Ocular response analyzer and goldmann applanation tonometry: a comparative study of findings.

PURPOSE

Correlation of findings of the Reichert Ocular Response Analyzer (ORA) with Goldmann applanation tonometry (GAT).

DESIGN

Observational, cross-sectional study.

METHODS

The study was conducted on 103 eyes of 56 patients, aged 41 to 78 years; average (±SD) 58.9 (±9.8) years attending the outpatient clinic of the Department of Ophthalmology, Alexandria University, for a routine refraction. Full ophthalmic examination including slit lamp biomicroscopy and GAT, then Reichert ORA utilization to obtain the intraocular pressure cornea corrected (IOPcc), the IOP Goldmann (IOPg), the corneal resistance factor (CRF), the corneal hysteresis (CH), and the central corneal thickness (CCT). Exclusion criteria included previous ophthalmic surgery and any corneal pathology.

RESULTS

The mean (±SD) IOP GAT was 14.1 mm Hg (±3.0) (range: 8 to 22 mm Hg). The mean (±SD) IOPg, IOPcc, CRF, CH, and CCT was 15.5 (±4.0), 16.9 (±3.7), 9.6 (±2.0), 9.4 mm Hg (±1.7) and 540.8 (±32.6) μm, respectively. There was a significant correlation (P<0.0001) between IOP GAT and each of IOPg, IOPcc, and CRF; between IOPg and each of IOPcc, CRF, and CCT; between IOPcc and each of CRF and CH; and between CCT and each of CRF and CH at 0.01 level. The average (±SD) difference between IOP GAT and IOPg and IOPcc was -1.33 (±2.38) mm Hg and -2.81 (±2.66) mm Hg, respectively, and was statistically significant (paired t test in a 95% confidence interval).

CONCLUSIONS

The ORA is valuable for the evaluation of IOP and corneal biomechanics. However its results are not to be used interchangeably with the GAT findings.