Iridocyclitis: Description, Causes and Risk Factors:
Inflammation of both iris and ciliary body.
The iris is the coloured part of the eye which has a hole (the pupil) in the middle of it. The iris is a muscle which dilates the pupil, letting more light into the eye, or constricts it cutting down the amount of light that enters the eye. Behind this is another circular structure, the ciliary body. This produces the clear fluid which fills the eye, passing through the pupil and draining away near the edge of the iris. It also changes the eye's focus via muscles attached to the lens.
Iridocyclitis is the inflammation of the iris and the ciliary body of the eye. It can be caused by the eye's exposure to certain chemicals, different autoimmune disorders, or it can be a symptom of other infections like toxoplasmosis, syphilis, and herpes.
Acute iridocyclitis may occur as an isolated medical problem without any association with illness or inflammation elsewhere in the body. It might also arise as part of a localized infection such as that due to the virus that causes cold sores, herpes simplex. It can occur rarely as an adverse reaction to a medication. Acute iridocyclitis may also be associated with an illness affecting multiple parts of the body. The most common illnesses associated with acute iridocyclitis are also associated with a tissue type known as HLA-B27 (human leukocyte antigen B27). Most diseases of other organs that are linked to acute iridocyclitis are apparent from associated symptoms. For example, bowel inflammation or colitis can be associated with acute iridocyclitis. A patient who has this association would usually have abdominal problems such as crampy abdominal pain, weight loss, and/or diarrhea. Some of the less common diseases associated with acute iridocyclitis include sarcoidosis, interstitial nephritis (a rare kidney inflammation), relapsing polychondritis (a rare autoimmune disease), and vasculitis (an inflammation of the blood vessel wall).
Autoimmune conditions are considered the most common causes of chronic iridocyclitis, whether a specific disease is identified or not. Infectious diseases, such as tuberculosis and syphilis, among others, can result in chronic iridocyclitis , but these conditions are infrequent causes in industrialized countries.
Nearly half of all cases classified as acute iridocyclitis are not associated with other, underlying medical problems. Such cases can appear suddenly and usually do not last longer than six weeks. If there is another existing condition, such as an infectious or autoimmune disease, that illness must be treated to prevent recurrences, or chronic iridocyclitis.
The condition is usually marked by the reddening of the eye. While this coloration is a symptom, the eye is often not as red as it may be in someone with a common condition like conjunctivitis
, or pink eye. The patient may also be very sensitive to light or experience photophobia
, or fear of light. The eyes may water profusely and vision can become impaired or decrease drastically. Sometimes only one eye is affected, but shining a light into the seemingly unaffected eye can produce pain in the irritated eye.
These include a battery of tests because of its variedetiology. However, an experienced ophthalmologistsoon learns to order a few investigations ofconsiderable value, which will differ in individual casedepending upon the information gained fromthorough clinical work up. A few commoninvestigations required are listed here:
1. Hematological investigations
TLC and DLC (total leukocytes count and differential leukocytes count) to have a general informationabout inflammatory response of body.
- ESR (erythrocyte sedimentation rate) to ascertain existence of any chronicinflammatory condition in the body.
- Blood sugar levels to rule out diabetes mellitus.
Blood uric acid in patients suspected of havinggout.
- Serological tests for syphilis, toxoplasmosis,and histoplasmosis.
- Tests for antinuclear antibodies, Rh factor,LE cells, C-reactive proteins and antistreptolysin-o (ASO).
- Urine examination for WBCs, pus cells, RBCand culture to rule out urinary tract infections.
- Stool examination for cyst and ova to rule outparasitic infestations.
- Radiological investigations include X-rays ofchest, paranasal sinuses, sacroiliac joints andlumbar spine.
- Skin tests. These include tuberculin test, Kveim'stest and toxoplasmin test.
Mydriatic-cycloplegic drugs. These are very useful and most effective during acute phase of iridocyclitis. Commonly used drug is 1 percent atropine sulfate eye ointment or drops instilled 2-3 times a day. In case of atropine allergy, other cycloplegics like 2 percent homatropine or 1 percent cyclopentolate eyedrops may be instilled 3-4 times a day. Alternatively for more powerful cycloplegic effect a subconjunctival injection of 0.25 mL mydricain (a mixture of atropine, adrenaline and procaine) should be given. The cycloplegics should be continued for at least 2-3 weeks after the eye becomes quiet, otherwise relapse may occur. Mode of action. In iridocyclitis, atropine (i) gives comfort and rest to the eye by relieving spasm of iris sphincter and ciliary muscle, (ii) prevents the formation of synechiae and may break the already formed synechiae, (iii) reduces exudation by decreasing hyperaemia and vascular permeability and (iv) increases the blood supply to anterior uvea by relieving pressure on the anterior ciliary arteries. As a result more antibodies reach the target tissues and more toxins are absorbed.
- Corticosteroids, administered locally, are very effective in cases of iridocyclitis. They reduce inflammation by their anti-inflammatory effect; being anti-allergic, are of special use in allergic type of uveitis; and due to their antifibrotic activity, they reduce fibrosis and thus prevent disorganisation and destruction of the tissues. Commonly used steroidal preparations contain dexamethasone, betamethasone, hydrocortisone or prednisolone. Route of administration: Locally, steroids are used as (i) eye drops 4-6 times a day, (ii) eye ointment at bed time, and (iii) Anterior sub-Tenon injection is given in severe cases.
- Broad spectrum antibiotic drops, though of no use in iridocyclitis, are usually prescribed with topical steroid preparations to provide an umbrella cover for them.
Corticosteroids. When administered systemically they have a definite role in non-granulomatous iridocyclitis, where inflammation, most of the times, is due to antigen antibody reaction. Even in other types of uveitis, the systemic steroids are helpful due to their potent non-specific anti-inflammatory and antifibrotic effects. Systemic corticosteroids are usually indicated in intractable anterior uveitis resistant to topical therapy. Dosage schedules. A wide variety of steroids are available. Usually, treatment is started with high doses of prednisolone (60-100 mg) or equivalent quantities of other steroids (dexamethasone or betamethasone). Daily therapy regime is preferred for marked inflammatory activity for at least 2 weeks. In the absence of acute disease, alternate day therapy regime should be chosen. The dose of steroids is decreased by a week's interval and tapered completely in about 6-8 weeks in both the regimes.
Note: Steroids (both topical and systemic) may cause many ocular (e.g., steroid-induced glaucoma and cataract) and systemic side-effects. Hence, an eagle's eye watchfulness is required for it.
Immunosuppressive drugs. These should be used only in desperate and extremely serious cases of uveitis, in which vigorous use of steroids have failed to resolve the inflammation and there is an imminent danger of blindness. These drugs are dangerous and should be used with great caution in the supervision of a haematologist and an oncologist. These drugs are specially useful in severe cases of Behcet's syndrome, sympathetic ophthalmia, pars planitis and VKH syndrome. A few available cytotoxic immunosuppressive drugs include cyclophosphamide, chlorambucil, azathioprine and methotrexate. Cyclosporin is a powerful anti-T-cell immunosuppressive drug which is effective in cases resistant to cytotoxic immunosuppressive agents, but it is a highly renal toxic drug.
Hot fomentation. It is very soothing, diminishes pain and increases circulation, and thus reduces the venous stasis. As a result more antibodies are brought and toxins are drained. Hot fomentation can be done by dry heat or wet heat.
- Dark goggles. These give a feeling of comfort, especially when used in sunlight, by reducing photophobia, lacrimation and blepharospasm.
Specific treatment of the cause: The non-specific treatment described above is very effective and usually eats away the uveal inflammation, in most of the cases, but it does not cure the disease, resulting in relapses. Therefore, all possible efforts should be made to find out and treat the underlying cause. Unfortunately, in spite of the advanced diagnostic tests, still it is not possible to ascertain the cause in a large number of cases. So, a full course of antitubercular drugs for underlying Koch's disease, adequate treatment for syphilis, toxoplasmosis etc., when detected should be carried out. When no cause is ascertained, a full course of broad spectrum antibiotics may be helpful by eradicating some masked focus of infection in patients with non-granulomatous uveitis.
Treatment of complications
Inflammatory glaucoma (hypertensive uveitis). In such cases, drugs to lower intraocular pressure such as 0.5 percent timolol maleate eyedrops twice a day and tablet acetazolamide (250 mg thrice a day) should be added, over and above the usual treatment of iridocyclitis. Pilocarpine and latanoprost eye drops are contraindicated in inflammatory glaucoma.
NOTE: The above information is for processing purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.
- Post-inflammatory glaucoma due to ring synechiae is treated by laser iridotomy. Surgical iridectomy may be done when laser is not available. However, surgery should be performed in a quiet eye under high doses of corticosteroids.
- Complicated cataract requires lens extraction with guarded prognosis in spite of all precautions. The presence of fresh KPs (keratic precipitates) considered a contraindication for intraocular surgery.
- Retinal detachment of exudative type usually settles itself if uveitis is treated aggressively. A tractional detachment requires vitrectomy and management of complicated retinal detachment, with poor visual prognosis.
- Phthisis bulbi especially when painful, requires removal by enucleation operation.