Outcomes of ab interno trabeculectomy with the trabectome after failed trabeculectomy

Abstract

AimTo evaluate outcomes of ab interno trabeculectomy (AIT) with the trabectome following failed trabeculectomy.MethodsProspective study of AITs and phaco-AITs after a failed trabeculectomy. The indication for AIT was intraocular pressure (IOP) above target on maximally tolerated therapy, and for phaco-AIT a visually significant cataract and need to lower IOP or glaucoma medications. Outcomes included IOP, medications, complications, secondary procedures and success, defined as IOP of less than 21 mm Hg and a greater than 20% reduction from baseline without further surgery. Exclusion criteria were trabeculectomy less than 3 months prior to AIT or follow-up under 1 year.ResultsSeventy-three eyes of 73 patients with 1 year follow-up were identified. At 1 year, mean IOP in AIT significantly decreased by 28% from 23.7±5.5 mm Hg, and medications from 2.8±1.2 to 2±1.3 (n=58). In phaco-AIT, the mean IOP decreased 19% from 20±5.9 mm Hg and medications from 2.5±1.5 to 1.6±1.4 (n=15). Transient hypotony occurred in 7%, and further surgery was necessary in 18%. For AIT and phaco-AIT, the 1-year cumulative probability of success was 81% and 87%, respectively.ConclusionsBoth AIT and phaco-AIT showed a reduction in IOP and medication use after 1 year, suggesting that AIT with or without cataract surgery is a safe and effective option following failed trabeculectomy.

Combined analysis of trabectome and phaco-trabectome outcomes by glaucoma severity

“…The data presented here indicate that that this is mostly true also for more advanced glaucoma and consistent with two prior studies that demonstrated that significant conventional outflow can be recovered even after failed tube shunts 20 and after failed trabeculectomy 10 . Small differences of the eventually achieved pressures could be explained by an episcleral venous pressures that is higher in glaucoma 12 .…”

“…We also noted that trabectome surgery performed after failed trabeculectomy caused patients with more advanced visual field damage to have on average a greater pressure reduction despite similar medications 10 . In the current study we have consequently combined data of trabectome and phaco-trabectome surgery patients and stratified them by a glaucoma severity index.…”

“…However, more recent insight has also demonstrated a significant contribution to elevated pressure in glaucoma by an outflow resistance that is downstream of the trabecular meshwork 8– 10 . According to the Goldmann equation, the limiting factor in pressure reduction from ab interno trabeculectomy with the trabectome is this residual resistance and the pressure of the episcleral veins 11 , and this may vary depending on glaucoma type 12 and severity.…”

Longer-term Baerveldt to Trabectome glaucoma surgery comparison using propensity score matching

“…In contrast, epibulbar glaucoma drainage implants bypass both the conventional and the uveoscleral route entirely but are subject to encapsidation that is the result of fibrosis and a chronic foreign body reaction [19]. We recently expanded our practice pattern to use AIT as a first surgery for more than mild glaucoma because our studies suggested that AIT can be used after failed trabeculectomy [10], in narrow angles [20] and for more severe glaucoma [6][7][8]. BGIs lowered IOP to a similar extend as trabeculectomies in a randomized controlled trial but had a higher success rate [14].…”

“…In another analysis, we stratified AIT outcomes by glaucoma severity and found that a larger IOP and medication decrease can be achieved in more severe glaucoma [6][7][8]. Other investigators have used AIT after failed glaucoma drainage implants [9] or failed trabeculectomy [10,11] reflecting these observations.…”