The Assessment of the Filtering Bleb Function With Anterior Segment Optical Coherence Tomography

Abstract

To assess the usefulness of anterior segment optical coherence tomography (AS-OCT) in evaluating postoperative filtering bleb function. Forty-eight eyes of 39 patients who had earlier undergone trabeculectomy were enrolled. Blebs were imaged with a commercially available AS-OCT system. The correlation between intraocular pressure (IOP) and 4 quantitative parameters, bleb height, bleb wall thickness, and the height and extent of internal cavity, and 2 qualitative parameters, bleb wall reflectivity, and the presence or absence of posterior episcleral fluid, were analyzed. Of the 39 participants, 25 (64.1%) were males (mean age, 65.3±10.0 y). The height and extent of the internal cavity and the bleb height were not correlated with the IOP. The bleb wall thickness was negatively (P=0.004) correlated with the IOP. The mean IOP in eyes with a low-reflectivity bleb wall was significantly (P=0.001) lower than in eyes with a high-reflectivity wall. The IOP levels were significantly (P=0.008) lower in eyes with posterior episcleral fluid than in eyes without it. AS-OCT is a useful tool to evaluate filtering bleb function. The height and extent of the total bleb and the internal cavity were not correlated with IOP control. A low-reflectivity wall and the presence of episcleral fluid were associated with lower IOP.