title: Corneal Biomechanical Properties in Rheumatoid Arthritis.
abstract: OBJECTIVE
  To investigate the variations in biomechanical properties of the cornea in rheumatoid arthritis (RA) patients.
  
  
  METHODS
  A total of 53 RA patients, and 25 healthy individuals (control group) were enrolled. Rheumatoid arthritis patients were classified as in active phase (group 1; n=24) or in remission phase (group 2; n=29). Corneal biomechanical parameters including corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated intraocular pressure (IOPcc), and Goldmann-correlated IOP (IOPg) were measured with the Reichert Ocular Response Analyzer. Topographical measurements, including central corneal thickness (CCT), anterior chamber depth, iridocorneal angle, and corneal volume were measured using a Sirius corneal topographer.
  
  
  RESULTS
  The mean CH was 9.43±1.17 mm Hg in group 1, 9.42±1.84 mm Hg in group 2, and 10.47±1.68 mm Hg in the control group (P=0.03). The mean IOPcc was 17.85±3.2 mm Hg in group 1, 17.95±3.49 mm Hg in group 2, and 15.36±3.11 mm Hg in the control group (P=0.008). The CH showed a significant positive correlation with CRF (P=0.000, r=0.809) and CCT (P=0.000, r=0.461), and a significant negative correlation with IOPcc (P=0.000, r=-0.469).
  
  
  CONCLUSIONS
  Decrease in the mean CH measurements indicates that ultrastructural changes in the cornea may occur in the active phase, and these changes persist in the remission period. In addition, IOPcc is significantly affected by the corneal biomechanical properties. In RA patients, it is important to control the corneal parameters and IOP measurements against the irreversible changes on the optic nerve.
authors.affiliation: Department of Ophthalmology (M.E.C.), Ankara Kecioren Training and Research Hospital, Ankara, Turkey; Departments of Rheumatology (S.E.), and Ophthalmology (G.D.C., O.S., N.C.), Ankara Ataturk Training and Research Hospital, Yildirim Beyazit University, Ankara, Turkey; and Department of Ophthalmology (H.B.C.), Hacettepe University, Faculty of Medicine, Ankara, Turkey.
authors.forename: Mehmet Erol
authors.initials: ME
authors.lastname: Can
authors.forename: Sukran
authors.initials: S
authors.lastname: Erten
authors.forename: Gamze Dereli
authors.initials: GD
authors.lastname: Can
authors.forename: Hasan Basri
authors.initials: HB
authors.lastname: Cakmak
authors.forename: Ozge
authors.initials: O
authors.lastname: Sarac
authors.forename: Nurullah
authors.initials: N
authors.lastname: Cagil
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001172:Arthritis, Rheumatoid / Q000503:physiopathology*; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D003315:Cornea / Q000503:physiopathology*; D019781:Corneal Topography; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014065:Tonometry, Ocular; D055815:Young Adult