MAY 18, 2011
The authors conducted this retrospective case-control study to validate the international criteria for ocular sarcoidosis proposed by the First International Workshop on Ocular Sarcoidosis (FIWOS) held in Tokyo in 2006. The FIWOS diagnostic criteria are based on seven clinical intraocular signs and five laboratory investigations, with four levels of diagnostic certainty depending on the combination of results. The authors of the current study retrospectively compared the medical records of 50 patients with biopsy-proven sarcoidosis with 320 control patients with other uveitis entities and found that the FIWOS criteria are highly predictive for diagnosing ocular sarcoidosis. Although histological proof of non-caseating granuloma in biopsy tissues is the gold standard for ocular sarcoidosis diagnosis, biopsies of intraocular tissues are rarely performed.
Subjects in the study were 370 consecutive uveitis patients treated during a three-month period at one university hospital in Japan. The authors reviewed their medical records for the results of the FIWOS clinical signs and laboratory tests. The FIWOS clinical signs are mutton-fat keratic precipitate (large or small) and iris nodules at the pupillary margin or in the stroma; trabecular meshwork and/or tent-shaped peripheral anterior synechiae; snowball/string of pearls vitreous opacities; multiple chorioretinal peripheral lesions (active and atrophic); nodular and/or segmental periphlebitis (±candle wax drippings) and/or macroaneurism in an inflamed eye; optic disc nodule(s)/granuloma(s) and/or solitary choroidal nodule; and bilaterality (assessed by clinical examination or laboratory tests showing subclinical inflammation). The FIWOS laboratory tests for suspected ocular sarcoidosis are negative tuberculin test in a Bacillus Calmette-Guérin-vaccinated patient or one having had a positive purified protein derivative (or Mantoux) skin test previously; elevated serum angiotensis-converting enzyme and/or elevated serum lysozyme; chest X-ray, look for bilateral hilar lymphadenopathy; abnormal liver enzyme tests; and chest CT scan in a patient with a negative chest X-ray.
The authors found a significantly higher incidence of positive results in the biopsy-proven sarcoidosis patients than in the control uveitis patients for each of the clinical signs and laboratory tests except for the liver enzyme test. The sensitivity, specificity, positive predictive value and negative predictive value of the combined results were 1.000, 0.950, 0.758 and 1.000, respectively. However, the predictive value of the individual clinical signs and lab tests varied.
This study, which is the first to validate the international criteria for ocular sarcoidosis, demonstrated that the FIWOS criteria have high predictive value. In order to confirm these findings, an international prospective multicenter study should be conducted.