Postoperative Complications in the Primary Tube Versus Trabeculectomy Study During 5 Years of Follow-up.

PURPOSE: To describe postoperative complications encountered in the Primary Tube Versus Trabeculectomy (PTVT) Study during 5 years of follow-up. DESIGN: Multicenter randomized clinical trial. PARTICIPANTS: A total of 242 eyes of 242 patients with medically uncontrolled glaucoma and no previous incisional ocular surgery, including 125 patients in the tube group and 117 patients in the trabeculectomy group. METHODS: Patients were enrolled at 16 clinical centers and randomly assigned to treatment with a tube shunt (350-mm2 Baerveldt glaucoma implant) or trabeculectomy with mitomycin C (MMC, 0.4 mg/ml for 2 minutes). MAIN OUTCOME MEASURES: Surgical complications, reoperations for complications, visual acuity, and cataract progression. RESULTS: Early postoperative complications occurred in 24 patients (19%) in the tube group and 40 patients (34%) in the trabeculectomy group (P = 0.013). Late postoperative complications developed in 27 patients (22%) in the tube group and 32 patients (27%) in the trabeculectomy group (P = 0.37). Serious complications producing vision loss and/or requiring a reoperation were observed in 3 patients (2%) in the tube group and 9 patients (8%) in the trabeculectomy group (P = 0.11). Cataract progression was seen in 65 patients (52%) in the tube group and 52 patients (44%) in the trabeculectomy group (P = 0.30). Surgical complications were not associated with a higher rate of treatment failure (P = 0.61), vision loss (P = 1.00), or cataract progression (P = 0.77) CONCLUSIONS: A large number of surgical complications were observed in the PTVT Study, but most were transient and self-limited. The incidence of early postoperative complications was higher following trabeculectomy with MMC than with tube shunt surgery. The rates of late postoperative complications, serious complications, and cataract progression were similar with both surgical procedures after 5 years of follow-up. Surgical complications did not increase the risk of treatment failure, vision loss, or cataract progression.

Treatment Outcomes in the Primary Tube Versus Trabeculectomy Study after 5 Years of Follow-up.

PURPOSE: To report 5-year treatment outcomes in the Primary Tube Versus Trabeculectomy (PTVT) Study. DESIGN: Multicenter randomized clinical trial. PARTICIPANTS: A total of 242 eyes of 242 patients with medically uncontrolled glaucoma and no previous incisional ocular surgery, including 125 patients in the tube group and 117 patients in the trabeculectomy group. METHODS: Patients were enrolled at 16 clinical centers and randomly assigned to treatment with a tube shunt (350-mm2 Baerveldt glaucoma implant) or trabeculectomy with mitomycin C (MMC) (0.4 mg/ml for 2 minutes). MAIN OUTCOME MEASURES: The primary outcome measure was the rate of surgical failure, defined as intraocular pressure (IOP) > 21 mmHg or reduced < 20% from baseline, IOP ≤ 5 mmHg, reoperation for glaucoma, or loss of light perception. Secondary outcome measures included IOP, glaucoma medical therapy, and visual acuity. RESULTS: The cumulative probability of failure after 5 years of follow-up was 42% in the tube group and 35% in the trabeculectomy group (P = 0.21; hazard ratio = 1.31; 95% confidence interval = 0.86-2.01). At 5 years, IOP (mean ± standard deviation) was 13.4 ± 3.5 mmHg in the tube group and 13.0 ± 5.2 mmHg in the trabeculectomy group (P = 0.52), and the number of glaucoma medications (mean ± standard deviation) was 2.2 ± 1.3 in the tube group and 1.3 ± 1.4 in the trabeculectomy group (P < 0.001). CONCLUSIONS: Trabeculectomy with MMC and tube shunt surgery produced similar IOPs after 5 years of follow-up in the PTVT Study, but fewer glaucoma medications were required after trabeculectomy. No significant difference in the rate of surgical failure was observed between the 2 surgical procedures at 5 years.

Single Administration of Intracameral Bimatoprost Implant 10 µg in Patients with Open-Angle Glaucoma or Ocular Hypertension.

INTRODUCTION: This study evaluated the intraocular pressure (IOP)-lowering efficacy and safety of a single intracameral administration of bimatoprost implant 10 µg in adults with open-angle glaucoma or ocular hypertension. METHODS: Two identically designed, randomized, 20-month, parallel-group, phase 3 clinical trials (one study eye/patient) compared three administrations of 10- or 15-µg bimatoprost implant (day 1, weeks 16 and 32) with twice-daily topical timolol maleate 0.5%. An open-label, 24-month, phase 1/2 clinical trial compared one or two implants administered in the study eye with once-daily topical bimatoprost 0.03% in the fellow eye. Separate analyses of the pooled phase 3 and phase 1/2 study datasets evaluated outcomes in the 10-µg bimatoprost implant and comparator treatment arms after a single implant administration, up to the time of implant re-administration or rescue with IOP-lowering medication. RESULTS: In the phase 3 studies, 10-µg bimatoprost implant single administration demonstrated IOP reductions (hour 0) of 4.9-7.0 mmHg through week 15 from a mean (standard deviation, SD) baseline IOP of 24.5 (2.6) mmHg (n = 374); IOP in the topical timolol BID group was reduced by 6.0-6.3 mmHg from a mean (SD) baseline IOP of 24.5 (2.6) mmHg (n = 373). In the phase 1/2 study (n = 21), median time to use of additional IOP-lowering treatment (Kaplan-Meier analysis) was 273 days (approximately 9 months), and 5 of 21 enrolled patients (23.8%) required no additional IOP-lowering treatment up to 24 months after single administration. In each study, after a single implant administration there were no reports of corneal edema, corneal endothelial cell loss, or corneal touch, and no patients had 20% or greater loss in corneal endothelial cell density. CONCLUSIONS: Bimatoprost implant single administration lowers IOP and has a favorable safety profile. Additional studies are needed to further evaluate the duration of effect and factors predicting long-term IOP lowering after a single implant administration. TRIAL REGISTRATION NUMBERS: ClinicalTrials.gov NCT02247804, NCT02250651, and NCT01157364.

Urgent Virtual Eye Assessments During the COVID-19 Pandemic.

Purpose: We aimed to evaluate the effectiveness and safety of a virtual eye assessment triage system implemented in response to COVID-19. Patients and Methods: We conducted a retrospective cross-sectional study using a consecutive sample of all virtual assessments conducted from March 24 to June 7, 2020 at a single ophthalmology center in Toronto, ON, Canada. Visual acuity and smartphone photographs were uploaded to an electronic assessment website. All patients were virtually triaged to an email or phone consult. Patient outcomes and satisfaction were assessed with a quality assurance survey. Primary outcome measures were the incidence of unplanned additional in-person visits and changes in treatment. Results: We performed 1535 virtual assessments. Of the triage pathways, 15% received an email consult only and 85% received a phone consult. Subsequently, 15% required an in-person assessment, 3% were referred elsewhere, and 0.1% were sent to the emergency. Presentations were most commonly cornea (52%) and retina (25%). They were non-urgent in 68% of cases and no pharmacologic treatment was required for 49%. Of 397 patients that responded out of 653 patients surveyed, 4% had an unplanned additional visit to the emergency, after which two patients underwent urgent retinal surgery and one patient underwent urgent glaucoma surgery. Two patients (0.5%) had a minor change in treatment. Conclusion: As routine regular in-person visits were not possible during the COVID-19 lockdown, virtual eye assessments provided an opportunity to triage patients. Virtual assessments have the potential to reduce in-person visits, but caution must be exercised to not miss vision-threatening conditions.

Risk Factors for Failure of Tube Shunt Surgery: A Pooled Data Analysis.

PURPOSE: To identify the risk factors associated with failure of tube shunt surgery. DESIGN: Pooled analysis of 3 prospective multicenter, randomized clinical trials. METHODS: A total of 621 patients with medically uncontrolled glaucoma were enrolled, including 276 from the Ahmed Baerveldt Comparison Study, 238 from the Ahmed Versus Baerveldt Study, and 107 from the tube group of the Tube Versus Trabeculectomy Study. Patients were randomized to treatment with an Ahmed glaucoma valve (model FP7) or Baerveldt glaucoma implant (model 101-350). The associations between baseline risk factors and tube shunt failure were assessed using a Cox proportional hazards regression model. The primary outcome measure was the rate of surgical failure defined as intraocular pressure (IOP) > 21 mmHg or reduced < 20% from baseline, IOP ≤ 5 mmHg, loss of light perception vision, reoperation for glaucoma, or removal of implant. RESULTS: The cumulative probability of failure after tube shunt surgery was 38.3% after 5 years. In multivariable analyses, baseline factors that predicted tube shunt failure included preoperative IOP (≤ 21 mmHg compared to IOP > 21 and ≤ 25 mmHg; HR, 2.34; 95% CI, 1.52-3.61; P < .001), neovascular glaucoma (HR, 1.79; 95% CI, 1.28-2.52; P = .001), randomized treatment (for Ahmed glaucoma valve; HR, 1.36; 95% CI, 1.04-1.78; P = .025), and age (for 10 year decrease in age; HR, 1.19; 95% CI, 1.09-1.31; P < .001). CONCLUSIONS: Lower preoperative IOP, neovascular glaucoma, Ahmed implantation, and younger age were predictors of tube shunt failure. This Study provides the largest prospectively collected dataset on tube shunt surgery.

Ab Interno Canaloplasty in Open-angle Glaucoma Patients Combined With In Vivo Trypan Blue Aqueous Venography.

PURPOSE: To demonstrate canalogram patterns observed when trypan blue tracer is combined with oculoviscoelastic device during ab interno canaloplasty, and discuss surgical results and potential implications for diagnosis, prognosis, and treatment. METHODS: This is a retrospective small case series study. RESULTS: The authors performed this procedure on 5 patients with informed consent with 4 to 18 months of follow-up. All procedures have been complication free. The average preoperative intraocular pressure was 16.4 mm Hg with an average number of topical glaucoma medications being equal to 3.6. Postoperatively, the average intraocular pressure for the group was reduced to 13 mm Hg with a concurrent drop in the average number of topical medications used equaling 1.8. CONCLUSIONS: Currently, there are limited practical options to evaluate the patency of the aqueous outflow system in our patients. The primary purpose of this paper is to describe canalogram patterns observed during ab interno canaloplasty with trypan blue. This technique may allow us to further our understanding of the aqueous outflow system and its role in the underlying pathophysiology of glaucoma. Further research is required to evaluate the prognostic and diagnostic significance of this technique.

Comparison of Silicone- and Porous-Plate Ahmed Glaucoma Valves.

PURPOSE: Our aim was to evaluate and compare the clinical outcomes after implantation of the silicone-plate (model FP7) and porous polyethylene-plate (model M4) Ahmed Glaucoma Valves. PATIENTS AND METHODS: This was a prospective, multicenter, comparative series. A total of 52 eyes (52 patients) were treated with either the silicone or porous plate Ahmed Glaucoma Valve implant. Hypertensive phase was defined as intraocular pressure >21 mmHg during the first 3 months postoperatively. Success was defined as 5 mmHg ≤intraocular pressure ≤21 mmHg (with or without additional glaucoma medications), without loss of light perception and without additional glaucoma procedures. Patients were monitored for 1 year after surgery. RESULTS: The pre-operative intraocular pressure was 29.9 ± 6.6 mmHg and 33.8 ± 10.5 in the silicone-plate and porous-plate groups, respectively (P = 0.118). At 12 months after surgery, the mean intraocular pressure was 13.6 ± 4.7 mmHg in the silicone-plate group and 17.9 ± 10.9 mmHg in the porous-plate group (P = 0.141). The mean number of glaucoma medications at 12 months was 1.64 ± 1.40 mmHg and 1.89 ± 1.54 mmHg in the silicone- and porous-plate groups, respectively (P = 0.605). Hypertensive phase was not significantly different in the two groups (50.0% of the silicone-plate and 57.7% of the porous-plate groups, P = 0.578). At 12 months after surgery, the percent success for the silicone-plate and porous-plate groups was 88.5% and 53.8%, respectively (P = 0.005). Complications were similar in the two groups. CONCLUSION: The porous-plate Ahmed Glaucoma Valve showed similar average intraocular pressure reduction compared with the silicone-plate model. At 12 months after surgery, there was a significantly lower success rate in the porous-plate compared with the silicone-plate group.

Treatment Outcomes in the Primary Tube Versus Trabeculectomy Study after 3 Years of Follow-up.

PURPOSE: To report 3-year results of the Primary Tube Versus Trabeculectomy (PTVT) Study. DESIGN: Unmasked multicenter randomized clinical trial. PARTICIPANTS: Two hundred forty-two eyes of 242 patients with medically uncontrolled glaucoma and no previous incisional ocular surgery, including 125 in the tube group and 117 in the trabeculectomy group. METHODS: Patients were enrolled at 16 clinical centers and were assigned randomly to treatment with a tube shunt (350-mm2 Baerveldt glaucoma implant) or trabeculectomy with mitomycin C (MMC; 0.4 mg/ml for 2 minutes). MAIN OUTCOME MEASURES: The primary outcome measure was the rate of surgical failure, defined as intraocular pressure (IOP) of more than 21 mmHg or reduced less than 20% from baseline, IOP of 5 mmHg or less, reoperation for glaucoma, or loss of light perception vision. Secondary outcome measures included IOP, glaucoma medical therapy, visual acuity, and surgical complications. RESULTS: The cumulative probability of failure after 3 years of follow-up was 33% in the tube group and 28% in the trabeculectomy group (P = 0.17; hazard ratio, 1.39; 95% confidence interval, 0.9-2.2). Mean ± standard deviation IOP was 14.0±4.2 mmHg in the tube group and 12.1±4.8 mmHg in the trabeculectomy group at 3 years (P = 0.008), and the number of glaucoma medications was 2.1±1.4 in the tube group and 1.2±1.5 in the trabeculectomy group (P < 0.001). Serious complications requiring reoperation or producing loss of 2 or more Snellen lines developed in 3 patients (2%) in the tube group and 9 patients (8%) in the trabeculectomy group (P = 0.11). CONCLUSIONS: There was no significant difference in the rate of surgical failure between the 2 surgical procedures at 3 years. Trabeculectomy with MMC achieved lower IOP with use of fewer glaucoma medications compared with tube shunt surgery after 3 years of follow-up in the PTVT Study. Serious complications producing vision loss or requiring reoperation occurred with similar frequency after both surgical procedures.

Four-year results of a minimally invasive transscleral glaucoma gel stent implantation in a prospective multi-centre study.

IMPORTANCE: The transscleral XEN Glaucoma Gel Microstent (XEN-GGM, Allergan Plc., Parsippany, New Jersey) is implanted by a minimally invasive ab interno technique. BACKGROUND: The present study aims to assess the long-term clinical outcomes in patients after XEN-GGM implantation. DESIGN: This prospective, non-randomized, multi-centred study was conducted in three countries (Austria, Canada and Germany). PARTICIPANTS: Sixty-four consecutive eyes of 64 patients with open angle glaucoma received the XEN-GGM (63 µm) without Mitomycin C. Thirty-five (55%) were solo procedures, and 29 (45%) were combined with cataract surgery. METHODS: Visits were planned at baseline, 6 months, 1, 2, 3 and 4 years postoperatively. MAIN OUTCOME MEASURES: The main outcome measures were mean intraocular pressure (IOP), mean number of IOP lowering medication. Secondary outcome parameters were: visual acuity, visual fields and complete surgical failure (defined as presence of a secondary IOP lowering procedure or loss of light perception) at 4 years, postoperatively. RESULTS: Mean best-medicated baseline IOP was 22.5 ± 4.2 mmHg and decreased significantly to 13.4 ± 3.1 mmHg 4 years postoperatively (-40%, n = 34, P < 0.001). Mean number of IOP lowering medication decreased significantly from 2.4 ± 1.3 preoperatively to 1.2 ± 1.3 (-50%, n = 34, P < 0.001) postoperatively. Visual field mean deviation showed no significant change between preoperative and postoperative examinations. Complete surgical failure rate per year was 10%. CONCLUSIONS AND RELEVANCE: The XEN-GGM resulted in lower IOP and a reduction in medications from baseline over 4 years of follow-up. There was no detectable decrease in visual fields over the study. The surgical failure rate is comparable to other filtration surgeries.

Preference-based Glaucoma-specific Health-related Quality of Life Instrument: Development of the Health Utility for Glaucoma.

PURPOSE: To develop a descriptive system for a glaucoma-specific preference-based health-related quality of life (HRQoL) instrument: the Health Utility for Glaucoma (HUG-5). METHODS: The descriptive system was developed in 2 stages: item identification and item selection. A systematic literature review of HRQoL assessment of glaucoma was conducted using a comprehensive search strategy. Purposeful sampling was used to recruit patients with different clinical characteristics. Relevant items were presented to glaucoma patients through face-to-face, semistructured interviews. Framework methodology was applied to analyze interview content. The recurring themes identified through an iterative content analysis represented topics of most importance and relevance to patients. These themes formed the domains of the HUG-5 descriptive system. Three versions of the descriptive system, differing in explanatory detail, were pilot tested using a focus group. RESULTS: The literature review identified 19 articles which contained 266 items. These items were included for the full-text review and were used to develop an interview guide. From 12 patient interviews, 22 themes were identified and grouped into 5 domains that informed the 5 questions of the descriptive system. The HUG-5 measures visual discomfort, mobility, daily life activities, emotional well-being, and social activities. Each question has 5 response levels that range from "no problem" to "severe problem." The focus group comprised 7 additional patients unanimously preferred the version that contained detailed, specific examples to support each question. CONCLUSIONS: A 5-domain descriptive system of a glaucoma-specific preference-based instrument, the HUG-5, was developed and remains to be evaluated for validity and reliability in the glaucoma patient population.

Treatment Outcomes in the Primary Tube Versus Trabeculectomy Study after 1 Year of Follow-up.

PURPOSE: To report 1-year treatment outcomes in the Primary Tube Versus Trabeculectomy (PTVT) Study. DESIGN: Multicenter, randomized clinical trial. PARTICIPANTS: Two hundred forty-two eyes of 242 patients with medically uncontrolled glaucoma and no previous incisional ocular surgery, including 125 in the tube group and 117 in the trabeculectomy group. METHODS: Patients were enrolled at 16 clinical centers and assigned randomly to treatment with a tube shunt (350-mm2 Baerveldt glaucoma implant) or trabeculectomy with mitomycin C (MMC; 0.4 mg/ml for 2 minutes). MAIN OUTCOME MEASURES: Intraocular pressure (IOP), glaucoma medical therapy, visual acuity, visual fields, surgical complications, and failure (IOP of more than 21 mmHg or reduced by less than 20% from baseline, IOP of 5 mmHg or less, reoperation for glaucoma, or loss of light perception vision). RESULTS: The cumulative probability of failure during the first year of follow-up was 17.3% in the tube group and 7.9% in the trabeculectomy group (P = 0.01; hazard ratio, 2.59; 95% confidence interval, 1.20-5.60). Mean ± standard deviation IOP was 13.8±4.1 mmHg in the tube group and 12.4±4.4 mmHg in the trabeculectomy group at 1 year (P = 0.01), and the number of glaucoma medications was 2.1±1.4 in the tube group and 0.9±1.4 in the trabeculectomy group (P < 0.001). Postoperative complications developed in 36 patients (29%) in the tube group and 48 patients (41%) in the trabeculectomy group (P = 0.06). Serious complications requiring reoperation or producing a loss of 2 Snellen lines or more occurred in 1 patient (1%) in the tube group and 8 patients (7%) in the trabeculectomy group (P = 0.03). CONCLUSIONS: Trabeculectomy with MMC had a higher surgical success rate than tube shunt implantation after 1 year in the PTVT Study. Lower IOP with use of fewer glaucoma medications was achieved after trabeculectomy with MMC compared with tube shunt surgery during the first year of follow-up. The frequency of serious complications producing vision loss or requiring reoperation was lower after tube shunt surgery relative to trabeculectomy with MMC.

Five-Year Pooled Data Analysis of the Ahmed Baerveldt Comparison Study and the Ahmed Versus Baerveldt Study.

PURPOSE: To determine the relative efficacy of the Ahmed-FP7 and Baerveldt BG101-350 implants. DESIGN: Pooled analysis of 2 multicenter, randomized clinical trials. METHODS: A total of 514 patients aged 18 or older with uncontrolled glaucoma that had failed or were at high risk of failing trabeculectomy were randomized to receive an Ahmed implant (n = 267) or Baerveldt implant (n = 247). Cumulative failure rates (using an intraocular pressure [IOP] target of 6-18 mm Hg inclusive), de novo glaucoma surgery rates, mean IOP, mean glaucoma medication use, and visual acuity were compared. RESULTS: Baseline characteristics were similar between groups. Mean preoperative IOP of the study population was 31.5 ± 11.3 mm Hg on an average of 3.3 ± 1.1 glaucoma medications. At 5 years, mean IOP was 15.8 ± 5.2 mm Hg in the Ahmed group and 13.2 ± 4.7 mm Hg in the Baerveldt group (P < .001). Mean glaucoma medication use was 1.9 ± 1.5 in the Ahmed group and 1.5 ± 1.4 in the Baerveldt group (P = .007). The cumulative failure rate at 5 years was 49% in the Ahmed group and 37% in the Baerveldt group (P = .007). High IOP was the most common reason for failure in both groups, and de novo glaucoma surgery was required in 16% of the Ahmed group and 8% of the Baerveldt group (P = .006). Failure owing to hypotony occurred in 0.4% of the Ahmed group and 4.5% of the Baerveldt group (P = .002). Visual outcomes were similar between groups (P = .90). CONCLUSIONS: The Baerveldt group had a lower failure rate, lower rate of de novo glaucoma surgery, and lower mean IOP on fewer medications than the Ahmed group. Baerveldt implantation carried a higher risk of hypotony.

The Ahmed Versus Baerveldt Study: Five-Year Treatment Outcomes.

PURPOSE: To compare 2 frequently used aqueous shunts for the treatment of glaucoma. DESIGN: International, multicenter, randomized trial. PARTICIPANTS: Patients aged 18 years or older with uncontrolled glaucoma despite maximum tolerated medical therapy, many of whom had failed or were at high risk of failing trabeculectomy. METHODS: Eligible patients were randomized to receive an Ahmed-FP7 valve implant (New World Medical, Inc, Rancho Cucamonga, CA) or a Baerveldt-350 implant (Abbott Medical Optics, Inc, Santa Ana, CA) using a standardized surgical technique. MAIN OUTCOME MEASURES: The primary outcome was failure, defined as intraocular pressure (IOP) outside the target range (5-18 mmHg) or reduced <20% from baseline for 2 consecutive visits after 3 months, severe vision loss, or de novo glaucoma surgery. Secondary outcomes measures included IOP, medication use, visual acuity, complications, and interventions. RESULTS: A total of 238 patients were randomized; 124 received the Ahmed-FP7 implant, and 114 received the Baerveldt-350 implant. Baseline characteristics were similar between groups. Mean preoperative IOP was 31.4±10.8 mmHg on 3.1±1.0 glaucoma medications. At 5 years, the cumulative failure rate was 53% in the Ahmed group and 40% in the Baerveldt group (P = 0.04). The main reason for failure in both groups was high IOP, and the cumulative de novo glaucoma reoperation rate was 18% in the Ahmed group and 11% in the Baerveldt group (P = 0.22). Hypotony resulted in failure in 5 patients (4%) in the Baerveldt group compared with none in the Ahmed group (P = 0.02). Mean IOP was 16.6±5.9 mmHg in the Ahmed group (47% reduction) and 13.6±5.0 mmHg in the Baerveldt group (57% reduction, P = 0.001). Mean medication use was 1.8±1.5 mmHg in the Ahmed group (44% reduction) and 1.2±1.3 mmHg in the Baerveldt group (61% reduction, P = 0.03). The 2 groups had similar complication rates (Ahmed 63%, Baerveldt 69%) and intervention rates (Ahmed 41%, Baerveldt 41%). Most complications were transient, and most interventions were slit-lamp procedures. CONCLUSIONS: Both implants were effective in reducing IOP and the need for glaucoma medications. The Baerveldt group had a lower failure rate and a lower IOP on fewer medications than the Ahmed group, but had a small risk of hypotony that was not seen in the Ahmed group.

Early Clinical Results of a Novel Ab Interno Gel Stent for the Surgical Treatment of Open-angle Glaucoma.

PURPOSE: To evaluate the intraocular pressure (IOP) lowering effect of the XEN140 microfistula gel stent implant for the surgical treatment of open-angle glaucoma. PATIENTS AND METHODS: Forty-nine eyes of 49 patients with an IOP>18 mm Hg and ≤35 mm Hg were studied in a prospective nonrandomized multicenter cohort trial of the surgical implantation of the XEN140 implant in patients with open-angle glaucoma. Complete success was defined as a postoperative IOP≤18 mm Hg with ≥20% reduction in IOP at 12 months without any glaucoma medications. Failure was defined as vision loss of light perceptions vision or worse, need for additional glaucoma surgery, or <20% reduction of IOP from baseline. RESULTS: The average age was 64.3 (28.1 to 86.9) years old. Twenty-one eyes had prior failed trabeculectomy with mitomycin C surgery. IOP at 12 months decreased from a mean of 23.1 (±4.1) mm Hg to 14.7 (±3.7) mm Hg for a 36.4% reduction in IOP from baseline. The number of patients at 12 months who achieved an IOP≤18 mm Hg and ≥20% reduction in IOP was 40 (89%). The number of patients who achieved an IOP≤18 mm Hg and ≥20% reduction in IOP without antiglaucoma medications was 18 (40%). CONCLUSIONS: The XEN140 gel stent lowers IOP with few complications when implanted for the surgical treatment of open-angle glaucoma.

A Novel Schlemm's Canal Scaffold: Histologic Observations.

PURPOSE: To assess the biocompatibility of a novel implant made of Nitinol (nickel-titanium alloy), designed to improve aqueous humor outflow. MATERIALS AND METHODS: In the first arm of biocompatibility testing, microstents were surgically inserted into Schlemm's canal (SC) of 2 non-human primates (NHPs), and a third NHP served as a surgical sham control. After 13 weeks the animals were killed, and the eyes were examined by light and scanning electron microscopy. Two masked investigators evaluated the histology sections. The second arm utilized 8 New Zealand white rabbits; each rabbit received a microstent inserted into the sclera and subconjunctival space by means of passage across the anterior chamber thus providing contact with several representative ocular tissues. The fellow eye of each rabbit underwent a sham procedure without microstent insertion. The rabbits were killed after 26 weeks, and a trained ocular pathologist examined the specimens using light microscopy. RESULTS: Histologic and scanning electron microscopy analysis of the NHPs demonstrated that the microstents were located in SC. There was no evidence of an acute or chronic inflammatory response, granulation response, or fibrosis in the outflow system or in adjacent tissues. Rabbit eyes showed minimal mononuclear cell infiltration and minimal fibrotic responses at the site of the implants when compared with sham-treated control eyes. CONCLUSIONS: The Hydrus Microstent was associated with minimal inflammation in both NHP and rabbit eyes with extended follow-up. These preclinical studies demonstrate that the Hydrus Microstent appears to have excellent long-term biocompatibility.