Predictability of success and open conjunctival revision rates in the subsequent eye after XEN45 Gel Stent implantation according to lens status

Abstract

Purpose To determine the predictability of success and the risk of open conjunctival revision in the subsequent eye after XEN45 Gel Stent implantation according to lens status. Methods This was a retrospective single-centre study involving 132 eyes of 66 participants who had undergone intraocular pressure (IOP)-lowering XEN45 Gel Stent implantation, either as a standalone procedure in phakic and pseudophakic eyes or in combination with phacoemulsification. Successful surgery was defined by three scores: IOP at follow-up < 21 mmHg (score A) or < 18 mmHg (score B) and an IOP reduction > 20% or IOP ≤ 15 mmHg and an IOP reduction ≥ 40% (score C). In all scores, one open conjunctival revision was allowed, and additional repeat surgery was considered a failure. The predictability of success and revision rate depending on the outcome of the first eye were calculated using Bayes’ theorem. Results IOP-lowering did not differ significantly between the first and second eyes. Success rates of standalone surgery in the second eye after successful surgery in the first eye significantly exceed rates after prior failure. For the combined procedure, the rates did not differ significantly. For score A, we determined a 76.6% chance of success following a prior success and a 57.9% chance, if prior surgery failed. The corresponding probabilities were 75% and 59.1% for score B, while 66.7% and 15.7% for score C, respectively. We calculated a 60% risk for revision surgery in the standalone phakic group. If the first eye was not revised, the risk of revision in the subsequent eye was 20%. The corresponding risks were 72.7% and 5% for the standalone procedure in pseudophakic patients and 38.4% and 41.7% for the combined procedure, respectively. Conclusion The results of our study offer a tool to predict the outcome of subsequent eye surgeries based on either the outcome in the initial eye and the type of surgery performed, owing to the high predictive potential.

Predictability of success for combined iStent inject trabecular bypass implantation with phacoemulsification in the subsequent eye

“…Similar trends have been reported on trabeculectomy, 1 deep sclerectomy 2 as well as on XEN45 Gel Stent implantation 3,7 . Considering surgery targeting the iridocorneal angle primarily, Rosentreter et al made comparable observations on combined cataract surgery with trabecular aspiration 4 .…”

“…Similar trends have been reported on trabeculectomy, 1 deep sclerectomy 2 as well as on XEN45 Gel Stent implantation. 3,7 Considering surgery targeting the iridocorneal angle primarily, Rosentreter et al made comparable observations on combined cataract surgery with trabecular aspiration. 4 In addition, we recently provided data on a considerable predictive association between successful ab-interno trabeculectomy via Trabectome in first and subsequent eyes.…”

“…In a recent study, we determined a highly predictive potential for success in subsequently operated eyes, taking the outcome of the first eye being treated with Trabectome (Microsurgical Technology, Redmond, WA) mediated ab‐interno trabeculectomy into account using Bayes's theorem 6 . Applying the same mathematical model on XEN45 Gel Stent implantation in fellow eyes, we validated a dependancy on either lens status and the outcome of the first eye surgery 7 …”

“…6 Applying the same mathematical model on XEN45 Gel Stent implantation in fellow eyes, we validated a dependancy on either lens status and the outcome of the first eye surgery. 7 The iStent inject (Glaukos Corp., Laguna Hills, CA), being another option under the MIGS umbrella, also pursues an ab-interno approach. Therefore, the implantable device is a feasible tool, especially for the cataract surgeon, to perform combined glaucoma surgery.…”

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

“…[124][125][126][127] Reitsamer et al 128,129 did not find a difference if XEN was performed as a standalone or combined with cataract surgery in 2 studies with a 2 and 3-year follow-up. Kiessling et al 130 found a 60% risk for revision surgery in standalone XEN in phakic eyes, and Lewczuk et al 131 showed a 24% need for subsequent glaucoma surgery. Torbey et al 132 found complete success at 3 years to be a predictor for success at 5 years and needling was associated with failure.…”