Internal reflectivity of filtering blebs versus intraocular pressure in patients with recent trabeculectomy.

PURPOSE: The authors conducted a morphology analysis of filtering blebs with anterior segment optical coherence tomography (AS-OCT) in patients shortly after trabeculectomy to find further criteria for success or failure of a filtering bleb.

METHODS

Thirty-seven patients (43 eyes) who had recently (<2 years) undergone trabeculectomy were measured 1 to 4 times with AS-OCT. In contrast to ultrasound biomicroscopy, AS-OCT eliminates the need for a water bath in contact with the globe. This is of particular value in a study of morphologic parameters that may be altered by contact and in the postoperative period when concerns of infection are paramount. In this study, the internal reflectivity of the fluid-filled cavity of the filtering bleb was compared with the intraocular pressure (IOP).

RESULTS

Mean age of the patients was 69.5 years (range, 27-84 years). Average preoperative IOP of the 43 eyes was 20.6 mm Hg (range, 10-42 mm Hg), average postoperative IOP at the time of AS-OCT measurement was 10.6 mm Hg (range, 2-40 mm Hg), and mean IOP reduction was 10.0 mm Hg (48.5%). Internal reflectivity of the fluid-filled cavity of the filtering bleb correlated very well to the IOP (R(2) = 0.3762, n = 61, P < 0.0001).

CONCLUSIONS

AS-OCT is a promising tool with which to analyze the morphology of the filtering bleb after trabeculectomy. A highly significant correlation between the internal reflectivity of the fluid-filled cavity of the filtering bleb and the IOP could be shown that may have future impact in evaluating the postoperative success or failure of filtering blebs.