超音波乳化吸引術後に発症したepithelial downgrowthの1例

Epithelial downgrowth that developed after small incision phacoemulsification and aspiration

要約　目的：今回，小切開超音波乳化吸引術（PEA）後に発症したepithelial downgrowth（眼内上皮増殖）の1例を経験したので報告する。

症例：83歳，女性。2022年12月に前医でPEA，眼内レンズ挿入術を行った。術後の経過は問題なかったが，10か月経過した2023年10月に右視力低下を自覚した。前医を受診し右眼の極端な縮瞳と虹彩面上に異常血管を認めたため，福岡大学病院に紹介となった。初診時の右視力は20cm/手動弁であり，眼圧は16mmHgであった。瞳孔はほぼ閉鎖しており灰白色の膜様構造物があり，隅角には上方のみ異常血管を認めた。

結果：瞳孔閉鎖による視力低下を認めたため，瞳孔形成術を行ったが，術後3か月で再度瞳孔閉鎖をきたした。虹彩面上の灰白色の膜様組織と強角膜創部に間隙があったことから，epithelial downgrowthを疑い，再度瞳孔形成術，膜様組織の除去，ジアテルミーによる熱凝固を組織学的に行った。組織学的検査では重層の上皮組織を認め，epithelial downgrowthによる瞳孔閉鎖，虹彩面上への結膜組織の増生と考えられた。右眼の最終視力は（0.7）であり，現在眼内に結膜組織の再増生はみられない。

結論：Epithelial downgrowthは小切開PEAの長期経過後にも発症する可能性がある合併症として考慮すべきである。

Abstract　Purpose：A case of epithelial downgrowth development after small-incision phacoemulsification and aspiration（PEA）.

Case：An 83-year-old woman. underwent phacoemulsification, surgery, and intraocular lens implantation at a hospital in December 2022. There were no issues post surgery；however, 10 months later, in October 2023, she noticed a decrease in vision in her right eye. She visited the hospital where she was diagnosed with extreme miosis in her right eye with abnormal blood vessels were observed on the iris. As a result, she was referred to our hospital. At the time of the initial visit, her right eye visual acuity was 20 cm/hand motion, and intraocular pressure was 16 mmHg in the right eye. The pupil was nearly closed, and a thin fibrin-like membrane structure with abnormal blood vessels was observed in the upper part of the angle.

Results：Decreased vision due to pupillary closure was observed, and pupilloplasty was performed. However, the pupillaries closed again 3 months post surgery. A gap was observed between the white membranous tissue on the iris surface and the corneoscleral wound, epithelial downgrowth was suspected, and pupilloplasty was repeated. The membranous tissue was coagulated using diathermy, and a biopsy was performed. Pathological examination revealed stratified epithelial tissue. Epithelial downgrowth was thought to be the reason for pupil closure and the proliferation of the conjunctival tissue on the iris surface. The final corrected visual acuity was 0.7, and no signs of conjunctival tissue regrowth were observed.

Conclusion：Epithelial downgrowth should be considered a complication that can occur even well after small-incision PEA.