Benjamin W J, Hill R M
Institute for Contact Lens Research, University of Houston, College of Optometry, TX 77004.
Graefes Arch Clin Exp Ophthalmol. 1988;226(1):41-4. doi: 10.1007/BF02172716.
Corneal oxygen demands, expressed as ratios of uptake rate relative to baseline rates derived from unstressed corneas, were determined with a micropolarographic system for central (closed eye) and superior (open eye) locations of one cornea of each of seven human subjects. The closed-eye central corneal measurements were repeated during two additional experimental sessions. Intrasubject variability of the three mean closed-eye central corneal rate ratios ranged as high as 23%, possibly representing effects of homeostatic mechanisms on the palpebral conjunctival capillaries of some subjects. For the open-eye superior cornea, which was covered by the upper eyelid of every subject prior to measurement, oxygen demand was found to have a greater intersubject range, but was diminished in magnitude relative to the demand associated with the closed-eye central cornea. Superior corneal oxygen demand was not found to be predictable from closed-eye central corneal oxygen demand or extent of eyelid overlap onto the cornea and thus indicated localized open-eye superior corneal environments that were significantly different from those of the corresponding closed-eye central corneas. Such localized environments may be critically important when gauging the susceptibility of particular eyes to superior corneal pathology during contact lens wear.
用微极谱系统测定了7名人类受试者每只眼睛的中央（闭眼）和上方（睁眼）角膜位置的角膜需氧量，以摄取率与未受应激角膜的基线率之比表示。在另外两个实验阶段重复进行闭眼中央角膜测量。三个平均闭眼中央角膜率比的受试者内变异性高达23%，这可能代表了某些受试者体内稳态机制对睑结膜毛细血管的影响。对于睁眼上方角膜，在测量前每个受试者的上眼睑都覆盖着该角膜，发现需氧量在受试者间的范围更大，但相对于闭眼中央角膜的需氧量，其幅度有所减小。未发现上方角膜需氧量可根据闭眼中央角膜需氧量或眼睑覆盖角膜的程度来预测，因此表明睁眼上方角膜局部环境与相应闭眼中央角膜的环境有显著差异。在评估隐形眼镜佩戴期间特定眼睛对上方角膜病变的易感性时，这种局部环境可能至关重要。
