囊胞様腔内フィブリノゲン塊摘出術が奏効した黄斑部毛細血管拡張症1型

En bloc excision of fibrinogen clot in eyes with macular telangiectasia type 1

要約　目的：黄斑部毛細血管拡張症（MacTel）1型は特発性に黄斑部網膜の毛細血管拡張を呈する疾患で，片眼性が多く，中心窩耳側の毛細血管拡張，毛細血管瘤による滲出性病変が特徴である。治療は血管瘤に対する直接光凝固や抗血管内皮増殖因子（VEGF）薬の局所注射などが行われているが確立されていない。今回MacTel 1型の遷延性囊胞様黄斑浮腫に対して囊胞様腔内フィブリノゲン塊摘出術（以下，囊胞摘出術）が奏効した症例を報告する。

症例：67歳，女性。左眼視力低下のためにX−2年5月産業医科大学病院を紹介され受診した。初診時の視力は右（1.2），左（0.15）であった。眼底は右眼には異常なく，左眼は硬性白斑を認め，フルオレセイン蛍光眼底造影は両眼とも黄斑部の毛細血管拡張と蛍光漏出を認め，左眼には毛細血管瘤があった。光干渉断層計では両眼とも網膜外層には萎縮所見はなく，左眼に囊胞様黄斑浮腫があった。光干渉血管断層撮影では両眼とも黄斑部の深層毛細血管の密度が著明に減少していた。以上より，両眼の黄斑部血管密度の減少を伴うMacTel 1型と診断した。左眼は黄斑浮腫が持続したため，抗VEGF薬硝子体内注射を5回行ったが，再発を繰り返し視力が（0.1）に低下したため，X年6月に硝子体手術を行った。内境界膜剝離に加え，黄斑部囊胞に対して27G注射針で囊胞摘出術を行った。

結果：術後約3年が経過し黄斑浮腫は消失し，左視力は（0.15）であった。

結論：囊胞摘出術は糖尿病黄斑浮腫や網膜静脈閉塞症による黄斑囊胞で有効とされているが，MacTel 1型でも有効である症例がある。

Abstract　Purpose：Macular telangiectasia（hereafter referred to as MacTel）type 1 is a disease involving idiopathic telangiectasia of the macular retina and occurs, most commonly in one eye. It is characterized by telangiectasia of the temporal side of the fovea and exudative lesions due to microaneurysms. Although no treatment for this disease has been established yet, direct coagulation of the aneurysms and local injection of anti-vascular endothelial growth factor（VEGF）drugs have been used. We report a case of MacTel type 1 associated with persistent cystoid macular edema that was successfully treated by en bloc excision of a fibrinogen clot.

Case：62-year-old woman was referred to our hospital in May X−2 due to vision loss in her left eye. The decimal visual acuity at the initial examination was as follows：right eye（1.2）；left eye（0.15）. The fundus of the right eye showed no abnormality. Hard exudates were presentin the left eye. The fluorescein angiography showed capillary dilation and dye leakage in the macula of both eyes, with microaneurysms in the left eye. Optical coherence tomography revealed cystoid macular edema in the left eye and no evidence of atrophy in the outer retina of either eye. Optical coherence tomography angiography showed that the density of deep capillaries in the macula was markedly reduced in both eyes. We diagnosed the patient with MacTel type 1 with decreased macular vascular density in both eyes. The left eye had persistent macular edema and was treated with five intravitreal anti-VEGF drug injections, but repeated recurrences reduced visual acuity to（0.1）. Therefore, pars plana vitrectomy was performed in June X. In addition to the internal limiting membrane dissection, a cystectomy was performed for a macular cyst with a 27 G needle.

Result：No recurrence of macular edema was not observed for 2.5 years after surgery, and the patient had a visual acuity of 0.1 and no scotoma was observed at the macular area on performing the Humphrey visual field test.

Conclusion：Cystectomy was effective in resolving macular edema associated with MacTel type 1. It has been reported that cystoid macular edema may be caused by diabetic macular edema or retinal vein occlusion.