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Abstract #20795 Published in IGR 10-1
Reproducibility and clinical relevance of the ocular response analyzer in nonoperated eyes: corneal biomechanical and tonometric implications
Moreno-Montañés J; Maldonado MJ; García N; Mendiluce L; García-Gómez PJ; Seguí-Gómez MInvestigative Ophthalmology and Visual Science 2008; 49: 968-974
PURPOSE: To assess the reproducibility of the ocular response analyzer (ORA) in nonoperated eyes and the impact of corneal biomechanical properties on intraocular pressure (IOP) measurements in normal and glaucomatous eyes. METHODS: In the reliability study, two independent examiners obtained repeated ORA measurements in 30 eyes. In the clinical study, the examiners analyzed ORA and IOP-Goldmann values from 220 normal and 42 glaucomatous eyes. In both studies, Goldmann-correlated IOP measurement (IOP-ORAg), corneal-compensated IOP (IOP-ORAc), corneal hysteresis (CH), and corneal resistance factor (CRF) were evaluated. IOP differences of 3 mmHg or greater between the IOP-ORAc and IOP-ORAg were considered outcome significant. RESULTS: Intraexaminer intraclass correlation coefficients and interexaminer concordance correlation coefficients ranged from 0.78 to 0.93 and from 0.81 to 0.93, respectively, for all parameters. CH reproducibility was highest, and the IOP-ORAg readings were lowest. The median IOP was 16 mmHg with the Goldmann tonometer, 14.5 mmHg with IOP-ORAg (P < 0.001), and 15.7 mmHg with IOP-ORAc (P < 0.001). Outcome-significant results were found in 77 eyes (29.38%). The IOP-ORAc, CH, and CRF were correlated with age (r = 0.22, P = 0.001; r = -0.23, P = 0.001; r = -0.14, P = 0.02, respectively), but not the IOP-ORAg or IOP-Goldmann. CONCLUSIONS: The ORA provides reproducible corneal biomechanical and IOP measurements in nonoperated eyes. Considering the effect of ORA, corneal biomechanical metrics produces an outcome-significant IOP adjustment in at least one quarter of glaucomatous and normal eyes undergoing noncontact tonometry. Corneal viscoelasticity (CH) and resistance (CRF) appear to decrease minimally with increasing age in healthy adults.
Dr. J. Moreno-Montañés, Department of Ophthalmology, Clínica Universitaria, Universidad de Navarra, Pamplona, Spain
Classification:
6.1.1 Devices, techniques (Part of: 6 Clinical examination methods > 6.1 Intraocular pressure measurement; factors affecting IOP)
2.2 Cornea (Part of: 2 Anatomical structures in glaucoma)