Change in visual acuity 12 and 24 months after transscleral ab interno glaucoma gel stent implantation with adjunctive Mitomycin C.

PURPOSE: To analyze changes in best-corrected visual acuity (BCVA) after implantation of the transscleral ab interno glaucoma gel stent (XEN Gel Stent; Allergan, Dublin) in patients with open-angle glaucoma. METHODS: In a single-center, prospective, non-randomized study of 137 eyes with open-angle glaucoma which underwent implantation with XEN, 69 eyes underwent XEN implantation alone (group 1) and 68 eyes underwent XEN implantation and cataract surgery (group 2). BCVA (Bailey-Lovie chart, logMAR scale) was evaluated at baseline, postoperative day 1, weeks 1 and 2, and months 1, 3, 6, 12, and 24. Risk factors for decline in BCVA were analyzed in multivariate models. RESULTS: Baseline BCVA in group 1 was 0.21 ± 031; the group's mean BCVA did not change at any postoperative visit, although a ≥ 2-line loss of BCVA was detected in 15% (95% CI 7-29%) and 4% (95% CI 0-20%) after months 12 and 24, respectively. Baseline BCVA in group 2 was 0.33 ± 031; vision increased significantly at months 3 (0.22 ± 0.29, p = 0.015), 6 (0.20 ± 0.26, p = 0.006), 12 (0.18 ± 0.29, p = 0.001), and 24 (0.18 ± 0.29, p = 0.005). A ≥ 2-line loss of BCVA was reported in 4% (95% CI 1-15%) and 7% (95% CI 1-24%) after months 12 and 24, respectively. CONCLUSIONS: There was no deterioration of BCVA in group 1; those in group 2 had an overall significant increase in BCVA. BCVA decrease was lower than is typically reported in the literature post-trabeculectomy.

Effect of the outer stent position on efficacy after minimally invasive transscleral glaucoma gel stent implantation.

PURPOSE: The outer stent lumen can be located either deeper (in or under Tenon's layer) or more superficially in the conjunctival stroma after the transscleral XEN Glaucoma Gel Microstent (XEN-GGM; Allergan Plc., USA) implantation. The present study aimed to investigate the effect of the postoperative conjunctival implant position on surgical success and intraocular pressure (IOP) after XEN-GGM. METHODS: Prospective data from 66 consecutive open-angle glaucoma eyes of 54 patients were collected preoperatively and 1 and 2 weeks, and 1, 6 and 12 months postoperatively. The layer of implantation was determined in the first month postoperatively as intra- and subtenon or intraconjunctival depending on the location of the outer lumen of the stent in OCT (Visante OCT; Zeiss, Germany). Primary outcome measures were differences in relative IOP reduction at 12 months between the two groups. Further, complete and qualified surgical success, number of secondary needlings and number of IOP-lowering medications and absolute IOP were assessed. RESULTS: Relative IOP reduction was higher in intra- and subtenon group (n = 37/66, 56%) at week 1 (-54% versus -19%, p < 0.001), week 2 (-39% versus -21%, p = 0.02), month 1 (-42% versus -28%, p = 0.035) and month 12 (-39% versus -24%, p = 0.024). The mean absolute IOP was lower in intra- and subtenon group at week 1 (10.8 [95%CI, 8.8-14.1] versus 16.6 [95%CI, 14.1-19.0] mmHg, p < 0.001) and months 12 (13.9 [95%CI, 12.4-15.4] versus 16.7 [95%CI, 14.6-18.8] mmHg, p = 0.041). At month 6, a lower burden for IOP-lowering medication was shown for the intra- and subtenon group (0.2 ± 0.5 versus 1.0 ± 1.1, p = 0.034). The mean number of secondary needlings, which were done in 47/66 (71%) of the eyes, was lower in the intra- and subtenon group in the first year (1.9 ± 1.7 versus 1.2 ± 1.2, p = 0.03). Qualified surgical success was higher in the intra- and subtenon group (90% versus 61%, p = 0.01) after 1 year. CONCLUSION: The present study demonstrates a higher efficacy achieved with lower secondary needling rates in deeper implant positions in conjunctiva after XEN-GGM.