Two-year Outcomes of Bleb Needling Following Primary Glaucoma Filtering Surgery in Primary Open Angle Glaucoma

Two-year Outcomes of Bleb Needling Following Primary Glaucoma Filtering Surgery in Primary Open Angle Glaucoma Authors: Maryam Ashrafkhorasani MD1, Vaama Patel MD2, Gilbert Xue DO3, Mohamed Haidar DO3, Bryan Turco MD4, Sruti Ramamoorthy BS1, Matthew Mello BS1, Timothy Page BA1, Karim Dirani MD1, Vivian Rajeswaren MD1, Faisal Ridha Al-Timimi MD5, Mark Juzych MD1, Bret Hughes MD1 Kresge Eye Institute, Wayne State University, Detroit, MI, USA Vanderbilt University, Nashville, TN, USA Ascension Macomb Oakland Hospital, Warren, MI, USA Corewell Health Beaumont, Royal Oak, MI, USA Glaucoma Center of Michigan, Southfield, MI, USA Purpose: To evaluate the two-year success rate of bleb needling in a predominantly African American population and to identify factors contributing to successful outcomes. Methods: This retrospective study was conducted from 2008 to 2018 and included patients with primary open-angle glaucoma who underwent primary trabeculectomy, with or without EXPRESS shunt placement, followed by a bleb needling procedure. Patients were followed at three-month intervals for a period of two years. Failure was categorized into three stratified groups based on intraocular pressure (IOP), the number of glaucoma medications required, and the presence of complications (Table 1). Kaplan-Meier survival analysis was utilized to estimate bleb needling success rates, while multivariate Cox regression analysis was performed to identify variables associated with failure. Results: Seventy-four eyes from 71 patients were included in the study, with the majority of eyes (74.3%) from African Americans. The mean patient age was 68.3 ± 11.2 years. The mean pre-needling IOP was 27.4 ± 8.1 mmHg, the mean pre-needling mean deviation in Humphrey field analysis was -20.8 ± 8.6 dB, and the mean pre-needling number of medications was 3.0 ± 1.7. The overall success rate at 12 months and two years was 28.1% and 14.3%, respectively based on the least stringent criteria. However, the complete success rate (completely weaned off of medications) was 12.7% and 5.1% at 12 months and 2 years, respectively. COX regression analysis revealed age, prior laser surgery, interval between glaucoma filtering surgery-bleb needling, hyperlipidemia, hypertension, diabetes mellitus, and the number of medications pre-bleb needling were not significantly associated with success. The most frequent reasons for bleb needling failure included increased number of glaucoma medications (40%), surgical revision (31.7%), and IOP that exceeded threshold (21.7%). Conclusion: The trends in mean intraocular pressure (Figure 1) and the mean number of glaucoma medications (Figure 2) over the two-year follow-up period demonstrate an initial improvement post-needling, followed by stabilization. The two-year success rate of bleb needling observed in our study is lower compared to previous reports, which may be attributed to the greater severity of glaucoma in our patient population.