Morphological analysis of functional filtering blebs with anterior segment optical coherence tomography: A short-term prediction for success of trabeculectomy

Abstract

Purpose The aim of the study was to analyze morphological parameters of apparently functional filtering blebs with anterior segment optical coherence tomography at 1 month post trabeculectomy and to correlate these parameters with intraocular pressure at 6 months of follow-up to predict the short-term success of trabeculectomy. Methods In this cross-sectional, descriptive study, apparently functional blebs were evaluated using anterior segment optical coherence tomography with crossline scans after 1 month of trabeculectomy. Results A total of 55 eyes of 55 cases with mean age 49.29 ± 13.72 years were included in the study. On anterior segment optical coherence tomography examination, the mean bleb height and mean bleb wall thickness, subconjunctival fluid space, and scleral flap thickness were 1.45 ± 0.39 mm, 0.63 ± 0.25 mm, 0.64 ± 0.26 mm, and 0.45 ± 0.068 mm, respectively. There was statistically significant negative correlation between intraocular pressure at 1 month and bleb height ( r = −0.25, p = 0.05). There was statistically significant negative correlation between extent of cavity and intraocular pressure at 6 months ( r = −0.318, p = 0.018). Bleb height showed significant negative correlation with supra-scleral space ( r = −0.31, p = 0.02). Multi reflective bleb walls showed statistically significant increased chances of successful functioning blebs at 6 months as compared to uniform wall reflectivity ( p = 0.00). Bleb function was successful in 37 (67.3%) and unsuccessful in 18 (32.7%) in short term of 6 months of follow-up. Conclusion Bleb walls with multiform wall reflectivity on anterior segment optical coherence tomography at 1 month post trabeculectomy show increased chances of success of functioning filtering bleb at 6 months. Bleb wall characteristics on anterior segment optical coherence tomography at 1 month can predict the short-term success of blebs at 6 months.