地域住民を対象とした白内障の疫学的調査

Epidemiological survey of cataract in a local population

　都市近郊型に属する一定地域の40歳以上の住民1,020名を対象に、構成人口基盤による白内障の疫学的検索を行った．水晶体の混濁の状況は，散瞳下に細隙灯で観察した所見と，スリット像，および徹照像の撮影画像から総合的に判定した．白内障の程度は，初期変化を含めたもの，初発白内障がはじまったもの，明らかに進行をはじめた白内障の3段階に分類した．混濁の形態は，皮質，核，嚢下皮質，これらの混合型，およびその他に分類した．初期白内障性変化を含めた有所見率は，40代で33.9％，50代62.8％，60代76.2％，70代84％，80代100％であった．明らかな白内障を呈していたものは，40代で1.6％，50代3.1％，60代19.0％，70代28.6％，80代57.1％であった．60歳代までは皮質混濁単独のものが主体であったが，70歳代からは，核部，おもび後嚢下混濁を伴うものが増加した．核部のみの混濁は70代になり増えていた．赤道部皮質の混濁は初期には21％が下方に，13％が全周から出現した．50代以降では下方の混濁が上方に比べ有意に高くなっていた．

We performed an epidemiological survey of cata-ract in a geographically limited local population in suburban Kanazawa. A total of 1,020 individuals aged 40 years and over were evaluated. After takinghistories, we examined each individual as to visual acuity, intraocular pressure, funduscopy and slit-lamp examination of the lens under mydriasis. The state of the lens was recorded by Scheimpflug and retroillumination photography.

The cataract was graded into 3 groups : early senile changes, incipient cataract and advanced cataract.

The incidence of cataract, including early senile changes, amounted to 33.9% in the fifth decade, 62.8% in the sixth, 76.2% in the seventh, 84% in the eighth and 100% in the ninth.

Marked cataractous opacification was present in1.6% in the fifth decade, 3.1% in the sixth, 19.0% in the seventh, 28.6% in the eighth and 57.1% in the ninth. Before the age of 60, the lens opacity was mainly of cortical type. After the age of 70, there was an increase in cortical opacity associated with nuclear and/or subcapsular opacities. Pure nuclear opacity increased after the age of 70. As regards cortical opacity in the equator, 21% were located in the inferior nasal quadrant and 13% were located inall the four quadrants. Equatorial cortical opacities in individuals over 50 years in age were located more frequently in the inferior two quadrants than in the superior ones.

Rinsho Ganka (Jpn J Clin Ophthalmol) 41(7) : 763-767, 1987