Purpose To evaluate the efficacy of postoperative management with 5-fluorouracil injections after XEN Gel Stent implantation. Methods Prospective real-world evidence study included 39 eyes (of 36 patients) with primary openangle glaucoma without previous glaucoma surgery and with uncontrolled intraocular pressure (IOP), glaucoma progression, or intolerance to IOP-lowering therapy. Patients underwent mitomycin C-augmented XEN implantation either as a stand-alone procedure or combined with cataract extraction. 5-Fluorouracil subconjunctival injections were a first-choice therapy for bleb failure and were administered according to predetermined criteria (analogous to pro re nata regimen in age-related macular degeneration treatment). Primary outcome was unqualified success, defined as postoperative IOP \ 18 mmHg and[ 20% reduction from medicated baseline without any antiglaucoma medications and no detected glaucoma progression. Results At median follow-up of 8 months (range 3-24 months), IOP decreased from a medicated baseline value of 23 mmHg (95% CI 21-24 mmHg) to 13 mmHg (95% CI 12-15 mmHg) and number of medications decreased from 3 (95% CI 2-3) to 0 (p \ 0.0001 for both). Median number of 5-fluorouracil injections per eye was 3 (95% CI 2-3), and median time to first injection was 0.5 months (95% CI 0.25-3 months) after surgery. Thirteen eyes (33.3%) underwent C 1 needling, and surgical revision was performed in three cases (7.7%). The primary outcome measure, which allows performing additional procedures, was achieved in 27 eyes (69%). Conclusions 5-Fluorouracil subconjunctival injections are safe and effective in postoperative management of bleb failure after XEN implantation and represent a viable alternative to other methods.

Purpose: Little is known about short-term changes in intraocular pressure (IOP) following minimally invasive glaucoma surgeries, such as post-XEN GelStent implantation. Although the importance of corneal biomechanics in glaucoma diagnostics has been reported, little work has been conducted on postoperative description of changes when the structure of the anterior segment is altered. The aim of presented study was to evaluate the changes in the biomechanical parameters of the anterior segment of the post-XEN GelStent implantation eyes. Patients and Methods: This investigator-initiated, open-label, prospective, single-center study recruited patients. Patients with primary open-angle glaucoma (POAG) after XEN GelStent implantation versus matched POAG controls (considered as control group/CG) treated pharmacologically were screened. Water loading was conducted using 10 mL of water per kilogram of body weight for ≤5 min. Goldmann applanation tonometry (GAT), corneal hysteresis (CH), and corneal resistance factor (CRF) were performed before water loading and after every 15 min up to 1 h. Results: The water drinking test (WDT) was positive in 3.7% (1 out of 27) of patients in the post-XEN group compared with 22.7% (5 out of 22) of patients in the control group (CG; p < 0.05). Mean fluctuations in GAT during the WDT were higher in the CG group (3.6 ± 2.5 mmHg vs. 2.9 ± 1.3 mmHg, p < 0.001). CRF and CH changed significantly only in the post-XEN group. The mean peak of CH and CRF occurred at 15 and 30 min of the test in the post-XEN group (p = 0.001). Conclusion: WDT is important to assess the ability of compensation mechanisms to reduce fluctuations in IOP after water upload. The relationship between biomechanics of the anterior segment and glaucoma may have substantial impact on surgical outcome evaluation.

Biomechanics of the cornea have significant influences on the non-contact measurement of the intraocular pressure. The corneal behaviour during tonometry is a fundamental factor in estimating its value. The aim of the study was to analyse the behaviour of the cornea during tonometric measurement with the forced change in intraocular pressure during the water drinking test. Ocular Response Analyser (Reichert) was used to the measurement. Besides four basic parameters connected with intraocular pressure (IOPg, IOPcc) and biomechanics (corneal hysteresis CH and corneal resistance factor (CRF), other parameters representing the behaviour of the cornea during a puff of air were analysed. There were 47 eyes included in the study, including 27 eyes with a XEN GelStent implanted and 20 without it. The eyes of people with monocular implementation were the reference group. The values of analysed parameters were compared before and after 10, 25, 40, and 55 min after drinking the water. The intraocular pressure increased by 2.4 mmHg (p < 0.05) for eyes with a XEN stent and 2.2 mmHg for eyes without a stent (p < 0.05) in the tenth minute after drinking of water. This change caused a decreasing of corneal hysteresis (p < 0.05) without significant changes in the corneal resistance factor (p > 0.05). Corneal hysteresis changed similarly in the reference group and the group with a XEN GelStent. The analysis of additional parameters showed a difference in the behaviour of the cornea in eyes with a XEN GelStent in comparison to the corneas of eyes without a stent. This was particularly visible in the analysis of the cornea’s behaviour during the second applanation, when the cornea returns to its baseline state after deformation caused by air puff tonometry.