○ Subacute/chronic: gradually enlarging painless rounded nodule (Fig. 1.2B).

☐ Acute: sterile inflammation or bacterial infection with localized cellulitis (Fig. 1.2C); differentiation may be difficult. A secondarily infected meibomian gland is referred to as an internal hordeolum.

○ A nodule within the tarsal plate, sometimes with associated inflammation.

○ Bulging inspissated secretions may be visible at the orifice of the involved gland.

○ There may be an associated conjunctival granuloma (Fig. 1.2D).

○ A lesion at the anterior lid margin – a marginal chalazion (Fig. 1.2E) – may be connected to a typical chalazion deeper in the lid or be due to isolated involvement of a gland of Zeis.

Oral antibiotics are required for significant bacterial infection, but not for sterile inflammation.

Conservative. At least a third of chalazia resolve spontaneously so observation may be appropriate, especially if the lesion is showing signs of improvement, though early definitive treatment has been reported to lead to higher patient satisfaction.

Hot compress application several times daily may aid resolution, particularly in early lesions.

Expression. Compression between two cotton-tipped applicators is sometimes effective in expressing the contents of a fresh lesion near the lid margin.

Steroid injection into or around the lesion has been reported to give similar resolution rates to incision and curettage (see below). It may be preferred for marginal lesions or lesions close to structures such as the lacrimal punctum because of the risk of surgical damage.

○ Reported regimens include 0.2–2 ml of triamcinolone acetonide aqueous suspension diluted with lidocaine to a concentration of 5 mg/ml, and 0.1–0.2 ml of 40 mg/ml, injected with a 27- or 30-gauge needle.

☐ The success rate following one injection is about 80%; a second can be given 1–2 weeks later.

☐ Local skin depigmentation and fat atrophy are potential but uncommon complications, the risk of which may be reduced by avoidance of infiltration immediately subcutaneously or by utilizing a conjunctival approach.

○ Retinal vascular occlusion has been described as a complication, probably due to intravascular injection with subsequent embolization.

○ Limited excision of solid inflammatory material (sent for histopathology) with fine scissors may be helpful in some cases, especially if there is no focus of secretions.

○ A suture should not be used.

○ Topical antibiotic ointment is used three times daily for 5–7 days following curettage.

Marginal lesions can be managed by steroid injection, by curettage of an associated deeper chalazion, by shave curettage or by incision and curettage via a horizontal incision on the conjunctival surface or vertically through the grey line.

○ Treatment of blepharitis, e.g. daily lid hygiene regimen.

○ Systemic tetracycline may be required as prophylaxis in patients with recurrent chalazia, particularly if associated with acne rosacea.

Cyst of Zeis is a small, non-translucent cyst on the anterior lid margin arising from obstructed sebaceous glands associated with the eyelash follicle (Fig. 1.3A).

Cyst of Moll (apocrine hidrocystoma) is a small retention cyst of the lid margin apocrine glands. It appears as a round, non-tender, translucent fluid-filled lesion on the anterior lid margin (Fig. 1.3B).

Sebaceous (pilar) cyst is caused by a blocked pilosebaceous follicle and contains sebaceous secretions; the gland orifice will often be visible (Fig. 1.3C). It is only rarely found on the eyelid although it may occasionally occur at the inner canthus.

Comedones are plugs of keratin and sebum within the dilated orifice of hair follicles that often occur in patients with acne vulgaris. They may be either open (blackheads) containing a darkened plug of oxidized material (Fig. 1.3D), or closed (whiteheads).

Milia are caused by occlusion of pilosebaceous units resulting in retention of keratin. They are tiny, white, round, superficial papules that tend to occur in crops (Fig. 1.3E).

Epidermal inclusion cyst is usually caused by implantation of epidermis into the dermis following trauma or surgery. It is a slow-growing, round, firm, superficial or subcutaneous lesion containing keratin (Fig. 1.3F).

Epidermoid cyst is uncommon and usually developmental, occurring along embryonic lines of closure. It is similar in appearance to an epidermal inclusion cyst.

Dermoid cyst is usually subcutaneous or deeper and is typically attached to the periosteum at the lateral end of the brow (Fig. 1.3G). It is caused by skin sequestered during embryonic development.

Eccrine hidrocystoma is less common but similar in appearance to a cyst of Moll except that it is usually located along the medial or lateral aspects of the lid, and is close to but does not involve the lid margin itself (Fig. 1.3H).