Inaug.-diss.-Bern. / Benützte literatur : p. [63]-64.

No description available.

Afhandling - Copenhagen, 1959. / Summary in English and Danish.

Afhandling - Copenhagen, 1959. / Summary in English and Danish.

This project has provided a better understanding of the human conjunctiva, the glistening tissue covering the white of the eye, at the cellular level. The observations of this study may serve as a useful marker against which changes in conjunctival tissue due to disease, surgery, drug therapy or contact lens wear can be assessed. Laser scanning confocal microscopy was used to observe and measure characteristics the conjunctiva of healthy human volunteer subjects. It was concluded that this technique is a powerful tool for studying the human conjunctiva and assessing key aspects of the structure of this tissue. The effects of contact lens wear on the conjunctiva can be investigated effectively at a cellular level using this technology.

No description available.

The exact role of mycoplasma in feline ocular and respiratory disease is not yet understood. The results of previous studies are contradictory in this regard. There is some evidence to suggest that M. felis has a pathogenic role in such diseases, but it is inconclusive. / The aim of this study was to investigate the prevalence and anatomical distribution of mycoplasmas in a population of shelter cats, to determine which species were present, and establish the association of their presence with ocular or respiratory disease. / The prevalence of mycoplasma in the 110 cats examined was 71.8%, as determined by in vitro culture. Mycoplasma was most commonly isolated from the pharynx, followed by the bronchus and conjunctiva. In infected cats, mycoplasmas were likely to be isolated from multiple anatomical sites. / The polymerase chain reaction (PCR) was used to amplify part of the 16S rRNA gene, and the mutation scanning technique non-isotopic single-strand conformation polymorphism (SSCP) was utilised to delineate mycoplasma isolates based on nucleotide sequence variation. PCR-SSCP proved to be a useful method to screen large numbers of samples for variation and to group them according to species. / The species of mycoplasma identified by nucleotide sequencing were M. felis and M. gateae. It was not determined whether it was possible to differentiate between M. gateae and M. arginini based on SSCP profile results with the target DNA region used due to their almost identical nucleotide sequence. This group of M. gateae/M. arginini served as a useful non-pathogenic comparison group to M. felis. / There was no statistically significant difference between M. felis and the M. gateae/M. arginini group with respect to prevalence or anatomic distribution. There was no evidence of any association of mycoplasma with disease linked to any of the anatomic locations studied. / Mycoplasmas were isolated from the lower respiratory tract in 42.7% of cats. The isolation of mycoplasmas from the lower respiratory tract of healthy cats has been reported once, but this is the first report of M. felis being isolated from this location in healthy cats. This finding indicates that the isolation of mycoplasmas from the lower respiratory tract is not sufficient evidence to implicate a role in respiratory disease. / Mycoplasmas were not significantly involved in ocular or respiratory disease in the population of cats studied. More likely, they are commensal organisms in the conjunctiva, pharynx and bronchus. Whether they are capable of playing an opportunistic role in disease, or what conditions may facilitate such a role remains to be determined.

A microbiota normal exerce função protetora na superfície ocular, competindo por nutrientes e secretando substâncias com propriedades bactericidas, o que dificulta a invasão de patógenos. Animais diabéticos apresentam diferentes alterações ceratoconjuntivais, tais como maior concentração de glicose no filme lacrimal, menor quantidade e qualidade da lágrima e diminuição da sensibilidade corneal, diferenças clinicamente relevantes que podem alterar essa microbiota. Traumas oculares também podem apresentar tal alteração por promoverem a quebra da barreira de proteção da superfície ocular. A correta identificação do agente etiológico, além de proporcionar um tratamento eficiente em alterações oculares, direciona a antibioticoterapia profilática tópica nos casos cirúrgicos e evita o uso abusivo de antibióticos, o que pode levar a destruição da microbiota normal da superfície ocular, facilitando assim o crescimento de bactérias e fungos patogênicos. Com o intuito de minimizar as complicações pós-operatórias das cirurgias intra-oculares, como as facectomias, freqüentemente realizadas nos cães diabéticos por serem predispostos a apresentarem catarata, este estudo visou avaliar a prevalência dos principais microrganismos da microbiota conjuntival de cães diabéticos. Foram avaliadas as microbiotas conjuntivais de 29 cães diabéticos, atendidos no Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, totalizando 58 olhos. Estes, não estavam utilizando qualquer medicação tópica e não apresentavam alterações oculares ou doença sistêmica infecciosa que pudesse interferir nos resultados. As amostras foram colhidas do saco conjuntival com auxilio de zaragatoas, cuidando para que não houvesse contaminação pelo contato com pálpebras e cílios. As amostras foram inoculadas em meio enriquecedor Brain Heart Infusion (BHI) e caldo Sabouraud-dextrose e semeados em ágar sangue, MacConkey e Sabouraud-dextrose com cloranfenicol. Os microrganismos foram identificados por suas características morfológicas na bacterioscopia, pela coloração de gram e pelas características macro e microscópicas das colônias, além de testes bioquímicos. Houve maior prevalência de Staphylococcus (32,79%), principalmente coagulase negativos, que são os mais freqüentemente isolados nas infecções oculares: S. klosii, S. simulans, S. capitis, S. pasteuri, S. saprophyticus, S. haemolyticus. Também foram isolados Bacillus sp. (11,48%), S. intermedius (6,56%), Streptococcus sp (1,64%) e alguns fungos, como Cladosporium sp e Candida parapsilosis. Não houve crescimento de microrganismos gram negativos, anaeróbios estritos ou facultativos. Sugere-se que os resultados encontrados se relacionam diretamente às alterações ceratoconjuntivais dos animais analisados, local do exame, clima e diferentes raças. Sabendo-se que cães diabéticos são prováveis candidatos à facectomia, intervenção que promove quebra da barreira de proteção da superfície ocular e que existem microrganismos potencialmente patogênicos na conjuntiva destes animais, sugere-se análise da microbiota ocular antes da intervenção cirúrgica, para uso profilático de agentes antimicrobianos. / Normal ocular flora avoids infection depriving investor microorganisms of nutrients and by the secretion of bactericidal substances. Diabetic animals usually develop keratoconjunctival abnormalities, such as the higher concentration of glucose in the tear film; qualitative and quantitative tear deficiency and a decrease of the cornea sensitivity, what probably changes their conjunctival flora either. The same alteration may happen after ocular traumas, when the ocular barrier of protection is discontinued. The identification of agent etiology allows the efficient treatment of ocular infections, the prophylactic prescription of antibiotics before surgery and avoids destruction of normal ocular flora or multiplication of pathogens. Aiming to minimize complications on intraocular surgeries, such as facectomies, frequently realized in DM dogs for its predisposition to develop cataract, this study evaluated the prevalence of microorganisms in their conjunctival flora. The conjunctival flora of 29 diabetic dogs (58 eyes), attended at the Ophthalmology Service, of the Veterinary Hospital of the Veterinary College University of São Paulo were evaluated. These dogs werent using any kind of eyedrops, didnt present any ocular or systemic disease other than diabetes mellitus, what could change the results. Samples were taken with sterile swabs from the conjunctival sac and inoculated on Brain Heart Infusion (BHI) and Sabouraud-dextrose broth, then sown in blood agar, MacConkey and Sabouraud-dextrose-cloranfenicol. Contamination was avoided during procedure not touching the swab on eyelid or eyelashes. Microorganisms were identified by their morphological aspects at bacterioscopy, gram staining, macro and microscopy characteristics of the colonies and by biochemical tests. Staphylococcus presented the higher prevalence (32,79%), mostly the coagulase negative ones (S. klosii, S. simulans, S. capitis, S. pasteuri, S. saprophyticus, S. haemolyticus), which are frequently isolated from ocular infections. Either isolated, were Bacillus sp. (11,48%), S. intermedius (6,56%), Streptococcus sp (1,64%) and some fungus, such as Cladosporium sp and Candida parapsilosis. Gram negative bacteria, anaerobic stricts or facultative were not identified during the study. We suppose that these results are strictly correlated to keratoconjunctival alterations in DM dogs, procedure, weather and breed. We conclude that, as DM dogs presents potential pathogens on its conjunctiva and are probable candidates to cataract surgery, which discontinues the ocular barrier of protection, we suggest the identification of the agent etiology before surgery and the proper use of antibiotic before and after any intraocular intervention.

Philosophiae Doctor - PhD / Purpose: High risk human papillomavirus (HR-HPV) is well established as a causative agent of squamous cell carcinoma (SCC) of the orophaynx. HR-HPV has also been reported in periocular cancers and precancers, but controversy exists about its overall incidence and clinicopathologic profile. The purpose of this study is to evaluate the role of HR-HPV infection in periocular cancers and precancers, using multiple methods of detection. Design: Retrospective observational case series with laboratory investigations. Methods: Sequential surgical samples of 87 carcinomas (invasive SCC, SCC in situ and sebaceous carcinoma) from three different periocular sites (conjunctiva, lacrimal sac and the eyelid) diagnosed over a 15-year period (2000-2015) were selected for evaluation. Unstained paraffin sections of 87 cases of periocular carcinomas were analyzed with immunohistochemistry (IHC) for p16 as a screening test. p16 positive conjunctival- and lacrimal sac SCC were further evaluated for HR-HPV using DNA in situ hybridization (DNA ISH), and a subset was also analyzed by DNA Polymerase Chain Reaction (DNA PCR). p16 positive periocular sebaceous carcinomas (SC) were analyzed with PCR, and a subset of 18cases was further studied with a novel method of mRNA ISH, an advanced technique with an enhanced sensitivity and specificity. Relevant patient clinical information was obtained from review of the electronic medical records.

Introduction The ocular surface provides a unique opportunity to study hemodynamics since the vessels can be visualized directly, without treatment and non-invasively. The availability of instruments to measure various hemodynamic parameters on the ocular surface in an objective manner are lacking. The quantification of red blood cell velocity, blood oxygen saturation and conjunctival redness on the ocular surface using novel, validated techniques has the potential of providing useful information about vascular physiology. The specific aims of each chapter are as follows: Chapter 3: The objective was to design, develop and validate a system that would non-invasively quantify the red blood cell velocity in the conjunctival vessels. A tool was developed to automatically analyze video sequences of conjunctival vessels, digitally imaged with high enough magnification to resolve movement of the blood within the vessel. Chapter 4: The objective was to: a) design and develop a method in order to non-invasively quantify the changes in blood oxygen saturation (SO2) in the conjunctival vessels and demonstrate reliability of the measures and, b) demonstrate the application of the method by showing a response to an isocapnic hyperoxic provocation and compare those values to the results from a valid instrument. Chapter 5: The aim of this experiment was to examine variations in ocular redness levels, red blood cell velocities and oxygen saturation levels over time in clinically healthy participants and also to compare differences between two age groups. Chapter 6: The aim of this experiment was to examine the ocular redness levels, red blood cell velocities and oxygen saturation levels in clinically healthy participants when a topical ophthalmic decongestant was instilled onto the eye and to demonstrate the validity of the use of two novel techniques. Chapter 7: The aim of this experiment was to examine ocular redness, red blood cell velocity and oxygen saturation in participants who were habitual soft contact lens wearers (study) compared to those that did not (control) and also to compare differences in silicone (SH) and non-silicone hydrogel wearers. Methods Chapter 3: Simulations representing moving RBCs within a vessel and the random variation of each cell in terms of speed, shape and intensity were created in order to evaluate the performance of the algorithm. For each vessel, a signal that correlated to blood cell position was extracted from each frame, and the inter-frame displacement was estimated through a modified dynamic time warping (DTW) algorithm. This provided the red blood cell velocity over time in each point of the vessels. Thus, from these estimates, the mean red blood cell velocity for each vessel was easily evaluated. The true mean velocity from the simulation with the one estimated by the algorithm was compared and the system accuracy was determined. Chapter 4: a) Conjunctival vessels were imaged with two narrow-band interference filters with O2-sensitive and O2-insensitive peak transmissions using a Zeiss slit lamp at 32x magnification. Optical densities were calculated from vascular segments using the average reflected intensities inside and outside the vessels. Optical density ratios were used to calculate relative oxygen saturation values. Video images of the bulbar conjunctiva were recorded at three times of the day. Measurement repeatability was assessed over location at each time and across consecutive frames. b) Subjects initially breathed air for 10 minutes followed by pure oxygen (O2) for 20 minutes, and then air for a final 10 minute period using a sequential re-breathing circuit. Simultaneously, SO2 values measured with a pulse oximeter ear clip and finger clip were recorded. The validity of the dual wavelength method was demonstrated by comparing the values to those from the ear clip pulse oximeter. Chapter 5: Participants attended eight separate visits over the course of a day. Levels of bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured on a vessel of interest. Chapter 6: Participants attended three separate visits during an allotted 60 minute session. Bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured on a vessel of interest, pre-insertion, just after insertion and, 10 minutes after insertion of a topical ocular decongestant. Significant differences between the three measures were assessed and correlations between the three parameters were reported. Chapter 7: Participants were measured 8 times over the course of a day with their contact lenses in place. Bulbar conjunctival redness, red blood cell velocity and blood oxygen saturation were measured. Results Chapter 3: Results for the simulated videos demonstrated a very good concordance between the estimated and actual velocities supporting its validity. The mean relative error for the modified Dynamic Time Warping (DTW) method is 6%. Chapter 4: The intraclass correlations (ICCs) between the three locations at each time point were 0.93, 0.56 and 0.86 respectively. Measurements across 5 consecutive frames showed no significant difference for all subjects (ICC = 0.96). The ICCs between the two methods at each time point were 0.45, 0.10 and 0.11 respectively. a) There was no significant difference in SO2 between the three locations measured using the dual wavelength method for all subjects. There was also no significant difference between the three locations at any of the time points for the dual wavelength method. b) In response to isocapnic hyperoxic provocation using the dual wavelength method, blood oxygen saturation was increased from control values and subsequently recovered after withdrawal of hyperoxia. Blood oxygen saturation values recorded from the ear clip and finger clip of the pulse oximeter also showed an increase from control values and subsequently recovered after withdrawal of hyperoxia. SO2 comparison between the dual wavelength method and the ear-clip pulse oximeter method did not show a significant difference. The interaction between the two methods and time on SO2 was not significant. Chapter 5: From baseline, the group mean redness and oxygen saturation did not change significantly over time. There was a significant difference in the group mean red blood cell velocity values over time. There was no significant difference between age strata for all three measures. Chapter 6: After drop instillation redness values decreased significantly. There was no change in red blood cell velocity and oxygen saturation over time. There was a moderate significant correlation between SO2 and red blood cell velocity just after drop insertion. Chapter 7: When comparing the study and control groups, no significant difference in redness or SO2 over time was found. RBC velocity over time was found to be significantly different between groups. When comparing the two study groups (SH vs. hydrogel) no significant difference across either measure over time was found. Conclusions Chapter 3: Signal displacement estimation through the DTW algorithm can be used to estimate mean red blood cell velocity. Successful application of the algorithm in the estimation of RBC velocity in conjunctival vessels was demonstrated. Chapter 4: The application of the dual wavelength method was demonstrated and optical density ratios can be used in a reliable manner for relative oxygen saturation measurements. This valid method promises to enable the study of conjunctival O2 saturation under various experimental and physiological conditions. Chapter 5: The results of this study support the theory of metabolic regulation. The lack of any significant change across time for redness and oxygen saturation along with significant changes in red blood cell velocity substantiates this notion. Chapter 6: This study supports the literature regarding metabolic regulation of the microvasculature during the use of various stimuli. The results demonstrated that oxygen saturation levels remain stable even when a significant decrease in ocular redness is measured. The novel techniques used in this experiment demonstrated the expected action of the decongestant further contributing to their application and validity. Chapter 7: In summary, the participants in the study group were habitual contact lens wearers that had lower RBC velocities when compared to the control group supporting the notion that contact lenses initiate a hypoxic response. The lack of change in SO2 in either group supports the theory of metabolic regulation.