最近20年間における未熟児網膜症の発症率と治療率の検討

Rate of occurrence and treatment of retinopathy of prematurity in the past twenty years

要約　目的：未熟児網膜症の発症率と治療率の，過去20年間の変遷の報告。対象と方法：1988～2007年に眼科的に検索した極低体重児960例を調査した。1996年までを前期，1997年以後を後期とした。結果：全例が出生体重1,500g以下で，403例が1,000g未満の超低出生体重児であった。未熟児網膜症の発症率は，前期では454例中250例（55.1％），後期では506例中204例（40.3％）であり，後期で有意に低かった（p＜0.05）。治療率は，前期16.8％，後期26.1％であった。超低体重児では，発症率が前期85.4％，後期64.2％であり，治療率は前期20.9％，後期34.9％であった。結論：未熟児網膜症の発症率は，1996年以前よりも1997年以後で低かった。治療を必要とした症例は，超低体重児と在胎週数28週未満児で前期よりも後期で多かった。

Abstract.　Purpose：To report changing trends of retinopathy of prematurity（ROP）during the past 20 years. Cases：This retrospective study was made on 960 infants with very low birthweight who were examined ophthalmologically from 1988 through 2007. Results：Birthweight was 1,500g or less in all and 1,000g or less in 403 cases. Incidence of ROP was 55.1％ before 1996 and 40.3％ after 1997. The difference was significant（p＜0.05）. Treatment for ROP was performed on 16.8％ and 26.1％ in the same periods. In 403 cases with birthweight of 1,000g or less,incidence of ROP was 85.4％ before 1996 and 64.2％ after 1997. Treatment was performed on 20.9％ and 34.9％ of cases in the same periods. Conclusion：Incidence of ROP was significantly lower after 1997 than before 1996. More treatment had to be performed after 1997 in infants with birthweigt of 1,000g or less or with gestational age less than 28 weeks.