Bleb Wall Thickness Not Associated With Secondary Interventions After Preserflo MicroShunt Implantation

PurposeThis study aimed to evaluate the anterior segment optical coherence tomography (AS-OCT) parameters bleb wall thickness (BWT) and total bleb height (TBH) in the early postoperative phase after Preserflo MicroShunt (PM) implantation for their correlation with (a) secondary interventions and (b) AS-OCT angiography (AS-OCTA)-derived bleb vessel density (BVD).Materials and methodsIn a prospective longitudinal study of 23 open-angle glaucoma patients, AS-OCT measurements of BWT and TBH and AS-OCTA measurements of BVD were obtained at 1, 2, and 4 weeks (1 W, 2 W, and 4 W), as well as at 2, 3, 6, 9, and 12 months postoperatively. Secondary interventions (needling or open revision) were recorded. The correlations of BWT and TBH with (a) secondary interventions and (b) BVD were assessed.ResultsA total of 10 of 23 patients needed secondary interventions between 4 and 48 weeks after PM implantation. At 1, 2, and 4 weeks after surgery, neither BWT nor TBH was significantly associated with future secondary interventions (BWT/TBH p-values: 1 W: 0.217/0.878, 2 W: 0.670/0.528, and 4 W: 0.171/0.430). Similarly, no correlations between BWT or TBH and BVD were found.ConclusionStructural AS-OCT-based bleb thickness parameters (BWT and TBH) in the early postoperative phase were not significantly associated with future secondary interventions after PM implantation and did not correlate with AS-OCTA-derived BVD. BVD, which was shown to be a viable biomarker for future secondary interventions in a previous analysis of the same cohort, could be a better predictor of secondary interventions after PM implantation than BWT/TBH. Larger studies are necessary to confirm these hypothesis-generating findings.