Iritis

Pathophysiology:

Inflammation by various local and systemic etiologies. Pain in iritis is caused by irritation of ciliary nerves and by ciliary muscle spasm. Cilieary spasm irritates the trigeminal nerve and cause photophobia. Keratitic precipitates (KP) are deposits of inflammatory cells on the corneal epithelium. Proteinaceous exudate from uveal vessels occur in the anterior chamber and causes the flare seen with the slit lamp. Flare looks like headlights through fog at night. White blood cells released from the uveal vessels may be seen in the anterior chamber with the slit lamp can are called cells. Cells look like snowflakes in a headlight beam at night. So you get Flare and Cells.

Technique for slit lamp: The narrow slit-lamp is directly obliquely across the anterior chamber.

DDx of Iritis:

• • Systemic diseases

    • Juvenile rheumatoid arthritis

    • Anklylosing spondylitis and other HLA B27 related d/os

    • Iridocyclitis

    • Lupus

    • Psoriatic arthritis

    • Ulcerative colitis

    • Crohn's disease

    • Sarcoidosis

    • Reiter's syndrome

    • Behcet's syndrome

  • Infectious

    • TB

    • Herpes simplex

    • Herpes zoster

    • Toxoplasmosis

    • Syphilis

    • Lyme disease

    • Adenovirus

    • Malignacies

    • Leukemia

    • Lymphoma

    • Malignant melanoma

  • Trauma/environmental

    • Corenal FB

    • Postraumatic (blunt trauma)

    • UV keratitis.

History:

Pt. c/o unilateral pain, although the pain may be bilateral with systemic disease. There may be complaints of conjunctival injection, photophobia, and decreased vision. Usually, no ocular discharge.

Systemic sx: arthritis, urethritis, and recurrent GI are not unusual.

PMH of exposure to TB, h/o genital herpes. H/o similar sx. Recent trauma or exposure to UV light without protective goggles

Physical Examination:

Perilimbal flush, diffuse conjunctival injection without mucopurulent discharge. Photophobia is usually present. Blepharospasm. Consensual photophobia (which occurs when shining light on the unaffected eye causes pain the the affect eye) is highly suggestive or iritis. Pupil is miotic and poorly reactive. VA may be decreased with severe inflammation and clouding of the aqueous humor.

Slit-lamp examination will reveal flare and cells in the anterior chamber, culminating in a hypopyon when disease is severe. Anterior or posterior synechiae may occur with chronic disease. IOP may be decreased if the ciliary body is involved secondary to decreased production of aqueous humor. Fluorescein staining of the cornea may show abrasions, ulcerations, or dendritic lesions (herpes simplex keratitis).

Tx:

Reduce inflammation and prevent complications such as posterior synechiae formation.

Block the pupillary sphincter and ciliary body with a long-acting cyclopegic agent, such as atropine (7 days' duration), homoatropine (2 days' duration), or tropicamide (24 h duration) will decrease pain. Administration of steroid drops (prednisolone 1%) helps decrease the inflammation and prevent complications. Make sure it is not herpes simplex keratitis you are treating, as it may have potential complications if treated with steroids..

Refer patient to ophthalmologist in 24 - 38 hours.