Prevalencia de ceguera y limitación visual severa, en personas mayores de 50 años de Ciudad de La Habana / Prevalence of blindness and severe visual shortage in over 50 years-old adults in the City of Havana province

RESUMEN

Se realizó un estudio descriptivo de corte transversal, cuyo universo estuvo constituido por la población mayor de 50 años perteneciente a Ciudad de La Habana, en el período comprendido entre junio de 2004 a junio del 2005. Para la determinación del tamaño de la muestra se asumió como universo los 633 396 habitantes mayores de 50 años de Ciudad Habana, con una estimación de la prevalencia esperada de 4,0 por ciento, un error aceptable del 3 por ciento y un efecto de diseño de 70 por ciento. Se efectuó un muestreo sistemático por conglomerados y se determinó como muestra 2 760 habitantes de Ciudad de La Habana, representada por 46 cluster de 60 individuos cada uno. Se definió como ceguera la agudeza visual con corrección, inferior a 20/400 y la deficiencia visual grave como la agudeza visual con corrección >20/400 y <20/200, a partir del ojo que presentara mayor posibilidad de corrección (mejor ojo). Se realizó además una variación entre observadores para disminuir la introducción de errores por esta causa. El estudio tuvo una cobertura de 98,4 por ciento de la muestra seleccionada. La prevalencia de ceguera por sexos fue de 2,4 por ciento en total. La prevalencia por edad aumenta desde un 2,6 por ciento con 50 años a 15,2 por ciento con 80 años y más de personas ciegas bilaterales...

ABSTRACT

The universe of a cross-sectional descriptive study, which was carried out from June 2004 to June 2005, was made up of people aged over 50 years, who lived in the City of Havana. In order to determine the sample size, 633 396 over 50 years-old inhabitants were taken as the universe of study, with an expected prevalence estimation of 4.0 percent, an allowable error of 3 percent and a design effect of 70 percent. On the basis of these data, systematic cluster sampling was made to determine a sample of 2 760 inhabitants from the City of Havana, represented by 46 clusters of 60 subjects each. Blindness was defined as corrected visual acuity lower than 20/400 and severe visual shortage as corrected visual acuity >20/400 and <20/200 in the best eye and with the best available correction. An inter-observer variation to reduce errors for this reason was also made. The study coverage was 98.4 percent of the selected sample. The blindness prevalence by sex was 2.4 percent. Prevalence of bilateral blind persons by age increases from 2.6 percent at 50 years to 15,2 percent at 80 years and over. The most important causes of bilateral blindness were cataract (50 percent), glaucoma (26 percent) and diabetic retinopathy (9 percent) for a total number of 15 201 bilateral blind people due to all these causes, 27 236 with low vision and 42 437 individuals with visual acuity under 20/200 of whom 16 468 were affected by cataract. The main barriers to cataract surgery was mostly found in the group of persons (41 percent) who stated that they did not know they had this disease; 25.2 percent of responses came from individuals who presented with a disease that contraindicated the surgery; 10.1 percent of responses were given by those waiting for cataract maturation and 6.5 percent did not have any accompanying person to take care of them after being operated on...