Assessment of Ocular Surface in Patients With Ankylosing Spondylitis

Purpose: To evaluate the clinical findings and ocular surface changes in patients with ankylosing spondylitis (AS). Methods: This prospective study involved 45 patients with AS (group 1) and 28 healthy subjects (group 2). Patients in group 1 were in the inactive period. The study subjects underwent a complete ophthalmic examination. The right eyes of the subjects in each group were tested for the study including slit-lamp examination, Schirmer I test, tear break-up time (TBUT), conjunctival impression cytology (CIC), and ocular surface disease index (OSDI). Results between the two groups were compared. Results: The mean Schirmer I test result was found as 12.2 +/- 8 mm in group 1 and 20.3 +/- 9.9 mm in group 2 (P<0.001), whereas the mean TBUT value was found as 3.8 +/- 1.9 sec in group 1 and 10.1 +/- 4.8 sec in group 2 (P<0.001). The OSDI scores were significantly higher in group 1 (36.5 +/- 19.4) than in group 2 (9.1 +/- 12.9, P<0.001). The CIC scores were significantly higher in group 1 (2.12 +/- 0.7) than in group 2 (0.57 +/- 0.6, P<0.001). Notably, none of the patients in group 1 showed grade 0 differentiation, and none of the patients in group 2 showed grade 2 or 3 differentiation. The CIC scores were significantly higher in group 1 (2.12 +/- 0.7) than in group 2 (0.57 +/- 0.6, P<0.001). Conclusion: Ocular surface changes, including squamous metaplasia in the bulbar conjunctiva, can be observed in patients with AS.