Oral doxycycline and topical azithromycin shows stabilization of tear film in Meibomian gland dysfunction
Ocular surface disease (OSD) is a multifactorial and a highly frequent problem which may lead to pain, inflammation, irritation, photophobia, blurred vision, and vision loss. There are many essential causes of OSD such as inadequate or unstable tear film and neurotrophic keratopathy (NK) which is a degenerative corneal disorder that affects the health and integrity of the ocular surface secondary to impairment of corneal nerves that alters their trophic and sensory function. Also, meibomian gland dysfunction (MGD) incidence varies widely based on ethnicity, sex, and age. MGD also has a significant influence on the patients’ life quality, as it is frequently a contributing factor to evaporative dry eye and is responsible for symptoms of irritation of the eyelid and ocular surface. Risk factors of MGD include aging, deficiency of sex hormones specially androgens, other systemic diseases such as Stevens–Johnson syndrome (SJS), atopy, Sjogren’s syndrome (SS), psoriasis, and hypertension. Also, ophthalmic disorders such as chronic blepharitis, contact lens wear, and trachoma may play a role.
MGD pathophysiology is caused by obstruction of meibomian gland and hyper-keratinization of the epithelium of the meibomian duct which results in decreased meibum availability over the tear film aqueous layer. Reduced meibum leads to elevation of bacterial growth on the margin of the lid, instability of the tear film, increased hyperosmolarity, and tears evaporation. MGD choices of treatment vary from initial conservative interventions involving eyelid massage, eyelid expression, and warm compression to, in more severe cases, medical intervention with anti-inflammatory drugs. In past trials, antibiotics such as doxycycline and azithromycin were proven to effectively treat both the signs and symptoms of MGD patients.
Doxycycline is one of the standard treatments for MGD, which is a derivative of tetracycline and has been used because of its lipid-regulating, anti-inflammatory, and antimicrobial characteristics. It suppresses matrix metalloproteinases, which are responsible for connective tissue degradation. Topical azithromycin has been identified as a potentially well-tolerated and effective treatment for MGD and diseases of the lid margin in clinical trials. Azithromycin is a macrolide antibiotic that has a broad-spectrum action, antiinflammatory characteristics, and a lipid-regulating effect. In addition, at concentrations achieved by topical administration, it displayed bacteriostatic activity, resulting in the bacterial growth suppression on the lid margin. The study by Marwa Aly Zaky et al aimed to compare topical azithromycin eye drops versus oral doxycycline efficacy in MGD patients.
This prospective comparative cohort research was carried out on 56 patients of both sexes of any age with symptomatic MGD. Randomly, patients were classified into two equal groups: Group 1 was treated twice daily for 4 weeks with topical azithromycin 1% eye drops, while group 2 received oral doxycycline 100 mg capsules twice daily for 4 weeks.
In the 1st follow-up, there was a significant difference between the studied groups in pain and discomfort degree (P value = 0.024) as group 1 showed a higher number of patients with a mild pain degree (P value = 0.013) while group 2 showed a higher number of patients with a severe pain degree (P value = 0.022).
There was an insignificant difference between the studied groups in moderate pain degree and lid margin telangiectasia. Conjunctivitis, frothy discharge, and meniscus floaters were significantly higher in group 2 than in group 1 (P value = 0.013, 0.028, and 0.031, respectively). In group 1, the break-up time test was significantly higher than in group 2 (P value = 0.023). In the 2nd follow up, in group 2 only meniscus floaters were significantly higher than in group 1 (P value = 0.044), while in group 1 break-up time test was significantly higher than in group 2 (P value = 0.029). Otherwise, there is no significant difference between both the groups.
Obstructive MGD is the most prevalent cause of EDE and occurs as a primary disorder or secondary to seborrheic or atopic dermatitis, acne rosacea, and cicatrizing conjunctival disorders, such as erythema multiforme, trachoma, and cicatricial pemphigoid. The main goal of the treatment of MGD is to improve the quality and quantity of meibomian glands secretion and thus relieve discomfort.
Meibomian gland dysfunction (MGD) could be treated effectively with oral doxycycline and topical azithromycin by improving symptoms, clinical signs, and stabilization of the tear film. Moreover, topical group seemed to be superior over oral group in improving the quality of the tear film in the short term, with fewer side effects, more compliance, and better tolerability.
