Corneal biomechanical parameters in systemic autoimmune diseases

The relationship between the cornea and systemic autoimmune diseases has been demonstrated in prior studies. Corneal Visualisation Scheimpflug Technology (Corvis ST) provides a specific and detailed assessment of corneal biomechanical features, such as stiffness and elasticity.

This study aims to evaluate corneal biomechanical changes in patients with systemic autoimmune diseases using Corvis ST.

This prospective study included 36 patients with ankylosing spondylitis (AS), 38 patients with rheumatoid arthritis (RA), and 36 age- and sex-matched healthy subjects. After ophthalmologic examinations Pentacam HR and Corvis ST was performed on all eyes. The mean keratometric and pachymetric data, corneal biomechanical parameters, biomechanical intraocular pressure (bIOP) were analysed.

There was no statistically significant differences among the groups regarding age, gender, refraction, visual acuity, IOP, pachymetry and keratometry. Compared to healthy controls, the mean velocity values of applanation 1 (A1V) and 2 (A2V), deformation amplitude (DA), and corvis biomechanical index (CBI) were statistically significantly higher and stiffness parameter at first applanation (SPA1) was statistically significantly lower in AS and RA patients (all p < 0.05). In both AS and RA groups, disease duration was found to be negatively correlated with SPA1 (p = 0.043, 0.027, respectively) and positively correlated with CBI (p = 0.022, 0.020, respectively).

AS and RA patients have a decreased corneal stiffness compared to healthy subjects. Disease duration seems to be correlated with these changes.