Visual impairment in Nordic children

Abstract

The diagnoses, according to type and site and the degree of visual impairment, responsible for severe visual impairment in children below the age of 18, were analyzed in a material compiled from the national registers of visually impaired in Denmark, Finland, Iceland and Norway. Among 2527 children the predominant causes of visual impairment are ascribed to congenital malformations, neuro-ophthalmological diseases and retinal diseases. Optic atrophy is the leading single cause of severe visual impairment when all diagnoses are compared, and this also applies when all categories of visual impairment are included. Retinopathy of prematurity is the second principal cause of severe visual impairment, while cerebral amblyopia rates as the third most significant cause. Congenital cataract is also of considerable importance when all categories of visual impairment are compared. The differences registered between the Nordic countries were found to be within reasonable limits, except for a preponderance of neuro-ophthalmological diseases in the Danish material. This could be explained by a better medical supervision of mentally retarded patients in Denmark. Additional impairments occur in a large percentage of patients, but are unevenly distributed in the disease groups. A high frequency of additional impairments are found in the neuro-ophthalmological group and in the groups with congenital malformations, emphasizing the importance of a multidisciplinary evaluation when dealing with the visually impaired child.

Visual impairment in Swedish children

“…In a similar study from the other Nordic countries ) the most common diagnoses are the same, but in the Swedish material we have considerably higher prevalences of cerebral visual impairment and nonhereditary optic atrophy, as well as hypoplasia of the optic nerve, while the prevalence of retinopathy of prematurity was lower. From a general point of view, these four diagnoses in addition to malformations have been the predominant causes of visual impairment in a number of studies performed during the last decades (Skydsgaard 1955;Vannas & Raivio 1964;Lindstedt 1972Lindstedt , 1975Pearce 1975;Schappert-Kimmisjer 1975;Halldorsson & Bjornsson 1980;Hansen Peckham 1986;van der Pol 1986;Rosenberg 1987;Hansen et al 1992). …”

“…In 1990 data from the continuous registration in Denmark, Finland, Iceland and Norway were compiled into a common database, resulting in a register of 2527 children altogether. Based on this a thorough analysis was made of prevalence, etiologies and diagnoses Rosenberg et al 1992;Hansen et al 1992). Sweden could not be included, since the earlier registration (Lindstedt 1972(Lindstedt , 1975 had been dormant.…”

Visual impairment in Nordic children

“…A detailed description of the registers and the methods of compilation is presented by Riise et al (1992). Hansen et al (in press) describes the material from a nosological point of view.…”

“…This age group counted 3.303.698 individuals with the following distribution; Denmark (D): The inclusion criterion for registration in Denmark was a best corrected visual Snellen acuity equal to or lower than 6/18 of the better eye, or binocularly. In Finland, Iceland, and Norway a visual acuity lower than 6/18 was required for registration, Riise et al (1992).…”

Visual impairment in Swedish children

“…In the Nordic countries there exists a well established tradition of registration of visual impairment (Norrie 1927;Holst 1950;Skydsgaard 1955;Vannas & Raivio 1964;Lindstedt 1972;Halldorsson & Bjornsson 1980;Hansen 1981;Rosenberg 1987). In 1990 data on 2527 visually impaired children included in the national registers in Denmark, Finland, Iceland and Norway were compiled into a common database by the so-called Nordsyn study group (Riise et al 1992a,b;Rosenberg et al 1992;Hansen et al 1992;Rudanko et al 1993). The Swedish register formed in the 1960's (Lindstedt 1972(Lindstedt , 1975a had not been kept updated and Sweden could thus not be included in this common Nordic work.…”