Clairton de Souza

Macromolecular cell markers are essential for the classification and characterization of the highly complex and cellularly diverse vertebrate retina. Although a plethora of markers are described in the current literature, the immunoreactivity of these markers in normal human tissue has not been fully determined. This is problematic as they are quintessential to the characterization of morphological changes associated with human retinal disease. This review provides an overview of the macromolecular markers currently available to assess human retinal cell types. We draw on immunohistochemical studies conducted in our laboratories to describe marker immunoreactivity in human retina alongside comparative descriptions in non-human tissues. Considering the growing number of eye banks services offering healthy and diseased human retinal tissue, this review provides a point of reference for future human retina studies and highlights key species specific disease applications of some macromo...

To evaluate the treatment of subfoveal and juxtafoveal choroidal neovascularization (CNV) using verteporfin photodynamic therapy (vPDT) in patients affected by punctate inner choroidopathy (PIC). A chart review of 8 patients with CNV associated with PIC treated with vPDT was done. The 8 patients (8 eyes) included 4 men and 4 women with a mean age of 30.9 years. Six of them presented juxtafoveal CNVs, and two had subfoveal CNVs, at presentation. Mean follow-up time was 22.7 months. The VA improved in five eyes, and three eyes declined. One patient developed a new CNV a few days after vPDT, and one had multiple CNVs at presentation. Two of the 3 patients with longer follow-up period presented late recurrences. vPDT is a beneficial resource in stabilizing and also improving VA in PIC patients affected with subfoveal and juxtafoveal CNV, although one third of the patients retain poor visual acuity.

Gap junctions are intercellular channels that have been implicated in the pathogenesis of neuronal death after central nervous system injury. This study determines the expression pattern of gap junction protein connexin43 in the human retina and optic nerve. An affinity-isolated polyclonal antibody to the C-terminal segment of the cytoplasmic domain of human connexin43 was used to determine connexin43 localization. Postmortem human eyes were examined by immunohistochemical staining of frozen sections using antibodies to connexin43. Antibody binding was detected using confocal microscopy and fluorochrome-conjugated secondary antibodies. Double-label immunohistochemistry identified the cell types expressing connexin43. Connexin43 immunoreactivity was detected in the human retina on glial fibrillary acidic protein (GFAP)-positive astrocytes in the retinal ganglion cell layer and, to a lesser extent, on the processes of glutamine synthetase-labeled Müller cells. The retinal and choroidal circulations showed strong connexin43 immunolabeling. Dense connexin43 immunoreactivity was present between adjacent cells of the retinal pigment epithelium, and there was diffuse connexin43 immunoreactivity on GFAP-positive astrocytes in the optic nerve. In the human retina and optic nerve, connexin43 is present on glia, blood vessels, and epithelial cells. An understanding of the distribution of connexin43 in the normal retina and optic nerve may be used to evaluate changes associated with retinal and optic nerve disease.

To present the outcomes of various retinal conditions treated with the sutureless 25-gauge (25G) vitrectomy technique. Retrospective case review of 232 eyes of 228 patients who underwent 25G vitrectomy from January 2003 to August 2006. Follow-up was a minimum of 3 months. Indications for surgery included idiopathic macular hole, rhegmatogenous retinal detachment, epiretinal membrane and proliferative diabetic retinopathy. Main outcome measures included final visual acuity, re-operation rate and surgical complications such as endophthalmitis, hypotony and retinal (re)detachment. For all cases, the mean overall visual acuity (logMAR) improved from 0.9 preoperatively to 0.5 (P < 0.0001). The improvement in acuity was highest in the rhegmatogenous detachment and diabetic groups. Transient postoperative hypotony was observed in 15 cases (9.2%) on day 1 after surgery but all these cases resolved. In 7.3% of the cases (17 out of 232) additional surgery was performed due to retina (re)detachment but final anatomic success was achieved in all cases; the detachments occurred within the first 3 months. One patients developed endophthalmitis (0.4%) which coincided with subconjunctival antibiotics being discontinued in favour of topical treatment. The 25G system remains a safe and effective technique for a variety of retinal conditions; significant fast visual rehabilitation is an advantage.

ABSTRACT Caso clínico: Se describe un caso de oftalmía simpática (OS) desarrollado tras un traumatismo contuso tratado mediante vitrectomía (que se complicó con una hemorragia supracoroidea masiva) y taponamiento con perfluorocarbono líquido (PFCL). Discusión: La presentación de OS en un paciente vitrectomizado tras un traumatismo ocular contuso grave con taponamiento intra-ocular prolongado con PFCL permitiría plantear la hipótesis de que la reacción inflamatoria crónica producida por estos compuestos podría haber colaborado en el desarrollo de la OS. Sin embargo, existen otros posibles factores causales como el propio traumatismo, la vitrectomía en sí o el desprendimiento de coroides con posible incarceración de tejido uveal en las incisiones.

Purpose: To identify the distribution of creatine transporter (CRT) in the aged human retina and how this expression pattern is modified after retinal detachment.Methods: An affinity-purified antibody raised against the CRT was used in the immunohistochemical investigation. The anti-CRT antibody was colocalized with neuronal markers (calbindin, parvalbumin, Islet-1, calretinin, GAD67, Go-alpha), glia markers (glutamine synthetase, glial fibrillary acid protein), and a blood vessel basal membrane marker (laminin). Confocal microscopy was employed to visualize the labeling patterns in retinal sections. The level of CRT expression was determined in the retina using a semi-quantification METHOD: Results: Immunohistochemical assessment of CRT expression in the normal aged retina revealed strong labeling in photoreceptor synaptic terminals and in inner and outer segments. Labeling was also observed on subpopulations of amacrine cells and ganglion cells as well as in the outer and inner pl...