Am Masmali, Ra Fagehi, El-Naggar Ahmad H, Tm Almubrad
Cornea Research Chair, Department of Optometry, College of Applied Medical Science, King Saud University, Riyadh, Saudi Arabia.
Soil Sciences Department, College of Food & Agriculture Sciences, King Saud University, Riyadh, Saudi Arabia.
Mol Vis. 2018 Apr 16;24:305-314. eCollection 2018.
This study aimed to investigate the tear ferning pattern and chemical elements of the tear film of camel tears compared with human tears and Refresh Plus eye lubricant. Refresh Plus was used as a control because it provides a healthy ferning pattern, due to the presence of an optimum ratio of carboxymethylcellulose (CMC) sodium and electrolytes. The main research focus is elucidating the viability of camel tear film in the dry, harsh environment of the desert.
The tears were collected from five camels, five male desert workers (20-25 years old) at a small village located 100 km from Riyadh, Saudi Arabia, and five male subjects (20-25 years old) from Riyadh. A small drop (1 μl) of tears was dried on a glass slide and observed under a light (Olympus BX1) and scanning electron microscope (Inspect S50, Field Electron and Ion Company [FEI]). Energy-dispersive X-ray spectroscopy (EDS) of the tear film and Refresh Plus were investigated with a JEOL 1400 scanning transmission electron microscope.
The camel tear film pattern was surrounded by thick, peripheral, homogenous layers containing small oily droplets, particles, and tiny branches in the tear ferning. The tear ferning of the camel was grade 0-1, whereas the tear ferning of human tears and Refresh Plus was grade 1-2. The mass percentage of chloride was highest in the camel tears. The mass percentage of potassium in the camel tears was greater than that in the human tears, but it was less than that in the Refresh Plus lubricant.
Camel tears exhibit a better quality than human tears and Refresh Plus lubricant do. The presence of oily droplet-like structures at the periphery of tear ferning suggests that camel tear film may have a higher quality and quantity of minerals and lubricants, which may help the animal to avoid eye dryness. Future work is required to investigate the identification of the elements present in the peripheral and central part of the tear ferning.
本研究旨在调查骆驼眼泪的泪液蕨样形态和泪膜化学元素，并与人类眼泪及Refresh Plus眼用润滑剂进行比较。将Refresh Plus用作对照，因为由于其羧甲基纤维素（CMC）钠和电解质的比例最佳，可呈现出健康的蕨样形态。主要研究重点是阐明骆驼泪膜在沙漠干燥、恶劣环境中的生存能力。
从五只骆驼、沙特阿拉伯利雅得100公里外一个小村庄的五名男性沙漠工作者（20 - 25岁）以及利雅得的五名男性受试者（20 - 25岁）收集眼泪。将一小滴（1微升）眼泪滴在载玻片上晾干，然后在光学显微镜（奥林巴斯BX1）和扫描电子显微镜（Inspect S50，场发射电子与离子公司[FEI]）下观察。用JEOL 1400扫描透射电子显微镜对泪膜和Refresh Plus进行能量色散X射线光谱（EDS）分析。
骆驼泪膜形态被厚的、周边均匀的层包围，泪液蕨样形态中含有小油滴、颗粒和微小分支。骆驼泪液蕨样形态为0 - 1级，而人类眼泪和Refresh Plus的泪液蕨样形态为1 - 2级。骆驼眼泪中氯的质量百分比最高。骆驼眼泪中钾的质量百分比高于人类眼泪，但低于Refresh Plus润滑剂中的钾质量百分比。
骆驼眼泪比人类眼泪和Refresh Plus润滑剂质量更好。泪液蕨样形态周边存在油滴状结构表明，骆驼泪膜可能具有更高质量和数量的矿物质及润滑剂，这可能有助于动物避免眼睛干燥。未来需要开展工作来鉴定泪液蕨样形态周边和中央部分存在的元素。
