照度変化に伴う瞼裂高・瞳孔径の変動

Changes in eyelid fissure height and pupillary size induced by different illuminations

　種々の照度下で眼瞼・瞳孔の動きを測定する装置を自作し，屋外での太陽光によるこれらの動きと眼の光被曝との関係を検討した。健常ボランティア，白内障術前患者を対象に検査を行った。検査装置はゴールドマン視野計の半球内部を照明するもので，本体の観察部にCCDカメラを装着した。眼瞼，瞳孔の動きはNIH imageで定量化した。健常者，白内障患者の瞳孔径は室内環境で3mm，屋外では天候の如何を問わず2mm前後を維持していた。照度の上昇に伴い最初に瞳孔径が変化し，次いで上眼瞼の下垂，下眼瞼の上昇の順に変化した。濃いサングラスを装用すると瞳孔，瞼裂が散大することも証明された。

We constructed an equipment to measure the height of eyelid fissure and pupillary size under ambient illumination. It is composed of illuminated hemisphere and recording system housing a CCD video camera. The stored anterior eye segment images can be analyzed through an NIH imaging program. The participants of the study comprised 12 healthy volunteers and 20 cataract patients. The pupillary diameter in both groups averaged 3 mm when measured indoors and 2 mm outdoors irrespective of weather conditions. When measured against a bright light, the pupillary size responded first, followed by eyelid squinting including drooping of the upper eyelid, and then by elevation of the lower eyelid. It also found that the pupil and the eyelids were open when dark sunglasses were worn, suggesting that wearing sunglasses without ultraviolet absorbing lenses could increase the risk of cataractogenesis.