Alternaria属による角膜真菌症の2例

Two cases of keratomycosis caused by Alternaria species

　黒色糸状菌の1つAlternaria属による角膜真菌症の2症例を経験した。1例は70歳男性で農作業中にみかんの枝で右眼を受傷した。細菌性角膜炎の診断で治療を受けたが改善せず，受傷10週後に受診した。右眼視力は0.09で，角膜潰瘍と実質の浸潤があった。角膜擦過物に菌糸が認められ，角膜真菌症と診断した。ミコナゾールの点眼などで治療し，3週間後に角膜潰瘍と浸潤は消失し，1.0の最終視力を得た。ほかの1例は70歳女性の農業従事者で，左眼の角膜ヘルペスとして治療を受けたが改善せず，発症から6週後に受診した。左眼視力は0.06で，角膜潰瘍と実質の浸潤があった。ミコナゾールの点眼などで治療し，3週後に角膜潰瘍と浸潤は消失し，0.6の最終視力を得た。両症例とも経過中に角膜擦過物の培養で糸状菌が分離され，Alternaria属と同定された。両症例に共通した所見として，角膜潰瘍の辺縁が不整で浸潤が角膜浅層に限局し，前房蓄膿がなく，進行が緩除であり，さらにアゾール系とポリエン系の抗真菌剤によく反応した。

　We observed two cases of keratomycosis caused by Alternaria species. A 70-year-old male was hit by a branch of orange tree in his right eye. Treatment for bacterial keratitis was futile. When seen by us 10 weeks after injury,the affected eye had visual acuity of 0.09 and had corneal ulcer with infiltrate in the anterior stroma. Hyphae were found in the corneal smear,leading to the diagnosis of keratomycosis. The corneal lesion promptly reacted to topical myconazol and others. The corneal ulcer healed 3 weeks later with the visual acuity of 1.0. The other was a 70-year-old female farmer. She was seen by us after 6 weeks of futile treatment for corneal herpes in her left eye. She showed similar findings as the former case. In both cases,culture of corneal scrapings showed filamentous fungi that were later identified as Alternaria species. The corneal lesion was characterized by irregular edge of ulcer,involvement of anterior corneal stroma only,absence of hypopyon,slow progression,and prompt response to azole and polyene antifungal agents.