ヒト生体角膜内皮同一細胞群の2年間の観察でわかった細胞脱落前後の細胞動態と恒常性維持機構

Dynamics of corneal endothelial cells before and after cell drop-out and mechanism of stabilization in human eyes based on observation for two years

要約　目的：ヒト角膜内皮細胞の動態の報告。対象と方法：健康人8名16眼の角膜中央部の内皮を，スぺキュラーマイクロスコープで1週間に1回，2年間記録した。年齢は22～76歳（平均39歳）である。横断的解析群として，外来患者104名の角膜を同様に記録した。結果：角膜内皮には，細胞脱落前から多形性と大小不同が生じ，脱落後にこれが顕著化し，最終的に細胞面積が均等化した。これらの変化は，脱落細胞を囲む細胞群のみにあった。すべての細胞群で，内皮細胞の角数の平均は6.0であった。角数の変化は，細胞移動と脱落を反映した。結論：健康なヒト角膜内皮の細胞脱落は，プログラムされた現象であり，細胞角数の変化が細胞の移動と脱落を反映する指標であり，角膜面に垂直な方向から見た内皮細胞を正六角形に維持する機構があることが推測される。

Abstract.　Purpose：To report the dynamics of corneal endothelial cells in human eyes. Cases and Method：This retrospective study was made on 16 eyes of 8 healthy persons. The age ranged from 22 to 76 years（mean age 39 years）. The endothelium in the corneal apex was recorded by specular microscopy once a week for 2 years. Another series of 104 patients were examined and recorded by specular microscopy. Results：Corneal endothelial cells showed pleomorphism and polymegetism before drop-out of cells. The finding became more apparent after drop-out. The cell size finally approximated the average value. Oserved pleomorphism and polymegetism were present in cell group around the drop-out cells. In all cell groups, the number of angles averaged 6.0. Changes in the number of angles reflected cell migration or drop-out. Conclusion：The findings seem to show that endothelial cell drop-out occurs as a programmed phenomenon, that changes in the number of angles reflect migration or drop-out of endothelial cells, and that a mechanism is present to keep the hexagonal shape of endothelial cells when seen vertical to the corneal surface.