Early posttrabeculectomy IOP spike not associated with subsequent VF loss

It has been reported in a recent study published in the Journal of Glaucoma that early posttrabeculectomy intraocular pressure (IOP) spike was not linked with subsequent visual field (VF) loss in patients of the Collaborative Initial Glaucoma Treatment Study.

Dr Philip P. Chen, Department of Ophthalmology, University of Washington, Seattle, Washington, USA, led the study aimed at determining the effect of early post-op IOP spike in patients in the Collaborative Initial Glaucoma Treatment Study who have had primary trabeculectomy.

The surgeons determined which patients had an IOP spike of more than or equal to 5 mmHg above baseline one day after surgery as well as those patients that did not experience an increase in IOP. Follow-up was then performed at 6 months, 1, 2, 3 and 5 years post surgery and the mean deviation (MD), pattern standard deviation (PSD) and corrected PSD of the patients VF were measured along with the IOP.

Out of the 300 patients in the study group 17 had an IOP spike. The clinicians compared the groups MD, PSD and corrected PSD, controlling for baseline VF severity, and found that there was no significant difference at each of the follow up points. However, a significantly higher difference was noted in the mean IOP after 3 and 5 years in the patients who had experienced a spike post-op.

It was determined that there was no association with a post-op IOP spike of more than or equal to 5 mmHg to VF loss after primary trabeculectomy surgery but there was an association with higher IOP levels at the longer follow up periods in Collaborative Initial Glaucoma Treatment Study patients.