Makindo Medical Notes.com

Interstitial Keratitis (IK) is a form of corneal inflammation that primarily affects the stroma, the thick middle layer of the cornea. Unlike other forms of keratitis, it does not involve the corneal epithelium or endothelium. Interstitial Keratitis often leads to corneal opacification and can cause significant visual impairment if not treated promptly.

Causes: can result from various infectious and non-infectious causes

• Infectious Causes:
  • Syphilis: One of the most common causes, particularly congenital syphilis.
  • Herpes Simplex Virus (HSV): Can cause recurrent episodes of keratitis.
  • Leprosy: Associated with chronic inflammation in the cornea.
  • Lyme Disease: Can lead to ocular involvement, including IK.
  • Other Infections: Tuberculosis, Epstein-Barr Virus (EBV), and others can also be associated.
• Non-Infectious Causes:
  • Autoimmune Disorders: Conditions like sarcoidosis and rheumatoid arthritis can lead to IK.
  • Idiopathic: In some cases, no specific cause can be identified.

Clinical

• Redness and pain in the eye
• Photophobia (sensitivity to light)
• Blurred vision due to corneal opacification
• Watering and discomfort in the affected eye
• Corneal edema and stromal infiltrates visible on slit-lamp examination

Investigations

• Serological Testing: For syphilis, Lyme disease, and other infections.
• Corneal Sensitivity Testing: To assess for HSV involvement.
• Imaging: Anterior segment optical coherence tomography (OCT) may be used to assess the extent of stromal involvement.
• Slit-Lamp Examination: To observe the characteristic signs such as stromal haze, vascularization, and infiltrates.

Differential Diagnoses of Interstitial Keratitis

• Syphilis, tuberculosis, Brucellosis
• Lyme disease, chlamydia, leprosy
• Mumps, Epstein-Barr virus, Rubeola, herpes zoster and simplex)
• Granulomatosis with polyangiitis
• PAN, RA, relapsing polychondritis
• Lymphoma, Sarcoidosis, Cogan's syndrome

Management

• Antibiotics: Penicillin or doxycycline for syphilis, and appropriate antibiotics for other bacterial infections.
• Antiviral Therapy: Acyclovir or valacyclovir for HSV-related keratitis.
• Anti-inflammatory Therapy: Topical corticosteroids are often used to reduce inflammation but must be used cautiously, particularly in cases associated with infection.
• Management of Underlying Conditions: Treating the primary disease (e.g., autoimmune disorder) is crucial for managing IK.

Prognosis

• Early and appropriate treatment can prevent permanent vision loss.
• In untreated or severe cases, corneal scarring and vascularization can lead to chronic visual impairment.
• Regular follow-up is essential to monitor for recurrence and to manage any complications, such as secondary glaucoma.
• Early diagnosis and prompt treatment are critical for preserving vision in patients with Interstitial Keratitis