Intermediate Uveitis Workup

Updated: Feb 06, 2023
  • Author: Robert H Janigian, Jr, MD; Chief Editor: Hampton Roy, Sr, MD  more...
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Laboratory Studies

Laboratory studies include the following:

  • The diagnostic approach to intermediate uveitis should center on the history and clinical examination.

  • As demonstrated by Henderly et al and also by Rodriguez et al, approximately two thirds of patients will have idiopathic intermediate uveitis. [6, 7]

  • Since intermediate uveitis has been described in association with several systemic disorders, the initial diagnostic evaluation should serve to exclude masquerade syndromes and infectious diseases in which immunosuppression may be ineffective or contraindicated.

  • A minimum workup should include a serum ACE level, chest x-ray, Venereal Disease Research Laboratory (VDRL) test, fluorescent treponemal antibody absorption (FTA-ABS) test, and CBC. The laboratory workup can be expanded, depending upon the clinical history and physical findings.

    • Focus on excluding sarcoidosis and MS with a thorough review of systems. Patients with intermediate uveitis due to MS are usually older than 25 years, and they may require an MRI. In general, order an ACE level and chest x-ray on all patients to rule out subclinical sarcoidosis.

    • If the above are inconclusive or negative in a setting of a strong clinical suspicion, a Gallium scan or pulmonary function tests can be obtained as well.

    • Patients from endemic areas for Lyme disease with a history of a rash typical of erythema migrans, chronic arthritis, or cranial nerve palsies should undergo testing for antibodies to Borrelia burgdorferi.

    • Seek consultation with a gastroenterologist in patients with symptoms suggestive of inflammatory bowel disease or Whipple disease, if the diagnosis has not already been established.

    • Older patients presenting with vitreous cells should raise the suspicion for intraocular lymphoma. Diagnostic vitrectomy, cytological evaluation of cerebrospinal fluid, and neuroimaging may be necessary. Intraocular lymphoma may respond to steroids to some extent.

    • The white lesion in toxocariasis, if affecting the peripheral retina, can be confused with a snowbank, especially when associated with the usual vitritis. The patients are usually younger, and the disease tends to be unilateral.

    • Other diseases associated with intermediate uveitis include HTLV-1 infection and syphilis.

    • In one case report, a patient with cat scratch disease presented with pars planitis. There is usually a retinitis with optic nerve and/or choroidal involvement.

    • Irvine-Gass syndrome, a postoperative intraocular inflammation associated with CME, is in the differential. It should generally not present much confusion since most patients will have recently undergone cataract surgery.


Imaging Studies

Fluorescein angiography

Fluorescein angiography is useful in determining the presence and extent of CME.

Knowing if CME exists helps in choosing the appropriate treatment plan.

The angiogram provides information about the integrity of the retinal vasculature. Staining of the vessel walls and/or leakage indicates a perivasculitis.

Retinal neovascularization and optic nerve edema can be recognized easily.

B-scan ultrasonography

When media are obscured by vitreous hemorrhage, inflammatory debris, cyclitic membrane, or cataract, B-scan ultrasonography can be useful.

Obtain B-scan ultrasonography to document the extent of vitreous debris, retinal detachment, and cyclitic membranes.

Ultrasound biomicroscopy may show features that are not clinically obvious, such as uveal thickening, the exact nature of inflammatory condensations in the vitreous, and vitreoretinal adhesions with traction.

Both 50 MHz and 20 MHz ultrasound imaging in patients with intermediate uveitis readily demonstrated inferior pars plana exudates and cyclitic bands, which are of extreme value in preoperative planning in patients with dense media and/or a secluded pupil due to posterior synechiae.

Optical coherence tomography (OCT)

OCT has replaced traditional fluorescein angiography as the imaging modality of choice in establishing a diagnosis of CME.

OCT can help demonstrate the presence of cysts in the fovea and measure macular thickness. OCT is a highly sensitive, noninvasive method to help diagnose CME and provides the best method to monitor the therapeutic response of patients to treatment as macular thickness appears to correlate with visual acuity to some degree.

OCT can also help demonstrate the presence of epiretinal membranes, a known late complication of ocular inflammation.

The presence of neurologic symptoms or a history of optic neuritis should prompt the clinician to obtain an MRI of the brain and subsequent consultation with a neurologist to rule out MS.

If there is a high clinical suspicion of sarcoidosis as the cause of intermediate uveitis, a chest X-ray or a Gallium scan should be obtained as indicated. Older women with a negative chest X-ray and ACE may have hilar adenopathy identified on chest CT.


Histologic Findings

Histologic examination of the pars plana snowbank shows that it is not a true protein exudate. The snowbanks are predominantly a combination of collapsed vitreous, blood vessels, inflammatory cells (mainly lymphocytes), fibroblasts, and glial elements. Histologic studies also failed to identify cells positive for GFAP, an important glial cell marker, within the snowbanks. Peripheral veins may manifest lymphocytic infiltration and cuffing. The vascular component of the snowbanks has been shown to be continuous with retinal vessels. Vitreous snowballs are composed of epithelioid cells and multinucleated giant cells.