Is Pulse Synchronized Pneumotonometry More Reproducible than Routine Pneumotonometry and More in Agreement with Goldmann Applanation Tonometry?

Purpose

This study compared the variability of intraocular pressure (IOP) measurements taken with pulse synchronized pneumotonometry (PNT) and with routine PNT (without pulse synchronization) and evaluated the agreement between PNT and Goldmann applanation tonometry (GAT).

Methods

In this prospective study, 148 eyes from 78 patients were enrolled. Patients were randomized into two groups. In the first group (A), the sequence of measurements was pulse synchronized PNT, routine PNT, and GAT. In the second group (B), the sequence of measurements was routine PNT, pulse synchronized PNT, and GAT. The mean of three measurements was averaged for PNT and GAT. All the measurements were performed by the same investigator, who was masked to GAT measurements. The mean IOP measurements and intrapatient standard deviations among the three tonometers were compared using analysis of variance measurement. Bland & Altman plots were used to assess the agreement between PNT and GAT.

Results

The variability of IOP measurements taken with pulse synchronized PNT was significantly lower than with routine PNT in both groups (1.2±0.7 vs 1.3±0.7 mmHg in group A and 1.1±0.9 vs 1.3±1.0 mmHg in group B [p<0.001], respectively). PNT measurements with and without pulse synchronization were on average ±2 mmHg higher than GAT measurements in both groups (p<0.001). The 95% limits of agreement between PNT and GAT varied between −3.8 and 8.5 mmHg.

Conclusions

Pulse synchronized PNT gives more reproducible measurements than routine PNT. The agreement between PNT and GAT is poor. (Eur J Ophthalmol 2007; 17: 178–82)

Safe trabeculectomy technique: long term outcome

AIM

To assess the long term outcome of a new trabeculectomy technique.

METHODS

Trabeculectomy was performed using a fornix based conjunctival flap, an anterior chamber maintainer, a standardised punch technique, and a combination of adjustable and releasable sutures in 56 eyes of 53 patients. The main outcome measures were the postoperative intraocular pressure (IOP) and the frequency of early postoperative complications. The mean follow up time was 15.7 (range 12-21) months.

RESULTS

The mean preoperative and postoperative IOP at 12 months were 21.2 (SD 6) and 12.8 (3.0) mm Hg, respectively. All patients had an IOP of <21 mm Hg, 90.9% had an IOP <18 mm Hg, and 61.4% had an IOP <14 mm Hg. Postoperative complications were infrequent: flat anterior chamber (1.8%), bleb leakage (0%), or hypotony (1.5%) beyond 3 weeks, or choroidal detachment at any time point (8.9%).

CONCLUSIONS

This novel trabeculectomy method offers the possibility to tailor the IOP postoperatively with a minimum of postoperative complications and excellent IOP control at the long term follow up.