[Rebound tonometry in a clinical setting. Comparison with applanation tonometry].

PURPOSE

Rebound tonometry has recently been modified for its use in humans. The purpose of our study was to determine the precision of the ICare(R) rebound tonometer (RBT) as compared with the Goldmann applanation tonometer (GAT).

METHODS

Patients were recruited from our Hospital's Glaucoma Unit. In each patient, intraocular pressure (IOP) was measured without anaesthesia using the RBT and ten minutes later using the GAT. Central corneal thickness (CCT) was measured by pachymetry.

RESULTS

Sixty-eight patients were recruited (132 eyes). Mean IOP readings with RBT were 18.9 +/- 7.2 (SD) mmHg and were 15.5 +/- 5.7 mmHg with GAT (p<0.001). There was a good correlation between both instruments (r = 0.87, p<0.001). In most cases (84.6%) the IOP measured with the RBT was greater than that measured with the GAT. The mean difference between both instruments was 3.4 +/- 3.6 mmHg. There was a trend towards greater differences between those obtained using the RBT than the GAT when IOP values were higher. A statistically significant correlation was found between IOP readings with both tonometers and CCT, with higher differences being seen as the CCT increased.

CONCLUSION

The RBT can be employed in a clinical setting taking into account that it usually overestimates IOP as compared with the GAT. It could be especially useful in glaucoma screening campaigns since it can be operated by a trained technician.