3次元モデルを用いた脈絡膜血管構造の加齢性変化

Aging of the choroidal vasculature evaluated by three-dimensional models

要約　目的：脈絡膜血管3次元モデルを用いて脈絡膜血管構造を数量的解析し，年齢や脈絡膜厚との関連を検討した。

対象と方法：眼軸長を調整した屈折異常以外の眼科的疾患のない66例100眼を対象とした。Swept-source OCTを用いて撮影を行った。既報に基づき脈絡膜3次元モデルを作製し，脈絡膜体積，脈絡膜血管容積，脈絡膜血管密度を算出，年齢や脈絡膜厚との関連をそれぞれ検討した。

結果：年齢と脈絡膜体積，脈絡膜血管容積とは，中心窩中央，傍中心窩ともに負の相関があった。年齢と脈絡膜血管密度とは，中心窩中央では相関性はなかったが，傍中心窩では負の相関があった。中心窩下脈絡膜厚と脈絡膜血管密度とは中心窩中央，傍中心窩ともに正の相関があった。

結論：3次元モデルの使用により，より詳細な脈絡膜構造解析が可能となった。脈絡膜血管は，その部位により加齢による構造変化が異なる可能性がある。

Abstract　Purpose：To investigate the choroidal vasculature using three-dimensional models and its correlations with aging and choroidal thickness.

Methods：Sixty-six normal subjects with one hundred eyes were examined. Long axis length and severe myopia were excluded. Three-dimensional models of choroidal vessels were created using swept-source optical coherence tomography. Choroidal volume, choroidal vessel volume, and choroidal vessel density were calculated. The correlation coefficients between age and the other parameters were calculated by Pearson product-moment correlation coefficient. The 66 subjects were classified into two groups based on age：young group（under 40 years old）and old group（40 years old and over）. Intergroup differences in each parameter were calculated by the Wilcoxon rank sum test.

Results：Choroidal volume and choroidal vessel volume showed negative correlations with age in the fovea and parafovea. Choroidal vessel density was negatively correlated with age at the fovea center, but not correlated with age at the parafovea. Subfoveal choroidal thickness was positively correlated with choroidal vessel density.

Conclusions：Three-dimensional models enabled more detailed analysis of the choroidal vasculature. Choroidal vasculature changes that occur with aging may be different in the fovea center than that in the parafoveal area.