Purpose: A population-based cataract epidemiological study, the Reykjavik Eye Study, was conducted to determine the prevalence and characteristics of lens opacities in Iceland. The results were compared with those from previous surveys in Japan to determine the influence of race and environmental factors. Methods: 1,635 randomly selected residents of Reykjavik, Iceland, were enrolled, and among them, 1,045 responded and took part in the study. The subjects received ophthalmological examination of both 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 of the extent of lens opacificiation were done using a standardized scheme, and the data were analyzed with Student’s test, the χ2 test and the Mantel-Haenszel test. Results: The prevalence of lens opacities in subjects in their 50s, 60s, 70s and in those 80 years and older was 42.7, 61.0, 85.3 and 100%, respectively. Grade II and III lens opacities were found in 2.2% of subjects in their 50s and in 10.5, 35.9 and 62.3% in their 60s, 70s, and over 80 years, respectively. Cortical opacities predominated in all age groups followed by nuclear opacities; subcapsular opacities, on the other hand, were quite rare. A unique type of opacity, i.e., granular opacity, seldom seen among the Japanese, was found in 6.6% of the Icelandic subjects. Conclusions: Our results show that cortical opacity is the major type of opacity in Icelandic subjects, although its prevalence was lower than that in the Japanese subjects. Interestingly, the first appearance of lens opacities of grades II and III in Icelanders was delayed by 10 years compared to the Japanese suggesting fewer or less severe risk factors for cataract formation in Iceland.

Keywords:
Ultraviolet light, Lens opacity, Lens opacity, epidemiology, Reykjavik Eye Study, Scheimpflug photography
1.
Maraini G, Pasquini P, Sperduto RD, Rosmini F, Bonacini M, Tomba MC, Corona R: Distribution of lens opacities in the Italian-American case-control study of age-related cataract. Ophthalmology 1990;97:752–756.
2.
Klein BEK, Klein R, Linton KLP: Prevalence of age-related lens opacities in a population. The Baever Dam Eye Study. Ophthalmology 1992;99:546–552.
3.
Mitchel P, Cumming RG, Attebo K, Panchapakesan J: Prevalence of cataract in Australia: The Blue Mountains Eye Study. Ophthalmology 1997;104:581–588.
4.
Taylor HR, West SK, Rosenthal FS, Muñoz B, Newland HS, Abbey H, Emmett EA: Effect of ultraviolet radiation on cataract formation. N Engl J Med 1988;319:1429–1433.
5.
Sasaki K, Ono M, Aoki K, Katoh N, Morine M, Nakaizumi H, Fujisawa K, Kojima M, Sakamoto Y, Hatano T: Cataract epidemiology survey in the three climatically different areas in Japan: Prevalence of cataracts and types of lens opacification (in Japanese). J Jpn Ophthalmol Soc 1995;99:204–211.
6.
Sasaki K, Kojima M, Sakamot Y, Fujisawa K, Asano K, Ono M, Katoh N: A current UV-B-related catarct epidemiology study in Japan. Dev Ophthalmol 1997;27:32–41.
7.
Chylack LT, Leske C, McCarthy D, Khu P, Kashiwagi T, Sperduto R: Lens Classification System II (LOCS II). Arch Ophthalmol 1989;107:991–997.
8.
Chylack LT, Wolfe JK, Singer DM, Leske MC, Bullimore MA, Bailey IL, Friend J, McCarthy D, Wu SY: The lens opacities classification and grading sytem III. Arch Ophthalmol 1993;111:831–836.
9.
Sasaki K, Shibata T, Obazawa H, Fujiware T, Kogure F, Obara Y, Itoi M, Katoh K, Akiyama K, Okuyama S: Classification system for cataracts. Application by the Japanese Cooperative Cataract Epidemiology Study Group. Ophthalmic Res 1990;22(suppl):46–50.
10.
West SK, Rosental F, Newland HS, Taylor HR: Use of photographic techniques to grade nuclear cataracts. Invest Ophthalmol Vis Sci 1988;29:73–77.
11.
Taylor HR, West SK: The clinical grading of lens opacities. Austr NZ J Ophthalmol 1989;17:81–86.
12.
Sasaki K, Karino K, Takizawa A, Kojima M, Sakamoto Y, Zainuddin D, Kawano S, Kawano T: Epidemiological survey of cataract in a local population. Jpn J Clin Ophthalmol 1987;41:763–767.
13.
Sasaki K, Zainuddin J, Fujisawa K, Kojima M, Sakamoto Y: Cataract epidemiology study in West Sumatra. Dev Ophthalmol 1989;17:26–32.
14.
Zainuddin D, Sasaki K, Kojima M, Sakamoto Y, Fujisawa K: Risk factor analysis in a cataract epidemiology survey in West Sumatra, Indonesia. Dev Ophthalmol 1991;21:78–86.
15.
Sasaki H, Asano K, Kojima M, Sakamoto Y, Kasuga T, Nagata M, Takahashi N, Sasaki K, Ono M, Katoh N: Epidemiological survey of ocular diseases in K Island, Amami Islands: Prevalence of cataract and pterygium (in Japanese). J Jpn Ophthalmol Soc 1999;103:556–563.
16.
West SK, Muñoz B, Rubin GS, Schein OD, Bandeen-Roche K, Zeger S, German S, Fried LP: Function and visual impairment in a population-based study of older adults: The SEE Project. Salisbury Eye Evaluation. Invest Ophthalmol Vis Sci 1997;38:72–82.
17.
Kelsy JL, O’Brien LA, Grisso JA, Hoffman S: Issues in carrying out epidemiologic research in the elderly. Am J Epidemiol 1989;130:857–866.
18.
Sakamoto Y, Sasaki K: Accuracy of biochemical data obtained from the NIDEK EAS-1000. Opthalmic Res 1994;26(suppl):26–32.
19.
Shibata T, Sasaki K, Sakamoto Y, Takahashi N: Quantitative chamber angle measurement utilizing image-processing techniques. Ophthalmic Res 1990;22(suppl):81–84.
20.
Katoh N, Sasaki K, Obazawa H: Interview form applied to a cataract epidemiologic study. Dev Ophthalmol 1991;21:108–114.
21.
Sasaki K, Shibata T, Masuyama M, Hatano T: Judgement of cataractous changes applying a new system of image analysis in epidemiological studies. Dev Ophthalmol 1994;26:19–24.
22.
Sasaki K, Sakamoto Y, Fujisawa K, Kojima M, Shibata T: A new grading system for nuclear cataracts – An alternative to the Japanese Cooperative Cataract Epidemiology Study Group’s grading. Dev Ophthalmol 1997;27:42–49.
23.
Sasaki K: Current cataract epidemiology in Japan. 1st Int Symp Ophthalmol (Japan), Jpn Ophthalmol Soc, Tokyo, 1996.
24.
World Health Organization. Environmental Health Criteria 160. Ultraviolet Radiation. Geneva, World Health Organization, 1994.
25.
WHO: The effect of solar UV radiation on the eye. Report of an informal consultation. Geneva, 30 August–3 September, 1993. WHO/PBL/94.1.
26.
Sasaki K, Sakamoto Y, Shibata T, Emori Y: Multi-purpose camera: A new anterior eye segment analysis system. Ophthalmic Res 1990;22(suppl):3–8.
27.
Cruickshanks KJ, Klein BEK, Klein R Ultraviolet light exposure and lens opacities: The Beaver Dam Eye Study. Am J Public Health 1992;82:1658–1662.
28.
West SK, Duncan DD, Muñoz B, Rubin GS, Fried LP, Bandeen-Roche K, Schein OD: Sunlight exposure and risk of lens opacities in a population-based study. The Salisbury Eye Evaluation Project. JAMA 1998;280:714–718.
29.
Leske MC, Connell AM, Wu SY, Hyman L, Schachat A: Prevalence of lens opacities in the Barbados Eye Study. Arch Ophthalmol 1997;115:105–111.
30.
Jonasson F, Thordarson K: Prevalence of ocular disease and blindness in a rural area in the eastern region of Iceland during 1980 through 1984. Acta Ophthalmol 1987;65(suppl):40–43.
31.
Cumming RG, Mitchell P: Hormone replacement therapy, reproductive factor, and cataract. The Blue Mountains Eye Study. Am J Epidemiol 1997;145:242–249.
32.
Kahn HA, Leibowitz HM, Ganley JP, Kini MM, Colton T, Nickerson RS, Dawber TR: The Framingham Eye Study. II. Association of opthalmic pathology with single variables previously measured in the Framingham Heart Study. Am J Epidemiol 1977;106:33–41.
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2000
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