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MattiSeppänen

Iritis (Inflammation of the Iris)

Essentials

  • Inflammation of the iris (iritis) is anterior uveitis of the eye. It is the most common intraocular inflammation.
  • Symptoms of iritis include circumcorneal injection (redness; picture 1) and aching of the eye, local tenderness in the eye or photophobia.
    • Note: a patient with juvenile rheumatoid arthritis may have iritis even if the eyes are symptomless.
  • Other diseases predisposing to iritis should be identified and treated.
  • The diagnosis should be made and treatment defined by an ophthalmologist.

Epidemiology and aetiology

  • Incidence of acute iritis: 12/100 000/year (all uveitis 20/100 000/year)
  • Mainly affects young adults.
  • Uncommon in children (except with chronic juvenile arthritis) and in middle-aged or elderly persons (except with diabetes, herpes zoster infection and vasculitis; lymphoma is taken into account in differential diagnostics).
    • Juvenile chronic arthritis is in 20% of the cases associated with an asymptomatic, often chronic and bilateral iritis.
  • Acute iritis tends to recur. It often occurs in one eye at a time, but changes from one eye to another.
  • Active infection focus elsewhere may trigger iritis, (especially in HLA-B27 positive persons Yersinia enterocolitica, Salmonella, Campylobacter, Chlamydia immunotypes D and E, Klebsiella).
  • Iritis may be the manifestation of the following systemic diseases:
    • ankylosing spondylitis
    • sarcoidosis
    • systemic lupus erythematosus (SLE)
    • arthritic psoriasis
    • reactive arthritis
    • juvenile chronic arthritis, particularly oligoarthritis of small children
      • A patient with juvenile rheumatoid arthritis (even when the symptoms are mild: sometimes only one joint, for example in a finger, is affected) may have iritis even if the eyes are symptomless (chronic silent form of the disease).
    • Behçet's disease (HLA-B51 individuals)
    • systemic infections, such as herpes viruses, borreliosis Lyme Borreliosis (LB), toxoplasmosis Toxoplasmosis, toxocariasis, HIV, syphilis, cytomegalovirus, tuberculosis
    • sinusitis
    • dental root infection
    • intestinal inflammations (in ulcerative colitis and in Crohn's disease in about 3-10% of cases)
    • diabetes mellitus
      • Iritis may be one of the first symptoms leading to the diagnosis of type 1 or 2 diabetes (a child or an adolescent; a middle-aged patient with the metabolic syndrome) or it may be associated with the progression of fundus changes in a diabetic patient.
  • May be associated with anterior segment infection, e.g. keratitis or trauma such as a long-standing corneal foreign body or ocular contusion.
  • In elderly persons, iritis may be associated with disturbances in arterial circulation (so-called ocular ischaemic syndrome).
  • Many patients are otherwise healthy and no cause is identified (idiopathic).

Symptoms and findings

  • Symptoms of iritis have the following essential features:
    • dull pain in the eye
    • photophobia
    • pericorneal injection (may also be absent)
    • reduced visual acuity (not in all patients)
    • often miotic pupil.
  • In long-standing inflammation the iris may adhere to the anterior surface of the lens (posterior synechiae).
  • Other uveitides (cyclitis, i.e. inflammation of the ciliary body or intermediate uveitis, and choroiditis, i.e. inflammation of the choroid or posterior uveitis) are significantly less common. They may involve milder symptoms but cause impaired vision.
    • Patients with uveitis usually seek an ophthalmologist due to the visual disturbances caused by increasing vitreous opacities or because of impaired vision.

Examination of the patient and initiation of treatment

  • Any of the three symptoms (pain, photophobia or pericorneal injection) justifies the suspicion of iritis.
  • The patient needs to be referred to an ophthalmologist within 24 hours.
  • Also, if a patient with an underlying disease that predisposes to uveitides presents with impaired vision without general symptoms or clearly abnormal findings, he/she should be promptly referred to an ophthalmologist for consultation.
  • Diagnosis is confirmed with microscopic examination (cells in the anterior chamber, there can also be flare).
  • Patients with recurrent iritis, knowing their disease well, may start mydriatic therapy independently, but they should be advised to visit an ophthalmologist within 24 hours.
  • In recurrent iritis, mydriatic therapy is always started at a low threshold even if the symptoms were very mild. The movement of the iris prevents the formation of synechiae, and in addition the mydriatic drops relieve pain.
  • In special cases (e.g. long distance to an ophthalmologist) a general practitioner may consult an ophthalmologist by telephone and, if necessary, start, following the ophthalmologist's advice, the therapy in a patient with recurring iritis.
    • It is recommended to examine the cornea with a loupe and fluorescein to rule out corneal ulcer (see keratitis dendritica Corneal Ulcers).
    • An examination by an ophthalmologist, including examination with an eye microscope, should be arranged for later.
  • In the first iritis in one eye of an adult, HLA-B27 should be tested; extensive aetiological studies are not required.
  • In recurrent or bilateral iritis, aetiological investigations are considered according to the clinical picture.
    • Exclusion of sarcoidosis: fasting serum ACE, chest x-ray
    • Paranasal sinus x-ray if there are symptoms of sinusitis
    • Dentist's examination to detect a dental infection
    • Tests for chlamydia and intestinal infections
    • Investigations for other systemic infections
    • In case of joint symptoms or back pain refer the patient to a rheumatologist.
  • In children, paediatric rheumatological investigations are started right away.

Treatment

  • Started after confirmation of the diagnosis.
    1. Topical glucocorticoid therapy, e.g. dexamethasone drops, one drop every 1-2 hours at the beginning, later 4-6 times a day. A dose of glucocorticoid ointment is administered for the night.
    2. At the same time, mydriatic eye drops, e.g. tropicamide, one drop 3 times daily for one week, then one drop once daily for another week.
  • The treatment is continued until the first check up (according to local practice) and after that according to the response.
    • It is recommended to check the intraocular pressure once during the first glucocorticoid treatment. This can be done either in primary care or in specialized care, depending on local practice.
  • In severe iritis (fibrin, even hypopyon in the anterior chamber, high intraocular pressure, posterior synechiae) paraocular glucocorticoid injections or peroral glucocorticoids may be indicated.
  • In frequently recurring iritis, sulphasalazine may be tried as a prophylaxis for patients with a rheumatoid disease.
  • Methotrexate or biological drugs are sometimes required in the management of iritis in children with juvenile rheumatoid arthritis.
    • If a child with rheumatoid arthritis starts to suffer from episodes of iritis more frequently, the treatment should be intensified, which decreases the occurrence of both joint symptoms and the episodes of iritis.

    References

    • Gueudry J, Muraine M. [Anterior uveitis]. J Fr Ophtalmol 2018;41(2):170-182. [PubMed]
    • Relvas LJ, Caspers L, Chee SP, et al. Differential Diagnosis of Viral-Induced Anterior Uveitis. Ocul Immunol Inflamm 2018;26(5):726-731. [PubMed]
    • Sharma SM, Jackson D. Uveitis and spondyloarthropathies. Best Pract Res Clin Rheumatol 2017;31(6):846-862. [PubMed]
    • Gutteridge IF, Hall AJ. Acute anterior uveitis in primary care. Clin Exp Optom 2007;90(5):390; author reply 390. [PubMed]