網膜剝離手術時にシリコーンオイルを注入した症例における抜去後の眼圧変化の検討

Intraocular pressure after extraction of silicone oil after retinal detachment

要約　目的：難治症例に対する硝子体手術時にシリコーンオイル（SO）を注入し，その後抜去した症例では，眼圧の変動を生じることが知られている。今回，裂孔原性網膜剝離（RRD）手術時にSOを注入し，その後抜去した症例における，抜去術前後の眼圧の変化を検討した。

対象と方法：過去36か月間に，再手術を含むRRDに対して硝子体手術時にSO注入を施行した14例15眼を対象とした。初診時，SO抜去術前，抜去後6か月の矯正視力（logMAR値）と眼圧を測定し，緑内障点眼スコアや緑内障手術の有無などを後ろ向きに検討した。

結果：症例の平均年齢は56.7±17.2歳，SO注入から抜去までの平均日数は120.9±27.0日であった。抜去前時点で緑内障治療なしの症例は6眼で，治療ありの症例は9眼であった。対象症例全体の初診時と抜去後6か月のlogMAR値は0.83±0.67，0.26±0.15で，術後の有意な改善がみられた。抜去前時点で緑内障治療なしの症例のSO抜去前，抜去後6か月の眼圧は21.00±5.87mmHg，16.67±5.85mmHgと，抜去により有意な下降がみられた。抜去前時点で緑内障治療ありの症例においてSO抜去前，抜去後6か月の緑内障点眼スコアは2.8±1.30，1.8±1.48であり，平均値は減少したが有意ではなかった。SO抜去までの期間と眼圧，緑内障点眼スコアともに相関関係はなかった。

結論：SO抜去により眼圧の下降や点眼スコアの減少がみられる一方，SO抜去後も緑内障治療が必要な症例が多くみられた。

Abstract　Purpose：The injection of silicone oil（SO）during intractable vitreous surgery and its subsequent removal can cause fluctuations in intraocular pressure. In this study, we examined changes in intraocular pressure before and after removing SO injected during rhegmatogenous retinal detachment（RRD）surgery.

Cases and methods：We retrospectively examined 15 eyes of 14 patients who had receceived underwent SO injections during vitrectomy for RD, including reoperation, in the past 36 months. We measured the corrected visual acuity（logMAR）and intraocular pressure at the initial examination, before SO removal, and 6 months after removal, and retrospectively examined the glaucoma eye drop score and whether glaucoma surgery was performed.

Results：The average age of the cases was 56.7±17.2 years, and the average number of days from SO injection to SO removal was 120.9±27.0 days. There were 6 patients without glaucoma treatment at the time of SO removal and 9 patients with glaucoma treatment. The logMAR visual acuity values at the first examination and 6 months after SO removal for all cases were 0.83±0.67 and 0.26±0.15, respectively, showing significant improvement after surgery. In cases where there was no glaucoma treatment before SO removal, the intraocular pressures before and after 6 months of SO removal were 21.00＋5.87 and 16.67±5.85 mmHg, respectively, showing a significant decrease after SO removal. In cases where glaucoma treatment was being administered at the time of SO removal, the average glaucoma eye drop scores before and 6 months after SO removal were 2.8±1.30 and 1.8±1.48, respectively, showing a non-significant decrease. There was no correlation between the time until SO removal and either intraocular pressure or glaucoma eye drop score.

Conclusion：SO removal was found to lower intraocular pressure and reduce the number of eye drops used. However, many patients require glaucoma treatment after SO removal.