ACTA OPHTHALMOLOGICA 66 (1988) SUPPI. 184, 120-122

PREVALENCE OF EXFOLIATION SYNDROME IN FINLAND

U. Krause, H. I . Alanko, J. Karna, R. Miettinen, T. Larmi, E. Jaanio, 0-1. Ollila and J. Takala

Department of Ophthalmology (Head: Professor P. J . Airaksinen) University of Oulu, Oulu, Finland

Abstract. Three separate investigations are reported, covering a total of 795 patients from different parts of Finland, two of them consisting of inmates of old people’s homes in two towns (N=205 and 262) and one a randomly selected population from Q rural com- mune (N = 328). They show the mean prevalence of ex- foliation syndrome (PS) to be 14.2 Vo in age group 60 <69 years, 21.9 Vo in age group 70-79 and 34.7 Yo in age group 2 80. The prevalence increases statistically significantly with age. The mean prevalence of PS in all three groups was 22.4 Vo. No isolate-like accumula- tion of PS could be demonstrated. The figures seem representative of the hole country.

Key words: exfoliation syndrome - epidemiology - prevalence - age dependence.

I n t roduct ion

The exfoliation syndrome (ES), originally de- scribed in a little observed thesis by the Finnish ophthalmologist Lindberg in 1917, has later been studied in several Finnish investigations. Tark- kanen (1962) for example, presented some pedi- grees showing the hereditary nature of PS and Vannas (1969) has described the occurrence of new vessels in the iris stroma by fluorescein angiography .

The prevalence of ES in the region of Oulu in the middle of Finland has been analysed in three separate investigations. Of all glaucoma patients treated at the Department of Ophthalmology in Oulu, 26.1 Vo had capsular glaucoma (Krause 1973). Inmates of an old people’s home in that

120

region had a mean prevalence of ES of 21.8 Vo (Krause et al. 1973). The incidence increased with age and showed a prevalence value of 35.7 Vo among patients aged 80-89 years. A material consisting of 100 consecutive eyes operated on for senile cataract (Krause & Tarkkanen 1976) revealed a histopathological occurrence of ex- foliation material on the Iens in a total of 33 eyes, with a tendency toward a higher prevalence in the older patients, the figure being 50 Yo in the age group > 80 years. As the population of the Oulu region was relatively stationary in earlier times, a possible genetically determined accumulation of PS could not be excluded.

The purpose of this article is to evaluate the prevalence of ES in Finland, based on similarly designed investigations in three different parts of the country.

Material and Methods

The series consisting of 795 persons (Table l), is based on three separate groups: Group I consists of 205 in- mates of an old people’s home in the town of Oulu aged 2 60 years (Krause et al. 1973), Group I1 is simi- larly composed of inmates from old people’s home from Helsinki, all 2 60 years (N = 262) (Karna et al. unpublished data), and Group I11 consisted of 328 ran- domly sampled patients aged > 65 years (Alanko et al. unpublished data) corresponding to 26.1 Yo of the 1257 inhabitants of that age in the commune of Kuusamo in the eastern part of Finland.

The patients from Groups I and I1 were investigat- ed according to the following protocol: The occurrence

PREVALENCE OF PSEUDOEXFOLIATION

M group I Oulu N=205 w group II Helsinki N=262 pd group Ill Kuusamo N.328

% I % 50

40

3 0

20

10

-

-

-

-

-

P 50

40

30

20

1 0 1 d

-

-

-

-

L 60-69 70-79 80- Age

PREVALENCE OF PSEUDOEXFOLIATION

IN FINLAND N.795

L 60-69 70-79 80- Age

Fig. 1. The prevalence of exfoliation syndrome (ES) in groups 1-111 (Yo). Insert: Map of Finland.

Fig. 2. Mean prevalence of exfoliation syndrome (ES) in groups 1-111 (Yo).

of exfoliation was diagnosed by biomicroscopy after instillation of mydriatics if exfoliation particles were found at the pupillary border, lenticular surface or pos- terior corneal surface. Only definite findings were recorded as positive. Aphakic eyes, eyes with pupil- lary synechiae caused by uveitis and badly injured eyes were excluded from the investigation because of dif- ficulties to diagnose early stages of PS without my- driasis. The age and sex of the patient were recorded and also the place of birth, in order to evaluate wheth- er or not the group could be characterised as an isolate. In Group 111 the diagnostic criteria were the same, but 9.5 Yo of the eyes were examined without mydriasis. The material includes 24 patients with aphakia, in whom signs of exfoliation were sought in the anterior vitreous face as well as the customary locations.

Resu I ts

As reported earlier (Krause et al. 1973), 10.0 070 of those investigated in the age group 60-69 years in Group I had ES, of the age group 70-79 23.2 070 and 35.7 070 of those aged 80 years or more (Fig. 1). Most of the patients were born in or around Oulu, and may thus represent an iso- late with an accumulation of the ES. The cor- responding figures in group I1 were 19.1 070, 21.6 070 and 28.4 070, respectively (Fig. 1). The pa- tients were born all over the country with a defi- nite dominance on the part of the town of Hel- sinki. There is no statistical difference between

Table 1. The investigated material and the prevalence of exfoliation syndrome (ES) in the age groups.

Age groups Group I Group I1 I Group 111 I Total/ES 1 ES Yo I N/ES 1 N/ES N/ES

60-69* 70-79 80- >

50/5 47/9 142/20 239/34 14.2 99/23 134/29 150/32 383/84 21.9 56/20 8 1 /23 36/17 173/60 34.7

Total 205/48 262/6 1 328/69 795/178 22.4

N =number of patients ES = patients with exfoliation syndrome * =in Group 111 the age group is 65-69 years

121

the prevalence of PS in group 1 and I1 (chi- square, p > .05) in each age group.

In group 111 the figures for ES were 14.1 Yo, 21.3 Yo and 47.2 Yo for the three age groups (Fig. 1). Eight aphakic patients had ES. Statistically the figures for the prevalence of ES in this group do not differ f rox those in Groups I and I1 (chi- square, p:C).OS). Although not tested in detail, it seems that the place of birth with a few excep- tions was identical to the place of residence.

As we could not observe any aifferences between these three populations by statistical methods, we concluded that they were similar and added the results together. The prevalence of ES in this combined series was 14.2 Yo, 21.9 Yo and 34.7 Yo in the three age groups respectively (Fig. 2). The difference between the prevalence figures of the age groups was statistically significant (p < .05, chi-square). The mean prevalence of ES was 22.4 Yo in the total material.

Discussion

Two of the series in which the prevalence of ES was investigated (Group I and 11) consisted of people living at old people’s homes. Most of the patients in Group I had been born in or near the town of Oulu, indicating immobility in the population, and as expected, it was found that the place of birth in Group I1 covered large areas of the south of Finland. The result may have been influenced by selection in the material, but, the figures for the prevalence of ES are nevertheless statistically similar to those in Group 111, con- taining randomly sampled patients. The notes on

the places of birth thus seem to exclude the pos- sibility of an isolate-determined incidence of ES in any of the groups. It seems justified to con- clude that each of the groups is representative of the prevalence of ES in the whole country and shows it tg be both age dependent and to be one of the highest prevalence figures reported.

Reterences

Krause U (1973): Frequency of capsular glaucoma in central Finland. Acta Ophthalmol (Copenh) 51:

Krause U, Helve J , Forsius H (1973): Pseudoexfolia- tion of the lens capsule and liberation of iris pig- ment. Acta Ophthalmol (Copenh) 51: 39-46.

Krause U, Tarkkanen A (1978): Cataract and pseudo- exfoliation. A Clinicopathological Study. Acta Ophthalmol (Copenh) 56: 329-334.

Karna J , Krause U, Larmi T: Prevalence of pseudo- exfoliation of the lens capsule in southern Finland. To be published.

Lindberg J G (1917): Kliniska undersokningar over depigmenteringen av pupillarranden och genom lys- barheten av iris vid fill av Bldersstarr samt i nor- mala ogon hos gamla personer. Thesis. Helsinki.

Tarkkanen A (1962): Pseudoexfoliation of the lens cap- sule. Acta Ophthalmol (Copenh) Suppl 71.

Vannas A (1969): Fluorescein angiography of the ves- sels of the iris in pseudoexfoliation of the lens cap- sule, capsular glaucoma and some other forms of glaucoma. Acta Ophthalmol (Copenh) Suppl 105.

235-240.

Author‘s address: U. Krause, MD, Department of Ophthalmology, Kajaanintie 50, SF-90220 Oulu, Fin- land.

122