長期経過観察できた黄斑部毛細血管拡張症（MacTel）type 2の3例

Three cases of macular telangiectasia（MacTel）type 2 with long-term follow-up

要約　目的：黄斑部毛細血管拡張症（MacTel）type 2に対して長期経過観察ができた3症例を報告する。

症例と結果：症例1は42歳，女性。視力は両眼とも（0.4）。両眼黄斑部に網膜内層の囊胞様変化，両眼中心窩耳側に毛細血管拡張を認め，両眼MacTel type 2非増殖期と診断した。初診後6年が経過したが視力低下はない。症例2は65歳，女性。視力は両眼とも（1.0）。右眼中心窩から傍中心窩にかけてのellipsoid zoneの欠損，蛍光眼底造影で両眼中心窩耳側に蛍光漏出を認め，両眼MacTel type 2非増殖期と診断した。初診後8年が経過したが右眼に色素沈着のわずかな増加はあるものの，両眼とも視力低下はない。症例3は33歳，男性。視力は右（0.9），左（0.1）。左眼に網膜下新生血管（SRNV）を認め，右眼はMacTel type 2非増殖期，左眼は増殖期と診断した。左眼SRNVに対してベバシズマブ硝子体内投与（IVB）を計2回施行した。経過中に右眼にもSRNVが出現し，右眼SRNVに対してもIVBを施行した。その後，両眼とも再発はなく，早期に治療を開始できた右眼は良好な視力を維持できている。

結論：MacTel type 2は比較的視力が保たれる疾患だが，SRNVを合併すると急激な視力低下をきたすことがあるため，定期的な経過観察が必要である。

Abstract　Purpose：To report cases of three patients with macular telangiectasia（MacTel）type 2 who underwent long-term follow-up.

Cases and Findings：Case 1 is a 42-year-old woman with best-corrected visual acuity（BCVA）of（0.4）in both eyes. Fundus examination revealed dilation of the retinal capillaries in the foveal area, located temporal to the fovea and cystoid space in the inner retinal layer of both eyes. The patient was diagnosed with bilateral MacTel type 2, non-proliferative stage, and visual acuity has been preserved from the past six years after the diagnosis. Case 2 is a 65-year-old woman with BCVA of（1.0）in both eyes. Fundus examination revealed loss of the ellipsoid zone in the right eye, and fluorescence angiography showed leakage from temporally located parafoveal telangiectasia in both eyes. She was diagnosed with bilateral MacTel type 2, non-proliferative stage. Eight years after the diagnosis, visual acuity has been preserved despite a slight increase in pigmentation. Case 3 is a 33-year-old man with BCVA of（0.9）in the right eye and（0.1）in the left eye. He was diagnosed with MacTel type 2, non-proliferative stage in the right eye and MacTel type 2, proliferative stage, in the left eye due to subretinal neovascularization（SRNV）. Intravitreal bevacizumab（IVB）was administered twice for SRNV. During the course of the disease, SRNV also occurred in the right eye, for which IVB was administered. Since then, there has been no recurrence, and visual acuity has been preserved.

Conclusion：MacTel type 2 is a disease in which visual acuity is relatively preserved；however, when associated with SRNV, it can result in significant loss of vision. Therefore, regular follow-up is mandatory.