AB0712 RETINAL AND CHOROIDAL VASCULAR STRUCTURES ARE AFFECTED IN AXIAL SPONDYLOARTHRITIS: AN OPTICAL COHERENCE TOMOGRAPHY STUDY

Abstract

Background Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that mainly affects axial skeleton. Ocular inflammation is one of the most common extra-articular manifestations of axSpA, mainly form of acute anterior uveitis (AAU). However posterior segment of the eye was rarely evaluated. The inaccessibility of posterior structures like choroid and retina to direct examination led clinicians to use non-invasive imaging technics. Optical coherence tomography (OCT) is an imaging technology providing, high-resolution, and non-invasive cross-sectional view of microscopic, anterior and posterior ocular structures. Objectives To evaluate the retina and choroidal vascular structures in axSpA patients by using the advantage of OCT and to compare the changes (if any) with healthy control subjects. Methods In total 70 (66% male; mean age 39.7 ± 10.4 years) axSpA patients (50 radiographic- and 20 nr-axSpA) and 50 (mean age 41.2 ± 6.2 years) healthy control subjects were included in the analysis. All patients underwent a detailed ophtalmalogic examination by the same opthtalmologist. All individuals with significant refractive errors (>3 diopters of spherical equivalent refraction) and intraocular pressure ≥21 mmHg were excluded from the analysis. Choroidal thicknes (ChT), macula, and the ganglion cell complex (GCC) were measured by spectral domain optic coherence tomography (SD-OCT) by the same experienced operator. Results Mean (± SD) BASDAI score was 3.6 ± 2.5, BASFI score was 3.4 ± 2.9, aSDAS-CRP was 2.6 ± 1.3 in axSpA patients and 14% of them has a history of aAU and 61% ever treated with TNFi agents. There was no significant difference between groups regarding refractive error ( P =0.640), intraocular pressure ( P =0.815) and BMI ( P =0.124) that could affect the OCT measurements. ChT ( P <0.001) were increased and GCC thickness ( P <0.001) were decreased in axSpA patients however both layer thicknesses were similar between r- and nr-axSpA patients ( P =780 and P =0.677) (Table). History of uveitis was not associated with ChT and GCC. Although GCC was further decreased in TNFi treated patients (105.8 vs 113.3) this difference did not reach significance ( P =0.058). Education level was associated both ChT and GCC measurement. GCC thickness was also releted with BMI and sex in univarite analysis. Other disease related characteristics including the ones related with disease activity were not related with posterior segment measurements. Conclusion Our results showed that beside anterior segment inflammation, posterior segment of the eye could be affected in both r- and nr-axSpA patients. Retina and choroidal vascular network forms the posterior segment of the eye. The thinning of GCC which form the inner neural layer of the retina is a good indicative of micro-neurotoxicity in axSpA. Elevation of the ChT may be an important indicator of inflammation. View this table: Table. Demographic features and eye assessment results of study population Acknowledgement None Disclosure of interests Berkay akmaz: None declared, Fahrettin akay: None declared, Dilek Solmaz: None declared, onay Gercik: None declared, Gokhan Kabadayi: None declared, Idil Kurut: None declared, Servet akar Grant/research support from: MSD, abbvie, Roche, UCB, Novartis, Pfizer, amgen, Consultant for: MSD, abbvie, Roche, UCB, Novartis, Pfizer, amgen, Speakers bureau: Pfizer