New research published in the Hindawi Journal of Ophthalmology compared the use of azithromycin topical eye drops to oral doxycycline in patients with meibomian gland dysfunction (MGD).
First off, talk about MGD treatment.
Typical therapy treatment for MGD can range from “initial conservative interventions” such as eyelid massages or expression and warm compresses to increased severity that might require “medical intervention with anti-inflammatory drugs.”
Now these two therapies.
Doxycycline, considered an oral treatment option for MGD, is known for its anti-inflammatory, lipid-regulating, and antimicrobial properties.
Conversely, azithromycin as a topical therapy is a macrolide antibiotic with anti-inflammatory characteristics and lipid-regulating effects—similar to doxycycline.
To note, previous research has found azithromycin to be well-tolerated and effective for treating diseases of the lid margin (and potentially MGD).
And this study.
Investigators conducted the comparative prospective cohort study with 56 patients diagnosed with symptomatic MGD.
Each patient was subject to an exam that included:
- Measurement of visual acuity (VA)
- Manifest refraction
- Slit lamp biomicroscopy
How were participants divided?
Patients were randomly and equally divided into two groups:
Group 1 → treated twice daily for 4 weeks (topical azithromycin 1%) Group 2 → treated twice daily for 4 weeks (oral doxycycline 100 mg capsules)
Any other treatments?
All participants also received eyelid massages, cleaning via eye-friendly soap at night, warm fomentation (twice daily), and an artificial tear drop.
When was data collected?
Patient data was taken at baseline, after 2 weeks, and after 4 weeks (with parameters compared between both groups for each collection point).
And the measurement tools?
Investigators used the following:
- Pain assessment (per the Wong and Baker Face Pain Scale)
- Lid margin telangiectasia scale
- Tear break-up time test (TBUT)
Also assessed was the presence or absence of conjunctivitis, frothy discharge, and tear film meniscus floaters.
Of note, tear film meniscus floaters can be defined as trace fragments of debris, consisting of either dead epithelial cells or small fibrils of lipid-contaminated mucin, being carried along the upper and lower lid meniscus.
Now the findings.
Overall, both groups demonstrated a significant difference in the degree of pain and discomfort at the first follow-up visit:
- Group 1 (azithromycin) → higher number of patients with a mild pain degree
- Group 2 (doxycycline) → higher number of patients with a severe pain degree
Go on …
There was no significant difference between the two groups for moderate pain degree and lid margin telangiectasia; however, conjunctivitis, frothy discharge, and tear film meniscus floaters were significantly greater for Group 2.
What about TBUT?
A significantly higher TBUT was noted in Group 1 than Group 2.
Additionally, while Group 1 (azithromycin) had a significantly higher TBUT at the second follow-up visit, meniscus floaters were significantly higher in Group 2 (doxycycline).
Limitations?
The study authors noted the small sample size, short follow-up period, use of a single-centric study, and no visual function testing (contrast sensitivity and color vision tests) as limitations.
So what does all this mean?
The authors determined that both topical azithromycin and oral doxycycline are effective in improving MGD signs and symptoms as well as tear film.
However, they also noted azithromycin as superior to doxycycline “in improving the quality of the tear film in the short term, with fewer side effects, more compliance, and better tolerability.”