Glaucoma is a blinding disease characterized by damage to the optic nerve and often caused by an increase in the intra-ocular pressure. Glaucoma affects from 2% to 8% of the South African population, depending on race and age. Primary Open-angle Glaucoma (POAG) is found mostly in patients above the age of 40 years. POAG is more prevalent in black people, with the number of black persons contracting the disease double that of persons of European origin. In South Africa, the prevalence of blindness is estimated to be 0,6%, thus 240 000 out of a total of 40 million. Glaucoma is responsible for an estimated 20% of the total number of blind people, thus approximately 48 000. The treatment of glaucoma in Africa, and particularly in rural areas, presents many unresolved problems. Conventional conservative treatment with eye drops is difficult, due to the following reasons: -- Logistical problems of providing patients with a supply of medication. -- Appropriate use of drops requires education, together with a high degree of personal compliance. -- Cost of medical treatment. Patients require life-long treatment. Eye drops cost approximately R100,00 per person per month. Thus, over a ten-year period, the cost would be R12 000,00 per person and R576 million for the estimated 48 000 sufferers. Conventional surgery is not very effective, due to the following reasons: -- Scarring takes place at the surgical site. -- Can be performed only in main centres with microsurgical facilities and competent staff. -- Requires travelling expenses, not only for surgery, but also for periodical follow-up examinations. -- Surgical complications are not uncommon. Conventional laser surgery is not effective, for the following reasons: -- Can be performed only in main centres with laser surgery facilities and competent staff. -- Requires travelling expenses, not only for surgery, but also for periodical follow-up examinations. -- Complications of surgery are not uncommon. This dissertation describes an investigation concerning treatment of glaucoma, with specific reference to the use of optical energy sources. The spectral transmission of the human sclera is investigated. Alternative methods of sourcing optical energy to the ciliary processes are presented and compared. Results obtained can be summarized as follows: -- The spectral transmission of the sclera was measured. -- Trans-scleral transmission was measured to be very low (less than 5%). The result was confirmed by means of histological investigation, where high scleral absorption was found. -- Since no well-defined transmission window could be found, the application source need not be monochromatic. -- Results published in literature were found to be inconsistent. / Dissertation (MEng (Bio-engineering))--University of Pretoria, 2006. / Electrical, Electronic and Computer Engineering / unrestricted

La combinaison des avancées médicales et technologiques a rendu possible le monitoring à distance des patients, introduisant le paradigme de la e-santé (e-health en anglais). Il comprend des services ou des systèmes de convergence de la médecine, la santé et l’information, avec l’e-surveillance et la télé-médecine. Le type de dispositif médical "healthcare" doit assurer une sûreté de fonctionnement optimale, que ce soit pour une analyse médicale ou l’application d’un traitement. Le niveau de sûreté et de performance est critique pour la santé du patient.Maintenant que ces dispositifs s’appliquent à un nombre croissant de patients, tous différents et vivant dans des conditions différentes, ils doivent être capables de s’adapter en termes de performances et s’adapter à l’activité, à l’environnement et au patient lui-même. Une stratégie globale et réutilisable d’auto-adaptation à été définie dans le but de mettre en place méthodiquement et de façon optimale le processus et les étapes de l’auto-adaptation. Une des pathologies importantes actuellement est le glaucome, une neuropathie oculaire détériorant le nerf optique induisant une perte du champ visuel progressive et irréversible. Le diagnostique et le suivi de cette pathologie se fait par une mesure de la Pression Intra-Oculaire(PIO). La méthode utilisée actuellement est contraignante et requière la manipulation experte d’un dispositif de mesure ponctuelle. De nouveaux capteurs biométriques ont vu le jour permettant une mesure continue et portable amenant un meilleur diagnostic ainsi qu’un suivi plus simple. Notre cas d’étude sera donc centré sur l’utilisation d’un capteur biométrique de mesure de la PIO qui servira de plate-forme de validation aux solutions proposées sachant qu’il devra être auto-adapté aux différentes anatomies, physiologies, biomécaniques et environnements du patient. Tous les indicateurs perturbateurs ou informateurs de la mesure sont regroupés en deux catégories, ceux liés à l’environnement et ceux liés aux conditions d’utilisation. Un état de l’art est proposé pour la première catégorie et un modèle analytique est proposé pour la deuxième. L’état de l’art montre que les expérimentations in vivo sont nécessaires pour compléter les connaissances sur les indicateurs majeurs dans le cas d’une mesure de la PIO faite par un capteur biométrique. Le modèle analytique inclut le couplage électromagnétique entre les deux antennes du capteur, ainsi que des phénomènes perturbateurs. Il suggère de nouveaux indicateurs indirects (Pente de la baseline et le coefficient du second ordre de la courbe de phase) pour l’adaptation aux phénomènes perturbateurs. / Thanks to the combination of medical and technological advances, it becomes feasible and relevant to operate remotely monitoring of patients, introducing e-health paradigm. It includes services or systems that are at the convergence of medicine, health and information, including e-monitoring and telemedicine. Among existing medical devices, the "healthcare" type must ensure optimum operational reliability whether it is for a medical analysis or a treatment’s application. The level of safety and performance are critical for the patient’s health. Since these devices apply to a growing number of patients, all different from each other and living under different conditions, the device must therefore be able to adapt it self to the patient’s needs, activity, his environment but also to the patient himself. A general reusable strategy of self-adaptation, aiming to define methodically and optimally the steps and processes of self-adaptation, have been defines. Diseases recognized as being of the current centuries diseases require regular medical follow. Among them is glaucoma, an ocular neuropathy that deteriorates the optic nerve leading to a progressive and irreversible loss of the vision field. To diagnose and monitor it, a measurement of the intraocular pressure (IOP) is mandatory. Current techniques are constraining and require the manipulation of punctual measurement tools by a doctor. New biometric devices have emerged allowing continuous and portable measurements to allow a better diagnostic and a simplified monitoring. Our case study will therefore rely on the use of a biometric IOP measurement device which will be used as a validation platform for the proposed solutions knowing that it must be self-adapted to the different anatomies, physiologioes, biomechanics and environments of the patient. All the disturbing or informative mesurement indicators are regrouped in two types, the environmental and the variability in operation. A state of the art is proposed for the first type and an analytical model for the second one. The state of the art shows that In-vivo experimentations are mandatory to complete the knwoledge of major indicator influencing the IOP measurement with a biometric sensor. The analytical model include the magnetic coupling between antennas and the impact of some disturbances. It suggests a new ideal indirect indicator (the slope of the baseline and second coefficient order of the Bode phase plot) for the disturbances adaptation. This model is valid for sensors with different dimensions of antennas.

Este estudo teve por objetivo avaliar a influência da terapia hormonal sobre a pressão ocular de mulheres na pós-menopausa. A amostra foi constituída por 58 olhos de 58 pacientes no período da pós-menopausa, com indicação de terapia hormonal, com idade entre 41 e 65 anos, que não tenham utilizado hormônio nos últimos três meses. As pacientes foram randomizadas (por sorteio) em dois grupos: terapia hormonal contínua (n=32) com comprimidos de estradiol 2 mg e acetato de noretisterona 1 mg, diário durante três meses e grupo controle placebo (n=26). O estudo foi realizado de forma cega pela investigadora principal. As pacientes foram avaliadas quanto à pressão ocular, paquimetria, ceratometria e dosagens dos hormônios sexuais pré e pós-tratamento. A média de idade foi de 54,21 anos ± 4,95, sendo 53,66 anos ± 5,60 no grupo com terapia hormonal e de 54,88 anos ± 4,01 no grupo placebo. Não houve diferença significativa entre os grupos com relação a idade (p= 0,352), índice de massa corporal (p= 0,818), pressão ocular (p=0,697), ceratometria (p > 0,05), paquimetria central (p=0,580), e dosagens dos hormônios sexuais (p>0,05) no pré-tratamento. A pressão ocular média pré-tratamento foi de 14,08 mmHg ± 1,96 no grupo terapia hormonal e de 13,81 mmHg ± 3,28 no grupo placebo. Houve redução significativa da pressão ocular média entre o pré e o pós-tratamento (p=0,0009) no grupo terapia hormonal e redução não significativa no grupo placebo (p=0,108). Na avaliação entre os grupos, não houve diferença estatística nos valores de pressão ocular média no pós-tratamento. Na avaliação entre os grupos, não houve diferença estatisticamente significativa para os valores de paquimetria e ceratometria. O grupo com terapia hormonal apresentou aumento significativo dos níveis hormonais de estradiol e redução significativa nas dosagens hormonais médias de LH e FSH no pós-tratamento com 30, 60 e 90 dias (p=0,000). As dosagens hormonais no grupo placebo não apresentaram variação estatisticamente significante. No grupo terapia hormonal, houve correlação diretamente proporcional entre as pressões oculares médias e níveis hormonais de LH e FSH, e correlação inversamente proporcional com níveis hormonais de estradiol. Em resumo, houve redução da pressão ocular média no grupo terapia hormonal entre o pré e o pós-tratamento e os níveis pressóricos neste grupo se correlacionaram com os níveis hormonais de LH, FSH e estradiol / This trial aimed to assess the influence of hormonal therapy on intraocular pressure in post-menopausal women. The sample had 58 eyes of 58 patients during menopause period, indicated for hormonal therapy, they were between the age of 41 and 65 years, who have not taken hormone in the past three months. Patients were randomized (raffle) in two groups: continuous hormonal therapy (n=32) with 2 mg of estradiol and 1 mg daily of norethisterone acetate for three months and controlled placebo group (n=26). It was a blind study carried out by the main investigator. Patients were assessed regarding ocular pressure, pachymetry, keratometry and sex hormone\'s dosages, pre and post treatment. The average was 54.21 years old ± 4.95, where 53.66 years old ± 5.60 in the group with hormonal therapy and 54.88 years old ± 4.01 in the placebo group. There was no significant difference between the groups regarding age (p= 0.352), body mass index (p= 0.818), ocular pressure (p=0.697), keratometry (p > 0.05), central pachymetry (p=0.580), and sex hormone dosages (p>0.05) during pre treatment. The average pre treatment pressure was 14.08 mmHg ± 1.96 in the hormonal therapy group and 13.81 mmHg ± 3.28 in the placebo group. There was a significant reduction in the average ocular pressure between the pre and post treatment (p=0.0009) in the hormonal therapy group and not a significant reduction in the placebo group, (p=0.108). There was no statistically difference between the groups in the average ocular pressure values after treatment. There were no statistically significant differences between the two groups in the values of pachymetry and keratometry. The hormonal therapy group showed a significant increase in estradiol hormonal levels and a significant reduction in the average hormonal dosages of LH e FSH in the post treatment after 30, 60 and 90 days (p=0.000). The hormonal dosages in the placebo group no showed significant changed. In the hormonal group, there was a direct and proportional relation between the average ocular pressure and LH and FSH hormonal levels and a proportional contrariwise correlation with estradiol hormonal levels. In summary, there was a reduction in the ocular pressure average in the hormonal therapy group between the pre and post treatment and the pressure levels in this group were correlated with the hormonal levels of LH, FSH and estradiol

Este estudo teve por objetivo avaliar a influência da terapia hormonal sobre a pressão ocular de mulheres na pós-menopausa. A amostra foi constituída por 58 olhos de 58 pacientes no período da pós-menopausa, com indicação de terapia hormonal, com idade entre 41 e 65 anos, que não tenham utilizado hormônio nos últimos três meses. As pacientes foram randomizadas (por sorteio) em dois grupos: terapia hormonal contínua (n=32) com comprimidos de estradiol 2 mg e acetato de noretisterona 1 mg, diário durante três meses e grupo controle placebo (n=26). O estudo foi realizado de forma cega pela investigadora principal. As pacientes foram avaliadas quanto à pressão ocular, paquimetria, ceratometria e dosagens dos hormônios sexuais pré e pós-tratamento. A média de idade foi de 54,21 anos ± 4,95, sendo 53,66 anos ± 5,60 no grupo com terapia hormonal e de 54,88 anos ± 4,01 no grupo placebo. Não houve diferença significativa entre os grupos com relação a idade (p= 0,352), índice de massa corporal (p= 0,818), pressão ocular (p=0,697), ceratometria (p > 0,05), paquimetria central (p=0,580), e dosagens dos hormônios sexuais (p>0,05) no pré-tratamento. A pressão ocular média pré-tratamento foi de 14,08 mmHg ± 1,96 no grupo terapia hormonal e de 13,81 mmHg ± 3,28 no grupo placebo. Houve redução significativa da pressão ocular média entre o pré e o pós-tratamento (p=0,0009) no grupo terapia hormonal e redução não significativa no grupo placebo (p=0,108). Na avaliação entre os grupos, não houve diferença estatística nos valores de pressão ocular média no pós-tratamento. Na avaliação entre os grupos, não houve diferença estatisticamente significativa para os valores de paquimetria e ceratometria. O grupo com terapia hormonal apresentou aumento significativo dos níveis hormonais de estradiol e redução significativa nas dosagens hormonais médias de LH e FSH no pós-tratamento com 30, 60 e 90 dias (p=0,000). As dosagens hormonais no grupo placebo não apresentaram variação estatisticamente significante. No grupo terapia hormonal, houve correlação diretamente proporcional entre as pressões oculares médias e níveis hormonais de LH e FSH, e correlação inversamente proporcional com níveis hormonais de estradiol. Em resumo, houve redução da pressão ocular média no grupo terapia hormonal entre o pré e o pós-tratamento e os níveis pressóricos neste grupo se correlacionaram com os níveis hormonais de LH, FSH e estradiol / This trial aimed to assess the influence of hormonal therapy on intraocular pressure in post-menopausal women. The sample had 58 eyes of 58 patients during menopause period, indicated for hormonal therapy, they were between the age of 41 and 65 years, who have not taken hormone in the past three months. Patients were randomized (raffle) in two groups: continuous hormonal therapy (n=32) with 2 mg of estradiol and 1 mg daily of norethisterone acetate for three months and controlled placebo group (n=26). It was a blind study carried out by the main investigator. Patients were assessed regarding ocular pressure, pachymetry, keratometry and sex hormone\'s dosages, pre and post treatment. The average was 54.21 years old ± 4.95, where 53.66 years old ± 5.60 in the group with hormonal therapy and 54.88 years old ± 4.01 in the placebo group. There was no significant difference between the groups regarding age (p= 0.352), body mass index (p= 0.818), ocular pressure (p=0.697), keratometry (p > 0.05), central pachymetry (p=0.580), and sex hormone dosages (p>0.05) during pre treatment. The average pre treatment pressure was 14.08 mmHg ± 1.96 in the hormonal therapy group and 13.81 mmHg ± 3.28 in the placebo group. There was a significant reduction in the average ocular pressure between the pre and post treatment (p=0.0009) in the hormonal therapy group and not a significant reduction in the placebo group, (p=0.108). There was no statistically difference between the groups in the average ocular pressure values after treatment. There were no statistically significant differences between the two groups in the values of pachymetry and keratometry. The hormonal therapy group showed a significant increase in estradiol hormonal levels and a significant reduction in the average hormonal dosages of LH e FSH in the post treatment after 30, 60 and 90 days (p=0.000). The hormonal dosages in the placebo group no showed significant changed. In the hormonal group, there was a direct and proportional relation between the average ocular pressure and LH and FSH hormonal levels and a proportional contrariwise correlation with estradiol hormonal levels. In summary, there was a reduction in the ocular pressure average in the hormonal therapy group between the pre and post treatment and the pressure levels in this group were correlated with the hormonal levels of LH, FSH and estradiol