Ab interno canaloplasty combined with trabecular bypass stenting in eyes with primary open-angle glaucoma

Abstract

Purpose: Evaluate outcomes of trabecular meshwork (TM) bypass (iStent^® GTS100) with cataract extraction (CE) and TM-bypass + ab interno canaloplasty (CP) (VISCO360^®) with CE in patients with primary open-angle glaucoma (POAG).

Setting: Private surgical center for a comprehensive ophthalmology practice.

Design: Retrospective analysis of 186 eyes from 130 consecutive patients with 6 months follow-up.

Methods: Eligible eyes had POAG, indicated for CE, and had received CE + TM-bypass or CE + TM-bypass + CP. Exclusions: glaucomas not POAG, SLT within 6 months, or previous ALT. IOP, visual acuity, and medication use assessed at baseline, months 1, 3, and 6. Endpoints were mean reduction in IOP from baseline at 6 months, proportion with IOP reduction at 6 months of ≥20% and IOP <18 mmHg on same or fewer medications, mean medication reduction, and proportion medication independent.

Results: Eighty-six eyes comprised the CE + TM-bypass + CP group; 100 eyes in the CE + TM-bypass group. At 6 months: mean IOP reduction was 2.9±3.6 mmHg for CE + TM-bypass + CP and 1.7±3.1 mmHg for CE + TM-bypass group (P<0.05); the proportion with IOP reduction of ≥20% and an IOP <18 mmHg on the same or fewer medications was 46% for CE + TM-bypass + CP and 35% for CE + TM-bypass; for both CE + TM-bypass + CP and CE + TM-bypass, mean number of medications was decreased (0.9 and 0.7, P<0.0001) with 56% and 48% off all medication. The most common AE were inflammation (6%) for CE + TM-bypass + CP group and VA loss (8%) for CE + TM-bypass.

Conclusion: At six months, a greater proportion of CE + TM-bypass + CP patients achieved IOP reduction of ≥20% and an IOP <18 mmHg on the same or fewer medications than for TM-bypass + CE.

Keywords: 360-degree viscodilation; MIGS; VISCO360®; canaloplasty; glaucoma; viscodilation.

Figure 1

(A) VISCO360^® viscosurgical system. Illustration of the device showing a handpiece with a microcatheter, control wheel for advancing and retracting the microcatheter, viscoelastic reservoir/infusion pump and a locking mechanism. Images are sourced from Sight Sciences, http://sightsciences.com and used with permission. (B) The iStent^® GTS100 trabecular bypass system. Images are sourced from Glaukos Corp., https://www.glaukos.com and used with permission.

Figure 2

Mean IOP (±SD) for all follow-up visits for both cohorts. *P<0.05 compared with baseline. Patients were kept on their preop IOP-lowering medication regimens until after their 1-month IOP assessment. N=86 eyes at preop and 1 month visit, 75 for the 3 month visit, and 72 for the 6 month visit for CE + TM-bypass + canaloplasty; N=100 eyes for the preop, 1 month, and 3 month visits, and 94 for the 6 month visit for CE + TM-Bypass. Abbreviations: CE, cataract extraction; TM-bypass, iStent GTS100; SD, standard deviation; IOP, intraocular pressure.

Figure 3

Percent mean changes in IOP over time for both cohorts. Patients were kept on their preop IOP-lowering medication regimens until after their 1-month IOP assessment. N=86 eyes at 1 month visit, 75 for the 3 month visit, and 72 for the 6 month visit for CE + TM-bypass + canaloplasty; N=100 eyes for the 1 month and 3 month visits, and 94 for the 6 month visit for CE + TM-bypass. *P<0.05 comparing the two treatment groups. Abbreviations: IOP, intraocular pressure; CE, cataract extraction; TM, trabecular meshwork.

Figure 4

Treatment success defined as: Proportion of eyes with a reduction of ≥20% from baseline and IOP <18 mmHg with the same or fewer numbers of IOP-lowering medications than preop for both cohorts. N=86 eyes at 1 month visit, 75 for the 3 month visit, and 72 for the 6 month visit for CE + TM-bypass + canaloplasty; N=100 eyes for the 1 month and 3 month visits, and 94 for the 6 month visit for CE + TM-bypass. *P<0.05 comparing the two treatment groups. Abbreviations: IOP, intraocular pressure; CE, cataract extraction; TTM., trabecular meshwork.

Figure 5

Mean number of IOP-lowering meds (±SD) for all follow-up visits for both cohorts. Patients were kept on their preop IOP-lowering medication regimens until after their 1-month IOP assessment. *P<0.0001 compared with baseline; †P<0.001 between groups. Patients were kept on their preop IOP-lowering medication regimens until after their 1-month IOP assessment. N=86 eyes for CE + TM-bypass + canaloplasty; N=100 eyes for CE + TM-bypass. Abbreviations: SD, standard deviation; IOP, intraocular pressure; TM, trabecular meshwork.

Figure 6

Proportion of eyes on no IOP-lowering medications. Patients were kept on their preop IOP-lowering medication regimens until after their 1-month IOP assessment. N=86 eyes at 3 month and 6 month visit for CE + TM-bypass + canaloplasty; N=100 eyes for the 3 month and 6 month visits for CE + TM-bypass. TM-bypass = iStent GTS100. *P<0.001 comparing the two treatment groups. Abbreviations: IOP, intraocular pressure; CE, cataract extraction; TM, trabecular meshwork.