Envisioning a clear plan for diagnosis of ocular sarcoidosis

Oral corticosteroid therapy is essential for ocular sarcoidosis. A sub-Tenon's triamcinolone infusion, however, is useful for older patients to avoid the side effects of corticosteroids. Managing ocular sarcoidosis often requires vitrectomy for fibrotic lesions and photocoagulation for ischemic retinopathy and macroaneurysms, said Nobuyuki Ohguro, MD, Osaka University Medical School, Osaka, Japan.

When the first international workshop on ocular sarcoidosis was held in the fall 2007 in Tokyo, uveitis specialists from around the world and two pulmonologists who specialize in sarcoidosis identified seven signs of intraocular inflammation that suggest a diagnosis of ocular sarcoidosis: mutton-fat/granulomatous keratic precipitates and/or iris nodules; trabecular meshwork nodules and/or tent-shaped peripheral anterior synechiae; snowballs/string-of-pearls vitreous opacities; multiple chorioretinal peripheral lesions; nodular and/or segmental periphlebitis and/or a retinal macroaneurysm in an inflamed eye; optic disc nodule(s)/granuloma(s) and/or solitary choroidal nodule; and bilateral disease.

Dr. Ohguro said that five tests are useful to reach a definitive diagnosis: a negative tuberculin test in a patient with a bacille Calmette-Guérin vaccination or in a patient with a previous positive tuberculin skin test, elevated serum angiotensin converting enzyme value and/or elevated serum lysozyme value, a positive chest X-ray showing bilateral hilar lymphadenopathy (BHL), abnormal liver enzyme tests, and a chest computed tomography scan in patients with a negative chest x-ray.

Diagnostic criteria were determined based on ocular signs, investigational tests, and biopsy results reaching four levels of diagnostic certainty:

• Definite ocular sarcoidosis was indicated by a biopsy-supported diagnosis with compatible uveitis.
• Presumed ocular sarcoidosis described cases without a biopsy but with BHL with a compatible uveitis.
• Probable ocular sarcoidosis indicated cases without a biopsy, a chest x-ray without BHL, three suggestive intraocular signs, and two positive tests.
• Possible ocular sarcoidosis was indicated by a negative lung biopsy and at least four suggestive intraocular signs with at least two positive tests.

"The gold standard for diagnosing sarcoidosis was previously histopathologic proof using biopsy tissue," Dr. Ohguro said. "However, biopsy of intraocular tissue is not common and is unacceptable to patients with uveitis unless the tissue is obtained from an easily accessible site. The Tokyo Diagnostic Criteria is the first international diagnostic criteria for ocular sarcoidosis based on combined ophthalmic clinical signs and laboratory investigations without evident systemic involvement. Further discussion and prospective validation studies are needed."