Inflammation of the iris (iritis, or iridocyclitis) is anterior uveitis of the eye. It is the most common intraocular inflammation.
Symptoms of iritis include circumcorneal injection (redness) 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.
Healing is controlled in order to prevent chronicity and complications (glaucoma, cataract).
The patient is encouraged to treat the eye condition and to treat and prevent the predisposing factors (infections in HLA-B27 positive patients.
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 (tearing, blepharospasm)
pericorneal injection (may also be absent)
impaired vision (may be normal at the beginning)
no discharge or foreign body sensation (except when associated with keratitis)
almost invariably unilateral (except when associated with a systemic disease)
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, often virtually symptomless (only seldom cause reddening and pain of the eye) but may 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 and flare in the anterior chamber), because treating unspecific irritation with glucocorticoid eye drops may cause damage (e.g. concurrent herpes keratitis).
Patients with recurrent iritis, knowing their disease well, may start mydriatic therapy independently, but they are advised to visit an ophthalmologist within 24 hours. As prompt mydriatic as well as glucocorticoid therapy is beneficial and may shorten the duration of the disease, the patient could have mydriatic drops available all times.
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. If the patient definitely refuses to use the drops during daytime, they should at least be administered in the evening.
In special cases (e.g. long distance to an ophthalmologist) a general practitioner may start the therapy in a patient with recurring iritis if the patient feels that the symptoms are similar. It is advisable to consult an ophthalmologist by phone concerning the initiation of treatment.
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.
Aetiological investigations are performed according to the patient history; there are no routine tests. The first iritis in one eye of an adult does not yet warrant extensive aetiological investigations, but in recurrent or bilateral iritis they are started. In children, paediatric rheumatological investigations are started right away.
Chest x-ray if sarcoidosis is suspected (bilateral acute iritis)
Paranasal sinus x-ray if there are symptoms of sinusitis
Tests for chlamydia and intestinal infections
In case of joint symptoms or back pain refer the patient to a rheumatologist.
Treatment
Started after confirmation of the diagnosis.
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.
Long-acting cycloplegic medication (e.g. scopolamine or atropine), one drop 2-3 times daily, or short-acting tropicamide, one drop 3 times daily for one week, then one drop once daily for another week (in a very mild disease, administration for the night only is sufficient).
The treatment is continued until the first check up, usually within a week, and after that according to the response.
It is recommended to check the intraocular pressure once during the glucocorticoid treatment.
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.