Intraocular Pressure Change after Glaucoma Implant Surgery with Releasable suture

ABSTRACT

PURPOSE: To find the factor that affects the long-term intraocular pressure after glaucoma implant surgery with releasable suture. METHODS: We retrospectively reviewed the medical records of the 33 patients (36 eyes) who had undergone glaucoma implant surgery with our own expanded-Polytetrafluoroethylene (e-PTFE) membrane-tube implant with temporary closure of the tube by releasable suture. Data such as timing of suture release, IOP's before and after surgery and the amount of pressure change during follow-up were collected, and we tried to find the factor that influenced the IOP at the last visit. RESULTS: The preoperative IOP was 43.2+/-14.6 mmHg and the suture was released at day 17.9+/-9.5 after surgery. The IOP just before the release of suture was 33.5+/-17.1 mmHg. The pressure was dropped to 15.1+/-13.7 mmHg, measured at 30 minutes after the release of the suture. The IOP was stabilized to 14.9 +/-9.5 mmHg at 12.2+/-7.0 days after the release. The average follow-up was 32.8+/-26.3 months and the IOP at the last visit was 17.3+/-10.5 mmHg. Four eyes (11%) had hypotony (IOP less than 8 mmHg) before release of the suture, thirteen eyes (41%) showed hypotony 30minutes after release, and three eyes(8%) showed hypotony at the last visit. Multiple linear regression analysis revealed that the IOP at 30 minutes after release of the suture had a positive correlation with the IOP at the last visit (r=0.642,p=0.000). CONCLUSIONS: In the membrane-tube implant surgery for the refractory glaucoma, the releasable suture echnique is helpful to prevent the early postoperative hypotony. By measuring early post-release IOP after implant surgery with releasable suture technique, we might predict the behavior of long term IOP change; the lower post-release IOP, the better long-term pressure control.