Rheumatoid factor versus anti - cyclic citrullinated peptide antibody as screening tool for rheumatoid arthritis in an ophthalmic clinic.

Patients with moderate to severe dry eyes are often screened at the Dry Eye Clinic to rule out connective tissue diseases. Rheumatoid factor (RF) is one of the screening tools to rule out rheumatoid arthritis (RA). Patients who turn out positive for the RF are often subjected to anti-CCP antibody evaluation for confirmation of disease. This article tries to highlight 3 cases of negative and anti-CCP antibody positive cases which presented to the ophthalmic clinic, unaware of their systemic status. Though RF is the cheapest modality to screen for RA, it is not always a reliable marker. One should order anti-CCP antibody for patients where suspicion is high, despite RF being normal.