Influence of the postoperative restrictive methodologies and efficacy of the Baerveldt 350 implant after 12 months follow‐up

Abstract

Aims/Purpose: To assess the clinical outcomes subsequent to the implantation of a Baerveldt 350 drainage device, utilizing different restrictive methodologies to prevent sudden postoperative hypotony (HT) (IOP <6 mmHg), and their subsequent impact on the incidence of a Hypertensive phase (HP).Methods: A retrospective observational analysis of 71 consecutive eyes that had a Baerveldt 350 implanted. 50 eyes had 6 or 7/0 polyglactin tube ligation (ligature group = LG) and 21 eyes had a 3/0 polypropylene intraluminal tear cord 3/0 added to the ligation (ripcord‐ligature group = RLG), which was manually removed at the surgeon's discretion after spontaneous opening of the polyglactin. Intraocular pressure (IOP) and ocular hypotensive medication (OHM) lowering, failure rate, complete and partial success (CS and PS) and presence of HP were analysed.Results: The mean preoperative IOP was 26.14 (11.34) mmHg with 2.98 OHM for the LG and 28 (8.76) mmHg with 3.35 OHM for the RLG (p = 0.545 and p = 0.397). At the end of the follow‐up, the mean postoperative IOP was 13.35 (3.87) mmHg for the LG and 10.81(2.66) mmHg for the RLG (p = 0.01). The mean reduction of OHM was 2.25 (1.38) for the LG and 2.81 (1.6) for the RLG (p = 0.168). HP was noted in 26 patients (37.14%), 25 of them took place in the LG (50%); however, only 1 took place in the RLG (5%) (p = 0.00023). 35% of the patients who exhibited HP achieved CS, compared to 67.7% of the patients that did not show HP (p = 0.022). The survival analysis for a 12 months follow‐up period, showed that the estimate survival time for the LG was 10.97 (±0.521), and 11.64 (±0.342) for the RLG (p = 0.216). Two predictors were identified for risk of failure and CS: age of the patient before surgery (OR 0.157; 95% CI 0.029–0.865; p = 0.033) and the presence of HP (OR 3.90; 95% CI 1.189–12.794; p = 0.025). Lastly, HT was noted in 55 patients (80.9%), 45 of them took place in the LG (81.8%); however, only 10 took place in the RLG (18.2%) (Pearson Chi‐S p = 0.000225).Conclusions: Baerveldt 350 drainage device implantation has proven to be an effective procedure for glaucoma control. The use of the ripcord added to the absorbable ligature was associated with less risk of HP, and with better IOP results at the 12‐months follow‐up. Nevertheless, further research with larger population and larger follow‐up is needed to obtain robust results.