The effect of low-dose doxycycline therapy in chronic meibomian gland dysfunction.

PURPOSE The aim was to investigate the effect of low dose doxycycline (20 mg) therapy in patients with chronic meibomian gland dysfunction that were refractory to conventional therapy. METHODS The randomized prospective study enrolled 150 patients (300 eyes) who have chronic meibomian gland dysfunction and who didn't respond to lid hygiene and topical therapy for more than 2 months. All topical therapy was stopped for at least 2 weeks prior to beginning the study. After conducting the tear break up time test (TBUT) and Schirmer test, the authors randomly divided the patients into three groups a high dose group (doxycycline, 200 mg, twice a day), a low dose group (doxycycline, 20 mg, twice a day) and a control group (placebo). After one month, the author repeated the TBUT and Schirmer tests, and analyzed the degree of symptomatic improvement. RESULTS Compared to the control group, both the high and low dose group showed statistically significant differences after treatment in TBUT, Schirmer test, the number of symptoms reported and the degree of improvement of subjective symptoms. However, there was no statistically significant difference between the high and low dose group after treatment in TBUT (9.42 +/- 2.87 sec, 9.54 +/- 1.58 sec, p=0.726), Schirmer test (19.98 +/- 4.05 mm, 19.65 +/- 5.02 mm, p=0.624), the number of symptoms reported (1.45 +/- 0.62, 1.53 +/- 0.52, p=0.304), as well as the degree of improvement of subjective symptoms (p=0.288). The high dose group (18 patients, 39.13%) reported side effects more frequently than did the low dose group (8 patients, 17.39%) (P=0.002). CONCLUSIONS Low dose doxycycline (20 mg twice a day) therapy was effective in patients with chronic meibomian gland dysfunction that were refractory to conventional therapy.