低出生体重児における視力および屈折の変化

Longitudinal changes of refraction state and visual acuity in children with low birthweight

要約　目的：低出生体重児の視力と屈折の報告。対象と方法：出生時体重が1,500g未満であった171例342眼を検索した。屈折は等価球面度数で評価した。結果：光または冷凍凝固を受けない110眼では，2～5歳時の屈折は＋1.45±1.82D，半周に凝固を受けた88眼では－2.03±3.39D，全周に凝固を受けた94眼では－6.13±3.39Dであった。全周凝固群での5D以上の近視の頻度は在胎週数と反比例した。6歳時に矯正視力が1.0以上である頻度は，自然治癒群89.5％，半周凝固群83.3％，全周凝固群21.7％であった。5D以上の近視の頻度は，凝固の範囲と正の相関があった。全周凝固群の視力は半周群よりも有意に低かった（p＜0.01）。結論：光または冷凍凝固を受けない低出生体重児には強度近視が生じない。強度近視と視力発達遅延は全周凝固例に多い。

Abstract.　Purpose：To report refraction and visual acuity in children born with low birthweight. Cases and Method：We reviewed 342 eyes of 171 cases born with birthweight of 1,500 g or less. Refraction was evaluated as spherical equivalent. Results：At age 2 to 5 years,refraction averaged ＋1.45±1.82 D in 110 eyes that received no photo-or cryocoagulation,－2.03±3.39 D in 88 eyes with hemispherical,and －6.13±3.39 D in 94 eyes with circumferential coagulation. Incidence of myopia greater than 5 D was negatively correlated with gestational age. Incidence of visual acuity greater than 1.0 was 89.5％ in eyes without coagulation,83.3％ in eyes with hemispherical,and 21.7％ in eyes with circumferential coagulation. Incidence of high myopia was positively correlated with the extent of coagulation. Conclusion：Infants who received no coagulation did not develop high myopia. Circumferential coagulation resulted in high incidence of high myopia and impaired visual acuity.