Ação social para detecção e resolução de baixa de acuidade visual em adolescentes / Social action to detect and solve low visual acuity in adolescents

RESUMO Objetivo Verificar a prevalência e as principais causas de baixa acuidade visual encontradas em estudantes; resolver as alterações refracionais por meio de correção óptica e estabelecer uma relação entre visão e desempenho escolar. Métodos Estudo transversal, quantitativo, de ação social realizada em uma escola pública de ensino fundamental e médio de Araçatuba (SP). A avaliação especializada foi indicada aos estudantes que, em triagem visual, apresentaram acuidade visual ≤0,7 em um ou em ambos os olhos, com ou sem correção óptica prévia. Foram entregues óculos a todos que necessitavam, para melhorar visão. Foi realizada análise pela ficha de atendimento e pela nota escolar dos alunos, pelos programas Excel e BioEstat. Resultados Dos 503 alunos triados, 75 (15%) apresentaram baixa de acuidade visual. Compareceram à consulta agendada 66 (88%), e 50 (80,65%) receberam óculos prontos. A média de idade foi de 152 anos, e houve predominância do sexo feminino (64,5%). As alterações refracionais foram a principal causa da baixa visual (90,3%), e miopia, associada ou não a astigmatismo, foi a mais prevalente (63%). Dentre os casos, 13 (21%) tinham anisometropia. Não houve diferença estatisticamente significativa (p=0,5479) entre as médias anuais dos alunos com baixa de acuidade visual e aqueles com visão normal. Conclusão Projetos sociais de triagem visual são facilmente executáveis, têm baixo custo e alta resolutividade, uma vez que os transtornos refracionais são a principal causa e facilmente corrigidos com óculos. A baixa de acuidade visual detectada nos alunos não interferiu no desempenho escolar.

ABSTRACT Objective To verify the prevalence and the main causes of low visual acuity among students, to correct refractive errors with eyewear, and to establish a relation between vision and school performance. Methods This is a cross-sectional, quantitative study of a social action carried out in a public elementary and high school in the city of Araçatuba (SP). Specialized evaluation was indicated to students who presented visual acuity ≤0.7 in one or both eyes, with or without prior optical correction, upon triage. Glasses were delivered to everyone who needed better vision. The analysis was performed based on screening record and student's school grade, using Excel and BioEstat software. Results Out of 503 students screened, 75 (15%) presented low visual acuity. Sixty-six (88%) attended the scheduled visit and 50 (80.65%) received ready-made glasses. The mean age was 15±2 years, and there was a predominance of females (64.5%). Refractive errors were the main cause of visual impairment (90.3%) and myopia, associated or not to astigmatism, was the most prevalent condition (63%). Thirteen (21%) students had anisometropia. There was no statistically significant difference (p=0.5479) in annual average grade of students with low visual acuity and those with normal vision. Conclusion Social projects for visual triage are carried out without effort, have a low cost and high problem-solving capacity, since refractive errors are the most frequent diagnoses and easily corrected with glasses. The low visual acuity detected in students did not interfere in their school performance.

Tissue ingrowth into perforated polymethylmethacrylate orbital implants: an experimental study.

PURPOSE: To evaluate the clinical response and fibrovascular ingrowth into perforated acrylic orbital implants in a rabbit model. METHODS: Perforated implants were manufactured by drilling channels interconnected at the center in conventional 12- to 13-mm acrylic spheres. The implants were placed in 16 eviscerated eyes with posterior sclerotomy of 16 New Zealand white rabbits. Clinical evaluation was performed daily for the first 14 days after surgery and at 7-day intervals until the end of the study (180 days). Histopathologic analysis was performed at 14, 45, 90, and 180 days after implantation. Hematoxylin-eosin and picrosirius red staining was used to assess the inflammatory reaction and collagen formation. RESULTS: There were no signs of infection, implant exposure, or extrusion in any animal during the study. Tissue ingrowth in the implant center was already detected by 14 days. At the end of the study, there was a dense collagen ingrowth with just a few inflammatory cells inside the implant. No multinucleated giant cells were found in any implant. CONCLUSIONS: Similar to porous implants, perforated acrylic implants permit fibrovascular ingrowth from surrounding orbital tissues.

[Biodegradable systems containing prednisolone acetate for orbital administration]. / Sistemas biodegradáveis contendo acetato de prednisolona para administração orbitária.

PURPOSE: The present study aimed to evaluate an injectable extended-release formulation of prednisolone acetate (PA) for orbital administration. METHODS: Microspheres (MEs) of poly-e-caprolactone (PCL) containing PA were developed by the method of solvent evaporation. The MEs obtained were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), encapsulation efficiency and in vitro release profile. The in vivo release profile was evaluated in rabbits after periocular injection of an aqueous suspension of MEs. The local biocompatibility of the system was verified by histopathologic analysis of the deployment region. RESULTS: After MEs preparation, morphological analysis by SEM showed the feasibility of the employed method. The content of PA encapsulated was 43+/-7% and can be considered as satisfactory. The system characterization by DSC technique, in addition to confirm the system stability, did not indicate the existence of interaction between the drug and the polymer. The in vitro release study showed the prolonged-release features of the developed system. Preliminary in vivo study showed the absence of local toxicity and confirmed the prolonged release profile of PA from MEs, suggesting the viability of the developed system for the treatment of orbital inflammatory diseases. CONCLUSION: The results obtained in this work are relevant and accredit the system developed as a possible alternative to the treatment of inflammatory orbitopathy.

Sistemas biodegradáveis contendo acetato de prednisolona para administração orbitária / Biodegradable systems containing prednisolone acetate for orbital administration

OBJETIVO: O presente estudo objetivou o desenvolvimento e a avaliação de um sistema biodegradável de liberação de fármacos com característica de liberação prolongada, destinado à administração orbitária de acetato de prednisolona (AP). MÉTODOS: O sistema desenvolvido, na forma de microesferas (MEs) de poli-e-caprolactona (PCL) contendo o AP, foi obtido pelo método de evaporação de solvente. As MEs foram caracterizadas por microscopia eletrônica de varredura (MEV), calorimetria diferencial exploratória (DSC), avaliação do teor de encapsulação e pelo perfil de liberação in vitro. O perfil de liberação in vivo foi avaliado em coelhos após administração peribulbar de uma suspensão aquosa das MEs. A biocompatibilidade local do sistema foi verificada por meio de análise histopatológica da região de implantação. RESULTADOS: Após obtenção das MEs, a análise morfológica por MEV mostrou a viabilidade do método de obtenção do sistema. O teor de AP encapsulado foi de 43 ± 7 por cento e pode ser considerado bastante satisfatório. A caracterização do sistema por DSC, além de confirmar a sua estabilidade, não indicou a existência de interação entre o fármaco e o polímero. O estudo de liberação in vitro indicou que o sistema apresenta perfil de liberação prolongada. O estudo in vivo confirmou o perfil de liberação prolongado do AP a partir das MEs, sugerindo, também, a viabilidade do sistema devido à ausência de toxicidade local. CONCLUSÃO: O conjunto dos resultados obtidos neste trabalho é relevante e credencia o sistema desenvolvido como uma possível alternativa ao tratamento de orbitopatias inflamatórias.

PURPOSE: The present study aimed to evaluate an injectable extended-release formulation of prednisolone acetate (PA) for orbital administration. METHODS: Microspheres (MEs) of poly-e-caprolactone (PCL) containing PA were developed by the method of solvent evaporation. The MEs obtained were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), encapsulation efficiency and in vitro release profile. The in vivo release profile was evaluated in rabbits after periocular injection of an aqueous suspension of MEs. The local biocompatibility of the system was verified by histopathologic analysis of the deployment region. RESULTS: After MEs preparation, morphological analysis by SEM showed the feasibility of the employed method. The content of PA encapsulated was 43 ± 7 percent and can be considered as satisfactory. The system characterization by DSC technique, in addition to confirm the system stability, did not indicate the existence of interaction between the drug and the polymer. The in vitro release study showed the prolonged-release features of the developed system. Preliminary in vivo study showed the absence of local toxicity and confirmed the prolonged release profile of PA from MEs, suggesting the viability of the developed system for the treatment of orbital inflammatory diseases. CONCLUSION: The results obtained in this work are relevant and accredit the system developed as a possible alternative to the treatment of inflammatory orbitopathy.

Activated satellite cells in medial rectus muscles of patients with strabismus.

PURPOSE: The goal of this study was to determine whether the medial rectus muscles of patients with a history of medial rectus underaction or overaction show alterations in the process of satellite cell activation when compared with normal age-matched control muscles. METHODS: Medial rectus muscles were obtained with consent from adult patients undergoing surgical resection due to medial rectus underaction or overaction and were prepared for histologic examination by fixation and paraffin embedding. Control muscles were obtained from cornea donor eyes of adults who had no history of strabismus or neuromuscular disease. Cross sections were obtained and stained immunohistochemically for the presence of activated satellite cells, as identified by MyoD immunoreactivity, and the presence of the total satellite cell population, as identified by Pax7 immunoreactivity. The percentages of MyoD- and Pax7-positive satellite cells per 100 myofibers in cross section were calculated. RESULTS: As predicted from results in the literature, MyoD-positive satellite cells, indicative of activation, were present in both the control and resected muscles. In the underacting medial rectus muscles, the percentages of MyoD- and Pax7-positive satellite cells, based on the number of myofibers, were approximately twofold higher than the percentages in the control muscles. In the overacting medial rectus muscles, the percentage of MyoD-positive satellite cells was twofold less than in the control muscles, whereas the percentage of Pax7-positive satellite cells significantly increased compared with that in the control specimens. CONCLUSIONS: The presence of an increased number of activated satellite cells in the resected underacting medial rectus muscles and the decreased numbers of activated satellite cells in the overacting muscles was unexpected. The upregulation in the number of MyoD-positive satellite cells in underacting muscles suggests that there is potential for successful upregulation of size in these muscles, as the cellular machinery for muscle repair and regeneration, the satellite cells, is retained and active in patients with medial rectus underaction. The decreased number of activated satellite cells in overacting MR muscle suggests that factors as yet unknown in these overacting muscles are able to affect the number of satellite cells and/or their responsiveness compared with normal age-matched control muscles. These hypotheses are currently being tested.