Revision of encapsulated blebs after trabeculectomy: Long-term comparison of standard bleb needling and modified needling procedure combined with transconjunctival scleral flap sutures

Abstract

PurposeTo compare two surgical approaches for treating encapsulated blebs after trabeculectomy with mitomycin C, in terms of the development of intraocular pressure and progression of glaucoma in a long-term follow up: 1. bleb needling alone vs. 2. a combined approach of needling with additional transconjunctival scleral flap sutures, to prevent early ocular hypotony.MethodsForty-six patients with failing blebs after trabeculectomy with mitomycin C were enrolled in this study. Patients received either needling revision alone (group 1; n = 23) or a combined needling with additional transconjuctival flap sutures, if intraoperatively the intraocular pressure was estimated to be low (group 2; n = 23). Intraocular pressure (IOP), visual acuity, visual fields, and optic nerve head configuration by means of Heidelberg Retina Tomograph (HRT®) were analysed over time. Results from both groups were compared using Mann-Whitney U-test for single timepoints.ResultsIOP did not differ significantly between the two groups during follow-up at three months (P = 0.13), six months (P = 0.12), one year (P = 0.92) and two years (P = 0.57) after surgery. Furthermore, there was no significant difference in the course of glaucoma concerning the optic nerve anatomy between the two groups (Rim Area Change in the Moorfields Regression Analysis of HRT®) till two years after surgery (P = 0.289). No functional impairment in visual acuity and visual fields was found in the groups of the study.ConclusionsSingle needling procedure is a standard successful method for restoring the function of encapsulated blebs. Postoperative hypotony represents a possible hazard, which can be minimized by additional transconjunctival flap sutures. Long-term results suggest that this modification is equally effective in lowering the IOP and preventing the progression of glaucoma as the standard needling procedure. To our knowledge this is the first study to investigate the long-term effect of tranconjunctival sutures for the prevention of hypotony.

XEN® Gel Stent in Medically Refractory Open-Angle Glaucoma: Results and Observations After One Year of Use in the United States

“…Optimal time for needling with trabeculectomy varies widely, depending on surgical technique, surgeon preference, and patient population [32, 33]. As with trabeculectomy, the reported average time of needling after XEN ® stent insertion also varied with Mansouri et al (4.5 months) [27] and Hengerer et al [26] (1 week–3 months).…”

Numerical model to predict and compare the hypotensive efficacy and safety of minimally invasive glaucoma surgery devices

“…In our simulation, the decrease in IOP ranged from 29% to 22%, while the bleb pressure ranged from 17 to 20 mmHg. It is important to consider that, in routine clinical practice, manoeuvres such as needling of the filtration bleb are usually performed from 6 months to one year after surgery to prevent excessive scar formation, which could lead to more flow resistance in the bleb [49,50].…”

Efficacy of the Ologen collagen matrix in combination with the XEN gel stent implantation in the treatment of open‐angle glaucoma: A case‐control study

“…Conjunctival-tenon healing problems occur in 25% to 30% of glaucoma surgery. 1,2 Filtering surgery requires intensive postoperative follow-up, as well as frequent interventions for adequate management. [3][4][5] As surgeons, and for the well-being of our patients, there is need to develop surgical techniques that would improve results and simplify postoperative care.…”