The Application Of Anterior Segment Optical Coherence Tomography In Evaluating The Morphology And Function Of Filtering Blebs After Trabeculectomy

OBJECTIVE:To study the application of anterior segment optical coherence tomography (AS-OCT) in evaluating the morphology and function of filtering blebs after trabeculectomy.METHODS:103 eyes of 79 patients who had previously undergone trabeculectomy we followed up for 1-24 months were selected in this study. These filtering blebs were classified into four types as diffuse-like, cystic-like, encapsulating-like and flatten-like by the slit lamp microscope and AS-OCT. The consistency between the two methods was evaluated by the Chi-Square test. Intraocular pressure after trabeculectomy with four type filtering blebs was also compared by the t-test.RESULTS:Observation of the slit lamp microscope showed diffuse-like blebs in 59 eyes (59/103,57.28%), cystic-like blebs in 22 eyes (22/103,21.36%), encapsulating-like blebs in 8 eyes (8/103,7.77%) and flatten-like in 14 eyes (14/103, 13.59%). AS-OCT imaging showed diffuse-like blebs in 55 eyes (55/103,53.39%) with the average intraocular pressure of (12.76±3.97)mmHg, cystic-like blebs in 27 eyes (27/103,26.22%) with the average intraocular pressure of (15.07±3.43)mmHg, encapsulating-like blebs in 7 eyes (7/103,6.80%) with the average intraocular pressure of (28.40±7.42)mmHg, and flatten-like in 14 eyes (14/103,13.59%) with the average intrapcular pressure of (23.64±6.43)mmHg. This study discovered that AS-OCT has fine concordance with the slit lamp microscope in analyzing the morphology of filtering blebs-after trabeculectomy. (X2=271.58, P<0.05, Pearson=0.8515), for intraocular pressure, it also showed a statistically significant difference between diffuse-like and encapsulating-like blebs (t=3.205, P<0.01), a statistically significant difference between diffuse-like and flatten-like blebs (t=2.664, P<0.01), a statistically significant difference between cystic-like and flatten-like blebs (t=2.789, P<0.01) in the average intraocular pressure, there is not obvious difference berween between cystic-like and flatten-like blebs, there is no sense difference between diffuse-like and cystic-like blebs, either no sense difference between encapsulating-like and flatten-like blebs.CONCLUSIONS:AS-OCT is a precise tool with non invasive examination and high resolution, which may visualize the internal structure of filtering bleb, and evaluate its function and effect. This could be a important way to assess the postoperative healing process.