硝子体手術のための照明用plugの考案

Design of an endoillumination plug for four-port bimanual vitrectomy

　硝子体手術において，眼内での双手操作bimanual techniqueを可能とするために，強膜に縫合固定し，助手がこれを操作する形式の眼内照明器具を試作した．ファイバーには，直径0.75mmのモノフィラメントファイバーを用い，その一端にinfusion cannulaと同形状の強膜縫合固定用の金属パイプを被せてあり，Illumination Plugと名付けた．

　この方法では，4か所に強膜切開を置くfour-port vitrectomyとなり，眼内観察用のコンタクトレンズも助手が保持することが困難なので，floating contact-lensと固定用のリングを使用する必要がある．このため，多少手技は煩雑となり，また眼球の可動制限を生じ易いという欠点があるが，糖尿病性網膜症における後極部に厚い増殖膜を有する症例や，血管に富む線維性血管膜の切断が必要な症例では，眼内双手操作を併用することにより，出血量を減少させ，医原性裂孔の発生を抑える効果が期待でき，有用な方法であると考えられた．

We designed a new endoillumination system shaped as a plug for 4-port bimanual vitrectomy. The end of the plug is composed of a thin-walled stainless steel cannula with an outer diameter of 0.9 mm equivalent to a 20-guage needle. Inside the cannula is a monofilament optic fiber with a diame-ter of 0.75 mm. The cannula has two flanges for suturing to the sclera.

After preparation for conventional 3-port vitrectomy, the plug is inserted and fixed with sutures through an additional sclerotomy hole. The surgeon has thus two options for intraocular illumi-nation, either with the conventional hand-held optic probe or with the plug for more intricate bimanual manipulation. A holder for floating con-tact lens is essential for the use of this system. The 4-port system has some disadvantages as it limits rotation of eyeglobe and as it necessitates additional preparation. The disadvantages are off-set as it facilitates bimanual manipulation to treat difficult cases with thick or extensive proliferative membrane incurring lesser risk of bleeding or iatrogenic retinal breaks.

Rinsho Ganka (Jpn J Clin Ophthalmol) 42(10) : 1151-1154, 1988