The Effect of Early Posttrabeculectomy Intraocular Pressure Spike in the Collaborative Initial Glaucoma Treatment Study

Abstract

To examine effects of early postoperative intraocular pressure (IOP) spike in patients undergoing primary trabeculectomy in the Collaborative Initial Glaucoma Treatment Study. We identified patients with IOP spike ≥5 mm Hg above the baseline IOP on postoperative day 1 and those without IOP increase. The mean deviation (MD), pattern standard deviation (PSD), and corrected PSD of the visual field (VF) were compared at 6 months and years 1, 2, 3, and 5 after surgery, as was the IOP. Seventeen of 300 patients (5.7%) had IOP spike. After controlling for baseline VF severity in a generalized linear regression model that addressed change in MD, PSD, and corrected PSD, or in a logistic regression model for ≥3 dB of MD change, comparison between the groups revealed no significant difference at all time points examined (P>0.05). Patients with IOP spike had significantly higher mean IOP at years 3 and 5 of follow-up (P≤0.04). Among Collaborative Initial Glaucoma Treatment Study patients, early posttrabeculectomy IOP spike ≥5 mm Hg above baseline IOP was not associated with subsequent VF loss, but was associated with significantly higher IOP during long-term follow-up.