Ana Beatriz Toledo Dias

Ability of New Vital Dyes to Stain Intraocular Membranes and Tissues in Ocular Surgery

PURPOSE To evaluate the ability of novel dyes to stain lens capsule (LC), internal limiting membrane (ILM), epiretinal membrane (ERM), and vitreous. DESIGN Experimental study in animal and human donor eyes. METHODS Thirteen dyes, methyl violet, crystal violet, eosin Y, sudan black B, methylene blue, toluidine blue, light green, indigo carmine, fast green, congo red, evans blue, brilliant blue, and bromophenol blue, were injected onto the LC and ILM of enucleated porcine eyes. The vitreous was stained with 2 mL of dyes for 1 minute. Six dyes (indigo carmine, evans blue, fast green, light green, bromophenol blue, and brilliant blue) were selected for experiments in human donor eyes and freshly removed ERM. RESULTS In the porcine eyes, ILM staining with methylene blue, toluidine blue, indigo carmine, evans blue, bromophenol blue, and fast green was moderate, and methyl violet, crystal violet, brilliant blue, or sudan black resulted in strong staining. Methyl violet, crystal violet, sudan black, toluidine blue, and methylene blue caused histologic damage in porcine retinas. Vitreous examination revealed moderate staining with congo red, crystal violet, fast green, eosin Y, methylene blue, toluidine blue, brilliant blue, bromophenol blue, and methyl violet and strong staining with light green and evans blue. ERMs showed strong staining with 0.5% evans blue and moderate staining with 0.5% light green, fast green, brilliant blue, and bromophenol blue. Evaluation of donor eyes disclosed moderate staining with evans blue, light green, and bromophenol blue and strong staining with 0.5% brilliant blue. Moderate or strong staining of the vitreous occurred with most dyes. LC evaluation showed moderate staining with 0.5% evans blue, fast green, and brilliant blue, whereas 0.5% light green produced strong LC staining. CONCLUSIONS Brilliant blue shows the best ILM staining, whereas bromophenol blue, evans blue, and light green also stain ILM. Most dyes bind well to LC, vitreous, and ERM.

Achados histopatológicos em retinoblastoma

OBJETIVO: Descrever e analisar os principais achados histopatologicos no retinoblastoma com enfase na invasao de nervo optico e tunicas oculares, correlacionando-os ao tratamento realizado. METODOS: Vinte e oito olhos com diagnostico de retinoblastoma tratados por enucleacao na Universidade Federal de Sao Paulo entre dezembro de 2000 e outubro de 2002 foram submetidos a revisao histopatologica. Os dados clinicos incluiram idade, sexo, raca, lateralidade e tratamento realizado. Na revisao histopatologica foram avaliados neovascularizacao da iris e seio camerular, grau de diferenciacao do tumor e invasao do nervo optico e coroide de acordo com a classificacao de Khelfaoui. RESULTADOS: De 27 pacientes, 13 (48,1%) eram do sexo masculino e 14 (51,9%) eram do sexo feminino, 16 (59,3%) eram da raca branca, 5 (18,5%) eram da raca amarela, 4 (14,8%) eram pardos e 2 (7,4%) eram negros. A media da idade dos pacientes foi de 22,7 meses, sendo 13 casos bilaterais e 14 casos unilaterais. Com relacao ao tratamento utilizado, 13 (46,4%) olhos foram submetidos a enucleacao primaria e 15 (53,6%) tiveram tratamento previo. Na avaliacao histopatologica, 15 (53,6%) tumores eram bem diferenciados. Neovascularizacao da iris e/ou seio camerular foram observados em 60,6% e necrose e calcificacao em 89,2% dos casos. O envolvimento da coroide foi observado em 18 (64,2%) dos casos (grau II e III) e a invasao de nervo optico em 8 (28,5%) (graus II, III e IV). Dos casos submetidos ao tratamento previo 40% tinham algum grau de invasao das tunicas oculares e apenas 6,67% apresentavam simultaneamente invasao do nervo optico e das tunicas oculares. Entretanto nos olhos que foram submetidos a enucleacao primaria 30,7% apresentavam invasao das tunicas oculares e 53,8% apresentavam simultaneamente invasao do nervo optico e das tunicas oculares. CONCLUSAO: Neovascularizacao, necrose e calcificacao foram achados mais comumente observados. A invasao do nervo optico e coroide foram os dois fatores prognosticos mais importantes, encontrados em 28,5% e 64,2% dos casos respectivamente. Os casos tratados com enucleacao primaria apresentavam maior comprometimento ocular.

HER2 Overexpression in Retinoblastoma: A Potential Therapeutic Target

Background: Retinoblastoma (RB) is the most common primary intraocular malignancy. Current therapies are associated with high morbidity in the short- and long-term. Human epidermal growth factor receptor 2 (HER2) is a transmembrane protein detected in 15-30% of breast cancers, but it has also been described in other malignancies. Recently, it has been claimed that a truncated version of this protein is expressed in RB, responsive to directed therapies in vitro. We scored HER2 overexpression in RB tissue samples and discussed its potential clinical utility. Methods: HER2 overexpression was investigated using immunohistochemistry; the overexpression was evaluated with a score ranging from 0 to 3+ according to the membranous staining pattern in archival formalin-fixed, paraffin-embedded RBs. Results: A total of 60 RB cases and a RB cell line (Y79) were considered. The mean age at enucleation was 31.6 ± 31.5 months. The mean time from diagnosis to enucleation was 11.8 ± 11.2 months (range 1-44). Five (8%) cases were multifocal. HER2 overexpression was negative in all RB cases (49 cases scored 0 and 11 scored 1+) and in the Y79 cell line. Conclusions: Overall, we were not able to demonstrate the overexpression of HER2. Further studies should clarify and better elucidate the potential role of HER2-targeted therapies in RB.

Pericyte Status in Routinely Discarded Vitrectomy Samples May Be an Early Marker of Diabetic Retinopathy

Background: Diabetic retinopathy (DR) is the leading cause of blindness among the working-age population. The earliest morphological manifestation of the disease is pericyte loss, as shown by animal models. Aims: The purpose of this study was to evaluate the presence of pericytes in vitreous samples (VS) from diabetic and nondiabetic patients. Methods: VS from 125 patients with and without diabetes were analyzed. Thirty-three of the VS contained blood vessels and were therefore included in further analysis. Pericyte status was evaluated using α-smooth muscle actin and quantified using the following scoring system: total loss (3), >50% loss (2), <50% loss (1), and no loss (0). Results: Of the 33 VS, 29 samples were from patients with diabetes and 4 from nondiabetic patients. Six diabetic cases had a score of 1, 8 diabetic cases had a score of 2, and 15 cases had a score of 3. A positive correlation between glycemia levels and pericyte loss was observed (p = 0.0016; Spearmans r = 0.61). Moreover, all nondiabetic cases had a score of 0 (sensitivity and specificity = 100%). Conclusion: Pericyte loss in VS might be a sensitive and specific marker of DR that correlates with glycemia levels. Furthermore, VS, which are currently discarded, may contain valuable information for diabetic management.

Diagnostic value of SOX-10 immunohistochemical staining for the detection of uveal melanoma.

Objectives SOX-10 has been shown to be a sensitive marker of cutaneous melanoma. This study aimed to evaluate Sox-10 expression in uveal melanoma. Methods A total of 40 tissue blocks of enucleated eyes with uveal melanoma were cut and stained using an anti-SOX-10 mouse monoclonal antibody and HMB-45 antibody. Results SOX-10 showed exclusive nuclear positivity in 100% of the uveal melanoma cases (38/38). HMB-45 showed cytoplasmic positivity in 97.3 (37/38). Positivity for SOX-10 was also noted in the inner and outer nuclear layers of the retina in 78% of the enucleated eyes. Conclusions SOX-10 expression proved to be the most sensitive marker for uveal melanoma, and therefore, we propose a modified panel for the diagnosis of uveal melanoma that includes both SOX-10 and HMB-45. The observation of distinct, diffuse nuclear SOX-10 expression in retinal inner and outer nuclear layers is a finding that warrants further investigation as a marker for retinoblastoma.