前房灌流時の縮瞳反応—特に温度の影響について

Miosis induced by anterior chamber irrigation at low temperature

　前房洗浄時に際してのアトロピン抵抗性縮瞳反応にはインドメサシンの前処理が有効であるが，両者の存在下でもなお縮瞳反応を経験することがある．前房洗浄により虹彩の温度が急変することも予想されるので，前房の代用，0.2mlのacrylic chamberを作製し，また瞳孔径の代わりにウシ瞳孔括約筋の収縮記録を用いることにより，温度変化が虹彩に及ぼす影響について実験した．低温にすることにより摘出瞳孔括約筋のtoneは上昇し，薬物に対する感受性も増強した．

We evaluated the effect of temperature of the solu-tion on the tone of excised specimen of bovine iris sphincter muscle. Lowering the temperature to 29℃, 20℃ or 15℃ induced prompt contracture of the iris sphin-cter specimen. The observed contracture was a reversi-ble one. The reactivity to various sympathicomimetic drugs was also enhanced at the above low temperature levels.

We further evaluated the effect of low temperature on the pupil size by introducing a thermosensor, 1 mm in width, into the anterior chamber during cataract sur-gery. Cooling the anterior aqueous to 15℃ promptly resulted in miosis. The original pupil size was attained in less than one minute after cessation of cooling stimu-lation. The observed phenomenon appeared to be related, partially at least, to the miosis that frequently occurs during intraocular surgery.

Rinsho Ganka (Jpn J Clin Ophthalmol) 40(6) : 597-598,1986