円錐角膜に見られるボーマン膜断裂の臨床的意義について

Clinical significance of rupture in Bowman's layer in keratoconus

　円錐角膜でみられる角膜の形状変化を，細隙灯顕微鏡で観察されるボーマン膜断裂の変化に注目し，その関係について検討した．過去5年間に当科外来を訪れ，円錐角膜と診断された患者151名のうち，ボーマン膜断裂を認めたものが約40％あり，その変化を初期は棍棒状，中期は樹枝状，後期は網目状と分類した．その結果，樹枝状の時期を過ぎると角膜の形状変化が急速に進行し，網目状の時期になると角膜移植術を余儀無くされるために，樹枝状の時点で角膜熱形成術を施行することが望ましい．

A consecutive series of 151 cases with keratoconusduring the foregoing 5 years were evaluated with particular attention to the ruptures in Bowman's layer. A total of 254 eyes were affected as the series consisted of 103 bilateral and 48 unilateral cases. Keratoconus line was seen in 85% of affected eyes. Rupture in Bownman's layer and Descemet mem-brane was seen in 37% and 7% respectively.

Ruptures in Bowman's layer progressed in three stages manifesting: rod-like, dendritic and finally network structure. The protrusion of the corneatended to remarkably progress during the dendritic stage.

The findings indicate that energetic treatment is to be insituted during the dendritic stage including thermokeratoplasty and eventual penetrating ker-atoplasty.