Histopathological findings of failed blebs after microinvasive bleb surgery with the XEN Gel Stent and Preserflo MicroShunt.

PURPOSE: The success of XEN Gel Stent (XEN) and Preserflo MicroShunt (Preserflo) implantation depends mainly on the development of bleb fibrosis. This study aimed to describe the histological findings of bleb fibrosis after XEN and Preserflo surgery. METHODS: This retrospective study included patients with different types of glaucoma who underwent revision surgery after XEN or Preserflo implantation. The available clinical information and histological samples of removed fibrotic tissue were analyzed. RESULTS: Thirty-six patients were included. Revision surgery was performed at a median of 195 (range = 31-1264) days after primary surgery. The mean intraocular pressure changed from 29.1 (± 10.3) mmHg at baseline to 18.3 (± 8.7) mmHg (- 37%; p < 0.0001) and 16.2 (± 4.2) mmHg (- 45%; p < 0.0001) after 6 and 12 months, respectively. Histological analysis revealed an increase in activated fibroblasts and macrophages in all specimens and a parallel orientation of fibroblasts in a minor part of the probe in 60% of the specimens. No pronounced inflammatory reaction in the form of lymphocytic or granulocytic infiltration was observed. The comparison of specimens from uveitic glaucoma and primary open-angle glaucoma patients revealed no significant differences. CONCLUSIONS: The histological analysis of fibrotic blebs from the XEN and Preserflo implants did not show any pronounced immune or foreign-body reaction and revealed a similar histological pattern of failed blebs after trabeculectomy.

Intermediate-term impact on corneal endothelial cells and efficacy of Preserflo MicroShunt implantation in patients with open-angle glaucoma - a prospective study over two years.

INTRODUCTION: Preserflo MicroShunt is a novel microinvasive bleb forming device for the treatment of primary open-angle glaucoma. The intermediate- and long-term success and the impact of this procedure on corneal endothelial cell density remain to be investigated. METHODS: In this prospective observational study, 62 eyes of 55 glaucoma patients (mean age ± SD: 67.0 ± 15.0 years) receiving a Preserflo MicroShunt were included. Corneal endothelial cell density, intraocular pressure and best corrected visual acuity were assessed preoperatively and at 3, 6, 9, 12, 18 and 24 months postoperatively. Success rates, bleb revision rates and complications were analysed. Complete success was defined as an intraocular pressure reduction of ≥ 20% and achieving a target pressure of ≤ 18, ≤ 15 or ≤ 12 mmHg without antiglaucoma medication. Qualified success indicated that the criteria were reached with or without medication. RESULTS: Corneal endothelial cells showed no significant decline over 24 months (p > 0.05). Intraocular pressure showed a substantial reduction postoperatively (p < 0.001), decreasing from 29.6 ± 8,3 mmHg to 13.0 ± 4.3 mmHg after 24 months (p < 0.001). Complete and qualified success with a target pressure ≤ 15 mmHg was achieved in 52.9% and 54.6% of cases after 24 months, respectively. Best corrected visual acuity did not change after 24 months. CONCLUSION: Preserflo MicroShunt had no negative side effects on corneal endothelial cells and showed favourable success rates after 2 years in patients with open-angle glaucoma.

A COMPARATIVE ANALYSIS OF TRAUMATIC RETINAL DETACHMENT AFTER OPEN AND CLOSED GLOBE INJURIES IN CHILDREN.

PURPOSE: Pediatric traumatic retinal detachment (RD) resulting from open globe injuries (OGIs) or closed globe injuries (CGIs) presents unique challenges due to complexity often resulting in lifelong sequelae. This study compares pediatric traumatic RD outcomes and prognostic factors following OGI and CGI. METHODS: A retrospective analysis reviewed 47 cases of pediatric traumatic RD in children (age <18 years), who underwent RD surgery between 2002 and 2021. Among them, 25 cases were caused by CGI and 22 cases by OGI. Demographics, RD characteristics, surgical procedures, and anatomical and functional results were assessed. Predictive factors for visual outcomes were investigated. RESULTS: In the CGI group, mean (±SD) age was 11 years ± 4 years, and 10 years ± 5 years in the OGI group. Closed globe injury traumatic RD had significantly better preoperative (CGI: logarithm of the minimum angle of resolution 1.39 ± 0.19 (mean ± standard error); OGI: logarithm of the minimum angle of resolution 2.12 ± 0.20) and follow-up (CGI: logarithm of the minimum angle of resolution 0.94 ± 0.19; OGI: logarithm of the minimum angle of resolution 1.85 ± 0.20) best-corrected visual acuity (BCVA) ( P < 0.05). Initial BCVA improvement was observed in CGI only. In multivariable analysis, prognostic factors for favorable BCVA outcomes included higher preoperative BCVA, older age, and absence of proliferative vitreoretinopathy ( P < 0.05). CONCLUSION: Visual prognosis for pediatric traumatic RD remains limited, favoring CGI cases compared with OGI. Baseline BCVA emerged as a major determinant of final visual acuity. Tailored management approaches can optimize treatment results.

Long-term efficacy and safety of XEN-45 gel stent implantation in patients with normal-tension glaucoma.

BACKGROUND: Minimally invasive bleb surgery using the XEN-45 gel stent has not been established for the treatment of normal-tension glaucoma (NTG). The main objective of this study was to evaluate the long-term treatment efficacy and safety of XEN-45 in eyes with uncontrolled NTG. METHODS: A retrospective analysis of patients with NTG who underwent XEN-45 gel stent implantation at university hospital Tuebingen between 2016 and 2021. The primary outcome measure was surgical success after three years defined as lowering of intraocular pressure (IOP) of ≥ 20%, with target IOP between 6 and 15 mmHg. Success was complete without and qualified irrespective of topical antiglaucoma medication use. The need for further glaucoma surgery, except for needling, was regarded as a failure. The secondary outcome measures included changes in mean IOP, number of antiglaucoma medications, and needling and complication rates. RESULTS: Twenty-eight eyes from 23 patients were included in the final analysis. Complete and qualified success rates were 56.5% and 75% after three years, respectively. Mean postoperative IOP ± standard deviation decreased significantly after three years from 19.3 ± 2.0 mmHg at baseline to 13.7 ± 4.2 mmHg (n = 22; p < 0.0001). The median number of antiglaucoma medications decreased from 2 (range 0-4) to 0 after three years (range 0-3; p < 0.0001). Sixteen eyes (57%) required a median of 1 (range 1-3) needling procedures. One eye required further glaucoma surgery. No sight-threatening complications were observed. CONCLUSION: The XEN-45 stent is effective and safe for the long-term treatment of NTG. However, needling was frequently required to improve outcomes.

Preservation of optic nerve structure by complement inhibition in experimental glaucoma.

Glaucoma is characterized by a progressive damage of the retina and the optic nerve. Despite a huge research interest, the exact pathomechanisms are still unknown. In the experimental autoimmune glaucoma model, rats develop glaucoma-like damage of the retina and the optic nerve after immunization with an optic nerve antigen homogenate (ONA). An early activation of the complement system, even before optic nerve degeneration, was reported in this model. Here, we investigated the effects of a monoclonal antibody against complement factor C5 on optic nerves. Rats were immunized with ONA and compared to controls. In one eye of some ONA animals, the antibody against C5 was intravitreally injected (15 µmol: ONA + C5-I or 25 µmol: ONA + C5-II) before immunization and then every 2 weeks. After 6 weeks, optic nerves were processed for histology (n = 6/group). These analyses demonstrated that the intravitreal therapy reduced the depositions of the membrane attack complex compared to ONA animals (ONA + C5-I: p = 0.005; ONA + C5-II: p = 0.002). Cellular infiltration was significantly reduced in the ONA + C5-I group (p = 0.003), but not in ONA + C5-II tissues (p = 0.41). Furthermore, SMI-32 staining revealed that neurofilament was preserved in both treatment groups compared to ONA optic nerves (both p = 0.002). A decreased amount of microglia was found in treated animals in comparison to the ONA group (ONA + C5-I: p = 0.03; ONA + C5-II: p = 0.009). We observed, for the first time, that a complement system inhibition could prevent optic nerve damage in an autoimmune glaucoma model. Therefore, complement inhibition could serve as a new therapeutic tool for glaucoma.

XEN45 gel stent in the treatment of pigmentary glaucoma: A two-year follow-up.

PURPOSE: To investigate safety and efficacy of the XEN gel stent in patients with pigmentary glaucoma (PG). METHODS: A retrospective analysis of 26 eyes of 19 patients with PG undergoing XEN gel stent implantation was performed. Best-corrected visual acuity, intraocular pressure (IOP), and number of antiglaucoma medications were analyzed preoperatively, and at 2 weeks and 3, 6, 12, and 24 months after surgery. Success, needling, and complications were analyzed. Complete success was defined as an IOP reduction of >20% and achieving a target IOP of ≤18, ≤15, or ≤12 mmHg without antiglaucoma medication. Qualified success was indicated if the IOP target was reached with or without medication. RESULTS: Mean IOP decreased significantly from 27.6 ± 14.3 (standard deviation, SD) mmHg to 14.3 ± 4.6 mmHg after one year (p < 0.001) and 15.1 ± 2.7 mmHg (p < 0.001) after two years. The median number of hypotensive drugs declined significantly from 4 (range: 3-5) to 0 (0-2) and 0 (0-3) after one and two years, respectively. After two years, complete success with an IOP of ≤18 mmHg and ≤15 mmHg was achieved in 73.1% and 61.5%, respectively. Half of the eyes required needling after a median time of 8 months (0.5-34 months). No sight-threatening complications were observed. CONCLUSION: The XEN gel stent is a safe and effective surgical treatment option for PG. Needling is an important part of the procedure and should be communicated preoperatively to the patients.

Two-Year Results of XEN Gel Stent Implantation for Pseudoexfoliative Glaucoma in Phakic versus Pseudophakic Eyes.

Objectives: To investigate whether phakia affects the outcome of XEN-45 gel stent implantation in the treatment of pseudoexfoliative glaucoma (PXG). Methods: A retrospective, comparative cohort study of 30 phakic and 55 pseudophakic PXG patients who received the XEN-45 gel stent at a tertiary centre. The primary outcome measure was two-year success defined as a ≥20% lowering of intraocular pressure (IOP) and a target IOP of 6-21 mmHg. Success was complete without and qualified irrespective of antiglaucoma medication use. Further glaucoma surgery other than needling was regarded as a failure. The secondary outcome measures included changes in IOP, revision and complication rates. Results: The complete two-year success rates were 70% and 59% in the phakic and pseudophakic groups, respectively (p = 0.75, log-rank test), and the qualified rates were 80% and 72%, respectively (p = 0.89). The median IOP reduction from baseline was 54% in phakic, and 46% in pseudophakic eyes. While needling rates were similar, the incidence of early incisional bleb revisions was significantly higher in the phakic eyes (13% vs. 0% within 3 months; p = 0.0098, chi-square). Increasing after a year, significantly more pseudophakic eyes failed due to secondary glaucoma surgery (16% vs. 0%; p = 0.0191). Conclusions: The XEN-45 gel stent offers equally effective IOP control for both phakic and pseudophakic patients. However, the onset of bleb revisions and the necessity for secondary glaucoma surgery differed significantly between the groups.

Incidence of central retinal artery occlusion peaks in winter season.

Introduction: Stroke incidence exhibits seasonal trends, with the highest occurrences observed during winter. This study investigates the incidence of central retinal artery occlusion (CRAO), a stroke equivalent of the retina, and explores its monthly and seasonal variations, as well as potential associations with weather and ambient air pollutants. Methods: A retrospective search of medical records spanning 15 years (January 2008-December 2022) was conducted at the University Eye Hospital Tübingen, Germany, focusing on diagnosed cases of CRAO. Incidences were evaluated on a monthly and seasonal basis (winter, spring, summer, fall). Weather data (temperature, precipitation, atmospheric pressure) and concentrations of ambient air pollutants [fine particulate matter (PM2.5), coarse particulate matter (PM10), nitrogen dioxide (NO2), and ozone (O3)], were analyzed for a potential association with CRAO incidence. Results: Out of 432 patients diagnosed with CRAO between 2008 and 2022, significantly varying incidences were observed monthly (p = 0.025) and seasonally (p = 0.008). The highest rates were recorded in February and winter, with the lowest rates in June and summer. Concentrations of NO2, PM2.5 and lower ambient air temperature (average, minimum, maximum) showed significant correlations with CRAO incidence. Discussion: This comprehensive 15-year analysis reveals a pronounced winter peak in CRAO incidence, with the lowest occurrences in summer. Potential associations between CRAO incidence and ambient air pollutants and temperature underscore the importance of considering seasonal trends and call for further investigations to elucidate contributing factors, potentially leading to targeted preventive strategies and public health interventions.

New XEN63 Gel Stent Implantation in Open-Angle Glaucoma: A Two-Year Follow-Up Pilot Study.

Purpose: The XEN gel stent was developed to reduce the risks of filtration surgery by standardizing the outflow of aqueous humor into the subconjunctival space. Recently, a modified version of the XEN63 gel stent was introduced. The goal of this study was to assess its efficacy and safety. Methods: This is a prospective, nonrandomized, observational, consecutive case series study at a single tertiary centre. Patients with open-angle glaucoma with above target intraocular pressure (IOP) despite maximal tolerated medication were included. The primary outcome was a change of median IOP. Secondary outcomes included a change in the number of medications, complete success, needling and complication rates. Success was defined as a lowering of IOP > 20% from baseline and IOP ≤ 14 mmHg. Complete success indicated that the target IOP was reached without medications. Results: Six patients were included. The median IOP decreased from 35.5 mmHg (25.0-40.0 mmHg) at baseline to 11.5 mmHg (4.0-15.0 mmHg, p = 0.03), and median IOP-lowering medication was reduced from 4.0 (3.0-4.0) at baseline to 0 (0-1.0, p = 0.03) after two years. Five patients (83.0%) had a complete success after two years. Two patients (33.0%) required a needling procedure. Three patients (50.0%) required an intervention due to symptomatic hypotony within the first three weeks postoperatively. Hypotony resolved completely or was asymptomatic after three months. Conclusion: Our study demonstrated a statistically significant reduction in both IOP and number of IOP-lowering medications. Complications were well manageable and had no long-term sequelae.

Intravitreal Therapy Against the Complement Factor C5 Prevents Retinal Degeneration in an Experimental Autoimmune Glaucoma Model.

In glaucoma, studies revealed an involvement of the complement system. In an experimental autoimmune glaucoma model, immunization with an optic nerve homogenate antigen (ONA) led to retinal ganglion cell (RGC) loss, while intraocular pressure (IOP) remained unchanged. Here, we investigated the therapeutic effect of a complement system inhibition in this model. Hence, rats were immunized with ONA and compared to controls. In one eye of the ONA animals, an antibody against complement factor C5 was intravitreally injected (15 µmol: ONA+C5-I or 25 µmol: ONA+C5-II) before immunization and then every two weeks. IOP was measured weekly. After 6 weeks, spectral-domain optical coherence tomographies (SD-OCT), electroretinograms (ERG), immunohistochemistry, and quantitative real-time PCR analyses were performed. IOP and retinal thickness remained unchanged within all groups. The a-wave amplitudes were not altered in the ONA and ONA+C5-I groups, whereas a decrease was noted in ONA+C5-II animals (p < 0.05). ONA immunization provoked a significant decrease of the b-wave amplitude (p < 0.05), which could be preserved in ONA+C5-I, but not in ONA+C5-II animals. ONA animals showed a loss of RGCs (p = 0.001), while ONA+C5-I and ONA+C5-II retinae had similar cell counts as controls. A significant downregulation of apoptotic Bax/Bcl2 mRNA was noted in ONA+C5-I retinae (p = 0.02). Significantly more C3+ and MAC+ cells were observed in ONA animals (p < 0.001). The amount of C3+ cells in both treatment groups was significantly increased (p < 0.01), while the number of MAC+ cells in the treated retinas did not differ from controls. The number of activated microglia cells remained unchanged in ONA animals, but was increased in the treatment groups (p < 0.05). Recoverin+ cells were diminished in ONA animals (p = 0.049), but not in treated ones. Rho mRNA was downregulated in ONA and in ONA+C5-II retinas (both p = 0.014). Less opsin+ cones were observed in ONA animals (p = 0.009), but not in the treated groups. Our results indicate that the C5 antibody inhibits activation of the complement system, preventing the loss of retinal function as well as RGC, cone bipolar, and photoreceptor loss. Therefore, this approach might be a suitable new treatment for glaucoma patients, in which immune dysregulation plays an important factor for the development and progression of glaucoma.