特発性黄斑円孔自然閉鎖例の臨床的特徴

Clinical characteristics of cases of spontaneous closure of idiopathic macular holes

要約　目的：特発性黄斑円孔（IMH）自然閉鎖症例の特徴について検討したので報告する。

対象と方法：2016年1月〜2018年12月に大阪医科大学眼科でIMHと診断された110例112眼のうち，自然閉鎖した6例6眼について，初診から閉鎖までの期間，黄斑円孔（MH）のステージ，円孔径，閉鎖前，閉鎖直後の円孔底径，視力，視神経乳頭縁から黄斑耳側血管および鼻側血管までの距離を後ろ向きに検討した。

結果：自然閉鎖率は112眼中6眼（5.35％）。初診から閉鎖までの期間は平均18.2±8.8日。MHのステージは2が1眼，3が2眼，4が3眼であった。黄斑上膜併発例が2眼あった。初診時の円孔径は70.7±17.0μm，円孔底径は閉鎖前341.7±243.6μm，閉鎖直後266.0±334.6μmで閉鎖直後も円孔底に空隙が残存し閉鎖前後で有意差はなかった。logMAR視力は閉鎖前0.24，閉鎖後0.06で閉鎖前後で有意差はなかった（p＝0.11）。視神経乳頭縁から黄斑鼻側血管までの距離は閉鎖前3,607.2±301.7μm，閉鎖後3,647.0±304.2μm（p＝0.26），黄斑耳側血管までの距離は閉鎖前5,024.8±301.1μm，閉鎖後5,101.7±327.2μm（p＝0.06）と，閉鎖前後で有意差はなかった。

考按：円孔径が小さな症例では自然閉鎖する可能性があるため3週間程度は経過観察するのがよいと思われた。円孔閉鎖後も円孔底に空隙を認めることが多く，閉鎖前後で黄斑部周囲の明らかな網膜血管走行の移動は認められなかった。

Abstract　Purpose：To examine and present the characteristics of cases of spontaneous closure of idiopathic macular holes（IMH）.

Subjects and Methods：Of 112 eyes of 110 patients diagnosed with IMH at the Department of Ophthalmology, Osaka Medical College, between January 2016 and December 2018, 6 eyes of 6 patients with spontaneous IMH closure were retrospectively examined for the time from initial visit to closure, IMH stage, hole diameter, hole base diameter before and immediately after closure, visual acuity, and distance from the margin of the optic disc to the blood vessels in the macular temporal and nasal areas.

Results：Spontaneous closure occurred in 6 of 112 eyes（5.35％）. The mean time from initial visit to closure was 18.2 days. The IMH stage was graded stage 2 in 1 eye, stage 3 in 2 eyes, and stage 4 in 3 eyes. Two eyes had concurrent epiretinal membrane. The mean±SD of hole diameter was 70.7±17.0 μm, while the mean±SD of hole base diameter was 341.7±243.6 μm before closure and 266±334.6 μm immediately after closure. A gap remained at the hole base immediately after closure；thus, no significant difference was observed before and after closure. The visual acuity in log MAR scale was 0.24 before closure and 0.06 after closure, showing no significant difference before versus after closure（p＝0.11）. The mean distance from the margin of the optic disc to the blood vessel in the macular nasal area was 3,607.2±301.7 μm before closure and 3,647±304.2 μm after closure（p＝0.26）. The distance to the blood vessel in the macular temporal area was 5,024.8±301.1 μm and 5,101.7±327.2 μm, respectively（p＝0.06）. No significant difference was observed before versus after closure.

Discussion：Because a small IMH might close spontaneously, follow-up without treatment for approximately 3 weeks might be appropriate. After IMH closure, there is often a gap at the hole base with no obvious changes in the courses of the retinal vessels around the macular area are observed before versus after closure.