[Rebound tonometry with sterilized probes]

Intraoperative measurement of intraocular pressure (IOP) opens up possibilities to investigate the influence of IOP on the stability of the eyeball during the performance of surgical maneuvers. Few techniques have been described, none of which are commercially available. This study investigated the use of sterilized probes for rebound tonometry, which could be used intraoperatively.

Tonometry was performed on 30 eyes using a noncontact tonometer and rebound tonometry with the iCare 100 and iCare 200 (iCare Finland Oy, Vantaa, Finland) in a sitting and in a supine position. When performing rebound tonometry probes from the package were used sequentially with sterilized probes. The comparability of sterilized and nonsterilized probes was investigated using different rebound tonometers and different settings.

Measurements on a sitting subject were comparable with sterilized and nonsterilized probes. Statistically significant comparability was also found in a supine position. Measurements with identically sterilized probes on identically positioned subjects were comparable with iCare 100 und iCare 200 (T2 vs. T4, p = 0.003 und T3 vs. T5 p < 0.001). The comparison of measurements of the original probe with the sterilized probe in a sitting and in a supine position were possible with statistical significance (p < 0.005). Measuring with the iCare 200 in a sitting position showed a slightly lower IOP with the sterilized probe with the difference being statistically significant.

Single autoclaving does not alter the probes' ability to measure IOP.

The use of probes which have been sterilized according to the regulations for other surgical instruments opens up new possibilities for the intraoperative measurement of IOP. This facilitates the use in scientific studies on surgical techniques. In the postoperative period the use of sterilized probes can reduce the risk of infection.