Abstract
Abstract: :
Purpose:To establish the 5-year incidence and progression of three types of lens opacities in an Icelandic population 55 years and older. Methods: The 1045 subject who participated in The Reykjavik Eye Study in 1996 were reexamined 5 years later in 2001. During the 5 years, 87 had died and out of the 958 survivors, 842 or 88% participated. The mean age of the participants was 69.0 years old (55-100 years old). All the subjects received ophthalmological examination and photographic documentation of the anterior and the posterior segments. Changes in the crystalline lens were examined and photographed under maximal pupillary dilation. Classification of the opacity types and grading was done by a single observer using the Japanese Cooperative Cataract Epidemiology Study Group System (JCCESG System) and the simplified cataract classification and grading system established by WHO (WHO system).Results:Of the 842 participants in 2001, 81 (24.9%) of 324 subjects who had transparent lenses in both eyes in 1996 developed lens opacity (Grade 1 or over in JCCEG system) in 2001. The 5-year incidence was 25.0% in males and 24.9% in females. The 5-year incidence by age was 8.4% from 55 to 64 years old, 42.5% from 65 to 74 years old and 57.7% from 75 to 84 years old. The incidence of cortical, nuclear and subcapsular opacity (Grade 1 or over in JCCEG system) was 18.5%, 7.7% and 2.5%, respectively. Conclusion: The 5-year incidence of lens opacities in this Icelandic population was established. The incidence of lens opacification increased rapidly after age 60. Cortical opacity was most prevalent in this population.
Keywords: 338 cataract • 354 clinical (human) or epidemiologic studies: prevalence/incidence • 352 clinical (human) or epidemiologic studies: natural history