Doxycycline and other tetracyclines appear to inhibit bacterial lipase production. This reduces free fatty acids, which helps to reduce inflammation and the symptoms of dry eyes. Tetracyclines also help inhibit keratinization of the meibomian glands, and also reduce the number of eyelid bacteria.  The current modality is to prescribe doxycycline dosage 100mg twice a day for one month and reduce the dosage to 20mg to 50mg twice a day. for a two-month course. Patients may be kept on a maintenance dose as long as necessary.