Multimodal fundus imaging in heredodystrophic and degenerative diseases of the retina

A tomografia de coerência óptica incorporou-se gradativamente ao contemporâneo arsenal diagnóstico em Oftalmologia, passando a exercer papel fundamental na investigação e condução de doenças oculares, particularmente na especialidade de Retina e Vítreo. A disponibilização comercial da nova geração de aparelhos, chamada de tomografia de coerência óptica "espectral", baseada em conceito físico distinto que permite a aquisição de imagens em alta velocidade, marcou o início de uma nova era desta tecnologia de investigação auxiliar. Adicionalmente, sua recente combinação com o oftalmoscópio de varredura a laser confocal (confocal scanning laser ophthalmoscope) vem propiciando a aquisição de imagens tomográficas guiadas em tempo real pelos diferentes modos de imagem (autofluorescência de fundo, reflectância com luz "infravermelha" e angiografia com fluoresceína ou indocianina verde). A avaliação ocular multimodal (multimodal fundus imaging) permite a correlação real e minuciosa de achados da morfologia retiniana e do epitélio pigmentar com dados de estudos angiográficos e de autofluorescência ou reflectância, propiciando assim inferências valiosas sobre a fisiologia do tecido. Neste artigo, discutimos brevemente as possíveis implicações da avaliação ocular multimodal na prática da especialidade de Retina e Vítreo.Optical coherence tomography was progressively incorporated to the contemporary diagnostic arsenal in Ophthalmology, playing a crucial role in the diagnosis and management of eye diseases, particularly in the specialty of retina and vitreous. The commercial availability of the new generation of devices, coined "spectral" optical coherence tomography, which is based in a distinct physical concept that permits high-speed image acquisition, launched a new era for this investigative ancillary tool. In addition, the recent combination of this new technology with a confocal scanning laser ophthalmoscope has permitted the acquisition of tomographic images driven by different imaging modalities simultaneously (fundus autofluorescence, near-infrared reflectance, and fluorescein or indocyanine-green angiographies). Multimodal fundus imaging permits a reliable and detailed correlation between the morphological findings of the retina or retinal pigment epithelium and angiographic studies or fundus autofluorescence, leading to valuable insights about retina physiology. In this article, we briefly discuss possible practical implications of this new diagnostic modality for the retina specialist

Serum levels of neurotrophic factors in active toxoplasmic retinochoroiditis

Toxoplasmic retinochoroiditis (TR) is the most common identifiable cause of posterior uveitis in Brazil. Response to treatment and clinical presentation may vary significantly. We assessed serum levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), nerve growth factor (NGF), neurotrophin (NT)-3, and NT-4/5 in patients with active TR, before and after TR treatment. Methods: Twenty patients with active lesion and 15 healthy controls were enrolled in the study. Serum concentration of neurotrophic factors was determined by enzyme-linked immunosorbent assay. Results: BDNF levels were significantly higher in patients before treatment when compared with controls (p = 0.0015). There was no significant difference in pro-BDNF, NGF, GDNF, NT-3, and NT-4/5 levels between TR patients and controls. Treatment did not affect the levels of these factors. Conclusion: BDNF may be released in the context of the active TR inflammatory response. Keywords: Retinochoroiditis, Toxoplasma gondii, Brain-derived neurotrophic facto

Montmorillonite clay based polyurethane nanocomposite as substrate for retinal pigment epithelial cell growth.

The subretinal transplantation of retinal pigment epithelial cells (RPE cells) grown on polymeric supports may have interest in retinal diseases affecting RPE cells. In this study, montmorillonite based polyurethane nanocomposite (PU-NC) was investigated as substrate for human RPE cell growth (ARPE-19 cells). The ARPE-19 cells were seeded on the PU-NC, and cell viability, proliferation and differentiation were investigated. The results indicated that ARPE-19 cells attached, proliferated onto the PU-NC, and expressed occludin. The in vivo ocular biocompatibility of the PU-NC was assessed by using the HET-CAM; and through its implantation under the retina. The direct application of the nanocomposite onto the CAM did not compromise the vascular tissue in the CAM surface, suggesting no ocular irritancy of the PU-NC film. The nanocomposite did not elicit any inflammatory response when implanted into the eye of rats. The PU-NC may have potential application as a substrate for RPE cell transplantation