視力を基準に抗VEGF薬導入期加療を行った網膜静脈分枝閉塞症の12か月治療成績

Anti-VEGF for macular edema secondary to branch retinal vein occlusion: twelve-month outcomes of one initial injection to three monthly injections based on visual acuity

要約　目的：網膜静脈分枝閉塞症（BRVO）に伴う黄斑浮腫（ME）に対する抗血管内皮増殖因子（VEGF）薬硝子体内注射治療において，注射前最高矯正視力（BCVA）を基準として導入期注射回数を決定した治療プロトコールの注射後12か月間の治療成績を報告する。

対象と方法：対象は，2017年7月〜2020年3月の間に以下の基準で導入期注射回数を決定し，以降は必要時投与（PRN）とした中心窩を含むMEを伴うBRVO症例21例21眼（男性9例，女性12例，平均年齢69歳）。導入期注射回数は，BCVA（小数視力）0.5以上では1回（1＋PRN群），0.2〜0.4では2回（2＋PRN群），0.15以下では3回（3＋PRN群）と定めた。各群におけるBCVAの変化，導入期終了後再注射までの期間，初回注射後12か月間の総注射回数，中心窩網膜厚（CMT）の変化を調査した。

結果：21例のうち，1＋PRN群が9例，2＋PRN群が9例，3＋PRN群が3例であった。初回注射後12か月間の総注射回数は平均3.6回（1＋PRN群：2.8回，2＋PRN群：3.9回，3＋PRN群：5.0回）であった。各群ともに導入期終了時点でBCVAおよびCMTは改善し，初回注射後12か月まで維持できた。また，全例で導入期終了1か月後のBCVAは初回注射12か月後のBCVAと有意に相関していた（p＜0.01，r＝0.79）。

結論：注射前BCVAに基づいて導入期の抗VEGF薬硝子体内注射の回数を決定する方法は，BRVOに伴うME症例におけるBCVAおよびCMTの改善および維持に有用であった。

Abstract　Purpose：To report the 12-month outcomes of a treatment protocol in which the number of intravitreal injections of anti-VEGF agents in the loading phase was determined based on the best corrected visual acuity（BCVA）before injection in the treatment of macular edema（ME）associated with branch retinal vein occlusion（BRVO）.

Subjects and method：The subjects were 21 eyes of 21 patients with ME associated with BRVO（9 men and 12 women, mean age 69 years）treated between July 2017 and March 2020. The number of injections in the loading phase was determined based on the following criteria and thereafter administered as needed（PRN）：1 injection for BCVA of 20/40 or better（1＋PRN group）, 2 monthly injections for BCVA of 20/50-20/100（2＋PRN group）, and 3 monthly injections for BCVA of 20/150 or worse（3＋PRN group）. The changes in BCVA, the time interval from the end of the loading phase to re-injection, the total number of injections over 12 months, and the changes in the central macular thickness（CMT）in each group were investigated.

Results：Of the 21 patients, 9 were in the 1＋PRN group, 9 in the 2＋PRN group, and 3 in the 3＋PRN group. The mean number of injections over 12 months was 3.6（2.8 in the 1＋PRN group, 3.9 in the 2＋PRN group, and 5.0 in the 3＋PRN group）. In each group, BCVA and CMT improved at the end of the loading phase and maintained up to 12 months after the first injection. BCVA 1 month after the end of the loading phase was significantly correlated with BCVA 12 months after the first injection（p＜0.01, r＝0.79）.

Conclusion：The treatment protocol of determining the number of injections in the loading phase based on pre-injection BCVA was useful for maintaining the improvement in BCVA and CMT in patients with ME associated with BRVO.