Ab Interno Trabeculotomy: Key Prognostic Factors

Abstract

Précis: The preoperative factors associated with a decreased survival rate of ab interno trabeculotomy (AbIT) perfomed using a Trabectome in open-angle glaucoma were selective laser trabeculoplasty (SLT) performed previously and axial length (AL) over 23.82 mm. Purpose: The purpose of this study was to find preoperative factors that predict outcomes of AbIT by a Trabectome. Materials and Methods: This retrospective single-center cohort study involved consecutive patients with primary open-angle glaucoma and exfoliation glaucoma treated at Helsinki University Hospital with AbIT with preoperative intraocular pressure (IOP) ≥18 mm Hg and follow-up of at least 1 year. Success was defined as lowering of their IOP by at least 20% from baseline or reduction in glaucoma medications without any rise in IOP above baseline, and no subsequent glaucoma surgery. Results: Of the total 72 eyes of 67 patients, 51 eyes had exfoliation glaucoma and 21 had primary open-angle glaucoma. Mean preoperative IOP was 25.2±5.3 mm Hg, with a mean of 3.2±1.2 glaucoma medications. In the multivariable model, a history of preoperative SLT and higher preoperative AL had hazard ratios of 2.99 [95% confidence interval (CI): 1.26-7.10] and 1.53 (95% CI: 1.12-2.09) with statistical significance (P=0.013 and 0.007). The statistically significant cutoff point was 23.82 mm in AL in relation to the success rate, with success times taken into account (P<0.001). AL over 23.82 mm had hazard ratio of 5.75 (95% CI: 2.57-12.87, P<0.001). Conclusion: Previous SLT and AL over 23.82 mm reduce survival after AbIT.

Association of the prolonged use of anti‐glaucoma medications with the surgical failure of ab interno microhook trabeculotomy

“…Thus, we may have missed other factors that potentially contributed to surgical success or failure. For instance, a recent study suggested an inverse relationship between the longer axial length and preoperative corneal hysteresis (Kuusniemi et al 2020;Tracer et al 2021), which was not measured in the present study. Additionally, almost one-third of the patients with lTLO were excluded from our statistical analysis for various reasons, which may have also held some selection bias.…”

“…However, various pre-and perioperative backgrounds are known to affect the surgical outcomes of category 1 MIGS and ab externo TLO. For example, high preoperative IOP (Jea et al 2012;Ahuja et al 2013;Okeke et al 2017;Tojo et al 2017;Esfandiari et al 2019;Kono et al 2020) and previous selective laser trabeculoplasty (Ahuja et al 2013;Shoji et al 2016;Tojo et al 2017;Kuusniemi et al 2020) have been reported to be risk factors for surgical failure, whereas elderly age (Tanito et al 2002;Jea et al 2012;Ahuja et al 2013) and combined cataract surgery (Tanito et al 2002;Ting et al 2012;Ahuja et al 2013;Dang et al 2016;Tojo et al 2017;Hara et al 2019;Kono et al 2020) have been estimated to contribute to good surgical outcomes. In terms of the glaucoma type, steroid-induced glaucoma (Steroid G) is more likely to be associated with surgical success (Iwao et al 2011;Dang et al 2016).…”

“…2017; Kuusniemi et al. 2020) have been reported to be risk factors for surgical failure, whereas elderly age (Tanito et al. 2002; Jea et al.…”

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

“… 22 Our study was not sufficiently powered to assess other possible outcome factors such as axial length and state after SLT. 23 …”

Comparison of Surgical Outcomes Between Ab Interno Suture Trabeculotomy and Ab Externo Metal Trabeculotomy in Adult Patients with Glaucoma

“…If the main outflow resistance were distal to the collector channel, canal-based MIGS may be ineffective; thus, a longer axial length may cause elongation of the aqueous vein, thereby increasing aqueous venous pressure. Kuusniemi et al reported that a history of SLT before canal-based MIGS was a risk factor for surgical failure, 23 , 24 and while it is easy to recognize that canal-based MIGS might not be effective in patients resistant to SLT, no studies have reported a longer axial length to be a risk factor for SLT failure; therefore, further investigation is required.…”