Background: As a multifactorial disease glaucoma may be associated with pressure-dependent and -independent factors. Ocular hypertension (OHT) may develop into primary open angle glaucoma (POAG) for many patients. We compared groups with OHT and POAG for pressure-dependent and -independent risk factors. A high prevalence of any factor(s) could indicate a contribution to progression from OHT to POAG. Method: A sample of patients with POAG (n 438) and with OHT (n 301) were selected from those attending a tertiary referral private glaucoma practice, and data were collected regarding age and intraocular pressure at the time of diagnosis, gender, family history of glaucoma, systemic hypertension, diabetes, Raynaud's phenomenon, migraine and myopia. Results: After multivariate analysis, older age at time of diagnosis (P<0.001), myopia (odds ratio (O.R) 1.5, 95percent confidence interval (C.I)1.0-2.2; P 0.05), a family history of glaucoma (O.R 1.6, 95 percent C.I 1.1-2.3; P 0.01) and a high intraocular pressure (P 0.002) were associated with POAG. No other significant differences were found between the two groups. Conclusion: Patients who have OHT may be at higher risk of developing POAG if they also have myopia, a family history of glaucoma or are of older age.

Background: As a multifactorial disease glaucoma may be associated with pressure-dependent and -independent factors. Ocular hypertension (OHT) may develop into primary open angle glaucoma (POAG) for many patients. We compared groups with OHT and POAG for pressure-dependent and -independent risk factors. A high prevalence of any factor(s) could indicate a contribution to progression from OHT to POAG. Method: A sample of patients with POAG (n 438) and with OHT (n 301) were selected from those attending a tertiary referral private glaucoma practice, and data were collected regarding age and intraocular pressure at the time of diagnosis, gender, family history of glaucoma, systemic hypertension, diabetes, Raynaud's phenomenon, migraine and myopia. Results: After multivariate analysis, older age at time of diagnosis (P<0.001), myopia (odds ratio (O.R) 1.5, 95percent confidence interval (C.I)1.0-2.2; P 0.05), a family history of glaucoma (O.R 1.6, 95 percent C.I 1.1-2.3; P 0.01) and a high intraocular pressure (P 0.002) were associated with POAG. No other significant differences were found between the two groups. Conclusion: Patients who have OHT may be at higher risk of developing POAG if they also have myopia, a family history of glaucoma or are of older age.

Made available in DSpace on 2014-06-11T19:22:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-26Bitstream added on 2014-06-13T20:28:22Z : No. of bitstreams: 1 addad_mt_me_botfm.pdf: 674800 bytes, checksum: 101691ff84e6e0c57b104e36c6ab28a2 (MD5) / Comparar pico e flutuação de pressão intra-ocular (PIO) entre curva tensional diária e teste de sobrecarga hídrica, detectar os horários de pico de PIO, comparar os valores da PIO nos horários das 6 horas da manhã deitado e sentado. 30 olhos direitos de 30 pacientes portadores de glaucoma primário de ângulo aberto (GPAA) ou hipertensão ocular (HO), foram submetidos à curva tensional diária de 24 horas (CTD) e teste de sobrecarga hídrica (TSH). Foram avaliados: pico (maior valor da PIO durante a CTD e TSH ) e flutuação (maior valor da PIO menos o menor valor da PIO durante o CTD e TSH). A PIO foi avaliada, com tonômetro de aplanação de Goldmann às 9, 12, 15, 18, 21, 24 e 6h, com paciente sentado. As medidas das 3 e 6 horas da manhã foram realizadas no leito com tonômetro de Perkins com o paciente em posição supina (deitado). Imediatamente após a medida no leito deitado, foi realizada outra medida das 6 horas com o paciente sentado. Para realização do TSH, os pacientes ingeriam 1 litro de água, em até 5 minutos. A PIO foi avaliada imediatamente antes e durante uma hora após a ingestão de água, com intervalos de 15 minutos entre as medidas. O TSH foi realizado logo após a avaliação da PIO às 6h da manhã. Foram calculados valores de média (M) e desvio padrão (s) para pico e flutuação e mediana (Md) e quartís (Q2) para flutuação em porcentagem (%). Para comparação de médias foi realizado o teste t de Student para amostras dependentes. Foi utilizado teste de Wilcoxon para comparação de medianas entre amostras dependentes. Para todas as análises foi considerado nível de significância p <0,05. A média dos valores de pico de PIO foi significativamente maior na CTD (20,39 ±1,03 mmHg) do que no TSH (17,37 ± 0,78 mmHg), p < 0,001. A média dos valores de flutuação também foi maior na CTD (10,17 ± 0,90) do que no TSH (5,0 ± 0,45), p < 0,001... / Comparing peak and fluctuation of intraocular pressure (IOP) between diurnal tension curve and water drinking test, detect the peak of IOP, compare the IOP at 6AM in supine and sitting position. 30 right eyes of 30 glaucoma patients with open angle glaucoma (OAG) or ocular hypertension (HO) were submitted to water drinking test (WDT) and diurnal tension curve (DTC). Were evaluated: peak (higher value of IOP observed during WDT and DTC), fluctuation (difference between highest and lowest value of IOP WDT and DTC). IOP was measured with applanation Goldmann tonometry at 9AM, 12AM, 3PM, 6PM, 9PM, 12PM and 6 AM, with the patient sitting. Measurements of 3AM and 6AM were made in bed with Perkins tonometer with the patient in the supine position. Immediately after the measure in supine position, another measure was done at 6AM, with the patient seated. The WDT involved ingestion of 1 liter of tap water in 5 minutes. IOP was measured immediately before and one hour after ingestion of water at intervals of 15 minutes between measurements. The WDT was performed immediately after the measure IOP at 6 AM. For comparison of means was performed Student's t test for dependent samples. Wilcoxon test was used to compare medians between dependent samples. The level of significance was considered p <0.05. The mean peak IOP was significantly higher in the DTC (20.39 ± 1.03 mmHg) than in TSH (17.37 ± 0.78 mmHg), p <0.001. The mean fluctuation was also higher in the DTC (10.17 ± 0.90) than in WDT (5.0 ± 0.45), p <0.001. The value of the fluctuation in the DTC percentile was 90.46% (70.00, 129.90) while the WDT was 35.42% (27.92, 56.95), p <0.001. The IOP of 6 AM showed a statistically significant when performed with the patient in supine position (17,47 mmHg) and sitting (14,30 mmHg) and was significantly higher with the patient in supine position. (p < 0,001). The WDT peak and underestimates of ... (Complete abstract click electronic access below)

Resumo: Comparar pico e flutuação de pressão intra-ocular (PIO) entre curva tensional diária e teste de sobrecarga hídrica, detectar os horários de pico de PIO, comparar os valores da PIO nos horários das 6 horas da manhã deitado e sentado. 30 olhos direitos de 30 pacientes portadores de glaucoma primário de ângulo aberto (GPAA) ou hipertensão ocular (HO), foram submetidos à curva tensional diária de 24 horas (CTD) e teste de sobrecarga hídrica (TSH). Foram avaliados: pico (maior valor da PIO durante a CTD e TSH ) e flutuação (maior valor da PIO menos o menor valor da PIO durante o CTD e TSH). A PIO foi avaliada, com tonômetro de aplanação de Goldmann às 9, 12, 15, 18, 21, 24 e 6h, com paciente sentado. As medidas das 3 e 6 horas da manhã foram realizadas no leito com tonômetro de Perkins com o paciente em posição supina (deitado). Imediatamente após a medida no leito deitado, foi realizada outra medida das 6 horas com o paciente sentado. Para realização do TSH, os pacientes ingeriam 1 litro de água, em até 5 minutos. A PIO foi avaliada imediatamente antes e durante uma hora após a ingestão de água, com intervalos de 15 minutos entre as medidas. O TSH foi realizado logo após a avaliação da PIO às 6h da manhã. Foram calculados valores de média (M) e desvio padrão (s) para pico e flutuação e mediana (Md) e quartís (Q2) para flutuação em porcentagem (%). Para comparação de médias foi realizado o teste t de Student para amostras dependentes. Foi utilizado teste de Wilcoxon para comparação de medianas entre amostras dependentes. Para todas as análises foi considerado nível de significância p <0,05. A média dos valores de pico de PIO foi significativamente maior na CTD (20,39 ±1,03 mmHg) do que no TSH (17,37 ± 0,78 mmHg), p < 0,001. A média dos valores de flutuação também foi maior na CTD (10,17 ± 0,90) do que no TSH (5,0 ± 0,45), p < 0,001... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Comparing peak and fluctuation of intraocular pressure (IOP) between diurnal tension curve and water drinking test, detect the peak of IOP, compare the IOP at 6AM in supine and sitting position. 30 right eyes of 30 glaucoma patients with open angle glaucoma (OAG) or ocular hypertension (HO) were submitted to water drinking test (WDT) and diurnal tension curve (DTC). Were evaluated: peak (higher value of IOP observed during WDT and DTC), fluctuation (difference between highest and lowest value of IOP WDT and DTC). IOP was measured with applanation Goldmann tonometry at 9AM, 12AM, 3PM, 6PM, 9PM, 12PM and 6 AM, with the patient sitting. Measurements of 3AM and 6AM were made in bed with Perkins tonometer with the patient in the supine position. Immediately after the measure in supine position, another measure was done at 6AM, with the patient seated. The WDT involved ingestion of 1 liter of tap water in 5 minutes. IOP was measured immediately before and one hour after ingestion of water at intervals of 15 minutes between measurements. The WDT was performed immediately after the measure IOP at 6 AM. For comparison of means was performed Student's t test for dependent samples. Wilcoxon test was used to compare medians between dependent samples. The level of significance was considered p <0.05. The mean peak IOP was significantly higher in the DTC (20.39 ± 1.03 mmHg) than in TSH (17.37 ± 0.78 mmHg), p <0.001. The mean fluctuation was also higher in the DTC (10.17 ± 0.90) than in WDT (5.0 ± 0.45), p <0.001. The value of the fluctuation in the DTC percentile was 90.46% (70.00, 129.90) while the WDT was 35.42% (27.92, 56.95), p <0.001. The IOP of 6 AM showed a statistically significant when performed with the patient in supine position (17,47 mmHg) and sitting (14,30 mmHg) and was significantly higher with the patient in supine position. (p < 0,001). The WDT peak and underestimates of ... (Complete abstract click electronic access below) / Orientador: César Tadeu Spadella / Coorientador: Maria Rosa Bet de Moraes Silva / Banca: Maria de Lourdes Veronese Rodrigues / Banca: Roberto Murad Vessani / Mestre

Development of cataracts is a relatively frequent ocular disease of the dog and cataract extraction via phacoemulsification (PE) is commonly performed by veterinary ophthalmologists. Postoperative ocular hypertension (POH) describes the elevation of pressures within the eye during the acute postoperative period and can result in vision loss and poor surgical outcome. Relatively little is known about risk factors or efficacy of prophylactic treatment for POH, and current clinical practice with regard to pressure monitoring and medication administration are highly variable. The literature on POH prophylaxis in humans indicates that improved efficacy may be achieved with a multi-dose approach and that dorzolamide hydrochloride/timolol maleate (DHTM) may be more efficacious than other pressure lowering medications. The canine literature on POH prophylaxis is limited and DHTM has not yet been evaluated despite common use in the clinical setting. Our objectives, therefore, were to investigate risk factors for POH and to test the hypothesis that perioperative topical ophthalmic dorzolamide hydrochloride 2%/timolol maleate 0.5% (DHTM) reduces the prevalence and/or severity of postoperative ocular hypertension (POH) in dogs undergoing cataract extraction by phacoemulsification (PE). We employed a randomized double-masked placebo-controlled study and enrolled 103 dogs (180 eyes) presenting for unilateral or bilateral PE. Select historical, signalment, ophthalmic examination, and surgical data was collected. Dogs were treated with DHTM or Blink Contacts (BC) placebo at 14- and 2-h preoperatively and at conclusion of surgical closure. Intraocular pressures were assessed by rebound tonometry at 2, 4, 6, and 8 hours after surgery and at 8 am the following morning. POH was defined as IOP>25 mmHg and intervention consisted of latanoprost 0.005% if IOP rose to 26 mmHg - 45 mmHg or surgeon treatment of choice if >45 mmHg. Our investigation of risk factors yielded a statistically significant association only with surgeon and surgical time, which were also associated with one another. DHTM significantly reduced the prevalence of POH in comparison with BC (26% versus 49% of eyes, OR=0.36; 34% versus 62% of dogs, OR=0.32). There was also a trend toward reduction of POH severity in DHTM-treated eyes (POH value 37.17±10.47 mmHg with BC, 32.67±6.39 mmHg with DHTM). DHTM-treated eyes that developed POH were significantly more likely to respond favorably (1 hour post-treatment IOP <25 mmHg) to treatment with latanoprost than those in the BC group (76% versus 51%, OR=3.87). We conclude that multi-dose perioperative administration of DHTM may be recommended in dogs undergoing PE to reduce the risk of POH and improve responsiveness of POH to treatment with latanoprost. / Master of Science

Glaucoma is a degenerative disease that contributes greatly to vision loss and blindness worldwide. There are several treatments that focus on alleviating its symptoms, but few address the underlying pathophysiology, the blockage of aqueous outflow, and the onset of neuroretinal damage. Novel drugs under investigation have aimed to address this deficiency. Two of these Rho kinase inhibitors have been approved by national health agencies, and several are in clinical trials. This work investigates the promise of inhibitors of the Rho kinase signaling pathway to treat primary open-angle glaucoma.

Objetivos: Avaliar a capacidade do eletrorretinograma de padrão reverso (PERG) macular e multifocal (mf) de diferenciar pacientes com suspeita de glaucoma (SG) e glaucoma com defeito de campo hemianópico (GH) de controles, comparar a capacidade de discriminação do PERG e tomografia de coerência óptica (TCO) fourrier domain, e avaliar a relação entre as medidas do PERG e TCO. Métodos: Medidas do campo visual (CV) computadorizado, respostas do PERG transiente e modo estacionário e PERGmf foram obtidos dos SG (n=14, 24 olhos), GH (n=5, 7 olhos) e controles (n=19, 22 olhos). Os seguintes parâmetros de TCO foram investigados: camada de fibras nervosas da retina peripapilar (CFNRpp), espessura total da mácula e espessuras das camadas segmentadas da mácula. As medidas foram analizadas utilizando-se modelos lineares de efeito misto. Também foi avaliada a relação entre as medidas e a performance diagnóstica de cada tecnologia. Resultados: Comparado aos controles, a média do tempo de pico de P50 da resposta do PERG transiente estava reduzida nos SG e GH, enquanto que a fase, a amplitude do modo estacionário e respostas do PERGmf estavam anormais apenas no GH. A média das medidas da TCO de espessura macular e da CFNRpp nos SG e GH diferiram significativamente dos controles. Uma significativa relação foi observada entre o PERG e a maior parte dos dos parâmetros do CV central e TCO. A análise por regressão e componentes principais revelou que a TCO de nervo óptico e mácula, assim como o PERG transiente e PERGmf tiveram estatisticamente capacidade similar em discriminar os SG dos controles. Conclusões: Os parâmetros do PERG e da TCO podem estar anormais, com significativa relação entre as medidas, em uma porcentagem alta de olhos com SG com CV normal. Nossos achados sugerem que as duas tecnologias podem ser úteis e complementares na detecção precoce de glaucoma / Purpose: To evaluate the ability of macular and multifocal (mf) pattern electroretinogram (PERG) to differentiate glaucoma suspects (GS) and glaucoma with hemifield loss (GHL) from controls, to compare the discrimination ability of PERG and fourier-domain optical coherence tomography (fdOCT), and to assess the relationship between PERG and fdOCT measurements. Methods: Standard automated perimetry (SAP), steady-state and transient PERG responses and mfPERG measurements were obtained from GS (n=14, 24 eyes), GHL (n=5, 7 eyes) and controls (n=19, 22 eyes). The following fdOCT parameters were investigated: circumpapillary retinal nerve fiber layer (cpRNFL), full-thickness macula, and segmented macular layer thicknesses. Measurements were compared using mixed effects linear models. The relationships between measurements and the diagnostic performance of each technology were also assessed. Results: Compared to controls, average P50 peak time transient PERG responses were reduced in GS and GHL, whereas average phase and amplitude steady-state and mfPERG responses were abnormal only in GHL. The average fdOCT-measured cpRNFL and macular thickness measurements in GS and GHL differed significantly from controls. A significant relationship was found between PERG and most fdOCT or central SAP sensitivity parameters. Principal component regression analysis revealed that optic disc and macular OCT parameters, along with mfPERG and transient PERG parameters had statistically similar ability to discriminate GS from controls. Conclusions: PERG and OCT parameters may be abnormal, with significant correlations between measurements, in a high percentage of GS eyes with normal SAP. Our findings suggest that both technologies may be helpful and complementary in early glaucoma detection

Xu Li. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 204-242). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Glaucoma affects tens of millions of people and is the leading cause of irreversible blindness worldwide. Virtually all current glaucoma therapies target elevated intraocular pressure (IOP); however, the contribution of intracranial pressure (ICP) to glaucoma has recently garnered interest. Strain at the optic nerve head is now known to depend on the translaminar pressure difference (TLPD), which is the difference between IOP and ICP, rather than IOP alone. A better understanding of how IOP and ICP relate to glaucoma development and progression is essential for developing improved therapies and diagnostic tests. Glaucoma is commonly modeled in rats, yet aqueous humor dynamics are not well-documented in healthy nor diseased rat eyes. Moreover, because rats do not develop glaucoma spontaneously, it is essential to develop low-cost, reliable, and relevant models of glaucomatous pathology in the animal. The purpose of this dissertation work is to achieve the following goals: i) quantitatively assess aqueous humor dynamics in healthy, living rat eyes, ii) develop an ideal model of experimental glaucoma in rats, iii) quantitatively characterize aqueous humor dynamics throughout experimental glaucoma in living rats, and iv) investigate the effects of ICP manipulations on aqueous humor dynamics in living rats. Chapter 2 reports physiological parameters of aqueous humor dynamics for the first time in the eyes of living, healthy Brown-Norway rats, and presents a novel perfusion technique for efficiently and accurately estimating these parameters. Chapter 3 introduces the constant-pressure perfusion model of experimental glaucoma: a powerful new model which overcomes several limitations of existing techniques. The constant-pressure perfusion model induces IOP elevations which are prescribable and easily manipulated, does not directly target the trabecular meshwork or its vasculature, and offers continuous records of IOP rather than requiring regular animal handling and tonometry. Chapter 3 characterizes IOP-induced optic neuropathies in rats and demonstrates their resemblance to human glaucoma. Chapter 4 evaluates whether the constant-pressure perfusion model affects ocular physiology, specifically showing that resting IOP and conventional outflow facility are not permanently nor significantly altered in the model. Chapter 5 examines the effect of ICP manipulations on aqueous outflow physiology in living rats, and reports for the first time a graded effect of intracranial hypertension on conventional outflow facility. Evidence for a neural feedback mechanism that may serve to regulate the TLPD is also presented. Chapter 6 summarizes the results of this dissertation, provides recommendations for future work, and gives closing remarks. These collective projects provide insight into IOP regulation in both healthy and diseased rat eyes, advancing our understanding of glaucomatous development and damage in rats. A novel model of experimental glaucoma and several perfusion systems have been developed which are distinctly tailored for use in future glaucoma studies and will allow future investigators to study the disease with enhanced efficiency and exactitude. The results of this dissertation work suggest that detecting and correcting impairments of either IOP or ICP homeostatic capabilities may be of utmost importance for improving clinical outcomes in human glaucoma.

Objetivos: Avaliar a capacidade do eletrorretinograma de padrão reverso (PERG) macular e multifocal (mf) de diferenciar pacientes com suspeita de glaucoma (SG) e glaucoma com defeito de campo hemianópico (GH) de controles, comparar a capacidade de discriminação do PERG e tomografia de coerência óptica (TCO) fourrier domain, e avaliar a relação entre as medidas do PERG e TCO. Métodos: Medidas do campo visual (CV) computadorizado, respostas do PERG transiente e modo estacionário e PERGmf foram obtidos dos SG (n=14, 24 olhos), GH (n=5, 7 olhos) e controles (n=19, 22 olhos). Os seguintes parâmetros de TCO foram investigados: camada de fibras nervosas da retina peripapilar (CFNRpp), espessura total da mácula e espessuras das camadas segmentadas da mácula. As medidas foram analizadas utilizando-se modelos lineares de efeito misto. Também foi avaliada a relação entre as medidas e a performance diagnóstica de cada tecnologia. Resultados: Comparado aos controles, a média do tempo de pico de P50 da resposta do PERG transiente estava reduzida nos SG e GH, enquanto que a fase, a amplitude do modo estacionário e respostas do PERGmf estavam anormais apenas no GH. A média das medidas da TCO de espessura macular e da CFNRpp nos SG e GH diferiram significativamente dos controles. Uma significativa relação foi observada entre o PERG e a maior parte dos dos parâmetros do CV central e TCO. A análise por regressão e componentes principais revelou que a TCO de nervo óptico e mácula, assim como o PERG transiente e PERGmf tiveram estatisticamente capacidade similar em discriminar os SG dos controles. Conclusões: Os parâmetros do PERG e da TCO podem estar anormais, com significativa relação entre as medidas, em uma porcentagem alta de olhos com SG com CV normal. Nossos achados sugerem que as duas tecnologias podem ser úteis e complementares na detecção precoce de glaucoma / Purpose: To evaluate the ability of macular and multifocal (mf) pattern electroretinogram (PERG) to differentiate glaucoma suspects (GS) and glaucoma with hemifield loss (GHL) from controls, to compare the discrimination ability of PERG and fourier-domain optical coherence tomography (fdOCT), and to assess the relationship between PERG and fdOCT measurements. Methods: Standard automated perimetry (SAP), steady-state and transient PERG responses and mfPERG measurements were obtained from GS (n=14, 24 eyes), GHL (n=5, 7 eyes) and controls (n=19, 22 eyes). The following fdOCT parameters were investigated: circumpapillary retinal nerve fiber layer (cpRNFL), full-thickness macula, and segmented macular layer thicknesses. Measurements were compared using mixed effects linear models. The relationships between measurements and the diagnostic performance of each technology were also assessed. Results: Compared to controls, average P50 peak time transient PERG responses were reduced in GS and GHL, whereas average phase and amplitude steady-state and mfPERG responses were abnormal only in GHL. The average fdOCT-measured cpRNFL and macular thickness measurements in GS and GHL differed significantly from controls. A significant relationship was found between PERG and most fdOCT or central SAP sensitivity parameters. Principal component regression analysis revealed that optic disc and macular OCT parameters, along with mfPERG and transient PERG parameters had statistically similar ability to discriminate GS from controls. Conclusions: PERG and OCT parameters may be abnormal, with significant correlations between measurements, in a high percentage of GS eyes with normal SAP. Our findings suggest that both technologies may be helpful and complementary in early glaucoma detection