RESUMO
The cornea is a fundamental ocular tissue for the sense of sight. Thanks to it, the refraction of two-thirds of light manages to participate in the visual process and protect against mechanical damage. Because it is transparent, avascular, and innervated, the cornea comprises five main layers: Epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium. Each layer plays a key role in the functionality and maintenance of ocular tissue, providing unique ultrastructural and biomechanical properties. Bullous Keratopathy (BK) is an endothelial dysfunction that leads to corneal edema, loss of visual acuity, epithelial blisters, and severe pain, among other symptoms. The corneal layers are subject to changes in their biophysical properties promoted by Keratopathy. In this context, the Atomic Force Microscopy (AFM) technique in air was used to investigate the anterior epithelial surface and the posterior endothelial surface, healthy and with BK, using a triangular silicone tip with a nominal spring constant of 0.4 N/m. Six human corneas (n = 6) samples were used for each analyzed group. Roughness data, calculated by third-order polynomial adjustment, adhesion, and Young's modulus, were obtained to serve as a comparison and identification of morphological and biomechanical changes possibly associated with the pathology, such as craters and in the epithelial layer and exposure of a fibrotic layer due to loss of the endothelial cell wall. Endothelial cell membrane area and volume data were calculated, obtaining a relevant comparison between the control and patient. Such results may provide new data on the physical properties of the ocular tissue to understand the physiology of the cornea when it has pathology.
Assuntos
Doenças da Córnea , Edema da Córnea , Humanos , Endotélio Corneano/metabolismo , Lâmina Limitante Posterior/metabolismo , Edema da Córnea/metabolismo , Córnea/patologia , Doenças da Córnea/patologiaRESUMO
To report a case of ocular copper deposition in both eyes at the level of Descemet's membrane associated with a monoclonal gammopathy of undetermined significance (MGUS). A 49-year-old white woman had golden-brown metallic dust-like deposits on Descemet's membrane of both eyes. A systemic examination revealed an elevated serum copper, normal serum ceruloplasmin and a normal level of total protein. Serum protein electrophoresis demonstrated a single peak (M-spike) in the gamma region (M-protein in serum = 11 g/l). Flow cytometric analysis of the marrow aspirate identified a monoclonal plasma cell population that represents approximately 2% of the total marrow cells consistent with the diagnosis of monoclonal gammopathy of undetermined significance. Copper deposits at the level of Descemet's membrane may be a finding in a patient with monoclonal gammopathy of undetermined significance.
Assuntos
Cobre/análise , Lâmina Limitante Posterior/química , Gamopatia Monoclonal de Significância Indeterminada/diagnóstico , Paraproteinemias/diagnóstico , Eletroforese das Proteínas Sanguíneas , Cobre/sangue , Lâmina Limitante Posterior/metabolismo , Feminino , Humanos , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/sangue , Paraproteinemias/sangueRESUMO
Relatar um caso de depósito corneano de cobre em ambos os olhos a nível da membrana de Descemet associado a gamopatia monoclonal de significância indeterminada (GMSI). Paciente feminina, 49 anos, leucodérmica, apresentando depósito corneano de aspecto marrom-ouro a nível da membrana de Descemet em ambos os olhos. Exame sistêmico revelou cobre sérico elevado, ceruloplasmina sérica normal, e proteína total normal. Eletroforese de proteínas séricas demonstrou um pico único na região gama (proteína M = 11 g/l). Análise citométrica de aspirado medular evidenciou uma população de células plasmáticas monoclonais de aproximadamente 2% do total de células medulares consistente com o diagnóstico de gamopatia monoclonal de significância indeterminada. Depósitos de cobre a nível da membrana de Descemet podem ser encontrados em pacientes com gamopatia monoclonal de significância indeterminada.