Mathers William
Casey Eye Institute, Oregon Health and Sciences University, 3375 SW Terwilliger, Portland, OR 97201, USA.
Exp Eye Res. 2004 Mar;78(3):389-94. doi: 10.1016/s0014-4835(03)00199-4.
Evaporation from the ocular surface is dramatically reduced by the lipid layer which covers it. With this layer intact, evaporation represents a small loss of water for which the lacrimal gland easily compensates. When tear production is compromised evaporation becomes important, especially since evaporation in almost all ocular surface disease states and any surface perturbation, including contact lens wear, increases evaporation significantly. How the barrier function of the lipid layer accomplishes this reduction in evaporation is not understood and is probably quite complex as is the structure of the lipid layer. Improving this barrier function remains an important and elusive goal.
覆盖眼表的脂质层可显著减少眼表水分的蒸发。在该层完好无损时，蒸发导致的水分流失较少，泪腺能够轻松补偿。当泪液分泌受损时，蒸发就变得至关重要，特别是因为在几乎所有眼表疾病状态以及任何表面扰动（包括佩戴隐形眼镜）下，蒸发都会显著增加。脂质层的屏障功能是如何实现这种蒸发减少的尚不清楚，而且可能相当复杂，脂质层的结构也是如此。改善这种屏障功能仍然是一个重要但难以实现的目标。
