Don’t miss: Angle-closure glaucoma.
Conjunctiva:
-Conjunctivitis (Viral or Bacterial)
Cornea:
-Corneal abrasion (e.g. caused by trauma or foreign body)
-Foreign body
-Trauma
-Bacterial Keratitis;
-Viral Keratitis e.g. HSV (primary), or herpes zoster ophthalmicus (shingles)
-Parasitic keratitis (e.g. Acanthamoeba)
-Superficial punctate keratitis
-Ultraviolet (actinic) keratitis
-Dry eye syndrome
Sclera:
-Scleritis; episcleritis
Anterior chambers
-Acute angle-closure glaucoma
Uvea
-Anterior uveitis; iritis
Eyelid, Orbit, and surrounding structures disorders
-Stye (hordeolum)
-Chalazion
-Blepharitis
-Orbital cellulitis or Periorbital cellulitis
-Blocked tear duct
-Dacryocystitis (lacrimal sac infection)
Others
-Cluster headache; Migraine headache
-Optic neuritis
-Inverted eyelash (eg, entropion)
-Intracranial mass
-Giant cell arteritis
-Decreased tearing, eg, age-related, Sjögren’s syndrome, anticholinergics
Thinking through the Differential Diagnosis
The anatomy of the human eye.
Uvea = the pigmented layer of the eye, lying beneath the sclera and cornea, and comprising the iris, choroid, and ciliary body)
Periorbital cellulitis = Preseptal cellulitis.
-Notice the anatomical organization of the causes of a painful eye from conjunctiva, cornea, sclera, anterior chamber, uvea, etc.
Further Reading
Am Fam Physician. 2016 Jun 15;93(12):991-998. Evaluation of the Painful Eye. https://www.aafp.org/afp/2016/0615/p991.html