他覚的屈折度（等価球面度数）を30年以上追えた988眼の屈折度の変化

Longitudinal changes in objective fraction in 988 eyes during thirty years or over

要約　目的：等価球面度数と乱視度に重点を置き，988眼で30年以上の経過を追った他覚的屈折度の変化の報告。

対象と方法：初診時の年齢が1〜59歳までの526例1,052眼のうち，眼疾患がなく，視力が0.5以上の988眼を対象とした。他覚的屈折度を，手動または自動屈折計で測定した。屈折度の経過は，30年以上，39年までを測定した。

結果：30年後の屈折は，初診時の年齢が29歳以下では近視化，30歳以上では遠視化の傾向を示した。乱視軸については，各年齢層を通じ，ほとんど変化しなかった。

結論：同一人の他覚的屈折度は，30年以上を経過しても乱視軸は変化しなかった。

Abstract　Purpose: To report longitudinal changes in objective fraction in 988 eyes during thirty years or over.

Cases and Method: This retrospective study was made on 988 eyes out of a series of 1052 eyes in 526 cases. They were aged from one to 59 years at the initial examination, were free of eye diseases, and had visual acuity of 0.5 or over. Refraction was measured by manual or automated refractometer. Cases were followed up for 30 years at least and maximally for 39 years.

Results: Refraction after 30 years tended towards myopia in cases initially seen below 29 years of age. It tended towards hyperopia when initially seen at 30 years or over. Throughout the age groups, there was virtually no change in the axis of astigmatism.

Conclusion: There was no change in the axis of astigmatism during the follow-up for 30 years or over.