateral IOP-lowering efficacy: medetomidine>detomidine and MPV-1440>MPV-1441 and MPV-305BIII).

No description available.