Low Limit for Effective Signal Strength in the Stratus OCT in Imperative Low Signal Strength Cases
Korean Journal of Ophthalmology
; : 182-188, 2012.
Article
em En
| WPRIM
| ID: wpr-171224
Biblioteca responsável:
WPRO
ABSTRACT
PURPOSE:
To determine the lowest limit of signal strength that is still effective for accurate analysis of optic coherence tomography (OCT) values, we investigated the reproducibility of OCT scans by signal strength (SS).METHODS:
A total of 668 subjects were scanned for measurements of retinal nerve fiber layer (RNFL) thickness using the Stratus OCT twice on the same day. The variability of overall RNFL thickness parameters obtained at different SS was analyzed and compared by repeated-measures of ANOVA and Spearman's correlation coefficient. Values of the intraclass correlation coefficient (ICC) and variability (standard deviation) of RNFL thickness were obtained. The false positive ratio was analyzed.RESULTS:
When SS was 3, the variability of RNFL thickness was significantly different (low ICC, high variability) in comparison to when SS was 4 or greater. Significant negative correlations were observed between variability in RNFL thickness and signal strength. The difference of variability of average RNFL thickness between SS 4 (4.94 microm) and SS 6 (4.41 microm) was 0.53 microm.CONCLUSIONS:
Clinically, the difference of variability of average RNFL thickness between SS 4 and SS 6 was quite small. High SS is important, however, when signal strength is low due to uncorrectable factors in patients in need of OCT for glaucoma and retinal disease. Our results suggest that SS 4 is the lowest acceptable limit of signal strength for obtaining reproducible scanning images.Palavras-chave
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Base de dados:
WPRIM
Assunto principal:
Doenças Retinianas
/
Células Ganglionares da Retina
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Glaucoma
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Estudos Transversais
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Estudos Prospectivos
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Reprodutibilidade dos Testes
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Progressão da Doença
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Diagnóstico Diferencial
/
Reações Falso-Positivas
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
/
Prevalence_studies
/
Risk_factors_studies
Limite:
Adolescent
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Female
/
Humans
/
Male
Idioma:
En
Revista:
Korean Journal of Ophthalmology
Ano de publicação:
2012
Tipo de documento:
Article