Ophthalmology · Corneal Disorders
The facts most likely to be tested
Patients typically present with a foreign body sensation, gritty or sandy ocular irritation, and reflex tearing due to ocular surface instability.
The Schirmer test is the gold standard diagnostic tool, where a result of <10 mm of wetting after 5 minutes confirms decreased tear production.
Sjogren syndrome is the most common systemic autoimmune cause, characterized by the triad of xerophthalmia, xerostomia, and parotid gland enlargement.
Slit-lamp examination with fluorescein staining reveals punctate epithelial erosions (PEE) on the inferior cornea and conjunctiva.
First-line management consists of frequent use of preservative-free artificial tears and topical lubricants.
Refractory cases are managed with topical cyclosporine or lifitegrast to reduce ocular surface inflammation.
Chronic untreated disease leads to corneal ulceration, neovascularization, and potential vision loss due to scarring.
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A 54-year-old female presents to the clinic complaining of chronic eye irritation and a feeling of sand in her eyes for the past six months. She also reports a dry mouth and difficulty swallowing dry foods. On physical exam, she has bilateral parotid gland enlargement and conjunctival injection. Slit-lamp examination with fluorescein staining demonstrates punctate epithelial erosions on the inferior cornea. A Schirmer test shows 4 mm of wetting after 5 minutes.
What is the most likely underlying systemic diagnosis?
Sjogren syndrome
The patient presents with the classic triad of keratoconjunctivitis sicca (dry eyes), xerostomia (dry mouth), and parotid enlargement, which is pathognomonic for Sjogren syndrome.
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High yield triage
Etiology / Epidemiology
Common in postmenopausal women and patients with Sjögren syndrome; often secondary to aging or medication use.
Clinical Manifestations
Presents with gritty/sandy ocular irritation and foreign body sensation; symptoms worsen throughout the day.
Diagnosis
Gold standard is the Schirmer test; a result of <5 mm of wetting after 5 minutes is diagnostic.
Treatment
First-line therapy is artificial tears; use preservative-free formulations for frequent dosing.
Prognosis
Generally benign but chronic; severe cases risk corneal ulceration and permanent vision loss.
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Epidemiology & Etiology
Prevalence increases with age, particularly in postmenopausal women. Frequently associated with Sjögren syndrome, systemic autoimmune diseases, or chronic use of anticholinergics and antihistamines.
Pertinent Anatomy
The tear film consists of an outer lipid layer, middle aqueous layer, and inner mucin layer. Dysfunction of the lacrimal glands or Meibomian glands disrupts this film, leading to rapid evaporation.
Pathophysiology
Reduced aqueous production or increased evaporation leads to hyperosmolarity of the tear film. This triggers an inflammatory cascade on the ocular surface, causing epithelial cell apoptosis and loss of goblet cells.
Clinical Manifestations
Patients report burning, stinging, and foreign body sensation. Symptoms are classically worse in dry/windy environments. Red flags include severe pain, photophobia, or vision loss, which suggest corneal ulceration or secondary infection.
Diagnosis
The Schirmer test is the gold standard; wetting <5 mm in 5 minutes confirms aqueous deficiency. Fluorescein staining may reveal punctate epithelial erosions on the cornea.
Treatment
Initiate treatment with artificial tears (preservative-free). If refractory, add cyclosporine eye drops to increase tear production. Avoid long-term use of topical corticosteroids due to risk of glaucoma and cataracts.
Prognosis
Condition is chronic and requires lifelong management. Severe, untreated cases lead to corneal scarring and permanent visual impairment. Regular monitoring for corneal abrasions is essential.
Differential Diagnosis
Blepharitis: presence of crusting/scales on eyelid margins
Allergic conjunctivitis: intense pruritus and chemosis
Viral conjunctivitis: watery discharge and preauricular lymphadenopathy
Bacterial conjunctivitis: purulent discharge and matted eyelids
Scleritis: deep, boring pain and scleral injection