[Diagnosis of keratoconjunctivitis sicca in rheumatoid arthritis. The value of various tests].

In this study we examined 85 patients in the range of 25 to 60 years with rheumatoid arthritis (RA) and a control group of 35 persons without any systemic diseases. The 85 patients with RA were split into two groups: first group was made up of 32 patients with keratoconjunctivitis sicca (KCS) and the second of 53 patients without KCS. The aim was to decide whether the simple ocular ferning test has more diagnostic value than the "classical" tests: break-up time (BUT), Schirmer-1-test and concentration of lysozyme in the tear fluid. Therefore, we compared the tests with reference to sensitivity, specificity and prognostic value in the three groups. The results of the ocular ferning test are markedly better than the results of the other tests: sensitivity is 82.2%, specificity 92.5% and prognostic value 86.6%. The corresponding values are: BUT: 51.6%-77.8%-63.1%; Schirmer-1-test: 34.4%-90.8%-73.5%, lysozyme concentration: 73.4%-51.0%-52.7%. The ocular ferning test is an easy, practical, cheap, and reliable completion to the conventional tests; it is also easy on the patients.