In piglets we tested the applicability of digital video microscopy and diffuse reflectance spectroscopy for non-invasive assessments of limbal and bulbar conjunctival microcirculation. A priori we postulated that the metabolic rate is higher in limbal as compared to bulbar conjunctiva, and that this difference is reflected in microvascular structure or function between the two locations. Two study sites, Oslo University Hospital (OUH), Norway and Cleveland Clinic (CC), USA, used the same video microscopy and spectroscopy techniques to record limbal and bulbar microcirculation in sleeping piglets. Recordings were analyzed with custom-made software to quantify functional capillary density, capillary flow velocity and microvascular oxygen saturation in measuring volumes of approximately 0.1 mm³. The functional capillary density was higher in limbus than in bulbar conjunctiva at both study sites (OUH: 18.1 ± 2.9 versus 12.2 ± 2.9 crossings per mm line, p < 0.01; CC: 11.3 ± 3.0 versus 7.1 ± 2.8 crossings per mm line, p < 0.01). Median categorial capillary blood flow velocity was higher in bulbar as compared with limbal recordings (CC: 3 (1–3) versus 1 (0–3), p < 0.01). Conjunctival microvascular oxygen saturation was 88 ± 5.9% in OUH versus 94 ± 7.5% in CC piglets.

Non-invasive digital video microscopy and diffuse reflectance spectroscopy can be used to obtain data from conjunctival microcirculation in piglets. Limbal conjunctival microcirculation has a larger capacity for oxygen delivery as compared with bulbar conjunctiva.

在仔猪中，我们测试了数字视频显微镜和漫反射光谱法对角膜缘和球结膜微循环的非侵入性评估的适用性。我们先验地推测，与延髓结膜相比，角膜缘的代谢率更高，并且这种差异反映在两个部位之间的微血管结构或功能上。挪威奥斯陆大学医院（OUH）和美国克里夫兰诊所（CC）这两个研究地点使用相同的视频显微镜和光谱技术记录了熟睡仔猪的角膜缘和延髓微循环。使用定制软件分析记录，以量化约0.1 mm ^3的测量体积中的功能性毛细血管密度，毛细血管流速和微血管氧饱和度。在两个研究部位，角膜缘的功能性毛细血管密度均高于球结膜（OUH：每毫米线交叉点为18.1±2.9对12.2±2.9，p <0.01； CC：每毫米线交叉点为11.3±3.0对7.1±2.8，p <0.01）。与角膜缘记录相比，延髓中类别毛细血管的血流速度更高（CC：3（1-3）比1（0-3），p <0.01）。OUH的结膜微血管血氧饱和度为88±5.9％，而CC仔猪为94±7.5％。

非侵入性数字视频显微镜和漫反射光谱法可用于从仔猪结膜微循环获得数据。与球结膜相比，角膜结膜微循环具有更大的氧气输送能力。