Orgül S, Flammer J, Stümpfig D, Hendrickson P
University Eye Clinic, Basel, Switzerland.
Int Ophthalmol. 1995;19(2):95-9. doi: 10.1007/BF00133179.
The effects of intense systemic or local cooling on aqueous humor dynamics in animals are an increased total outflow facility and a decreased aqueous flow. Few studies suggest that only vasoconstriction of arteriolar segments of the episcleral vasculature may be the cause for a decrease in intraocular pressure after local cooling in humans. Because corneal changes may have influenced such studies, the effect of local cooling was assessed in normal subjects.
Intraocular pressure and corneal thickness were measured in 18 healthy human subjects before and after exposure of the right eye to both, an air stream at 20 degrees C, and an air stream at 0 degrees C.
No significant changes in IOP or corneal thickness occurred under 20 degrees C conditions. After local cooling, the mean corneal thickness increased from 0.52 +/- 0.01 mm to 0.57 +/- 0.02 mm (p < 0.001). Mean intraocular pressure decreased from 13.8 +/- 2.9 mmHg to 12.9 +/- 3.1 mmHg (p < 0.026). The observed decrease in IOP correlated significantly but negatively (R = -0.53; p = 0.024) with the increase in corneal thickness, indicating that the cooling effect on IOP may be rather underestimated.
The eye is very sensitive to local cooling effects, which may, however, partially be masked by changes in corneal thickness.
全身性或局部性的强烈降温对动物房水动力学的影响是总流出率增加和房水流量减少。很少有研究表明，人类局部降温后眼内压降低的原因可能仅仅是巩膜上血管小动脉段的血管收缩。由于角膜变化可能影响了此类研究，因此在正常受试者中评估了局部降温的效果。
在18名健康人类受试者中，测量了右眼暴露于20℃气流和0℃气流前后的眼压和角膜厚度。
在20℃条件下，眼压或角膜厚度没有显著变化。局部降温后，平均角膜厚度从0.52±0.01毫米增加到0.57±0.02毫米（p<0.001）。平均眼压从13.8±2.9毫米汞柱降至12.9±3.1毫米汞柱（p<0.026）。观察到的眼压下降与角膜厚度增加显著负相关（R=-0.53；p=0.024），这表明降温对眼压的影响可能被相当低估了。
眼睛对局部降温效应非常敏感，然而，这种效应可能会部分被角膜厚度的变化所掩盖。
