Blepharitis, Meibomitis, and Hordeola

Etiology

• Chronic lid margin inflammation is likely multifactorial
• Staphylococcal blepharitis
• Chronic colonization with low grade infection and/or inflammatory reaction to bacterial antigens and toxins
• Includes aerobic and anaerobic species – Staphylococcus aureus, Staphylococcus epidermidis, Propionibacterium acnes, Corynebacterium
• Seborrheic blepharitis
• Mechanical obstruction caused by scaling of eyelid margin
• Cyclical process with obstruction causing inflammatory changes of the eyelid
• From overproduction of sebum, causing greasy scaling
• Demodicosis
• Demodex mites are common incidental inhabitants of lash follicles.
• Mites may introduce bacteria or primarily exacerbate inflammation.
• Mites are frequently seen in eyelid colarettes (Gao, 2005).
• Meibomian gland dysfunction (MGD)
• Similar processes cause inflammation of the posterior eyelid margin.
• Altered meibomian gland secretions result in gland blockage.
• Decreased lipid layer in tear film and abnormal lipids contribute to ocular and eyelid inflammation and dry eyes.
• Can be associated with rosacea or seborrheic dermatitis
• Chalazion
• Plugging/inspissation of a meibomian or Zeis gland results in trapping of sebaceous material.
• The trapped material elicits inflammation, typically granulomatous.
• May have an infectious component, as described for staph blepharitis
• Staphylococcus aureus is most common pathogen
• Lash sampling was performed to microscopically count mite populations
• In 44 adult and 47 pediatric patients with chalazia and 34 adult and 30 pediatric age- and sex-matched patients without chalazia (Liang, 2014)
• Demodicosis was defined as presence of mites, present in 69% of chalazion patients, compared with 20% of controls. 
• Demodex brevis was significantly more prevalent than demodex folliculorum in patients with chalazia.
• Chalazia with demodicosis had signficantly more common recurrence after excision
• Patients with past history of rosacea were excluded from the study.  
• Terminology can be confusing – hordeolum is inspissation and infection of sebaceous glands
• Anterior lid (glands of Zeis, lash follicles): external hordeolum or stye
• Posterior lid (meibomian glands): internal hordeolum

Epidemiology

• Blepharitis
• May be changing as the epidemiology of staph species continues to change
• Role of community acquired MRSA is increasingly important
• Older literature suggested that staphylococcal disease occurs in younger individuals (McCulley 1985)
• Overall, blepharitis incidence increases in incidence with age (Driver 1996)
• In 1982, 590,000 patient visits were due to blepharitis (NDTI 1982).
• Blepharitis is observed in 37–47% of ophthalmologists’ and optometrists’ practices (Hom 1990, Lemp 2009)
• Keratoconjunctivitis sicca was found to be associated in 25–50% of cases (McCulley 1982 and 1985).
• Chalazia occurs in all ages, races, and sexes.

History

• Blepharitis and meibomitis
• Burning, itching, and foreign body sensation
• Usually worse in the morning
• Redness of the eyelids
• Crusting of the eyelids
• Filmy, blurred vision
• Recurrent chalazia/hordeola
• Chalazia
• Acute inflammation: rapid onset, mild pain, focal tenderness, and erythema
• Resolution can occur prior to the development of the chronic phase.
• Can fluctuate in size
• Can spontaneously drain posteriorly or anteriorly
• Blurred vision secondary to induced astigmatism with lid swelling
• Chronic form can follow, consisting of a painless, well-circumscribed mass within the tarsal/pretarsal eyelid
• Can present with pyogenic granuloma as mass or bleeding

Clinical features

• Blepharitis
• Hard scales and crusts around eyelid cilia called “sleeves” or “collarettes.”
• Staphylococcal debris and white blood cells congealed together and colonization by Demodex folliculorum (Favier, 2017)
• Seborrheic inflammation causes oily or greasy crusting
• There is a 95% incidence of associated seborrheic dermatisis (McCulley 1985). Manifests as yellow crusting also on eyebrows and scalp
• Erythema and telangiectasis of eyelid margins
• Poliosis
• Madarosis
• Trichiasis
• About 1/3 have keratoconjunctivitis sicca (Edwards 1987)
• Ocular surface inflammation can cause abnormal tear meniscus, abnormal tear break up time, foamy discharge, debris in tear film
• Conjunctival hyperemia and papillary reaction of tarsal conjunctiva
• Corneal changes such as punctate epithelial keratopathy, marginal infiltrates, phlyctenules
• Notching and thickening of the eyelid

• Meibomian gland dysfunction or meibomitis
• Inflammation of posterior lid margin
• Eyelid margin irregularity, scalloping, and thickening
• Prominent telangiectasis
• Pouting or plugged meibomian gland orifices
• Turbid, thick secretions (“toothpaste-like”)
• Foamy tear meniscus
• Conjunctival hyperemia, and often papillary reaction
• Corneal changes such as punctate epithelial keratopathy, marginal infiltrates, pannus
• Can have margin rounding, notching, dimpling, thickening, irregularity
• Arita et al (2016) developed a grading scale to describe severity of meibomitis
• Telangiectasia – 0 = no findings; 1 = mild telangiectasia; 2 = moderate telangiectasia or redness; 3 = severe telangiectasia or redness.
• Meibomian gland collapse – 0 = minimal; 1 = moderate; 2 = severe
• Irregularity, plugging, foaming, and thickness (each graded separately) – 0 = none; 1 = mild; 2 = severe. 
• Gland dropout was the most consistent evidence of severity. 

• Chalazia
• Overlying skin can have erythema
• Important to evert eyelid; nodule on the tarsal conjunctival surface
• Loculation of inflammatory material can cause chronic cyst-like nodule 
• Can localize anteriorly
• Elevated nodules may be near lid margin or up to 10 mm away (upper eyelid)
• Surrounding edema, erythema might indicate treatment for preseptal cellulitis

Testing

• Usually diagnosed clinically
• Several techniques to quantify meibomian gland dropout:
• Meiboscopy — clinical examination with transilluminated biomicroscopy of the glands (Robin 1985)
• Meibography — near-infrared light and camera capture images of the glands (Figure 1)

Figure 1. Top: Meibography of a normal eyelid. Bottom: Abnormal dilation of meibomian glands in a patient with meibomian gland dysfunction.

• Confocal microscopy
• Cultures are generally not helpful
• Yield is higher with frank purulence
• Staph epidermidis may be interpreted as normal flora even if clinically significant
• Culture for MRSA can support treatment, if oral antibiotics prescribed for acute signs of infection
• Demodex mites can be visualized by epilating lash, place on a glass slide, add a drop of fluorescein, place cover slip (Kheirkhah, 2007)
• Histopathologic confirmation of demodicosis for atypical, persistent, or recurrent lesions.

Blepharitis

• Dry eye syndrome
• Dermatologic conditions: e.g., seborrheic dermatitis
• Rosacea
• Oral retinoid therapy
• Demodicosis
• Giant papillary conjunctivitis

Chalazia/Hordeola

• Rosacea
• Chronic posterior blepharitis (meibomian gland dysfunction)
• Demodex might be a risk factor (Yam 2014).

Malignant tumors

• Sebaceous gland carcinoma
• Basal cell carcinoma
• Squamous cell carcinoma
• Merkel cell carcinoma (Rawlings 2007)
• Hemangioendothelioma (Al-Faky 2011)
• Plasmacytoma (Maheshwari 2009)
• Renal cell carcinoma (Tailor 2008)
• Pleural mesothelioma (Tsina 2006)

Benign tumors

• Pleomorphic adenoma (Ramlee 2007)
• Granular cell tumor (Scruggs 2014)
• Solitary neurofibroma (Shibata 2012)
• Plexiform neurofibroma (Tey 2006)
• Pilomatrixoma (Katowitz 2003)
• Keratoacanthoma
• Papilloma
• Ruptured epithelial inclusion cyst

Inflammatory disorders

• Sarcoidosis
• Atypical mycobacterial infection
• Wegener granulomatosis (Ismail 2007)
• Ruptured epithelial inclusion cyst
• Hyperimmunoglobulinemia E (Job) syndrome (Destefano 2004, Crama 2004)

Infectious

• Preseptal cellulitis
• Canaliculitis (Almaliotis 2013)
• Tuberculosis (Mittal 2013)
• Leishmaniasis (Rahimi 2009)

Other

• Retained soft contact lens (Agarwal 2013)
• Trichilemmal cyst (Meena 2012)
• Lacrimal gland duct stones (Kim 2014)

Natural history

• Blepharitis
• Chronic, with periods of exacerbation and remission
• Can begin in childhood, although typically onset is in middle age
• If severe, can cause eyelash loss, scarring of eyelids, trichiasis, secondary corneal scarring
• Chalazia
• Typically self-limiting, resolving in 1–2 weeks
• Chronic form may develop which can take many months to years to resolve.
• Eventually, virtually all chalazia resolve, even after years (Honda 2010).

Medical therapy

Blepharitis

• Eyelid hygiene
• Warm compresses
• Scrubs with water, dilute baby shampoo or commercially available eyelid wipes once or twice daily depending on severity
• Olenik study (Olenik 2013):
• Randomized double-blinded trial of baby-shampoo eyelid cleaning and preservative-free artificial tears with placebo or 1.5 gram of a composition (DHA, EPA, vitamins A, C, and E, tyrosine, cysteine, glutathione, zinc, copper, manganese, selenium, DPA)
• Measurements of staining, tear breakup time, Schirmer test, eyelid inflammation, ocular surface disease index (OSDI), meibomian gland expression
• After 3 months (64 patients), there was significant improvement of OSDI, TBUT, eyelid margin inflammation, meibomian gland expression, Schirmer test.
• For staphylococcal blepharitis treat with topical antibiotics, for example, erythromycin or bacitracin ophthalmic ointment
• Topical azithromycin ophthalmic solution 1%
• Has anti-inflammatory properties
• Studies have shown improvement for anterior and posterior blepharitis — open label studies (John 2008, Luchs 2008, Haque 2010, Opitz 2011).
• Dosing schedules are varied – 1 gtt BID x 2 days, then qday for 7–28 days (Opitz 2012)
• A multicenter, randomized study comparing Tobradex ST (4x/day x 14 days) to Durasite (2x/day x 12 days) for blepharitis favored Tobradex (Torkildsen 2011)
• Ivermectin cream 1% can reduce demodecosis (Favier, 2017)
• Ivermectin can be administered orally at a dose of 200 mcg/kg once, repeated in 7 days
• Reduces demodex folliculorum in refractory blepharitis (Holzchuh, 2011)
• Available as 3 mg tablet – 170 lb. (77 kg) adult would take 15 mg or five pills
• Minocycline or doxycycline 50–100 mg BID can be considered for chronic meibomitis
• Can taper to qday after the first month
• Slow-release formulation (50 mg qday) might be effective
• Alternatives include tetracycline 500 mg BID or azithromycin 250–500 mg, 1–3x/week; or 1g qweek x 3 weeks (caution in patients with cardiac conduction abnormalities)
• Treatment based on small clinical trials on symptoms improvement with ocular rosacea (Frucht-Pery 1993, Sobolewska 2014)
• Evidence of improving blepharitis symptoms (Dougherty 1991, Shine 2003)
• Short course of topical corticosteroids can be used when inflammation is severe.
• Eyelid thermal pulsation system (LipiFlow)
• Device uses pulsatile “milking” movements and application of heat to each eyelid
• A single treatment (12 minutes) can have improvement in ocular surface disease index (OSDI).
• Has been shown to be more effective than heat (warm compresses) alone
• No randomized controlled studies
• Xdemvy (lotilaner 0.25%, Tarsus Pharmaceuticals, Irvine, CA) was approved in 2023 for the treatment of Demodex blepharitis.
• 6-week treatment course, administered as 1 drop two times per day into the affected eye.
• GABA-receptor inhibitor that directly targets the parasite causing paralysis and eventual death of the mite.

Meibomitis

• 150 patients with clinical evidence of meibomitis were randomized into three groups, treated for one month with doxycycline 200 mg BID, doxycycline 20 mg BID, or placebo (Yoo, 2005).
• The study did not assess lid changes.
• Both treatment groups had improvement in tear breakup time and Shirmer test, compared with placebo.
• Quaterman reported improvement in eyelid inflammation at 12 weeks in open label trial of doxycycline 100 mg daily for 12 weeks (Quaterman, 1997). 
• Aronowicz (2006) treated 16 meibomitis patients with 50 mg minocycline daily for 2 weeks, followed by 10 weeks of 100 mg daily.
• Assessed appearance of the eyelids, degree of meibomian gland plugging and amount of secretion
• Noted improvement in eyelid margin thickening and vascularization
• Decrease in eyelid margin debris and less meibomian gland obliteration
• Effect continued three months after cessation of the medication.
• Igami (2011) treated 13 meibomitis patients who had not responded to topical corticosteroids and antibiotics with oral azithromycin.
• In 3 cycles of 500 mg/day for 3 consecutive days at 7-day intervals
• Using eyelid scoring system that measured severity of eyelid debris, telangiectasias, mucous secretion, and eyelid margin edema and erythema
• Found clinical improvement, except eyelid edema, thirty days after completion of therapy
• Once weekly azithromycin, 1 gram orally for three weeks, was assessed in 32 patients with meimobitis, using subjective improvement as the primary end point (Greene, 2014).
• Concurrently continued treatment with topical steroid drops and compresses
• At mean 5 week follow-up 75% reported symptomatic improvement
• GI upset was the most common side effect (9%)
• Literature assessment by the American Academy of Ophthalmology concluded that there is no level I evidence to support use of oral antibiotics including doxycycline, minocycline or azithromycin for meibomian gland related ocular suface disease (Wladis, 2016).

Chalazia/Hordeola

• Warm compresses and eyelid massage
• Eyelid hygiene/scrubs
• Topical antibiotics may be of value in treating staphylococcal blepharitis component.
• Systemic antibiotics are active against Staphylococcus aureus for accompanying preseptal cellulites.
• Systemic tetracyclines for treatment of chronic accompanying meibomitis, rosacea
• Topical or systemic tetracyclines can help improve meibomian secretions.
• Topical steroid can be used to decrease inflammatory component of skin (although not demonstrated in any studies).

Surgery

Blepharitis

• Intraductal meibomian probing (that is, Maskin probe) (Maskin 2010)
• Topical anesthetic or injected local anesthetic placed into the eyelid
• Start with 2-mm probe (Figure 2)

Figure 2. Maskin probe usage. Penetration through orifice with 2-mm probe. Note hemorrhage at orifice of adjacent gland.

• Can encounter resistance at meibomian gland orifice and within gland (fibrovascular tissue)
• Normal to have droplet of blood at orifice
• Then repeat with 4-mm probe
• Can be also done with hyfrecation tip (Figure 3) (Wladis 2012)
• Anatomic changes resulting in trichiasis or entropion might require surgical correction.

Figure 3. Meibomian probing. Image courtesy Edward J. Wladis, MD.

Chalazia/Hordeola

• Intralesional/perilesional corticosteroid injection
• Can be used for small marginal lesions or other lesions
• Multiple randomized controlled studies assessing injection versus excision (Ben Simon 2011, Goawalla 2007, Jacobs 1984)
• Can have similar rates of resolution, although Jacobs reported much higher rate of complete resolution with surgery (60% versus 8.7%)
• Multiple injections may be needed
• Can use 40 mg/mL or 10 mg/mL triamcinolone and inject 0.05 to 0.15 cc
• Most studies do not use a chalazion clamp at time of injection.
• Surgical drainage via a transconjunctival or cutaneous route
• Anesthetic
• Especially with small lesions, consider marking the skin prior to injection; otherwise, the location of the chalazion can be masked after infiltration.
• Consider using a pledget with 4% lidocaine (plain) between the globe and chalazion to help dull the pain of injection.
• Incision and curettage
• Chalazion clamp is placed on the eyelid to isolate the chalazion, and the eyelid is everted.
• Bard Parker #15 or #11 blade is used to make a stab incision through the posterior tarsal plate.
• Can be vertical or an “x;” some surgeons excise the flaps of the “x;” others leave them.
• Liquid and gelatinous material is expressed.
• Curettage can be performed with a chalazion curette.
• Excise granulomatous tissue and cyst wall especially in chronic forms with little or limited liquid/gelatinous material
• Caution to prevent violation of the skin.

• Cutaneous excision
• In cases of cutaneous changes (erythema, infiltration, thinning), limited excision of skin might be needed to resolve the lesion.
• Use caution in dark-pigmented patients because the visible scar can be more pronounced.
• Because the source of the chalazion is in the tarsal plate, this must also be addressed in addition to the skin.
• Trephination
• Through the conjunctival surface, a “punch” biopsy trephine can be used (Leachman).
• With the trephine (2–5 mm diameter), center it over the visible lesion, and then slowly rotate the trephine while applying pressure.
• Be careful to prevent penetration past the tarsal plate.
• Once through the full thickness of tarsus, use scissors and forceps to excise.
• Margin lesions
• Some suggest marginal curettage (Dubey).
• After placement of an appropriately sized clamp, the curette is placed into the chalazion and curetted.
• The remainder of the proximal chalazion is approached in the “standard” fashion.
• Care should be taken not to communicate the 2 areas to prevent notching.
• Combined excision and corticosteroid injection
• After excision is completed, some authors advocate for intratarsal injection of steroid.
• Best done with clamp in place to prevent embolization of steroid material
• Biopsy for recurrent or atypical lesions
• Caution for any atypical lesions in either appearance or history
• Concern for malignancy or other atypical lesions

Topical corticosteroids

• Increased intraocular pressure, cataract, infection
• Prevent by using lowest strength and dose possible for only brief period when inflammation severe

Systemic tetracyclines

• Photosensitization, gastrointestinal (GI) upset, azotemia, candidiasis
• Use is contraindicated in children and pregnant or nursing women.
• Taper based on clinical response and use the lowest dose possible.
• Cases of doxycycline induced Stevens-Johnson syndrome have been reported (Cac, 2007; Lau, 2011).
• Pseudotumor cerebri has been reported (Winn 2007).

Pyogenic granuloma formation

• Occurs in the presence of an underlying chalazion/hordeolum
• After excision of pyogenic granuloma, also excise the chalazion.

Globe perforation

• Results in severe visual loss
• Perforation during excision — 2 cases (Shiramizu 2004)
• Perforation during injection — 1 case (Hosal 2003)

Eyelid margin scarring or notching

• Use care when removing tissue at or near the lid margin because there is a risk for eyelid scarring or notching.
• Can revise severe scar or notch with full-thickness pentagonal wedge resection
• Horizontal scarring of tarsal plate
• Some suggest prevention by making only vertical incisions along meibomian gland.
• Make an enlarged excision of involved tarsus to prevent vertical shortening of eyelid.
• Repeated episodes or surgical treatments can lead to posterior lamellar scarring and misdirected eyelashes or eyelash loss.

Damage to surrounding meibomian glands

• Prevent by making vertical cuts through tarsal conjunctival surface.

Intralesional corticosteroid injection for chronic lesions (chalazion)

• Skin depigmentation
• Maintain deep (intratarsal or suborbicularis oculi) level of medication.
• Caution in dark-skinned patients
• Visible steroid (white sediment of triamcinolone) (Cohen 1979)
• Maintain deep (intratarsal or suborbicularis oculi) level of medication.
• Embolization of steroid to retina
• Extremely rare — 2 case reports (Yagci 2008, Thomas 1986)
• Consider use of chalazion clamp during injection to prevent emboli.

Damage to punctum or canaliculus

• Use caution when excising peripunctal or pericanalicular chalazia.
• If punctum or canaliculus is violated, repair with silicone stent intubation.

Blepharitis

• Corneal neovascularization and scarring
• Madarosis
• Trichiasis, marginal entropion
• Cicatricial entropion
• Chalazion
• Reflex epiphora
• Can have increased association with some inflammatory diseases, psychologic conditions, hypothyroidism, cardiovascular disease (Nemet 2011)

Chalazia/Hordeola

• Rarely eyelid scarring with or without trichiasis
• Eyelid malposition (for example, ptosis from longstanding lesion of upper eyelid)
• Recurrent lesions
• Preseptal/orbital cellulitis — with superinfection

Blepharitis

• Cure is often not possible eyelid hygiene will likely need to be performed indefinitely.
• Intermittently, the patient might need more aggressive therapy with topical or systemic medications.
• Return for recurrence of symptoms
• Follow-up in 3 to 4 weeks when symptoms severe and new medication is started

Chalazia/Hordeola

• Prevention of new chalazia with warm compresses, eyelid hygiene
• Return if chalazion/hordeolum recurs

• Meibomian glands first described by Heinrich Meibomius in 1666 (Meibomius)
• Blepharitis first described by Elschnig in 1908 (Mathers 1991)
• Radiation therapy has been described, without support of clinical trials

1. American Academy of Ophthalmology Cornea/External Disease Panel. Preferred Practice Pattern Guidelines. Blepharitis. 2013. Available at aao.org/ppp.
2. Basic and Clinical Science Course. Section 4: Ophthalmic Pathology and Intraocular Tumors; Section 6: Pediatric Ophthalmology and Strabismus; Section 7: Orbit, Eyelids, and Lacrimal System; Section 8: External Disease and Cornea, 2013-2014. San Francisco: American Academy of Ophthalmology.
3. Focal Points: Diagnosis and Treatment of Chronic Blepharitis, Module 10, 1989. San Francisco: American Academy of Ophthalmology.
4. Monograph 8, Surgery of the Eyelids, Lacrimal System, & Orbit, 2nd edition, 2011. San Francisco: American Academy of Ophthalmology.
5. Agarwal PK, Ahmed TY, Diaper CJ. Retained soft contact lens masquerading as a chalazion: a case report. Indian J Ophthalmol. 2013;61(2):80-81.
6. Al-Faky YH, Al Malki S, Raddaoui E. Hemangioendothelioma of the eyelid can mimic chalazion. Oman J Ophthalmol. 2011;4(3):142-143.
7. Almaliotis D, Nakos E, Siempis T, et al. A para-canalicular abscess resembling an inflamed chalazion. Case Rep Ophthalmol Med. 2013;618367.
8. Arita R, Minoura I, Morishige N, et al: Development of definitive and reliable grading scales for meibomian gland dysfunction. Am J Ophthalmol 2016; 169:125-137. 
9. Aronowicz JD, Shine WE, Oral D, et al. Short term oral minocycline treatment of meibomianitis. Br J Ophthalmol 2006;90:856–60.
10. Ben Simon GJ, Rosen N, Rosner M, Spierer A. Intralesional triamcinolone acetonide injection versus incision and curettage for primary chalazia: a prospective, randomized study. Am J Ophthalmol. 2011;151(4):714-718.
11. Cac NN, Messingham MJ, Sniezek PJ, Walling HW. Stevens-Johnson syndrome induced by doxycycline. Cutis 2007; 79:119-122.
12. Cohen BZ, Tripathy RC. Eyelid depigmentation after intralesional injection of a fluorinated corticosteroid for chalazion. Am J Ophthalmol. 1979;88(2):269-270.
13. Crama N, Toolens AM, van der Meer JW, Cruysberg JR. Giant chalazia in the hyperimmunoglobulinemia E (hyper-IgE) syndrome. Eur J Ophthalmol. 2004;14(3):258-260.
14. Destefano JJ, Kodsi SR, Primack JD. Recurrent Staphylococcus aureus chalazia in hyperimmunoglobulinemia E (Job’s) syndrome. Am J Ophthalmol. 2004;138(6):1057-1058.
15. Dougherty JM, McCulley JP, Silvany RE, Meyer DR. The role of tetracycline in chronic blepharitis: inhibition of lipase production in staphylococci. Invest Ophthalmol Vis Sci. 1991;32:2970-2975.
16. Driver PJ, Lemp MA. Meibomian gland dysfunction. Surv Ophthalmol. 1996;40(5):343-347.
17. Dubey R, Wang LW, Figueira EC, et al. Management of marginal chalazia: a surgical approach. Br J Ophthalmol. 2011;95:590-597.
18. Edwards RS. Ophthalmic emergencies in a district general hospital casualty department. Br J Ophthalmol. 1987;71:938-942.
19. Favier C. Demodex clusters. Ophthalmology 2017; 124:1474.
20. Frucht-Pery J, Sagi E, Hemo I, Ever-Hadani P. Efficacy of doxycycline and tetracycline in ocular rosacea. Am J Ophthalmol. 1993;116:88-92.
21. Gao YY, Di Pascuale MA, Li W, et al. High prevalence of Demodex in eyelashes with cylindrical dandruff. Invest Ophthalmol Vis Sci 2005;46(9):3089–3094.
22. Goawalla A, Lee V. A prospective randomized treatment study comparing three treatment options for chalazia: triamcinolone acetonide injections, incision and curettage and treatment with hot compresses. Clin Experiment Ophthalmol. 2007;35(8):706-712.
23. Greene JB, Jeng BH, Fintelmann RE, et al: Oral azithromycin for the treatment of meibomitis. JAMA Ophthalmol 2014; 132:121-122.
24. Greiner JV. A single LipiFlow thermal pulsation system treatment improves Meibomian gland function and reduces dry eye symptoms for 9 months. Curr Eye Res. 2012;37(4):272‑278.
25. Haque RM, Torkildsen GL, Brubaker K, et al. Multicenter open-label study evaluating the efficacy of azithromycin ophthalmic solution 1% on the signs and symptoms of subjects with blepharitis. 2010;29:871‑877.
26. HolzchuhFG, Hida RY, Moscovici BK, et al: Clinical treatment of ocular demodex folliculorum by systemic ivermectin. Am J Ophthalmol 2011; 151:1030-1034.
27. Hom MM, Martinson JR, Knapp LL, et al. Prevalance of Meibomian gland dysfunction. Optom Vis Sci. 1990;67:710‑712.
28. Honda M, Honda K. Spontaneous resolution of chalazion after 3 to 5 years. Eye Contact Lens. 2010;36(4):230‑232.
29. Hosal BM, Zilelioglu G. Ocular complication of intralesional corticosteroid injection of a chalazion. Eur J Ophthalmol. 2003;13(9‑10):798‑799.
30. Igami TZ, Holzchuh R, Osaki TH, et al. Oral azithromycin for treatment of posterior blepharitis. Cornea 2011;30:1145–9.
31. Ismail AR, Theaker JM, Manners RM. Wegener’s granulomatosis masquerading as upper lid chalazion. Eye (Lond). 2007;21(6):883‑884.
32. IovienoA, LambiaseA, MiceraA, etal. In vivo characterization of doxycycline effects on tear metalloproteinases in patients with chronic blepharitis. Eur J Ophthalmol 2009;19:708–16.
33. Jacobs PM, Thaller VT, Wong D. Intralesional corticosteroid therapy of chalazia: a comparison with incision and curettage. Br J Ophthalmol. 1984;68:836‑837.
34. John T. Use of azithromycin ophthalmic solution in the treatment of chronic mixed anterior blepharitis. Ann Ophthalmol. 2008;40(2):68‑74.
35. Katowitz WR, Shields CL, Shields JA, et al. Pilomatrixoma of the eyelid simulating a chalazion. J Pediatr Ophthalmol Strabismus. 2003;40(4):247‑248.
36. Kheirkhah A, Blanco G, Casas V, Tseng SC. Fluorescein dye improves microscopic evaluation and counting of Demodex in blepharitis with cylindrical dandruff. Cornea 2007;26(6): 697–700.
37. Kim SC, Lee K, Lee SU. Lacrimal gland duct stones: misdiagnosied as chalazion in 3 cases. Can J Ophthalmol. 2014;49(1):102‑105.
38. Lane SS, DuBiner HB, Epstein RJ, et al. A new system, the LipiFlow, for the treatment of Meibomian gland dysfunction. 2012;31:396‑404.
39. Lau B, Mutyala D, Dhaliwal D. A case report of doxycycline-induced Stevens-Johnson syndrome. Cornea 2011; 30:595-597.
40. Leachman JW, Boynton JR, Levin DB. Chalazion management by tarsus trephination. Ophthalmic Surg. 1978;9(1):89‑90.
41. Lemp MA, Nichols KK. Blepharitis in the United States: a survey based perspective on prevalence and treatment. Ocul Surf. 2009;7(Suppl 2):S1‑S14.
42. Liang L, Ding X, Tseng SCG. High prevalence of demodex brevis infestation in chalazia. Am J Ophthalmology 2014; 342-348.
43. Lindsley K, Matsumura S, Hatef E, Akpek EK. Interventions for chronic blepharitis. Cochrane Database Syst Rev. 2012;5:CD005556.
44. Luchs J. Efficacy of topical azithromycin ophthalmic solution 1% in the treatment of posterior blepharitis. Adv Ther. 2008;25(9):858‑870.
45. Maheshwari R, Maheshwari S. Extramedullary plasmacytoma masquerading as chalazion. 2009;28(2‑3):191‑193.
46. Maskin SL. Intraductal Meibomian gland probing relieves symptoms of obstructive Meibomian gland dysfunction. 2010;29(10):1145‑1152.
47. Mathers WD, Shields WJ, Sachdev MS, et al. Meibomian gland dysfunction in chronic blepharitis. 1991;10:277‑285.
48. McCulley JP, Dougherty JM, Deneau DG. Classification of chronic blepharitis. Ophthalmology. 1982;89(10):1173‑1180.
49. McCulley JP, Dougherty HM. Blepharitis associated with acne rosacea and seborrheic dermatitis. Int Ophthalmol Clin. 1985;25(1):159‑172.
50. Meena M, Mittal R, Saha D. Trichilemmal cyst of the eyelid: masquerading as recurrent chalazion. Case Rep Ophthalmol Med. 2012;261414.
51. Meibomius H. De Vasis Palpebrarum Novis Epistola Muller, Helmstadt, 1666.
52. Mittal R, Tripathy D, Sharma, Balne PK. Tuberculosis of eyelid presenting as a chalazion. Ophthalmology. 2013;120(5):e1‑4.
53. National Disease and Therapeutics Index (NDTI), IMS America, Dec 1982.
54. Nemet AY, Vinker S, Kaiserman I. Associated morbidity of blepharitis. Ophthalmology. 2011;118:1062‑1068.
55. Nichols JJ, Berntsen DA, Mitchell GL, et al. An assessment of grading scales for meibography images. 2005;24:382‑388.
56. Olenik A, Jimenez-Alfaro I, Alejandre-Alba N, Mahillo-Fernandez I. A randomized, double-masked study to evaluate the effect of omega‑3 fatty acids supplementation in Meibomian gland dysfunction. Clin Interventions Aging. 2013;8:1133‑1138.
57. Opitz DL, Tyler KF. Efficacy of azithromycin ophthalmic solution for treatment of ocular surface disease from posterior blepharitis. Clin Ep Optom. 2011;94(2):200‑206.
58. Opitz DL, Harthan JS. Review of azithromycin ophthalmic 1% solution (AzaSite) for the treatment of ocular infections. Ophthalmol and Eye Dis. 2012;4:1‑14.
59. Ozdal PC, Codere F, Callejo S, et al. Accuracy of the clinical diagnosis of chalazion. Eye (Lond). 2004;18(2):135‑138.
60. Papas A, Singh M. The effect of a unique omega‑3 supplement on dry mouth and dry eye in Sjogrens patients. ARVO Annual Meeting. 2007.
61. Peralejo B, Beltriani V, Bielory L. Dermatologic and allergic conditions of the eyelid. Immunol Allergy Clin North Am. 2008;28:137‑168.
62. Pinheiro MH Jr, Dos Santos PM, Dos Santos RC, et al. Oral flaxseed oil (Linum usitatissimum) in the treatment for dry-eye Sjogren’s syndrome patients. Arq Bras Oftalmol. 2007;70:649‑655.
63. Quarterman MJ, Johnson DW, Abele DC, et al. Ocular rosacea. Signs, symptoms, and tear studies before and after treatment with doxycycline. Arch Dermatol 1997;133:49–54.
64. Rahimi M, Moinfar N, Ashrafi A. Eyelid leishmaniasis masquerading as chalazia. Eye (Lond). 2009;23(3):737.
65. Raju VK, Raju LV, Kheirkah A. Demodex blepharitis. Ophthalmology 2012; 119-200. 
66. Ramlee N, Ramli N, Tajudin LS. Pleomorphic adenoma in the palpebral lobe of the lacrimal gland misdiagnosed as chalazion. 2007;26(2):137‑139.
67. Rawlings NG, Brownstein S, Jordan DR. Merkel cell carcinoma masquerading as a chalazion. Can J Ophthalmol. 2007;42(3):469‑470.
68. Robin JB, Jester JV, Nobe J, et al. In vivo transillumination biomicroscopy and photography of Meibomian gland dysfunction: a clinical study. Ophthalmology. 1985;82:1423‑1426.
69. Scruggs RT, Black EH. Granular cell tumor masquerading as a chalazion: a case report. Ophthal Plast Reconstr Surg. 2015;31(1):e6‑8.
70. Sherman RS, Hogan MJ. Radiation therapy in diseases of the eye. California Medicine. 1954;80(2):83‑90.
71. Shibata N, Kitagawa K, Noda M, Sasaki H. Solitary neurofibroma without neurofibromatosis in the superior tarsal plate simulating a chalazion. Graefes Arch Clin Exp Ophthalmol. 2012;250(2):309‑310.
72. Shine WE, McCulley JP, Pandya AG. Minocycline effect on meibomian gland lipids in meibomianitis patients. Exp Eye Res. 2003;76:417‑420.
73. Shiramizu KM, Krieger AE, McCannel CA. Severe visual loss caused by ocular performation during chalazion removal. Am J Ophthalmol. 2004;137(1):204‑205.
74. Sobolewska B, Doycheva D, Deuter C, et al. Treatment of ocular rosacea with once-daily low-dose doxycycline. 2014;33(3):257‑260.
75. Tailor R, Inkster C, Hanson I, et al. Metastatic renal cell carcinoma presenting as a chalazion. Eye (Lond). 2008;21(4):564‑565.
76. Tey A, Kearns PP, Barr AD. Plexiform neurofibroma masquerading as a persistent chalazion – a case report. Eye (Lond) 2006;20(8):946‑948.
77. Thomas EL, Laborde RP. Retinal and choroidal vascular occlusion following intralesional corticosteroid injection of a chalazion. Ophthalmology. 1986;93:405‑407.
78. Torkildsen GL, Cockrum P, Meier E, et al. Evaluation of clinical efficacy and safety of tobramycin/dexamethasone ophthalmic suspension 0.3%/0.05% compared to azithromycin ophthalmic solution 1% in the treatment of moderate to severe acute blepharitis/blepharoconjunctivitis. Curr Med Res Opin. 2011;27(1):171‑178.
79. Tsina EK, Papioannou D, Matsouka FO, Kosmidis PA. Metastatic pleural mesothelioma initially masquerading as chalazion. Br J Ophthalmol. 2006;90(7):921‑922.
80. US Food and Drug Administration. FDA Drug Stafety Communication. Azithromycin (Zithromax or Zmax) and the risk of potentially fatal heart rhythms. Available at fda.gov/drugs/drugsafety/ucm341822.htm.
81. Winn BJ, Liao YJ, Horton JC. Intracranial pressure returns to normal about a month after stopping tetracycline antibiotics. Arch Ophthalmol 2007;125(8):1137‑1138.
82. Wladis EJ, et al. Intense Pulsed Light for Meibomian Gland Disease: A Report by the American Academy of Ophthalmology. Ophthalmology, 2020; 127:1227-1233.
83. Wladis EJ. Intraductal Meibomian gland probing in the management of ocular rosacea. Ophthal Plast Reconstr Surg. 2012;28:416‑418.
84. Wladis EJ, Bradley EA, Bilyk JR, el al: Oral antibiotics for meibomian gland-related ocular surface disease: A report by the American Academy of Ophthalmology. Ophthalmology 2016; 123:492-496.
85. Wojtowicz JC, Butovich I, Uchiyama E, et al. Pilot, prospective, randomized, double-masked, placebo-controlled clinical trial of an omega‑3 supplement for dry eye. 2011;30:308‑314.
86. Yagci A, Palamar M, Egrilmez S, et al. Anterior segment ischemia and retinochoroidal vascular occlusion after intralesional steroid injection. Ophthal Plast Reconstr Surg. 2008;24(1):55‑57.
87. Yam JC, Tang BS, Chang TM, Cheng AC. Ocular demodicidosis as a risk factor of adult recurrent chalazion. Eur J Ophthalmol. 2014;24(2):159‑163.
88. Yoo SE, Lee DC, Chang MH. The effect of low-dose doxy- cycline therapy in chronic meibomian gland dysfunction. Korean J Ophthalmol 2005;19:258–63.