Comparison of Rebound Tonometry, Perkins Applanation Tonometry and Ocular Response Analyser in Mucopolysaccharidosis Patients

AIMS To investigate the feasibility and to compare three devices measuring intraocular pressure (IOP) in mucopolysaccharidosis patients (MPS): iCare rebound tonometer (RT), Perkins applanation tonometer (PAT) and ocular response analyzer (ORA). METHODS MPS patients who underwent at least two examinations out of: RT, PAT and ORA at the same visit were identified and retrospectively analyzed in this study. RESULTS 17 patients fulfilled the inclusion criterion. In all 17 patients IOP measurements were performed with RT (34 eyes) and ORA (33 eyes), while PAT measurement was possible in only 12 (24 eyes) patients. The RT, corneal-compensated intraocular pressure (IOPcc) and Goldmann-correlated intraocular pressure (IOPg) differed relevantly from IOP assessed with PAT. Corneal clouding in MPS patients correlated positively with PAT, RT and IOPg (r = 0.3, 0.5, and 0.5 respectively), but not with IOPcc (r = 0.07). The MPS-related corneal clouding correlated positively with biomechanical corneal parameters assessed with ORA: corneal hysteresis (r = 0.77) and corneal resistance factor (r = 0.77) either. CONCLUSIONS RT and ORA measurements were tolerated better than applanation tonometry in MPS patients. IOP measurements assessed with RT and ORA differed relevantly from PAT. Corneal-compensated IOP assessed with ORA seems to be less affected by the MPS-related corneal clouding than applanation or rebound tonometry. RT and ORA measurements should be preferred for IOP assessment in patients with MPS.