緑内障と眼圧の季節変動

Seasonal variation of intraocular pressure in normal and glaucomatous eyes

　眼圧の季節変動についてまとめた。正常眼，緑内障眼ともに冬に眼圧が上昇しやすく，緑内障眼のほうが眼圧変動幅は大きい。さらに，眼圧変動幅の大きい症例ほど視野障害も悪化しやすく，眼圧季節変動は視野障害悪化の危険因子と考えられている。冬に眼圧の上昇する機序については，寒冷による血中カテコラミンの上昇や血圧の上昇による房水産生の増加や房水流出の減少が考えられる。長期にわたり緑内障患者を管理する上で，眼圧の季節変動は常に考慮すべき1つの因子である。

Review of literature has shown that the intraocular pressure (IOP) tends to be higher during winterin normal and glaucomatous eyes. This tendency is more manifest in the latter. Greater seasonal fluctuation inIOP is one of risk factors in glaucoma as it is associated with a more frequent deterioration in the visual field.Various theories are present to account for the higher IOP level in winter including: elevated catecholaminesin the serum, increased aqueous secretion secondary to elevated blood pressure, and decrease in aqueous outflow.Seasonal variation in IOP has to be take into account in the long-term management of glaucoma patients.