Modern research methods in the diagnosis of anterior uveitis associated with spondyloarthritis

Relevance In 2017, the uveitis activity index (UVEDAI) was developed, which includes the following 7 indicators: inflammation of the anterior chamber and vitreous body, macular edema, retinal and choroidal lesions, optic neuropathy and subjective assessment of the activity of the inflammatory process by the patient. An important marker of inflammation in chronic anterior uveitis (PU) is the opacity of the anterior chamber fluid ("flare"), which is assessed by the number of cells using scales such as SUN. However, the accuracy of the assessment depends on the experience of the doctor, the resolution of the slit lamp and interaction with the patient. A more accurate method of examination is paracentesis with measurement of protein concentration, but it is invasive and not suitable for routine diagnostics [1]. This emphasizes the need to develop non-invasive methods for examining the anterior segment of the eye. Modern models of optical tomographs (OCT) make it possible to evaluate new parameters and identify their relationships. For example, Lu M. et al. (2020) used CASIA2 OCT to examine corneal precipitates, inflammatory cells, and their suspension in the anterior chamber, and developed a program to assess posterior corneal surface smoothness (PCSS) [2]. However, OCT has limitations: insufficient resolution at the cellular level, difficulties in visualization with corneal edema, and the need for a fixed patient position. Corneal confocal microscopy (CCM) provides high resolution at the cellular level, visualization of nerve fibers and Langerhans cells. The Liner 1.2S software for analyzing nerve fibers has been developed at the Research Institute of Clinical and Gynecological Diseases, and the use of CCM in diagnosing uveitis is being actively studied [3]. However, the method requires transparency of optical media and patient concentration. Gunes A. et al. studied the use of Pentacam for diagnosing uveitis and found a correlation of corneal parameters with dry eye tests and inflammatory markers [4]. However, keratotopography is an expensive method, has a limited view and depends on the patient's position. Conclusion At the moment, there is no universal method for diagnosing anterior segment structures in PU associated with SpA. OCT of the anterior segment and CMR, which demonstrate high-resolution images of the cornea and anterior chamber structures at the cellular level and make it possible to assess the effectiveness of the treatment, seem promising for further study. Key words: keratotopometry; corneal confocal microscopy; corneal nerve fibers; Langerhans cells; uveitis; HLA-B27