日本人角膜鉄線の形と分布にみる角膜鉄線発生機序の細隙灯顕微鏡写真による研究

Slit-lamp photographic study on the pathogenesis of corneal iron line in the Japanese

要約　目的：細隙灯顕微鏡写真に基づいた角膜鉄線の発症機序の検討。対象と方法：外来患者5,342名を対象とした。角膜を細隙灯顕微鏡に装着したビデオで記録し，印画紙に焼き付けて鉄線の形と分布を検索した。結果：鉄線の両側と両端に表層細胞からの表面反射がない透明域があった。この透明域は鉄線がない角膜でも観察された。透明域は表層細胞表面の絨毛が多い細胞群であると推定した。鉄線と透明域の分布は渦状角膜の形と一致した。角膜片雲周辺の透明域の形は，水流が障害物の間で淀んだり流れを変えたりする形に類似した。鉄線と透明域には渦があり，渦の中心部と鉄線と透明域の交差部で鉄線が太くなった。結論：角膜鉄線では，基底細胞の移動と分化の速度変化がその発症に関与する可能性がある。

Abstract.　Purpose：To discuss the pathogenesis of corneal iron line. Object and Method：This study was made on 5,342 outpatients. The cornea was recorded by a video camera attached to a slit-1amp microscope. The shape and location of iron line was analyzed using printed data. Results：A transparent area was present that lacked reflex from superficial corneal cells and that was located along and at the end of iron line. This area was also present in corneas without iron line. It appeared that the transparent area showed cell clusters of superficial cornea rich in microvilli. The shape of transparent area near corneal nebule simulated that of water flow that stagnated or changed its direction by obstacles. A vortex was present along or in iron line and transparent area. The iron line became wide at the center of the vortex or intersection of iron line and transparent area. Conclusion：Changes in velocity of migration of basal cells may be causatively associated with iron line of the cornea.