Predictability of ab‐interno trabeculectomy success in the subsequent eye: A contralateral eye comparison study

Abstract

Background To determine whether the outcome of the first eye may serve as a predictor for intraocular pressure (IOP)‐lowering effectiveness in the second eye following bilateral ab interno trabeculectomy. Methods This retrospective single‐centre study included 168 eyes from 84 participants, who underwent combined Trabectome surgery with phacoemulsification cataract surgery in a hospital setting. The clinical endpoint was defined as either ‘success’ or ‘failure’ based on four separate scores at the longest follow‐up time point: IOP at follow‐up <21 mm Hg (Score A) or IOP < 18 mm Hg (Score B), without re‐surgery and IOP reduction >20%; IOP ≤15 mm Hg without re‐surgery and IOP reduction ≥40% (Score C); and the sole absence of re‐surgery according to the discretion of the surgeon (Score D). Results No significant difference was observed between the outcomes of first and second eyes. The frequency of success in the second eye after effective surgery in the first eye significantly exceeded that after prior failure. Within our analysis, the probability calculations determined a 75% chance of success following prior success for Score A. If surgery in the first eye failed, the chance of success in the subsequent eye was 37%. The corresponding probabilities were 79% and 32% for Score B, 56% and 9% for Score C, and 99% and 50% for Score D. Conclusion The results of our study offer a useful tool to assess the success of subsequent eye surgeries based on the outcome in the initial eye, owing to the high predictive potential.

Effect of Preoperative Intraocular Pressure in Patients with and without Intolerance to Their IOP-Lowering Medication on the Outcome of Trabectome Surgery

“… 1 This compares well to a reduction of 32% in our patients, but cannot be generalized since the IOP-lowering effect seems to be closely linked to the preoperative IOP as our data demonstrate. The previously reported rate of 4.3% (4/9) of re-surgeries in combined phaco-AIT after a follow up time of 60 months 7 compares well to our outcomes within 12 months (5.3%, 4/76), whereas the number of revision surgeries in AIT alone in our series was higher (19.0%, 15/79, p = 0.013).…”

“… 5 Though being a simple and safe outpatient procedure with topical anesthesia, trabectome surgery has not found broad acceptance in the community due to a low predictability of success in a given case and the absence of randomized clinical trials confirming its effect and success rates. 6 Because the effect of AIT in one eye of a given patient seems predictive of the second eye, 7 it has to be assumed that as yet undefined individual rather than local factors drive the outcome. A 32% reduction (from 2.5 to 1.7) of anti-glaucoma medications, by contrast, is possibly not sufficiently meaningful to justify the use of AIT as a standard treatment in patients with intolerance to their medication if the IOP is sufficiently controlled.…”

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

“…The chances of success in the subsequent eye after successful or failed surgery in the first eye as well as the risk for open conjunctival revision in the second eye after revision or absence of revision surgery in the first eye were calculated according to Bayes' theorem. The use of the model for determining positive predictive values and conditional probabilities in clinical situations has been described in detail previously [13][14][15]. Statistical significance was set at p < 0.05.…”

Powerful predictors

“…Kiessling and co-workers examined the question of using first-eye outcome as a predictor of second-eye result in ab-interno trabeculectomy in a German population, using four different definitions of success and applying Bayes' theorem. 9 Taking an intraocular pressure of under 21 mmHg as the decider, probably of success in the second eye was 75% for first-eye success and 37% for first-eye failure.…”

“…Their results supported the combined use of both, with OTS used to predict no vision (100% specificity) and profound vision loss (100% specificity), and CART used to predict visual survival (98% sensitivity) and minimal‐to‐severe vision loss (100% sensitivity). Kiessling and co‐workers examined the question of using first‐eye outcome as a predictor of second‐eye result in ab‐interno trabeculectomy in a German population, using four different definitions of success and applying Bayes' theorem 9 . Taking an intraocular pressure of under 21 mmHg as the decider, probably of success in the second eye was 75% for first‐eye success and 37% for first‐eye failure.…”