Corneal biomechanics in connective tissue disorders

Purpose: The purpose of this study is to determine the corneal biomechanical properties in patients with connective tissue disorders (CTDs) and compare them with age-matched healthy control. Materials and Methods: In this cross-sectional study, 62 patients (study group) with CTDs and 44 healthy patients (control) were analyzed by Ocular Response Analyzer (Reichert Inc., Depew, N. Y., USA) and Corneal Pachymetry (SP-2000, Tomey, Nagoya, Japan). The right eye of all patients was assessed for corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPc), and Goldmann-correlated intraocular pressure (IOPg), and central corneal thickness (CCT). Results: Mean CH (9.54 ± 1.66 mm Hg [study group] and 10.62 ± 1.21 mm Hg [control]; P = 0.013) and mean CRF (9.95 ± 1.47 mm Hg [study group] and 10.76 ± 1.25 mm Hg [control]; P = 0.040) were significantly different between groups. Mean IOPc, IOPg, and CCT were not significantly different between groups. In the subgroup analysis of study cases (oral steroid versus nonsteroid therapy) of CTDs, CRF which was significantly lower in steroid (9.25 mm Hg) compared nonsteroid therapy (10.20 mm Hg) (P = 0.045), whereas, other parameters such as CCT, CH, IOPc, and IOPg were comparable between the two groups (P ≥ 0.05). Conclusion: CH is altered in CTDs which may be an independent risk factor for glaucoma and might underestimate intraocular pressure so CH is an important consideration in patients with CTDs.