Biometria óptica e ultrassônica guiada pelo modo-B em olhos com catarata e óleo de silicone intraocular
Data
2015-12-31
Autores
Souza, Paulo Henrique de 
Orientadores
Allemann, Norma
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: O preenchimento da cavidade vítrea com óleo de silicone após cirurgias vítreo-retinianas causa frequentemente a opacificação do cristalino. O óleo de silicone gera artefatos que dificultam a biometria modo-A. A biometria óptica tem sido o método de escolha para o cálculo da lente intraocular, porém pode se tornar impossível em opacificações mais densas. Objetivo: Comparar as medidas do comprimento axial utilizando a biometria óptica e a biometria ultrassônica de imersão guiada pelo modo-B em olhos fácicos portadores de óleo de silicone intraocular que serão submetidos à cirurgia de catarata. Métodos: 27 olhos com óleo de silicone intraocular foram submetidos à biometria óptica e à biometria guiada pelo modo-B, realizados pelo mesmo examinador. A biometria óptica (IOLMaster 500, Versão 7.5 Zeiss) foi obtida com a fixação em uma mira central. Foram obtidas 10 medidas com SNR maior que 1,5 mm para determinação do comprimento axial a ser utilizado na análise. A biometria guiada pelo modo-B (Ultrascan, Alcon) foi realizada através da técnica de imersão com o paciente em decúbito dorsal horizontal. Foram obtidas 4 medidas através do corte axial horizontal para determinação do comprimento axial médio a ser utilizado para análise. As medidas obtidas em cada método foram comparadas com teste de Wilcoxon para amostras pareadas e a análise de concordância foi realizada com o gráfico de Bland-Altman. As diferenças de comprimento axial também foram avaliadas considerando-se olhos maiores que 25,00 mm e a presença de interfaces artefatuais geradas pelo óleo de silicone. Resultados: Comprimento axial médio obtido pela biometria óptica: 25,34 mm +/- 2,23 (variação 22,79 a 30,75 mm); e pela biometria guiada pelo modo-B: 25,34 mm +/- 2,17 (variação 22,51 a 30,94 mm), sem diferença estatisticamente significante entre os métodos. Em 20 olhos (74,06%), a diferença de comprimento axial obtida por ambos os métodos foi menor que 0,4 mm, e em 13 olhos (48,14%) a diferença foi menor que 0,2 mm. O grupo que apresentou menor diferença entre os métodos (abaixo de 0,2 mm) incluiu olhos que apresentavam o preenchimento completo da cavidade vítrea por óleo de silicone e não mostravam preenchimento da câmara anterior. Conclusões: A biometria ultrassônica guiada pelo modo-B foi útil na diferenciação das estruturas anatômicas intraoculares na presença do óleo de silicone intraocular, fornecendo medidas de comprimento axial que concordam com as medidas obtidas através da biometria óptica.
Introduction: Vitreous cavity filling with silicone oil after vitreoretinal surgery often causes lens opacification. Silicone oil generates artifacts that hinder the A-scan biometry. Optical biometry has been the method of choice for intraocular lens calculation, but can become impossible in more dense opacities. Objective: To compare axial length measurements obtained using optical biometry and immersion b-mode guided ultrasound biometry in silicon oil-filled phakic eyes that will undergo cataract surgery. Methods: 27 silicone oil filled-eyes underwent optical biometry and b-mode guided biometry performed by the same examiner. Optical biometry (IOLMaster 500, Version 7.5 Zeiss) was acquired with fixation of a central aim. Ten measurements with SNR greater than 1.5 mm were obtained to determine the axial length measurement to be used for analysis. B-mode guided biometry (Ultrascan, Alcon) was performed with immersion technique, patient in supine position. Four measurements were obtained using the horizontal axial scan for determining the average axial length to be used for analysis. Measurements obtained by both techniques were compared using the Wilcoxon test for paired samples and correlation analysis was performed using Bland-Altman plot. The differences in axial length measurements were also evaluated considering eyes longer than 25.00 mm and the presence of artefactual interfaces generated by silicone oil. Results: Mean axial length obtained by optical biometry: 25.34 mm +/- 2.23 (range 22.79 to 30.75 mm); and using B-mode guided ultrasound biometry: 25.34 mm +/- 2.17 (range 22.51 to 30.94 mm), no statistically significant difference between the methods. In 20 eyes (74.06%), the difference in axial length obtained by both methods was smaller than 0.4 mm, and in 13 eyes (48.14%), the difference was smaller than 0.2 mm. The group that showed no difference between the methods (< 0.2 mm) included eyes that had the complete filling of the vitreous cavity with silicone oil and showed no filling of the anterior chamber. Conclusions: B-mode guided ultrasound biometry was useful in differentiating intraocular anatomical structures in the presence of intraocular silicone oil, providing axial length measurements that agreed with the measurements obtained by optical biometry.
Introduction: Vitreous cavity filling with silicone oil after vitreoretinal surgery often causes lens opacification. Silicone oil generates artifacts that hinder the A-scan biometry. Optical biometry has been the method of choice for intraocular lens calculation, but can become impossible in more dense opacities. Objective: To compare axial length measurements obtained using optical biometry and immersion b-mode guided ultrasound biometry in silicon oil-filled phakic eyes that will undergo cataract surgery. Methods: 27 silicone oil filled-eyes underwent optical biometry and b-mode guided biometry performed by the same examiner. Optical biometry (IOLMaster 500, Version 7.5 Zeiss) was acquired with fixation of a central aim. Ten measurements with SNR greater than 1.5 mm were obtained to determine the axial length measurement to be used for analysis. B-mode guided biometry (Ultrascan, Alcon) was performed with immersion technique, patient in supine position. Four measurements were obtained using the horizontal axial scan for determining the average axial length to be used for analysis. Measurements obtained by both techniques were compared using the Wilcoxon test for paired samples and correlation analysis was performed using Bland-Altman plot. The differences in axial length measurements were also evaluated considering eyes longer than 25.00 mm and the presence of artefactual interfaces generated by silicone oil. Results: Mean axial length obtained by optical biometry: 25.34 mm +/- 2.23 (range 22.79 to 30.75 mm); and using B-mode guided ultrasound biometry: 25.34 mm +/- 2.17 (range 22.51 to 30.94 mm), no statistically significant difference between the methods. In 20 eyes (74.06%), the difference in axial length obtained by both methods was smaller than 0.4 mm, and in 13 eyes (48.14%), the difference was smaller than 0.2 mm. The group that showed no difference between the methods (< 0.2 mm) included eyes that had the complete filling of the vitreous cavity with silicone oil and showed no filling of the anterior chamber. Conclusions: B-mode guided ultrasound biometry was useful in differentiating intraocular anatomical structures in the presence of intraocular silicone oil, providing axial length measurements that agreed with the measurements obtained by optical biometry.
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Citação
SOUZA, Paulo Henrique de. Biometria óptica e ultrassônica guiada pelo modo-B em olhos com catarata e óleo de silicone intraocular. 2015. 42 f. Dissertação (Mestrado Profissional em Tecnologia, Gestão e Saúde Ocular) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2015.