Current trends in newly registered blindness in Denmark

Abstract

Current pattern of blindness (i.e. visual acuity < or = 6/60) in Denmark was studied based on 1585 application forms for new membership to the Danish Society of the Blind during 1993. Statistics on blindness are very sensitive to the definitions used. A change of blindness definition to visual acuity < 6/60 reduced the number of formally blind subjects with 32%, and by using the definition of WHO (visual acuity < 3/60) only 562 subjects (35%) would have been considered blind. The prevailing causes of blindness were age-related macular degeneration with 1132 cases (71.4%), followed by diabetic retinopathy 133 cases (8.4%), and glaucoma 80 cases (5.0%). Among the younger subjects (133 persons) aged 20-59 years diabetic retinopathy comprised 36% and lesions of the optic pathways 26%, while myopia and retinitis pigmentosa accounted for 5% each. The majority of the applicants (92%) were > or = 60 years old. In this group, age-related macular degeneration was the main cause of blindness in 78%. Figures from 1993 were compared with six similar studies on newly registered blindness from the last 35 years. The annual number of registrations was doubled during the last 25 years. The annual number of registered blind due to diabetic retinopathy fell during the 60's and 70's followed by a constant rate during the last decades. Glaucoma blindness fell with a factor two, and declined from a relative frequency of 15% among the causes of blindness to 5%. The impact of age related macular degeneration increased from 20% to 70% during the same period.