====== Meibomianitis (Meibomitis): Causes and Treatments ======

  * Inflammation of the meibomian glands
  * A subtype of posterior blepharitis
  * A form of meibomian gland dysfunction (MGD)
  * Most common cause of evaporative dry eye disease.

===== Definition =====

The International Workshop on Meibomian Gland Dysfunction defines MGD as a "chronic, diffuse abnormality of the meibomian glands, commonly characterized by terminal duct obstruction and/or qualitative/quantitative changes in the glandular secretion". When MGD is accompanied by clinically apparent inflammation — visible lid margin redness, telangiectasia, and turbid or thickened secretions — it is termed **meibomitis** or **meibomianitis**.

===== Causes and Risk Factors =====

=== Obstructive Mechanisms ===

  * **Hyperkeratinization** of the meibomian gland duct epithelium leads to terminal duct obstruction, reduced meibum secretion, cystic dilation, and eventual acinar atrophy.
  * Stagnation of meibum within obstructed glands promotes bacterial proliferation and secondary inflammation.

=== Microbial Factors ===

  * **Bacterial colonization** — Proliferation of commensal bacteria (e.g., //Staphylococcus// spp.) within the meibomian glands produces lipolytic enzymes that alter meibum composition and drive inflammation.
  * **//Demodex// mite infestation** — //Demodex brevis// inhabits the meibomian glands and can block gland orifices, inducing MGD and secondary meibomitis. //Demodex folliculorum// infests the eyelash follicles and may cause anterior blepharitis that coexists with posterior disease. Cylindrical dandruff at the lash base is highly suggestive of Demodex infestation.

=== Systemic and Dermatologic Associations ===

  * **Acne rosacea** — One of the most important systemic associations; ocular rosacea frequently manifests as posterior blepharitis/meibomitis.
  * **Seborrheic dermatitis** — Oily, greasy scaling of the lid margin with overlap into MGD.
  * **Fibrosing conjunctival disorders** — Trachoma, erythema multiforme, and ocular cicatricial pemphigoid can cause secondary MGD.

=== Hormonal and Age-Related Factors ===

  * Androgen deficiency reduces meibocyte lipid production via downregulation of androgen receptor (AR) and PPARγ signaling, contributing to altered meibum composition and gland atrophy.
  * Prevalence of MGD increases significantly with age, particularly above 50 years.

=== Other Contributing Factors ===

  * Use of **isotretinoin** (causes meibomian gland atrophy).
  * Contact lens wear, giant papillary conjunctivitis, and environmental factors (low humidity, prolonged screen use).

===== Treatments =====

=== Conservative / First-Line Therapy ===

  * **Warm compresses** — Soften meibum, relieve duct obstruction, and improve gland function. Recommended as the mainstay of treatment.
  * **Lid hygiene** — Mechanical cleansing of the eyelid margins (eyelid scrubs, baby shampoo, or commercial lid wipes) reduces bacterial load.
  * **Meibomian gland expression/massage** — Manual expression of inspissated meibum from the glands.
  * **Artificial tears** — Lipid-containing lubricants to supplement the deficient tear film lipid layer.

=== Topical Pharmacological Therapy ===

  * **Topical antibiotics** — Azithromycin ophthalmic solution has both antibacterial and anti-inflammatory properties.
  * **Topical corticosteroids** — Short courses of low-dose glucocorticoids (e.g., loteprednol etabonate) for acute flares; requires monitoring for steroid-induced glaucoma and cataracts.
  * **Antibiotic–steroid combinations** — Topical combination drops/ointments for moderate-to-severe disease.
  * **Topical cyclosporine A** (Restasis, Cequa) — Immunomodulatory agent approved for dry eye disease; may be used as an adjunct, though evidence for superiority over placebo in MGD specifically is limited].
  * **Lifitegrast 5%** (Xiidra) — LFA-1/ICAM-1 antagonist approved for dry eye; has shown benefit in inflammatory MGD, with improvement in eye dryness, corneal staining, and eyelid redness compared with thermal pulsation in one RCT.

=== Systemic Pharmacological Therapy ===

  * **Oral tetracyclines** — Doxycycline (e.g., 50–100 mg daily for 6–12 weeks) or minocycline; exert anti-inflammatory, lipid-modulating, and anti-bacterial effects on the meibomian glands.
  * **Oral azithromycin** — Pulsed regimens (e.g., 500 mg day 1, then 250 mg days 2–5) offer a shorter course with fewer gastrointestinal side effects; one RCT showed comparable or superior efficacy to doxycycline.
  * **Omega-3 fatty acid supplementation** — May improve MGD symptoms and tear film stability.

=== Demodex-Directed Therapy ===

  * **Tea tree oil** (terpinen-4-ol) — Effective for MGD associated with //Demodex// infestation; applied as lid scrubs.
  * **Lotilaner 0.25% ophthalmic solution** (Xdemvy) — FDA-approved for Demodex blepharitis.

=== In-Office Procedural Treatments ===

  * **Thermal pulsation (LipiFlow)** — Automated device applying controlled heat (41–43°C) and pulsatile pressure to the eyelids for 12 minutes; may improve meibomian gland function and dry eye symptoms compared with warm compresses, though long-term durability is uncertain.
  * **Intense pulsed light (IPL) therapy** — Broad-spectrum light applied to the periocular skin; when combined with meibomian gland expression, may improve tear film stability, ocular surface staining, and lipid layer thickness.
  * **Meibomian gland probing** — Intraductal probing to relieve obstruction in refractory cases.
  * **Other thermal devices** — TearCare, MiBoFlo, and Systane iLux systems offer alternative in-office heat/expression modalities.

===== Complications of Untreated Meibomianitis =====

If left untreated, meibomitis can cause inflammation of the adjacent ocular surface, leading to:

  * **Meibomian keratoconjunctivitis** — corneal cellular infiltrates, neovascularization, and superficial punctate keratopathy.
  * Progressive **meibomian gland dropout** (acinar atrophy), which is considered a permanent pathological change.
  * Chronic evaporative **dry eye disease**.

=====References=====

  - [[https://pubmed.ncbi.nlm.nih.gov/34107053/|Oral Antibiotics for Chronic Blepharitis. Onghanseng N, Ng SM, Halim MS, Nguyen QD. The Cochrane Database of Systematic Reviews. 2021;6:CD013697]]
  - [[https://www-nejm-org.slhs.idm.oclc.org/doi/full/10.1056%2FNEJMra1407936|Dry Eye. Clayton JA. The New England Journal of Medicine. 2018;378(23):2212-2223]]
  - [[https://pubmed.ncbi.nlm.nih.gov/30481812/|Inflamed Obstructive Meibomian Gland Dysfunction Causes Ocular Surface Inflammation. Suzuki T. Investigative Ophthalmology & Visual Science. 2018;59(14):DES94-DES101]]
  - [[https://pubmed.ncbi.nlm.nih.gov/41831668/|Molecular Mechanisms and Pathophysiology of Meibomian Gland Dysfunction. Yang L, Li Z. Experimental Eye Research. 2026;267:110970]]
  - [[https://pubmed.ncbi.nlm.nih.gov/31895884/|A 6-Week, Prospective, Randomized, Single-Masked Study of Lifitegrast Ophthalmic Solution 5% Versus Thermal Pulsation Procedure for Treatment of Inflammatory Meibomian Gland Dysfunction. Tauber J. Cornea. 2020;39(4):403-407]]
  - [[https://pubmed.ncbi.nlm.nih.gov/41931217/|Pharmacological, Natural and Emerging Therapies for Meibomian Gland Dysfunction: A Review. Cooper JM, Mahmoud R, Jennings CJ, et al. Drugs. 2026;86(5):675-718]]
  - [[https://pmc.ncbi.nlm.nih.gov/articles/PMC10037201/#eoi230007f1|Pulsed Oral Azithromycin vs 6-Week Oral Doxycycline for Moderate to Severe Meibomian Gland Dysfunction: A Randomized Clinical Trial. Upaphong P, Tangmonkongvoragul C, Phinyo P. JAMA Ophthalmology. 2023;141(5):423-429]]
  - [[https://pubmed.ncbi.nlm.nih.gov/26707417/|Oral Antibiotics for Meibomian Gland-Related Ocular Surface Disease: A Report by the American Academy of Ophthalmology. Wladis EJ, Bradley EA, Bilyk JR, Yen MT, Mawn LA. Ophthalmology. 2016;123(3):492-6]].
  - [[https://pmc.ncbi.nlm.nih.gov/articles/PMC11613798/|Interventions for Dry Eye: An Overview of Systematic Reviews. McCann P, Kruoch Z, Lopez S, et al. JAMA Ophthalmology. 2024;142(1):58-74]]
  - [[https://pubmed.ncbi.nlm.nih.gov/37642619/|Thermal Pulsation in the Management of Meibomian Gland Dysfunction and Dry Eye: A Report by the American Academy of Ophthalmology. Tao JP, Shen JF, Aakalu VK, et al. Ophthalmology. 2023;130(12):1336-1341]]
  - [[https://pmc.ncbi.nlm.nih.gov/articles/PMC7077992/|Intense Pulsed Light (IPL) Therapy for the Treatment of Meibomian Gland Dysfunction. Cote S, Zhang AC, Ahmadzai V, et al. The Cochrane Database of Systematic Reviews. 2020;3:CD013559]]