Definition

For convenience, external eye infections can be grouped into four sets.

Infections of the lacrimal apparatus:

• Dacryocystitis, involving the draining canaliculi and lacrimal sac (Fig 1)
• Dacryoadenitis, involving the lacrimal gland (Fig 2)

Infections of the eyelid and associated glands:

• Blepharitis, involving the skin of the lid margin (Fig 3)
• Hordeolum (commonly called a stye), which may be external (pilosebaceous glands on the anterior surface of the eyelid) or internal (infection of the meibomian glands) (Fig 4)
• Chalazion (meibomian cyst), a granulomatous cyst of the meibomian gland. Although not typically infective, chalazia can form as a result of an unresolved internal hordeolum (Fig 5)

Infection of the skin and soft tissues anterior to the fibrous septum:

• Preseptal cellulitis (Fig 6)

Infection of the soft tissues posterior to the fibrous septum:

• Orbital cellulitis (Fig 7)

Click on the images to enlarge.

Fig 1. dacryocystitis

Fig 2. dacryoadenitis

Fig 3. blepharitis

Fig 4. hordeolum

Fig 5. Chalazion

Fig 6. preseptal_cellulitis

Fig 7. Orbital_cellulitis