Ab Interno Collagen Stent implantation as a treatment option for open angle glaucoma

Purpose To establish the efficacy and safety of an Ab Interno Collagen Stent (AICS) in combination with subconjunctival Mitomycin C (MMC) in patients with open angle glaucoma (OAG), in the reduction of intraocular pressure (IOP), hypotensive treatment (HT) and progression on structural retinal nerve fiber layer (RNFL) exams. Methods Prospective, non‐randomized study involving 10 eyes with OAG, not controlled by HT, submitted to AICS implantation (Xen Gel Stent, Aquesys, Calif., USA) following subconjuntival MMC, with 6 month of follow‐up. Patients were reevaluated on the 1st day, 1st week and at 1st, 3rd and 6th months of follow‐up. IOP and bubble dimensions were registered and the need for re‐interventions or HT was analyzed. Structural RNFL evaluation was performed at 6 months (Spectralis OCT, Heidelberg Engineering, Heidelb., Germany), and compared to preoperative values. Correlation analysis was made between IOP reduction, bubble dimensions and age. Results Mean IOP values were 21.8 ± 5.87 mmHg, 11.4 ± 4.5 mmHg, 13.2 ± 3.93 mmHg; 18.1 ± 6.9 mmHg, 14.2 ± 3.19 mmHg and 13.7 ± 3.10 mmHg and mean bubble dimensions were 3.1; 2.5; 2.5; 2.5 and 2.6 at 1st day, 1st week and 1st, 3rd and 6th months, respectively. Re‐interventions were necessary in 4 cases. IOP reductions compared to preoperative values were statistically significant at all follow‐up visits (p < 0.05), except for the 1st post‐operative month. There was a statistically significant correlation between bubble dimensions and IOP reduction (p < 0.05; r = −0.788). There was no significant progression of RNFL loss. Hypotensive medication was reduced by 87.5%. No complications were reported. Conclusions The insertion of an Ab Interno Collagen Stent with adjunctive MMC significantly reduced IOP over a 6 months follow‐up period without significant complications, notwithstanding a considerable need for re‐interventions.