白内障手術併用iStent®挿入術とiStent inject® W挿入術の短期成績の比較

Comparative evaluation of the short-term outcomes of iStent® and iStent inject® W implantation combined with cataract surgery

要約　目的：低侵襲緑内障手術の1つである従来のiStent^®（以下，iStent）と2020年9月にわが国で新たに使用可能となったiStent inject^® W（以下，inject W）の術後短期成績について検討する。

対象と方法：2019年1月〜2021年7月に当院で白内障手術と併用してiStentまたはinject Wの挿入術を施行し，3か月以上観察できた症例を対象とした。iStent群とinject W群に分けて，眼圧，点眼スコア（単剤1点，配合剤2点），術後合併症について診療録を基に後ろ向きに検討した。

結果：iStent群は39例54眼（年齢71.6±9.5歳），inject W群は27例37眼（年齢76.2±6.5歳）であった。術前，術後1週間，1か月，3か月の平均眼圧はiStent群では14.7±2.2mmHg，15.9±4.7mmHg，14.3±3.2mmHg，13.8±2.9mmHgで，点眼スコアは2.5±1.3，0.2±0.9，0.7±1.2，0.9±1.3であった。inject W群では平均眼圧は15.7±2.8mmHg，15.8±5.1mmHg，13.0±2.4mmHg，13.2±2.7mmHgで，点眼スコアは2.8±1.5，0.3±1.0，1.2±1.5，1.5±1.6であった。点眼スコアの減少幅は両群間に有意差はなかったが，眼圧は術後1か月と3か月の時点でinject W群のほうが有意に大きく下降していた（p＝0.01）。両群ともに重篤な術後合併症はなかった。

結論：両群ともに安全性が高く，点眼スコアと眼圧の減少を得た。術後3か月時点ではinject WのほうがiStentよりも眼圧下降に優れていた。

Abstract　Objective：The purpose of this study is to evaluate the short-term postoperative outcomes of iStent^®（iStent）, which became available in December 2016, a minimally invasive glaucoma surgery, and iStent inject^® W（inject W）, which became available in September 2020 in Japan.

Subjects and Methods：Patients who underwent iStent and inject W implantation between January 2019 and July 2021 in Juntendo University Urayasu Hospital and could be observed for more than 3 months were included in the study. We devided them into iStent and inject W groups；intraocular pressure（IOP）, glaucoma medication score（1 point for a single agent and 2 points for a combination agent）, and postoperative complications were reviewed retrospectively based on medical records.

Results：The iStent group consisted of 39 patients with 54 eyes（aged 71.6±9.5 years）, and the inject W group consisted of 27 patients with 37 eyes（aged 76.2±6.5 years）. In the iStent group, preoperative and 1 week, 1 month, 3 months after surgery, mean IOP were 14.7±2.2 mmHg, 15.9±4.7 mmHg, 14.3±3.2 mmHg, 13.8±2.9 mmHg, with glaucoma medication score of 2.5±1.3, 0.2±0.9, and 0.7±1.2, 0.9±1.3. In the inject W group, mean IOP was 15.7±2.8 mmHg, 15.8±4.1 mmHg, 13.0±2.4 mmHg, 13.2±2.7 mmHg and glaucoma medication score were 2.8±1.5, 0.3±1.0, and 1.2±1.5, 1.5±1.6. No significant difference was seen in the reduction in glaucoma medication score between the two groups, but IOP was significantly lower in the inject W group 1 month and 3 months after surgery（p＝0.01）. No serious complications were observed in either group.

Conclusion：Although both techniques were safe and achieved a reduction in glaucoma medication score, inject W was superior to iStent in lowering IOP at 3 months postoperatively.