ABSTRACT
La agudeza visual es la principal característica evaluada para conocer cómo ve una persona. Al medirla se utilizan Cartas de Agudeza Visual, de las cuales la más empleada en el medio colombiano es la carta Snellen. Objetivo: el propósito de esta investigación fue determinar la reproducibilidad ínter e intraobservador de la carta de letras serif Snellen para evaluar la agudeza visual (AV). Materiales y métodos: en un muestreo por conveniencia, dos evaluadores midieron en dos sesiones la AV con la carta de Snellen tipo serif en 110 estudiantes universitarios (220 ojos) entre 15 y 30 años de edad, con ametropía corregida, visión binocular normal y sin patologías del segmento anterior o posterior. Se repitieron las pruebas en los pacientes induciendo una miopía de 1,50 D. Los valores de AV fueron convertidos de la escala fraccional a la logarítmica. Resultados: los resultados mostraron que la AV promedio (LogMAR) fue -0,06 (20/20+5); con la miopía inducida, 0,51 (20/63). La prueba de Wilcoxon pareada mostró diferencias significativas para la primera sesión entre los dos evaluadores (p = 0,0001; p = 0,007) y con el defecto inducido interevaluadores en las dos sesiones (p = 0,03; p = 0,001). El coeficiente de correlación y concordancia de Lin (Pc) indicó pobre concordancia (Pc = 0,9) ínter e intraobservador, sin defecto inducido y con éste. Los límites de concordancia de Bland-Altman muestran variaciones de AV de 3 líneas en los sujetos corregidos y de 5 a 6 líneas de visión con la miopía inducida. Conclusiones: la carta de Snellen presenta concordancia baja y variabilidad en los resultados moderada-alta, por lo que se sugiere la realización de estudios que evalúen la validez de la prueba en las poblaciones sana y con alteraciones visuales.
The visual acuity is the main characteristic evaluated to know how a person sees. For the visual acuity measuring it is used the letter chart, in Colombia the most used it is the Snellen Chart. Objective: To determinate the reliability inter e intraevaluator of Snellen Chart to test visual acuity. Methods: With convenience sampling two evaluators tested visual acuity with serif Snellen Chart to 110 subjects (220 eyes) who were university students between 15-30 years old, full distance refractive correction, normal binocular vision, and no pathologies of anterior and posterior of eye. A refractive error (myopia 1.50D) was induced for all the subjects and the trials were carrying out.Results: Visual acuity means was -0.06 (20/20+5), with induced myopia 0.51 (20/63). Wilcoxon sign rank test showed difference between inter evaluators (p=0,0001; p=0,007) in first trial and wearing plus lens +1.50D between inter evaluators in both trials ((p=0,03; p=0,001). Conclusions: Correlation Coefficient and Concordance of Lin showed a poor concordance and a moderated-high variability in the outcomes; then, Snellen chart has a poor concordance and moderate variability, so we suggest achieving researches about the validity of this test in the population with normal and subnormal vision.
Subject(s)
Middle Aged , Research , Visual AcuityABSTRACT
[Purpose] In Kampo medicine, blood deficiency is considered to cause systemic symptoms such as insomnia and dizziness, in addition to skin-related symptoms such as xeroderma. Diagnosis of blood deficiency does not appear to be definitive since it is based on subjective judgment. To resolve this problem, we have attempted to establish an objective method for diagnosing blood deficiency by measuring skin moisture.[Methods] Using a skin moisture meter, we measured the skin moisture (at the neck, forearm, and abdomen) of 80 women during their first examination at our clinic. The patients were also classified according to their blood deficiency scores.[Results] A statistically significant difference was observed between patients with blood deficiency and those without blood deficiency with regard to the skin moisture at the neck and forearm. The coefficient of correlation between the skin moisture of the neck and the blood deficiency score was -0.41.The results of statistical analysis performed using a type1quantification method revealed high values even for some conditions not associated with the skin, such as hypomenorrhea and excessive strain of the abdominal muscles, in addition to high values for skin-associated conditions. And in pre-post-treatment comparisons, improvements in blood deficiency scores generally matched transitions in keratinous moisture.[Discussion] Due to the absence of a high correlation between skin moisture and the blood deficiency score, it is unlikely that skin moisture can be used instead of the blood deficiency score as a parameter for the accurate diagnosis of blood deficiency.[Conclusion] Although skin moisture levels may be an indicator of blood deficiency, further studies are required before this parameter can be applied in clinical diagnosis.