Anterior and Posterior Ocular Changes in Patients with Active and Inactive Ankylosing Spondylitis

BACKGROUND The 6-item Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) is a method for evaluating disease activity in ankylosing spondylitis (AS). This study included 78 patients with active and inactive AS and aimed to evaluate anterior and posterior segment ocular changes. MATERIAL AND METHODS Seventy-eight patients and 70 control subjects were enrolled in this study. All participants underwent a complete ophthalmic evaluation. The patients were subdivided into 2 groups according to their BASDAI scores: the active group (BASDAI³4) (n: 38) and the inactive group (BASDAI<4) (n: 40). RESULTS Endothelial cell density (ECD) and hexagonality (HEX) decreased, while coefficient of variation (CV) and average cell size (AVG) increased significantly in AS patients compared with the control cases (P 0.001). However, there was no statistically significant difference between active and inactive groups related to these parameters. Central corneal thickness (CCT) and corneal volume were significantly lower in AS patients (P 0.001, P 0.04), without any statistically significant difference between active and inactive groups. Tear break-up time (TBUT) and Schirmer test results were lower and the findings of corneal fluorescein staining and ocular surface disease index scores (OSDI) were higher in AS patients compared with the control cases, without any significant differences between the active and inactive groups (P 0.001). Choroidal thickness was significantly higher in all 5 points investigated - subfoveal (P 0.018), 1000 Nasal (N) (P 0.003), 2000 N (P 0.001), 1000 Temporal (T) (P 0.007), and 2000 T (P 0.013)  in AS patients compared with the control group. CONCLUSIONS AS can cause anterior and posterior changes, even in the absence of uveitis. Therefore, more attention should be paid to ocular surgery and follow-up of ocular diseases in AS patients.