Loading...
12 results
Search Results
Now showing 1 - 10 of 12
- Relationship between intraocular pressure and anterior lamina cribrosa depth : a cross-sectional observational study in a healthy Portuguese populationPublication . Sousa, David Cordeiro; Leal, Ines; Marques-Neves, Carlos; Pinto, Filomena; Pinto, LuisPurpose: To investigate the association between anterior lamina cribrosa depth (ALCD), determined with enhanced depth imaging spectral-domain optical coherence tomography (EDI-OCT), and intraocular pressure (IOP) in a healthy Portuguese population. Methods: In this cross-sectional observational study conducted between January and July 2015, 2 optic nerve head (ONH)-centered EDI-OCT cross-scans were performed and ALCD was defined as the perpendicular distance between the line connecting both edges of Bruch's membrane opening and the anterior border of the lamina cribrosa at the maximum depth point. A multivariate regression model was performed to assess the association of IOP and ALCD. Results: The studied population included 59 subjects (35 women) with a mean age of 61.7 ± 15.1 years. Mean vertical and horizontal maximum ALCD was 444.5 ± 92.2 μm and 427.6 ± 82.7 μm, respectively. When controlling for age and spherical equivalent, maximum vertical and horizontal ALCD were positively correlated with intraocular pressure (R2>0.20) by 8.58 μm (95% confidence interval [CI] 2.80-14.36 μm; p<0.01) and 8.25 μm (95% CI 2.71-13.78 μm; p<0.01) per mm Hg of IOP, respectively. Conclusions: Our sample of healthy subjects presented a statistically significant positive correlation between IOP and ALCD when controlling for possible confounding factors. These results may trigger further studies to better elucidate the role of IOP in the morphologic and functional dynamics of the ONH.
- A non-infectious uveitis multidisciplinary clinic in a tertiary referral center: clinical impact and added valuePublication . Leal, Ines; Romão, Vasco C.; Sousa Mano, Sofia; Khmelinskii, Nikita; Campanilho-Marques, Raquel; Ponte, Cristina; Macieira, Carla; Oliveira Ramos, Filipa; Vieira De Sousa, Elsa Cristina; Rosa, Carlos Miranda; Rodrigues, Walter; Pinto, Luis; Marques-Neves, Carlos; Fonseca, João EuricoNon-infectious uveitis (NIU) is a group of sight-threatening diseases that generates significant burden for the healthcare systems due to its adverse outcomes, irreversible structural complications in the eye with loss of visual function, limited clinical expertise and low-grade evidence for best practice. The usefulness of multidisciplinary care, specifically close collaboration between Rheumatologists and Ophthalmologists in NIU, has been emphasized in the literature. In this paper, the assessment tools and protocols used in our clinic are depicted and an overview of our activity with a brief description of the patients included in our registry, between 2018 and 2020 is provided. The cohort of 290 patients assessed in our NIU clinic, their demographics, sources of referral, details about immunosuppression treatment, and internal and external collaborations is described. This experience-based manuscript aims to describe the general functioning of our multidisciplinary NIU clinic, highlighting the benefits and drawbacks of multidisciplinary team management in patients with NIU, ultimately initiating a dialogue on what an NIU clinic should be and providing information for newly NIU clinics start-up. In conclusion, establishing a standardized and multidisciplinary clinic in NIU allows to systematically observe and follow-up this infrequent disease at a tertiary hospital level, thus improving quality of care delivery and research avenues.
- Corneal properties and glaucoma : a review of the literature and meta-analysisPublication . Gaspar, Ricardo; Pinto, Luis; Sousa, David CordeiroPurpose: Studies have suggested that corneal biomechanical properties influence intraocular pressure (IOP) measurements, namely central corneal thickness (CCT) and corneal hysteresis (CH). The present study aimed to investigate the associations of CH and CCT with glaucoma development. Methods: We performed a review of the literature and meta-analysis of observational studies (2006-2016) that included both adult glaucoma patients and controls and reported CCT and CH as outcomes. Nineteen studies were conside red eligible, and the mean difference (MD) between groups (patient and control) for both variables was used for statistical analyses. Results: A total of 1,213 glaucoma and 1,055 healthy eyes were studied. Quan titative analysis suggested that CH was significantly lower in the glaucoma group than in the control group (MD=-1.54 mmHg, 95% CI [-1.68, -1.41], P<0.0001). Additionally, CCT was significantly lower in the glaucoma group than in the control group (MD=-8.49 µm, 95% CI [-11.36, -5.62], P<0.001). Conclusion: Corneal properties appear to differ between glaucoma patients and healthy controls. Our results emphasize the importance of corneal biomechanical properties in IOP interpretation and should support further studies on the influence of CH and CCT in glaucoma screening and diagnosis.
- A protocol to evaluate retinal vascular response using optical coherence tomography angiographyPublication . Sousa, David Cordeiro; Leal, Ines; Moreira, Susana; Vale, Sónia do; Silva-Herdade, Ana S.; Aguiar, Patrício; Dionísio, Patrícia; Pinto, Luis; Castanho, Miguel A. R. B.; Marques-Neves, CarlosIntroduction: Optical coherence tomography angiography (OCT-A) is a novel diagnostic tool with increasing applications in ophthalmology clinics that provides non-invasive high-resolution imaging of the retinal microvasculature. Our aim is to report in detail an experimental protocol for analyzing both vasodilatory and vasoconstriction retinal vascular responses with the available OCT-A technology. Methods: A commercial OCT-A device was used (AngioVue®, Optovue, CA, United States), and all examinations were performed by an experienced technician using the standard protocol for macular examination. Two standardized tests were applied: (i) the hypoxia challenge test (HCT) and (ii) the handgrip test, in order to induce a vasodilatory and vasoconstriction response, respectively. OCT-A was performed at baseline conditions and during the stress test. Macular parafoveal vessel density of the superficial and deep plexuses was assessed from the en face angiograms. Statistical analysis was performed using STATA v14.1 and p < 0.05 was considered for statistical significance. Results: Twenty-four eyes of 24 healthy subjects (10 male) were studied. Mean age was 31.8 ± 8.2 years (range, 18–57 years). Mean parafoveal vessel density in the superficial plexus increased from 54.7 ± 2.6 in baseline conditions to 56.0 ± 2.0 in hypoxia (p < 0.01). Mean parafoveal vessel density in the deep plexuses also increased, from 60.4 ± 2.2 at baseline to 61.5 ± 2.1 during hypoxia (p < 0.01). The OCT-A during the handgrip test revealed a decrease in vessel density in both superficial (55.5 ± 2.6 to 53.7 ± 2.9, p < 0.001) and deep (60.2 ± 1.8 to 56.7 ± 2.8, p < 0.001) parafoveal plexuses. Discussion: In this work, we detail a simple, non-invasive, safe, and non-costly protocol to assess a central nervous system vascular response (i.e., the retinal circulation) using OCT-A technology. A vasodilatory response and a vasoconstriction response were observed in two physiologic conditions—mild hypoxia and isometric exercise, respectively. This protocol constitutes a new way of studying retinal vascular changes that may be applied in health and disease of multiple medical fields.
- The role of optic nerve sheath ultrasonography in increased intracranial pressure: a systematic review and meta analysisPublication . Berhanu, David; Cardoso Ferreira, Joana; Pinto, Luis; de Sousa, Diana Aguiar; Lucas Neto, Lia; Tavares Ferreira, JoanaObjectives: To review the optimal diagnostic cut-off of ultrasonographic optic nerve sheath diameter (ONSD) in the diagnosis of increased intracranial pressure (IICP). Methods: A systematic search was conducted of available studies assessing the use of ONSD ultrasonography in patients with suspected IICP. Meta-analysis of diagnostic accuracy of ultrasonographic ONSD was performed using a bivariate model of random effects to summarize pooled sensitivity and specificity. A summary receiver operating characteristics (SROC) curve was plotted. Accuracy measures associated with ONSD cut-off and predefined covariates were investigated with meta-regression. Results: We included 38 studies, comprising a total of 2824 patients. A total of 21 studies used invasive techniques as a reference standard estimation of IICP and meta-analysis revealed a pooled sensitivity of 0.90 (95% CI 0.85-0.93) and specificity of 0.87 (95% CI 0.80-0.91). Optimal ONSD cut-off values ranged between 4.1 mm and 7.2 mm. Meta-regression analysis showed that ONSD cut-off values of 5.6 to 6.3 mm were associated with higher pooled specificity compared to cut-off values of 4.9 to 5.5 mm (0.93, 95% CI 0.85-0.97 vs. 0.78, 95% CI 0.65-0.87; p = 0.036). Conclusions: Ultrasonography of ONSD shows a high diagnostic accuracy for IICP, with high pooled sensitivity and specificity. Additionally, larger cut-off values seem to significantly increase specificity without compromising sensitivity, which support their use as optimal ONSD cut-off. The overall high sensitivity of ultrasonographic ONSD suggests its usefulness as a screening tool for IIC, which may provide an estimate of when invasive methods are warranted. Clinical relevance: ONSD ultrasonography is a fast and cost-effective method with a high diagnostic accuracy to detect IICP. The optimum ONSD cut-off hasn't been established before, but we suggest the 5.6 to 6.3 mm range as the best for the diagnosis of IICP.
- Glaucoma triage system: results of implementing a virtual clinicPublication . Matos, Diogo Bernardo; Correia Barão, Rafael; José, Patrícia; Lima-Cabrita, Afonso; Barata, Andre; Pinto, LuisPurpose: This study describes the virtual clinic triage system implementation process at Hospital Santa Maria-Centro Hospitalar Universitário Lisboa Norte (HSM-CHULN) and analyzes its results regarding healthcare outcomes for the patients and the system. Methods: A retrospective analysis was performed, comparing two cohorts (pre-virtual cohort; virtual triage cohort). Outcomes related to waiting time, number of hospital visits, decisions at first contact, and ancillary exam-based decisions were reported. Results: Two hundred and ninety-two charts were reviewed (pre-virtual cohort: 132; virtual cohort: 160). Mean waiting time between referral and the first medical contact with the glaucoma department decreased on average by 71.3 days (human contact: 286.6 days; virtual triage contact: 215.3 days). Triage system significantly decreased waiting time for glaucoma patients, with an average decrease of 326.8 days between referral and treatment decision. Triage staging allowed to label 107 (66.9; 95% confidence intervals (CI): 59.6%, 74.2%) as non-urgent; 30 (18.8%; 95% CI: 12.7%, 24.9%) as urgent, and 23 (14.3%; 95% CI: 8.9%, 19.7%) as immediate contact, with the scheduling of future appointments reflecting National Institute for Health and Care Excellence (NICE) guidelines in every patient. Moreover, the number of visits to perform the same exams and obtain the same clinical decisions was reduced by 63.6%. Conclusion: Our virtual screening strategy significantly decreased waiting time, number of hospital visits, and increased chances of data-assisted clinical decision. While results can be further improved, this system can add value in an overburdened healthcare system, where triage systems with remote decision-making may be valuable tools in optimizing glaucoma care, even without allocation of extra resources.
- Retinal vascular reactivity in type 1 diabetes patients without retinopathy using optical coherence tomography angiographyPublication . Sousa, David Cordeiro; Leal, Ines; Moreira, Susana; Vale, Sónia do; Silva-Herdade, Ana S.; Aguiar, Patrício; Dionísio, Patrícia; Pinto, Luis; Castanho, Miguel A. R. B.; Marques-Neves, CarlosPurpose: We hypothesize that patients with type 1 diabetes (T1D) may have abnormal retinal vascular responses before diabetic retinopathy (DR) is clinically evident. Optical coherence tomography angiography (OCTA) was used to dynamically assess the retinal microvasculature of diabetic patients with no clinically visible retinopathy. Methods: Controlled nonrandomized interventional study. The studied population included 48 eyes of 24 T1D patients and 24 demographically similar healthy volunteers. A commercial OCTA device (AngioVue) was used, and two tests were applied: (1) the hypoxia challenge test (HCT) and (2) the handgrip test to induce a vasodilatory or vasoconstrictive response, respectively. The HCT is a standardized test that creates a mild hypoxic environment equivalent to a flight cabin. The handgrip test (i.e., isometric exercise) induces a sympathetic autonomic response. Changes in the parafoveal superficial and deep capillary plexuses in both tests were compared in each group. Systemic cardiovascular responses were also comparatively evaluated. Results: In the control cohort, the vessel density of the median parafoveal superficial and deep plexuses increased during hypoxia (F1,23 = 15.69, P < 0.001 and F1,23 = 16.26, P < 0.001, respectively). In the T1D group, this physiological response was not observed in either the superficial or the deep retinal plexuses. Isometric exercise elicited a significant decrease in vessel density in both superficial and deep plexuses in the control group (F1,23 = 27.37, P < 0.0001 and F1,23 = 27.90, P < 0.0001, respectively). In the T1D group, this response was noted only in the deep plexus (F1,23 = 11.04, P < 0.01). Conclusions: Our work suggests there is an early impairment of the physiological retinal vascular response in patients with T1D without clinical diabetic retinopathy.
- XEN‐augmented Baerveldt surgical success rate and comparison with the Ahmed ValvePublication . Jorge Teixeira, Filipa; Sousa, David Cordeiro; Machado, Nuno Martins; Caiado, Filipa; Correia Barão, Rafael; Sens, Paula; Pinto, LuisPurpose: The Baerveldt-XEN technique is intended to reduce the risk of early hypotony after Baerveldt implant, while keeping a good long-term intra-ocular pressure (IOP) control. The aim of this study is to discuss the surgical success rate of the Baerveldt-XEN and compare it with the commercially available flow-restrictor device (Ahmed glaucoma valve - AGV). Methods: Single-centre, cohort study. Consecutive glaucoma patients with uncontrolled IOP > 21 mmHg on maximum tolerated medical therapy, and who had an aqueous shunt as the planned surgical procedure. Patients underwent implantation of Baerveldt-XEN. An age-, gender- and glaucoma aetiology-matched database of AGV patients was used for comparison. Complete surgical success was defined as a final IOP between 6 and 21 mmHg, and 20% reduction from baseline with no need for IOP-lowering medication. Qualified success was the same criteria but resorting to medications. Results: Twenty-four eyes from 24 subjects with glaucoma were included in this study, 12 patients underwent Baerveldt-XEN implantation and 12 AGV. Twelve months after the Baerveldt-XEN implant, the IOP reduced from 33 ± 9 mmHg to 14 ± 3 mmHg (p < 0.001). The qualified and complete success rate was 50% and 25%, respectively. With the AGV, the IOP reduced from 29 ± 7 mmHg to 16 ± 7 mmHg (p = 0.001). The matched AGV group compared to the Baerveldt-XEN, presented a higher complete success rate (58.3%) and a qualified success rate of 33.3% (p = 0.72). No sight-threatening complications were recorded in both groups. Conclusions: The Baerveldt-XEN disclosed a low complete success rate at 1 year of follow-up, although with no major safety concerns. While studies with a longer follow-up are needed to demonstrate the potential advantages and disadvantages of the Baerveldt-XEN, this technique may be less likely to achieve drop-free efficacy when compared to other flow-restrictor strategies.
- Venous circulation in glaucomaPublication . Pinto, Luis; Neves, Carlos Marques, 1960-; Stalmans, Ingeborg, 1971-A pulsatilidade venosa espontânea (SVP) da veia central da retina (CRV) é um sinal oftalmológico conhecido há mais de um século. Apesar da sua utilidade ser já reconhecida em várias doenças do foro neurológico e oftalmológico, trabalhos recentes têm sugerido que poderá também ter relevância em doentes com glaucoma. Os mecanismos envolvidos na formação deste sinal não são consensuais, existindo várias teorias sobre a sua génese. Esta ausência de consensos tem levado a várias hipóteses sobre o porquê da baixa frequência desta SVP em doentes com glaucoma (glaucoma primário de ângulo aberto – POAG) quando comparados com a população em geral. O nosso estudo prospectivo, caso-controlo apresenta a maior série publicada sobre o tema, incluindo o uso de tecnologias e variáveis ainda não estudadas neste contexto. Mais ainda, pela primeira vez foram estudados doentes em que a componente vascular terá um componente significativo na patogénese e evolução da doença (doentes com glaucoma normotensional – NTG). O nosso trabalho confirmou a diminuição significativa na identificação da SVP quer em doentes POAG (50%), quer em doentes NTG (51%) quando comparados com a população controlo (82%). Não se verificaram contudo diferenças na prevalência deste fenómeno entre os dois grupos com glaucoma. O facto mais interessante do nosso trabalho será talvez o facto de nos doentes com NTG, a ausência de SVP associar-se a danos funcionais significativamente mais avançados do que a verificada nos doentes NTG com SVP. A ausência deste sinal ao exame objectivo, ao indentificar doentes com patologia mais avançada, poderá ser particularmente útil na avaliação clínica dos doentes com esta forma da doença. Os nossos resultados sugerem ainda que esta diferença poderá estar associada a alterações da actividade metabólica das células ganglionares da retina, uma vez que apesar das diferenças funcionais, não registámos diferenças estruturais na camada de fibras nervosas retinianas. A verificação do fenómeno SVP não se correlacionou com nenhuma variável morfológica das topografias da cabeça do nervo óptico, quer em indivíduos saudáveis quer em doentes com glaucoma. Como um aumento da escavação do disco óptico influencia necessariamente o trajecto e grau de curvatura dos vasos papilares (e consequentemente os padrões de fluxo intraluminal), os nossos resultados parecem sugerir que alterações de fluxo assim induzidas serão insuficientes para modificar o status SVP. Para os mesmos intervalos de IOP, os doentes com glaucoma apresentam um registo menor de doentes com SVP. No entanto, nos doentes com POAG, um aumento deste factor mecânico está associado a uma maior prevalência do fenómeno, enquando que nos doentes com NTG essa prevalência não é alterada, o que parece sugerir que a ausência deste fenómeno nesta população não se deverá a factores mecânicos intraoculares. As pressões extraoculares, avaliadas indirectamente pelo diâmetro da bainha do nervo óptico (ONSD), parecem ter um impacto diferente nos vários grupos experimentais. Em indivíduos controlo, maiores ONSD estiveram associadas a uma menor frequência de detecção do fenómeno. Nos grupos com glaucoma, apesar das menores frequências de registo, essa prevalência não é alterada ao longo dos valores de ONSD. Estes doentes NTG sem SVP têm contudo uma associação importante com o ONSD, na medida em que se parece correlacionar positivamente com a IOP. Os nossos resultados parecem assim sugerir que neste tipo de glaucoma, a drenagem do humor aquoso pelo sistema venoso poderá ser particularmente sensível a alterações das pressões orbitárias retro-oculares. As duas populações de glaucoma apresentaram ainda correlações distintas com esta variável (ONSD), em que apenas doentes com POAG sem SVP apresentaram uma correlação entre o ONSD e as velocidades de fluxo dos vasos centrais da retina. Os nossos resultados sugerem assim que a veia central da retina (CRV) dos doentes com POAG poderá ser mais susceptível a uma compressão extrínseca, particularmente se esta for aplicada a jusante do ponto major de obstrução do vaso (a passagem pela lamina crivosa). Os doentes com NTG, em que possivelmente se regista uma alteração do microambiente no que diz respeito aos agentes vasoactivos, poderão apresentar uma alteração estrutural dos vasos – provavelmente hipertrofia da parede vascular – e consequentemente menos maleáveis a pressões externas. Estes estudos com Eco-Doppler dos vasos centrais da retina identificaram que os doentes NTG sem SVP apresentaram menores velocidades arteriais e venosas, enquanto que os doentes com POAG registaram apenas alterações venosas. Uma vez que a associação a um estadio de doença glaucomatosa mais avançada apenas se observou nos doentes em que co-existiam alterações arteriais e venosas, os nossos resultados parecem sugerir que ainda que a ausência de SVP possa estar associada a alterações venosas, apenas existindo um envolvimento arterial se verifique a associação a com maior dano glaucomatoso A análise efectuada das frentes da onda Doppler da artéria oftálmica (OA) identificou diferenças entre os grupos, reforçando a hipótese de existirem variações estruturais ao nível da parede dos vasos entre os doentes NTG com e sem SVP. Os nossos dados não sustentam que o status SVP identifique limiares de resistência vasculares que têm sido sugerido como limiares de autoregulação vascular nos doentes com glaucoma. Na medida em que os limiares utilizados parecem reflectir uma incapacidade de adaptação por parte dos capilares a condições de hipoperfusão, o status SVP poderá reflectir, não uma disfunção capilar, mas uma disfunção arterial e venosa ainda não esclarecida. Do ponto de vista hemodinâmico, a única diferença identificada nos indivíduos controlo foi um aumento das velocidades mínimas da veia central da retina (Vmin) nos indivíduos sem SVP. Este padrão tem sido descrito em situações de estase venosa no restante organismo. Estudos adicionais serão ainda necessários para validar esta teoria. Outro dado interessante do nosso trabalho é a associação nos doentes POAG entre a ausência de SVP e maiores valores de pressão arterial diastólica. Dado este ser um factor de risco conhecido no desenvolvimento da oclusão da CRV, a ausência deste sinal em doentes POAG poderá identificar os doentes com glaucoma em maior risco de desenvolverem esta patologias vascular. Serão contudo necessários estudos com maior follow-up para confirmar esta suspeita. As limitações do nosso estudo estão condicionadas por falhas metodológicas e insuficiências tecnológicas. O nosso estudo de caso-controlo carece de informação sobre a medicação sistémica e baseia-se na descrição pelo próprio dos seus antecedentes médicos sistémicos e oftalmológicos. Adicionalmente, as limitações referentes a qualquer estudo doppler retrobulbar (em que não é possível extrair dados referentes ao diâmetro dos vasos analisados) bem como a incapacidade de clinicamente avaliar directamente as pressões retrobulbares, impôem limitações sobre a interpretação de fluxos e pressões arteriais e venosas. Por fim, e dado a elevada prevalência de SVP em indivíduos saudáveis, ainda que com a maior série registada na literatura, o nosso reduzido número de individuos controlo sem SVP poderá levantar reservas sobre a significância estatística a atribuir aos nossos resultados nesta população. Concluindo, e ainda que seja necessário ainda complementar o nosso estudo com outros trabalhos incidindo nesta vertente de circulação venosa no glaucoma, o nosso trabalho parece demonstrar que as pulsatibilidades venosas poderão ser particularmente importantes nos doentes com NTG, onde a ausência das mesmas poderá sinalizar não só uma disfunção vascular (arterial e venosa) como também uma forma mais avançada da doença.
- Optical coherence tomography angiography study of the retinal vascular plexuses in type 1 diabetes without retinopathyPublication . Sousa, David Cordeiro; Leal, Ines; Moreira, Susana; Vale, Sónia do; Silva-Herdade, Ana S.; Dionísio, Patrícia; Castanho, Miguel A. R. B.; Pinto, Luis; Marques-Neves, CarlosAim Previous data suggest the existence of retinal vascular changes and impaired autoregulation in the very early stages of diabetic retinopathy (DR). We compared the retinal plexuses between patients with type 1 diabetes (T1D) without DR and a demographically similar healthy cohort, using optical coherence tomography angiography (OCT-A). Methods Patients with T1D and no signs of DR were prospectively recruited from an outpatient clinic. Using OCT-A (AngioVue®), the parafoveal superficial (SCP) and deep (DPC) capillary plexus as well as the foveal avascular zone (FAZ) and perimeter were gathered. Mean comparison tests and linear regression analysis were used as statistical tests (STATA v14). Results Studied population included 48 subjects (24 T1D). The analysis of SCP revealed an attenuation of the capillary network compared with the control group in both parafoveal (51.8 ± 4.5 vs. 55.8 ± 3.2, p < 0.001) and perifoveal (51.9 ± 3.3 vs. 53.9 ± 1.9, p = 0.01) regions. A similar finding was observed in the DCP for both parafoveal (56.4 ± 4.3 vs. 60.4 ± 2.2, p < 0.001) and perifoveal (54.7 ± 3.9 vs. 60.8 ± 3.4, p = 0.001) sectors. Also, a longer time since T1D diagnosis was associated with a larger FAZ area (p = 0.055) and perimeter (p = 0.03). Conclusions Significant differences in the retinal microvasculature were observed between healthy subjects and T1D patients using OCT-A, even before clinically detectable disease on fundus biomicroscopy.