1. Each eyelid of the long-tailed vole has around 3-4 meibomian glands . 2. Sullivan has been studying the use of testosterone eye drops to restore Meibomian gland function. 3. The outermost layer is oily, produced by the Meibomian glands at the edge of the eyelid. 4. Isotretinoin is known to cause meibomian gland dysfunction which causes persistent keratoconjunctivitis sicca ( dry eye ). 5. Examples of holocrine glands include the sebaceous glands of the skin and the meibomian glands of the eyelid. 6. IPL is increasingly used in ophthalmology as well, to treat evaporative dry eye disease due to meibomian gland dysfunction. 7. Factors that contribute to meibomian gland dysfunction can include things such as a person's age and / or hormones. 8. In both men and women, dry eye can also result from a malfunctioning meibomian gland , producing too few oily tears. 9. Since then, Toyos has developed the use of IPL to treat chronic dry eye conditions such as meibomian gland dysfunction. 10. Meibomian gland dysfunction is more often seen in women and is regarded as the main cause of dry eye disease.