Effects of Anti-TNF and NSAID Therapy on Choroidal and Macular Thickness in Ankylosing Spondylitis: An OCT-Based Evaluation of Subclinical Inflammation

This study aimed to evaluate the effects of non-steroidal anti-inflammatory drugs (NSAIDs) and anti–tumor necrosis factor-α (anti-TNF-α) therapy on retinal and choroidal thickness in ankylosing spondylitis (AS) patients without uveitis and to compare these findings with healthy controls. A total of 65 AS patients and 30 age- and sex-matched healthy controls were included. Macular thickness, retinal nerve fiber layer (RNFL) thickness, and subfoveal choroidal thickness were measured using spectral-domain optical coherence tomography (SD-OCT). Patients receiving NSAIDs and/or sulfasalazine (Group 1, n = 30) were compared with patients receiving anti-TNF-α therapy (Group 2, n = 35) and with healthy controls (Group 3, n = 30). Mean subfoveal choroidal thickness was significantly greater in Group 1 compared with Group 2 and controls (p < 0.05). Nasal inner (p = 0.008) and nasal outer (p = 0.003) macular subfield thicknesses were significantly lower in both AS groups compared with controls, while RNFL thickness did not differ significantly among groups (p = 0.069). Covariance analysis showed that age and disease duration had no significant effect on these outcomes. These findings suggest that choroidal and macular thickness may be altered by subclinical inflammation in AS even in the absence of uveitis, and that anti-TNF-α therapy may provide superior suppression of inflammation compared with NSAIDs. OCT-based choroidal assessment may serve as a useful indicator for monitoring inflammatory activity and treatment response in AS.