The diagnosis of IU is based on clinical findings. Patient's complaints of defective vision and/or floaters in the absence of pain, redness, photophobia should alert the ophthalmologist. Presence of vitreous cells that outnumber anterior chamber cell infiltration, vitreous snowballs, and the presence of pars plana exudation, suggest IU. Laboratory and ancillary tests are not necessary to establish the diagnosis; however, with a careful history, ocular and systemic examination together with laboratory studies, we may be able to exclude an associated disorder.
The patient's history should concentrate on the duration of symptoms, the number of recurrences, and findings that might be associated with systemic disorders. Fever, fatigue, or night sweats are typical signs of sarcoidosis and tuberculosis, whereas loss of sensitivity or paresthesias of the hands, arms, or legs are suggestive of possible MS. Signs of dermatitis may point to Lyme disease, tuberculosis, or syphilis, whereas arthritis of the knee may suggest the possibility of Lyme's, disease, and contact with cats may raise the possibility of Bartonella infection.[1
A routine baseline workup comprising complete blood count which includes total and differential count/ hemoglobin/ platelet count, erythrocyte sedimentation rate, purified protein derivative skin test (PPD) and chest X-ray are mandatory. Total count is increased in –infections, chronic inflammation and autoimmune disease. Infections predominantly cause an increase in neutrophils, and lymphocytosis may indicate a possible tuberculosis etiology. Chest X-ray studies may disclose findings indicative of sarcoidosis or tuberculosis.
A PPD test is needed to exclude tuberculosis/sarcoidosis.
In cases of IU, only a few laboratory and serologic tests are necessary. These tests include determination of the angiotensin-converting enzyme (ACE) level. Serologic testing for cat-scratch disease, syphilis, and Lyme's: disease should be seriously considered in cases of IU.
Subclinical pulmonary sarcoidosis, undetectable by chest X-ray study, may be detected via computed tomography (CT) of the chest or by gallium scan, or both. A combination of serum ACE level and whole-body gallium scan increases the diagnostic specificity without affecting sensitivity in patients with clinically suspicious ocular sarcoidosis who have normal or equivocal chest radiographs. Fluorescein angiography (FA) alerts one to the presence of vasculitis, areas of retinal nonperfusion and neovascularization and CME. It is useful in following up a patient as well.
Using ultrasound biomicroscopy (UBM), it is possible to demonstrate pars plana exudates, and even inflammatory cell aggregates in the vitreous. Ultrasonography (USG) can be done to rule out RD, intraocular tumors.
Diagnostic vitrectomy is done in cases when tumors are suspected, in patients with severe vitreous inflammation where retinitis, endophthalmitis cannot definitely be excluded and in cases where response to medical therapy is refractory.[1
Intermediate uveitis in children: Uveitic entities with an etiologic diagnosis seen in the pediatric age group are: juvenile idiopathic arthritis (30%), toxoplasmosis (3.3%), HLA-B27-associated iritis (1.89%), acute retinal necrosis (1.1%), tubulointerstitial nephritis associated anterior uveitis (1.1%), Kawasaki-related anterior uveitis (0.7%), and Vogt–Koyanagi–Harada syndrome (1.1%), isolated cases of sarcoid uveitis, multifocal choroiditis and panuveitis, Behçet's disease, Herpes simplex virus keratouveitis, masquerade syndrome, late-onset retinoblastoma, systemic lupus erythematosus, sympathetic ophthalmia, toxocariasis, Varicella-zoster virus iritis, and infectious endophthalmitis.
IU accounts for 1.8-29% of uveitis seen in the pediatric age group. All cases were reported to be idiopathic IU in three studies reported from various parts of the world.[58
] This is in contrast to a report from south India. Idiopathic uveitis in children accounted for only 25.5% of cases, whereas infectious uveitis was found in 58%.[10
] Mean age of onset of uveitis is 8.5-10.9 years. There is a male preponderance. Bilateral involvement is seen in 84-94% patients. Chronicity of uveitis is 84-100%. Mean time to remission is 6.4 years. Common complications seen are: disc edema, CME, cataract, glaucoma, and band-shaped keratopathy. Epiretinal and neovascular membranes occur. Snowbanking is seen in 28% of patients.[58
Since the etiology of IU remains elusive in most cases, the therapy is mainly symptomatic. The presence of CME is an indication for treatment with periocular corticosteroid injections with or without a short-term course of systemic corticosteroids. Boer et al
. conclude that IU in children might resolve after several years and, despite a high ocular complication rate, severe visual loss is uncommon.[62