Browsing by Author "Amado, D"
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- Análise das Camadas Retinianas em Doentes com Lesão Isquémica da Artéria Cerebral Posterior Unilateral: um Estudo de Tomografia de Coerência ÓpticaPublication . Anjos, R; Cardigos, J; Costa, L; Borges, B; Alves, N; Amado, D; Ferreira, J; Cunha, JPIntrodução: A degeneração transneuronal retrógrada (DTR) das células ganglionares tem sido implicada na fisiopatologia de lesões na via visual posterior. Apesar de estarem descritas alterações nas camadas mais externas da retina na patologia do nervo óptico, esta relação com lesões a nível occipital permanece desconhecida. O objectivo do presente estudo é a avaliação das camadas nuclear interna (CNi), plexiforme externa (CPe), nuclear externa (CNe) e dos fotoreceptores (CFo) em doentes com lesões isquémicas da artéria cerebral posterior (ACP) com tomografia de coerência óptica (OCT). Métodos: Estudo transversal observacional, caso-controlo de doentes com hemianópsia homónima decorrente de lesão unilateral isquémica da ACP seguidos no departamento de Neuroftalmologia do Centro Hospitalar de Lisboa Central. Todos os doentes realizaram OCT macular em ambos os olhos. Após segmentação automática das diferentes camadas, foram obtidos os valores de espessuras correspondentes às regiões nasal e temporal entre 1 a 3mm (N1-3 e T1-3) e entre 3 e 6 mm (N3-6 e T3-6) centradas na fóvea. Resultados: Dez doentes com lesão da PCA e um grupo de controlo pareado para o sexo e idade foram incluidos no estudo. Quando comparados ambos os olhos do mesmo doente, verificou-se um aumento da espessura da CNi em N3-6 (p=0,005) do olho contralateral e em T3-6 (p=0,011) no olho ipsilateral, assim como da CPe em N3-6 (p=0,034) do olho contralateral. Não se verificaram diferenças estatisticamente significativas no grupo controle. Conclusão: Além da já documentada associação entre lesões isquémicas occipitais e as alterações nas camadas internas da retina, podemos ainda observar algumas alterações nas camadas retinianas mais externas. É possível que a DTR no sistema visual seja um processo que não se esgota nas células ganglionares, afectando camadas mais externas da retina.
- Diabetes Mellitus as a Risk Factor in Glaucoma's Physiopathology and Surgical Survival Time: A Literature ReviewPublication . Costa, L; Cunha, JP; Amado, D; Abegão Pinto, L; Ferreira, JGlaucoma is a multifactorial condition under serious influence of many risk factors. The role of diabetes mellitus (DM) in glaucoma etiology or progression remains inconclusive. Although, the diabetic patients have different healing mechanism comparing to the general population and it has a possible-negative role on surgical outcomes. This review article attempts to analyze the association of both diseases, glaucoma and DM, before and after the surgery. The epidemiological studies, based mainly in population prevalence analyzes, have shown opposite outcomes in time and even in the most recent articles also the association remains inconclusive. On the contrary, the experimental models based on animal induced chronic hyperglycemia have shown an important association of both diseases, explained by common neurodegenerative mechanisms. Diabetic patients have a different wound healing process in the eye viz-a-viz other organs. The healing process is more and it results in lower surgical survival time, higher intraocular pressure (IOP) levels and, therefore, these patients usually need more medication to lower the IOP. Both randomized and nonrandomized retrospective and experimental molecular studies have shown the association between DM and glaucoma. Further studies are needed to get better explanations about outcomes on more recent surgical procedures and with the exponential use of antifibrotics. How to cite this article: Costa L, Cunha JP, Amado D, Pinto LA, Ferreira J. Diabetes Mellitus as a Risk Factor in Glaucoma's Physiopathology and Surgical Survival Time: A Literature Review.
- O Efeito de Pulfrich e a Esclerose MúltiplaPublication . Ferreira, J; Abegão Pinto, L; Amado, D; Cunha, JPIntrodução: O efeito de Pulfrich é um fenómeno psicofísico em que o movimento lateral/pendular de um objecto num plano bidimensional pode ser interpretado pelo córtex visual como um movimento tridimensional devido à diferença relativa do tempo de latência entre os dois olhos. Objectivo: Determinar se a neuropatia óptica desmielinizante unilateral ou assimétrica origina o fenómeno de Pulfrich. Métodos: Pesquisámos em 22 doentes com o diagnóstico de neuropatia óptica desmielinizante a percepção do fenómeno através de uma imagem pendular gerada por computador. Avaliámos as acuidades visuais corrigidas, realizámos Potenciais Evocados Visuais (PEV) para quantificação do tempo de latência da onda P100 e recorremos à interposição de um filtro polarizado de 70% para verificar a sua anulação. Resultados: Dez dos 22 doentes observaram o fenómeno e este foi abolido após interposição de um filtro polarizado. Conclusões: A neuropatia óptica pode originar o efeito de Pulfrich e explicar algumas queixas visuais aparentemente inespecíficas, sem alterações evidentes das acuidades visuais ou da estereopsia.
- Macular Ganglion Cell Layer and Peripapillary Retinal Nerve Fibre Layer Thickness in Patients with Unilateral Posterior Cerebral Artery Ischaemic Lesion: An Optical Coherence Tomography StudyPublication . Anjos, R; Vieira, L; Costa, L; Vicente, A; Santos, A; Alves, N; Amado, D; Ferreira, J; Cunha, JPThe purpose of this study is to evaluate the macular ganglion cell layer (GCL) and peripapillary retinal nerve fibre layer (RNFL) thickness in patients with unilateral posterior cerebral artery (PCA) ischaemic lesions using spectral-domain optical coherence tomography (SD-OCT). A prospective, case-control study of patients with unilateral PCA lesion was conducted in the neuro-ophthalmology clinic of Centro Hospitalar Lisboa Central. Macular and peripapillary SD-OCT scans were performed in both eyes of each patient. Twelve patients with PCA lesions (stroke group) and 12 healthy normal controls were included in this study. Peripapillary RNFL comparison between both eyes of the same subject in the stroke group found a thinning in the superior-temporal (p = 0.008) and inferior-temporal (p = 0.023) sectors of the ipsilateral eye and nasal sector (p = 0.003) of the contralateral eye. Macular GCL thickness comparison showed a reduction temporally in the ipsilateral eye (p = 0.004) and nasally in the contralateral eye (p = 0.002). Peripapillary RNFL thickness was significantly reduced in both eyes of patients with PCA compared with controls, affecting all sectors in the contralateral eye and predominantly temporal sectors in the ipsilateral eye. A statistically significant decrease in macular GCL thickness was found in both hemiretinas of both eyes of stroke patients when compared with controls (p < 0.05). This study shows that TRD may play a role in the physiopathology of lesions of the posterior visual pathway.
- Optical Coeherence Tomography: a Window to Multiple Sclerosis?Publication . Proença, R; Cardigos, J; Costa, L; Vicente, A; Santos, A; Amado, D; Ferreira, J; Cunha, JPIntroduction: Multiple sclerosis (MS) is an inflammatory immune-mediated demyelinating disease that frequently affects the central nervous system. Approximately 20% of patients have optic neuritis has the first manifestation of the disease. Its frequency, heterogeneity and absence of definitive treatment make it a therapeutic and diagnostic challenge for both the patient and the clinician. Material and methods: Retrospective study of 133 eyes of 87 patients, 38 patients with MS (Group 1), 9 patients with isolated optic neuritis (Group 2) and 40 healthy patients (Group 3) from the Neurophthalmology Department of Centro Hospitalar de Lisboa Central from January 2013 to August 2015. Patients were characterized according to gender, age, years of follow-up, best corrected visual acuity, presence of other ocular disorders and episodes of optic neuritis. Patients with other ocular pathologies were excluded. Optical coherence tomography (OCT Spectralis, Heidelberg Engineering) of the macular region was done in all patients, followed by automatic segmentation of the retinal layer. Statistical tests were made to calculate statistically significant results between different groups. Results: Of the 87 patients evaluated, the mean age in Group 1 was 41.55 compared to 36.88 in Group 2 and 44.73 in the control group. Mean age of diagnosis for patients with MS was 33.73 years with a mean follow up of 8.01 years, whereas patients with isolated optic neuritis had a mean age of diagnosis of 34.33 years, with a mean follow-up of 2.88 years. Best corrected visual acuity ranged from 0.2 to 1.0 in Group 1 and 0.5 to 1.0 in Group 2. In patients with previous episodes of optic neuritis isolated or associated with multiple sclerosis we observed a statistically significant (p<0.05) reduction of the average retinal thickness as well as a thinner retinal nerve fiber layer, ganglion cell layer and inner plexiform layer when compared to the control group. Conclusion: Thickness of the internal retinal layers was reduced (retinal nerve, ganglion cell and inner plexiform layer) in a statistically significant value (p<0.05) when compared to the control group.