BackgroundSarcoidosis (Sa) eye involvement is the most common extrapulmonary manifestation and is the initial presentation in 5–20% of cases. The definitive diagnosis is histopathological.The sensitivity (S) of the conjunctival biopsy is low,so Ocular Sa (OSa) diagnostic criteria (C) were proposed: IWOS (First International Workshop on Ocular Sarcoidosis), with high S and specificity (1/0.95). However, they have been poorly validatedObjectivesTo apply the IWOS C. and to analyze their consistency with the suspected diagnosis of OSa.To discuss differential features between patients with OSa and those with systemic involvementMethodsObservational cross-sectional study.Clinical records from patients with (presumed) Sa diagnosis who had been followed during the last 10 years in a multidisciplinar Uveitis Unit of a 3rd level hospital (Ophthalmology/Rheumatology) were reviewed.Clinical variables and complementary tests results were analyzed.IWOS C. were applied if OSa was suspected.For statistical analysis we use:Chi-square test and Kappa coefficientResults71 patients were included:47 OSa,13 with ocular-systemic involvement (OS-Sa) and 11 with systemic involvement (SSa). Women/Men 57%/43%, mean follow-up time 9.42 years (±8.55), with no intergroup differences.Significant differences between patients with OSa vs. OS-Sa/SSa were observed:mean age at diagnosis (40.23±18.18 vs. 57.54±17.65/48.27 ±17 years, p=0.01); mean ESR (16.74±12.73 vs. 26.38±15./19.4±31.55 mm/h, p=0.01); mean CRP (3.58±4.29 vs. 8.12±8.11/10.24±14.37 mg/L, p=0.03); CT abnormalities (16.6% vs. 90%/92%, p=0.001); positive biopsy (0% vs. 88/100%, p=0.002); general, joint, respiratory and skin symptoms (OSa 6–12% vs SSa 15–50%, p=0.002). ACE was increased in 74.6%, with a mean value of 71.98±33.59 U/L, with no intergroup differences. Altered lacrimal scintigraphy was more often found in the OSa subset (26.7%) vs. OS-Sa/SSa (23.1%/0%), without statistical significance. Comparing OSa vs. OS-Sa patients, ocular involvement was as follows: anterior segment involvement 48% vs 61.5%, intermediate segment 21.3% vs. 15.4%, posterior segment 8.5% vs 0%, panuveitis 10.6% vs. 7.7%, mixed involvement 10.6% vs. 15.4% (p=0.001). If OSa, bilateral involvement was present in 60% of patients, unilateral involvement was more frecuent in OS-Sa (76%), p=0.06.There were no significant differences regarding uveitis's presentation, course and number of crisis and specific intraocular findings. Applying IWOS Criteria and comparing OSa vs OS-Sa we can classify: Definite OSa 0% vs. 69.2%, Presumed OSa 23.4% vs. 7.7%, Probable OSa 14.9% vs. 15.4% and Possible OSa 2.1% vs. 0%; not fulfilling criteria: 59.6% vs. 7.7% (p=0.001). The kappa coefficient between suspicion of OSa/OS-Sa and not fulfilling/fulfilling criteria was 0.30 (p=0.003).ConclusionsWe could classify as Presumed OSa in 25% and as Probable OSa in 15% of patients with suspected OSa but who hadn't undergo a biopsy. We excluded the diagnosis in 60%. There wasn't a good consistency between the suspected diagnosis/IWOS C. fulfi...