[Occurrence of eardrum pathology in a cohort of adults born 1955].

The aim of this study was to estimate the prevalence of the different types of eardrum pathology in a cohort (cohort 1955) who were children before the era of ventilation tubes, and to compare these findings with the prevalence of eardrum pathology in a previous published cohort study on 222 children followed since the age of four years (cohort 1975) in the era of ventilation tubes. All inhabitants of Hillerød county born in 1955 were invited to a screening examination including otomicroscopy, tympanometry and audiometry. All eardrum pathology was recorded. In cohort 1955, 59% of 460 possible, attended the examination. In addition 9% returned a questionnaire enquiring their otologic history. In the cohort with no grommets, retraction of Shrapnell's membrane was found in 4% of the ears compared to 20% in the cohort with grommets. Tensa pathology was found in 6% of the ears in the old cohort and in 24% in the young cohort. Despite the increased attention to the diagnosis of secretory otitis, and the increased rate of surgical treatment, the prevalence of eardrum pathology seems to have increased. The reason for this increase is discussed.