超音波による新生児の未熟度と眼軸長の比較

Axial length in neonatal eyes related to the degree of prematurity

　新生児114例228眼の眼軸長計測を行い，全身所見との関連を検討した。眼軸長と出生体重，在胎週数，体表面積，頭囲，身長，胸囲に相関関係がみられた。また，眼軸長と未熟児網膜症のstageにおいては逆相関関係がみられた。未熟児網膜症で冷凍凝固を行ったstage 3は，眼軸長16.6mm以下で，出生体重1,080g以下，身長34cm以下，体表面積0.104m²以下，在胎週数28週4日以下，胸囲23.2cm以下，頭囲24.7cm以下に，全例が含まれた。

　出生体重2,500g未満の未熟児の眼軸長の平均は16.6mm，出生体重2,500g以上の成熟児の眼軸長の平均は16.9mmで，平均値の差の検定において2,500g未満の未熟児が有意に眼軸長が短かった（p＜0.001）。

We measured the axial length in 228 eyes in 114 newborn babies using A- and B-scan ultrasono-graphy. The axial length was positively correlated with gestational age, birthweight, body surface area,body height and chest girth. It was negatively correlated with the degree of prematurity. All the 6 eyes withstage 3 of retinopathy prematurity showed axial length of less than 16.6mm, birthweight under 1,080 g, bodyheight under 34cm, body surface area under 0.104m², gestational age under 29 weeks, chest girth under 23.2cm and head girth under 24.7cm. The axial length averaged 16.6mm in babies with birthweight less than2,500g and 16.9mm in those over 2,500g. The difference was significant (p＜0.001).