Outcomes Of Canaloplasty And Trabeculotomy In Glaucomatous Eyes With Previous Trabecular Micro-Bypass Implantation And Uncontrolled On Medication

Microinvasive glaucoma surgery (MIGS) has changed the treatment paradigm for open-angle glaucoma (OAG). Surgical treatment, once reserved for advanced and refractory glaucoma is now commonly employed in mild to moderate glaucoma due to the favorable safety profile of MIGS procedures. There are many MIGS options and trabecular microstents are frequently selected due to their efficacy and safety profile . However, should the glaucoma continue to progress, having the option of an additional MIGS would be desirable. The aim of this study was to evaluate effectiveness and safety outcomes for patients treated with canaloplasty and trabeculotomy in patients that had been previously treated with a trabecular microbypass stent.

Multicenter retrospective, study of all eligible eyes from 5 multi-subspecialty ophthalmic practices in 5 US states (AR, LA, NY, OK, SD). Eligible patients were treated with a trabecular bypass stent (TBS) (iStent or iStent inject, Glaukos) and subsequently with the OMNI surgical system (OSS) (Sight Sciences). TBS surgeries were between Sept 6, 2012 and Dec 9, 2020; OSS surgeries were from July 11, 2018 to Aug 11, 2021. IRB approval and waiver of consent was obtained prior to data collection.

Five surgeons contributed 22 patients meeting eligibility criteria: Diagnosed with OAG, Implanted with a TBS and subsequent surgery with OSS, Minimum of 3 months follow-up since the OSS surgery, Pre-OSS IOP ≥18 mmHg on 1 or more ocular hypotensive medications. No other laser or surgical procedures in the interval between TBS and OSS. Endpoints included proportion of patients with a 20% or greater reduction in IOP, proportion of patients with IOP between 6 and 18 mmHg, mean IOP, change in IOP, mean number of ocular hypotensive medications. Adverse events and secondary surgical interventions after OSS were recorded. Paired t-tests were used for comparison of pre-OSS IOP and medications with status at follow-up time points.

22 patients were included. Average age (SD) was 72.7 (10.7), 21 White, 1 Black, 18/22 had a diagnosis of primary OAG (82%), mean MD of -7.4 (6.5) dB, 11 males and 11 females. Mean IOP prior to OSS was 22.8 (4.4) mmHg on 2.4 (1.3) medications. At last follow-up (mean 14 months, max 42 months, min 3.1 months) mean IOP was 16.5 mmHg on 2.1 medications, a reduction of 6.3 mmHg (-28%, p<.001) and 0.3 meds (-13%, ns). 32% had a ≥20% reduction in IOP and 50% had IOP≤18. Adverse events were non-serious and included hyphema >1 mm (3, 13.6%), BCVA decrease (4, 18%), IOP spike (2, 9%). Secondary surgical intervention was required for 4 patients (18%). These had slightly higher pre-OSS IOP (23.4 mmHg) and slightly worse MD (-9.6 dB) on average.

Patients included in this study had IOP that was refractory to medication and a prior MIGS procedure (TBS). Prior to the availability of MIGS, these patients would likely have been candidates for traditional glaucoma surgery such as trabeculectomy and tube shunts. Canaloplasty and trabeculotomy (OSS) offered another minimally invasive option that provided effective IOP control and avoidance of invasive surgery for the majority of these eyes over a follow up period averaging 14 months and up to 42 months.