結核患者の右眼にみられた虹彩結節の1例

Iris tubercles in the right eye of a patient with tuberculosis

　49歳の男性肺結核患者の右眼に，結核治療開始7か月を経てのち，結節性虹彩炎が出現した。初診時は6時および12時部瞳孔縁に小結節が認められた。散瞳後，6時の虹彩裏面からカリフラワー状の多房性結節が前房中に出現した。既往歴から結核性を疑い，前房水を採取し，抗酸菌培養とPCR法にて検索したが陰性であった。すでに抗結核薬の投与を受けていたためステロイド点眼薬と散瞳薬を投与した。4か月後，結節のあった瞳孔縁に虹彩後癒着を残し，治癒となった。眼結核は右眼に多く，右片眼性の結節性虹彩炎は結核の可能性がある。結核は，内服開始後3か月を経過すると菌は検出できない。治療的診断であろうと，投薬前に菌の検査が必要である。

A 49-year-old male developed nodular iritis in his right eye 7 months after initiation of treatment for pulmonary tuberculosis. Two tubercles were present at the pupillary margin, at 6 and 12 o'clock positions. Following mydriasis, a multilobular tubercle emerged in the anterior chamber. No causative organisms could be isolated from the aqueous by polymerase chain reaction (PCR) or culture for acid-fast bacteria. Along with continued systemic treatment with three preparations for tuberculosis, the affected eye was treated by topical instillation of corticosteroid and mydriatics. A clinical cure was obtained 4 months later leaving posterior synechia. It is claimed that ocular tuberculosis tends to involve the right eye, so that nodular iritis in the right eye has a greater liability to be due to tuberculosis. It is advocated to isolate Mycobacterium tuberculosis at an early period, either by culture or PCR method, as it cannot be detected after 3 months of systemic treatment for tuberculosis.