Glaucoma Drainage Research Articles

Flow characterization and structural alterations in Ahmed glaucoma FP7 tubes after in-vitro aging in silicone oil.

Patients with intraocular silicone oil (SO) display higher odds of surgical failure after Ahmed glaucoma valve (AGV) implantation compared to patients without SO. However, the structural impact of SO exposure on silicone-made AGV tubes and the resulting changes in flow rate remain unexplored. This in-vitro study evaluated changes in tube dimensions and flow rates of AGV FP7 tubes after SO exposure to inform clinicians how such changes may impact AGV functionality. AGV FP7 tube segments underwent accelerated aging to approximate 90 days of exposure to the following media: Balanced Salt Solution (BSS), 1000 centistokes (cs) SO, and 5000cs SO. Tube dimensions were measured before and after aging. A constant gravity flow test setup was created to measure flow rates through tubes before and after aging. The students' T-test was used to compare the mean change between groups post-aging. Post-exposure, 1000cs and 5000cs SO tube segments increased in length by 5.94% and 5.55%, respectively, compared to 0.38% of BSS tubes (P < 0.05 for both). The inner lumen area expanded for tube segments in 1000cs and 5000cs SO by 11.75% and 2.70%, respectively, but contracted for tubes in BSS by -2.70% (P < 0.01 and P = 0.068 for 1000cs and 5000cs SO, respectively). Post aging, the flow rates increased on average by 61.0% and 98.6% for 1000cs and 5000cs SO, respectively, whereas flow rates for BSS tube segments slightly decreased by -4.92%. The difference was statistically significant for BSS vs. SO groups (P < 0.01 for both). Prolonged exposure to SO structurally altered the AGV FP7 tube segments by expanding their cross-sectional area, potentially leading to increased flow rates. These results may inform clinicians about potential in-vivo interactions in patients with the simultaneous presence of glaucoma drainage devices and intraocular SO.

Initial results of the Paul Ahmed Comparison (PAC) study in refractory childhood glaucoma

PurposeTo compare the effectiveness and safety of the Paul Glaucoma Implant (PGI) to the Ahmed Glaucoma Valve (AGV) in managing refractory childhood glaucoma. DesignRandomized controlled trial. SettingTwo clinical centers. MethodsAn ongoing randomized controlled trial including patients ≤18 years with refractory childhood glaucoma in whom glaucoma drainage implant surgery was planned. Patients were randomized to receive either PGI or AGV. The primary outcome was the intraocular pressure (IOP) reduction. Secondary outcomes included glaucoma medication reduction, success rate, and complications rate. The success rate was defined as achieving a postoperative IOP between 6-21 mmHg without or with glaucoma medications (up to three topical glaucoma medications), without the need for additional glaucoma surgeries, and without the occurrence of vision-threatening complications or evidence of disease progression. The use of oral glaucoma medications, such as acetazolamide, was considered a failure. ResultsThe current report included 44 patients (44 eyes) who completed the one-year postoperative follow-up (25 in the PGI group versus 19 in the AGV group). The mean age at the time of surgery was 96.9±59.1 months (90.5±60.04 months in the PGI group and 105.4±58.5 months in the AGV group. Preoperatively, the mean IOP was 32.6±6.1 mmHg with a mean of 3.6±0.6 glaucoma medications in the PGI group, compared with 29.8±6.1 mmHg (p=0.1) with a mean of 3.4±0.7 glaucoma medications (p=0.35) in the AGV group. At one year, there were no statistically significant differences in the mean IOP (14.9±4.1 mmHg in the PGI group versus 15.5±3.5 in the AGV group, p=0.6) and number of glaucoma medications (1.1±1 in the PGI group versus 1.6±1.03 in the AGV group, p=0.1). The success rate of PGI was 80% vs. 73.6% in the AGV (p=0.2). The postoperative complications rate was comparable in both groups (three eyes in each group). Conclusion/RelevanceAt one year postoperatively, the IOP reduction, reduction of glaucoma medications, success rates, and rate of complications were comparable between both groups.

Minimally Invasive Tube Surgery (MITS)-A Novel Method in Glaucoma Drainage Device Implantation.

Background/Objectives: We introduce a new surgical technique for inserting the eyePlate-300-a glaucoma drainage device (GDD). The flexibility of the eyePlate-300 allows for folding and insertion through a smaller conjunctival incision. The procedure is termed minimally invasive tube surgery (MITS). Methods: We performed a retrospective analysis of thirteen eyes to assess the efficacy of the MITS technique in a large London tertiary teaching eye hospital with 12 months follow-up. The primary outcome was complete success: defined as 'IOP > 5 mmHg, <21 mmHg and off drops'. Secondary outcomes: best corrected visual acuity at 12 months, complications, a reduction in the number of drops and need for further pressure-lowering surgery. Results: Twelve eyes (92%) achieved a lower IOP. The mean pre-operative IOP was 35.69 mmHg (20-53 mmHg); post-operatively, it was reduced to 11.08 mmHg (5-20 mmHg) (p < 0.001). The mean pre-operative drops were 3.462 (3-4), reducing to 0.85 (0-3) at 12 months (p < 0.001). There was no change in the mean BCVA. No intraoperative complications were recorded, and no further IOP lowering surgeries were required. Conclusions: The MITS technique facilitates the implantation of a glaucoma drainage device through a smaller, less traumatic incision. Preliminary one-year data suggest that the procedure may be safe and effective.

Trends in glaucoma surgery in a tertiary hospital in Spain: 2010-2022.

This study aims to conduct an analysis glaucoma surgeries performed over a 13-year period at a tertiary hospital affiliated with the Spanish National Health System, with the goal of assessing temporal trends. This retrospective observational study scrutinized surgeries undertaken in the glaucoma unit of a tertiary center in Spain between 2010 and 2022. Data collected included surgical dates, procedure performed, whether it was standalone or combined, as well as patient demographics including age, sex, and type of underlying glaucoma. Surgeries on individuals under 18 years of age were excluded. An annual comparative analysis was performed to ascertain the evolving trends in glaucoma surgical interventions. A total of 12,944 surgeries were included in the analysis, comprising 9428 isolated cataract surgeries and 2975 glaucoma procedures. Trabeculectomy, glaucoma drainage devices (GDD), and cyclodestruction, collectively referred to as traditional surgery, demonstrated a decline from 93.2% to 23.6% over the study duration. Minimally invasive glaucoma surgery (MIGS) and minimally invasive bleb surgery (MIBS) demonstrated a significant increase from 3.8% in 2010 to 74.7% in 2022, relative to the total glaucoma surgeries. Furthermore, combined surgeries manifested a noteworthy increase from 39.0% in 2010 to 44.2% in 2022, with 86.4% of combined procedures in 2022 being MIGS or MIBS. In recent years, there has been a noticeable change in the trend of glaucoma surgeries, with MIGS and MIBS procedures experiencing a significant increase and becoming the most commonly performed glaucoma procedures. Consequently, traditional glaucoma surgeries have decreased in frequency.

Pupillary Peaking & Presence of Dysphotopsias Following Glaucoma Tube Shunt Surgery

ABSTRACT Purpose To describe the presence of pupillary peaking and dysphotopsias in a sample of eyes following glaucoma drainage device (GDD) surgery. Methods Cross-sectional analysis of 68 glaucoma patients with GDD, 45 patients with glaucoma and no GDD, and 50 control patients was conducted in a single academic center. Patients with an appropriate diagnosis that met the inclusion criteria were asked to enroll in the study. All patients received an 8-item dysphotopsia questionnaire and were age-matched. Photographs of pupils were taken to assess pupillary peaking. One-way analysis of variance (ANOVA) testing was performed for statistical analysis. Results Of the 68 patients with GDD, 25 (36.76%) had pupillary abnormalities with peaking most commonly occurring in the direction of the tube entry superotemporally, and 50 (73.53%) had reported one or more dysphotopsias. In patients reporting one or more dysphotopsias, the rate of lines, crescents, ghost images, and shadows was significantly higher when compared to glaucoma patients without GDD and control patients (p < .01). This corresponded to a lower best-corrected visual acuity in the GDD group compared to the glaucoma and control groups (p < .001). Conclusions Over a third of glaucoma patients receiving GDD had pupillary abnormalities, and nearly 3 out of 4 patients with GDD reported one or more dysphotopsias when compared to glaucoma patients without GDD and an age-matched control group. Glaucoma specialists and patients should be aware of these complications when proceeding with GDD surgery.

Risk factors for receiving both scleral buckle and glaucoma drainage device in children

We conducted a retrospective review of patients (< 18 years) between 2013 and 2021 to determine risk factors of pediatric patients receiving a glaucoma drainage device (GDD) needing a scleral buckle (SB) and vice versa. The first population underwent an SB placement with no prior GDD. The second underwent a GDD implantation with no prior SB. We analyzed 133 eyes in the SB-first group. The common indications were retinal detachment associated with a syndrome/disease (41.2%), blunt trauma (21%), and non-syndromic pathologic myopia (11%). Twelve eyes (9%) required subsequent GDD implantation with a mean time to reoperation of 19.73 months (median 2.3 months). Eyes with trauma had a 5-fold risk (hazard ratio [HR] 4.81, p = 0.0069) of requiring a subsequent GDD. Each additional glaucoma medication before initial SB surgery increased the risk by 1.81 (p = 0.0096). 135 eyes were in the GDD-first group. Four eyes (3%) required a subsequent SB. The mean time to reoperation was 17 months (median 9.2 months). There was a statistically significant association with trauma (HR 12.3, p = 0.0341) only. Pediatric eyes with a history of trauma and/or multiple glaucoma medications before intervention have a high risk of requiring both an SB and GDD.

Managing Ocular Surface Disease in Glaucoma Treatment: A Systematic Review.

Ocular surface disease (OSD) is a frequent disabling challenge among patients with glaucoma who use benzalkonium chloride (BAK)-containing topical glaucoma medications for prolonged periods. In this comprehensive review, we evaluated the prevalence of OSD and its management, focusing on both current and future alternatives. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria were used to assess a) the impact of active ingredients and preservatives on the ocular surface and b) the efficacy of preservative-free (PF) alternatives and adjunctive therapies. BAK-containing glaucoma medications were found to significantly contribute to OSD by increasing corneal staining, reducing tear film stability, and elevating ocular surface disease index (OSDI) scores. Transitioning to PF formulations or those with less cytotoxic preservatives, such as Polyquad® and SofZia®, demonstrated a marked improvement in OSD symptoms. In particular, the use of adjunct cyclosporine A, through its anti-inflammatory and enhanced tear film stability actions, was shown to be very beneficial to the ocular surface. Therefore, the most effective management of OSD is multi-factorial, consisting of switching to PF or less cytotoxic medications, adjunct use of cyclosporine A, and early incorporation of glaucoma surgical treatments such as laser trabeculoplasty, trabeculectomy, glaucoma drainage devices, or minimally invasive glaucoma surgery (MIGS).

EndoArt®: results in patients with glaucoma drainage devices

EndoArt® (Eye Yon Medical, Ness Ziona, Israel) is anovel artificial corneal inner layer transplant and an innovative treatment alternative for patients at high risk for graft failure after posterior lamellar corneal transplantation (EK). We present the initial results of the EndoArt® implantation in patients with glaucoma drainage devices (GDD). In this study 12eyes with GDD were retrospectively evaluated. All had ahigh risk of transplant rejection in cases of EK (previous other glaucoma surgery in addition to GDD, n = 8, condition following Descemet membrane endothelial keratoplasty, DMEK, n = 9, uveitis, n = 2, or synechiae, n = 2). The EndoArt® was secured with agas bubble and one to three holding sutures. The preoperative and postoperative best spectacle-corrected visual acuity (BSCVA) and central corneal thickness (CCT) were determined. The need for additional gas injections (rebubbling) was analyzed. Octafluoropropane (C3F8) 12% was used in nine patients and sulfur hexafluoride (SF6) 20% in three patients as anterior chamber tamponade to ensure adhesion of the EndoArt®. At least one rebubbling was necessary in four eyes. The preoperative BSCVA was 1.6 (± 0.5) logMAR and significantly improved to 1.1 (± 0.6) logMAR after 12weeks (p = 0.028). The preoperative CCT was 719 µm ± 145.7, which significantly decreased to 622.4 µm ± 174.9 after six weeks (p = 0.004) and to 591.7 µm ± 190.8 after 12weeks (p = 0.096). In one eye, the prosthesis was explanted due to a suspected fibrotic remodelling of the cornea following multiple previous DMEKs. EndoArt® led to asignificant improvement in BSCVA and reduction in CCT; however, there was ahigh rebubbling rate in patients with GDD. In high-risk patients, the use of EndoArt® may be advantageous in avoiding graft failure after EK.

Incidence, etiology, and risk factors for tube explantation in patients undergoing patch-free glaucoma drainage device

Abstract Purpose: To report the incidence, etiology, and risk factors for tube explantation in patients undergoing patch-free glaucoma drainage device (GDD). Methods: Of the total 1303 patients who underwent patch-free GDD (703 non-valved GDD and 600 valved GDD) for refractory glaucoma during January 2020–October 2023, we identified five cases of postoperative complications following GDD that required tube or shunt removal. Results: Median (IQR) age of our study cohorts was 54.5 (8–66) years. The incidence of tube exposure and tube explantation was 0.003% and 0.004%, respectively. The median time interval for tube or plate explantation from the time of GDD surgery was 11.5 (2–16) months. The diagnoses of refractory glaucoma for which GDD was performed were secondary glaucoma following multiple vitreoretinal (VR) surgery (60%), primary open-angle glaucoma (20%), and aphakic glaucoma (20%). Of these, two patients (40%) presented with recurrent tube exposures, two patients (40%) with tube exposure and early endophthalmitis, and one patient (20%) with persistent hypotony. Four patients (80%) had undergone non-valved Aurolab aqueous drainage implant and one underwent (20%) Ahmed glaucoma implant. Three patients (60%) had diabetes mellitus with a history of multiple VR surgical intervention. GDD explantation was done in three patients (60%), and the remaining two patients (40%) required only tube amputation. One patient presented with orbital cellulitis, and there was no culture growth seen in any of our study cohorts. Conclusion: Tube and plate exposures pose a significant risk for potential infections and warrant prompt explantation of GDD to avoid endophthalmitis. Previous history of multiple VR surgeries, diabetes mellitus, and non-valved implants were the common risk associations noted for tube exposures in our retrospective study.

Primary implantation of glaucoma drainage device in secondary glaucoma: Comparison of Aurolab aqueous drainage implant versus Ahmed glaucoma valve.

Glaucoma drainage devices are invaluable in the management of secondary/ refractory glaucomas. This study aimed to compare the efficacy and safety of Aurolab Aqueous Drainage Implant (AADI) and the Ahmed Glaucoma Valve (AGV) in filtration-surgery-naïve secondary glaucoma eyes. For this purpose, a retrospective, comparative review was conducted on patients with secondary glaucoma (open and closed) who underwent primary tube procedures, either AADI or AGV. The primary outcome measure was intraocular pressure (IOP), and secondary measures included best-corrected visual acuity (BCVA), number of antiglaucoma medications (AGMs), and complications. This study included 59 eyes in the AADI group with a mean follow-up of 20.3 ± 12.9 months and 61 eyes in the AGV group with a mean follow-up of 19.8 ± 11.8 months. Preoperative IOP, AGM use, and BCVA did not significantly differ between the groups. However, at the last visit, both IOP and AGM use were significantly lower in the AADI group (12.9 ± 3.7 mmHg and 0.6 ± 0.9 vs. 15.7 ± 2.7 and 1.8 ± 1.0 respectively, all p < .001). Moreover, the AADI group exhibited a significantly higher rate of complete success (57.6%) compared to the AGV group (14.7%, p < .001); corresponding qualified success was 91.5% and 80.3%. Serious complication rates were comparable between the two groups. In conclusion, toth AADI and AGV procedures effectively reduced IOP and the need for AGMs. However, the reductions were significantly greater in the AADI group, which also showed a higher rate of complete success. Considering its affordability, AADI could have a substantial positive impact, particularly in resource-constrained settings.

Glaucoma Surgery SOS: Emergency Department Utilization Greater among Younger and First-Time Surgical Patients with Glaucoma

PurposeTo describe the frequency, findings, and interventions of patients’ emergency department visits after all types of glaucoma surgery DesignRetrospective cohort study SubjectsAll surgical glaucoma patients between 2013 and 2021 MethodsThis single institution study collected demographics, surgery type, and surgical parameters for each patient. Subsequently, for those visiting the emergency department within 50 days of surgery, data was collected on reason for visit, findings, and ophthalmic intervention. Logistic regression models were used to determine the odds of ED visits based on multiple risk factors. Main outcomePostoperative presentation to ED ResultsAmong 9155 surgeries in 5505 patients, 5.7% had ED visits within 50 days, with 46.3% having ocular complaints. Patients with ocular diagnoses presented earlier than those without (p < 0.001). Patients who presented to the ED with an ocular diagnosis were found to be significantly younger than those who did not present (62.2 ± 18.6 vs 65.4 ± 18.0 years old, p < 0.028). Furthermore, white patients were more likely than black patients to present with an ocular diagnosis compared to a non-ocular diagnosis (OR 2.64, 95% CI 1.67-4.18, p<0.001). Patients undergoing their first glaucoma surgery had a much higher chance of presenting to the ED compared to patients who had undergone more than one surgery (OR: 3.75, 95%CI 2.74 – 5.14, p < 0.001). Those who underwent traditional surgeries were more likely than patients with trabecular meshwork bypass stent (TMBS) to present to the ED with an ocular diagnosis (OR: 3.02, 95% CI 1.29 – 7.08, p = 0.011). Filtering surgeries and glaucoma drainage device (GDD) revisions exhibited more vision-threatening conditions than glaucoma drainage devices (p = 0.037 and p = 0.010 respectively). Ophthalmology consultation was sought for 88.0% of ocular diagnoses. Most received medical therapy (71.0%), primarily IOP-lowering drops. ConclusionED visits after glaucoma surgery are infrequent, yet more often seen in younger patients or those undergoing their first glaucoma surgery. TMBS, but not trabecular meshwork excision and/or Schlemm’s canal dilation (TME/SCD), were less likely to present to the ED than traditional surgeries. Filtering surgeries and tube revisions presented more often with visual threatening conditions.

Clinical Outcomes of Descemet Membrane Endothelial Keratoplasty for Iridocorneal Endothelial Syndrome With a Glaucoma Drainage Device.

The purpose of this study was to evaluate the feasibility and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) for treating iridocorneal endothelial (ICE) syndrome with a glaucoma drainage device (GDD). In this retrospective, interventional case series, data of ICE eyes with a GDD treated with DMEK were collected at the Zhongshan Ophthalmic Center. A total of 24 patients (24 eyes) with mild-to-moderate ocular anterior segment anomalies together with good intraocular pressure (IOP) control preoperatively were included between March 10, 2014, and November 11, 2021. Cases were performed DMEK with concomitantly procedures, such as goniosynechialysis, an entire recipient's Descemet stripping, trimming of glaucoma tubes, and an inferiorly peripheral iridotomy. Graft survival, corrected distance visual acuity (CDVA), endothelial cell loss, IOP, and surgical complications were documented. The mean length of follow-up after surgery was 30.8 ± 7.8 months. Postoperative CDVA improved significantly. At 1 and 2 years postoperatively, 10 (50%) of 20 eyes and 7 (47%) of 15 eyes achieved a CDVA of 20/32 or better, cumulative graft success rates by Kaplan-Meier survival analysis were 89% and 67%, and endothelial cell loss were (59 ± 10)% and (71 ± 7)%, respectively. Within the follow-up period, IOP elevation and progressive peripheral anterior synechiae occurred in 7 (29%) and 5 (21%) of 24 eyes, respectively. With specific technical modifications, DMEK had not increased the risk of postoperative complications and provided comparable clinical outcomes in the treatment of ICE eyes with a GDD with those observed in the treatment of ICE eyes without a GDD.

Ab-Externo XEN Gel stent implantation effectively treated refractory glaucoma with prior failed shunt tube

PurposeTo assess the efficacy of a gelatin stent (XEN 45 Gel Stent; Allergan) implant in advanced glaucoma eyes that have failed prior aqueous shunt implantation.MethodsWe retrospectively reviewed 6 patients with refractory glaucoma, defined as persistently high IOP (> 21 mmHg) despite taking at least 3 IOP-lowering medications subsequent to undergoing a glaucoma drainage device (GDD) with or without a second GDD or cilioablative procedure. Eyes with previous failed GDD underwent subconjunctival 0.3 cc (0.4 mg/ml) mitomycin C, tenonectomy, and placement of an ab- externo XEN stent. The outcome measures included change in IOP and the number of glaucoma medications. Success was defined as patients achieving an IOP ≤ 18 mmHg with a percentage reduction of 25% or 15 mmHg and 40% mean IOP reduction from baseline while taking the same number or fewer medications.ResultsAll six eyes with age of 77.6 ± 7.82 years who underwent XEN implantation following previous GDD surgery had primary open-angle glaucoma. The IOP decreased significantly from 32.33 ± 5.99 to 12.67 ± 3.27 mmHg (p < 0.001) with a follow-up of 13.9 ± 2 (11.7–16.7) months. Visual acuity and visual field remained stable after XEN placement. Compared to the baseline number of medications of 4.2 ± 0.8, all medication was discontinued except in one eye on two drops at the end of the follow-up. The overall surgical success rate was 100%. No complications, needling, or additional procedures were required.ConclusionThis study described successful implantation of the XEN stent following failed GDD. XEN Gel stent implantation associated with mitomycin C and tenonectomy can be considered a viable surgical option for patients with a history of previously failed tube shunt requiring further IOP lowering.

Evaluating the Safety and Efficacy of a Novel Glaucoma Drainage Device in High-Risk Adult Glaucoma Patients: A One-Year Pilot Study.

Background: We report on the 12-month safety and efficacy outcomes of a new non-valved glaucoma drainage device, the eyePlate-300 (Rheon Medical, Lausanne, Switzerland), in managing refractory glaucoma. Methods: A retrospective review was conducted on consecutive patients over 18 who underwent glaucoma drainage device (GDD) surgery with the eyePlate-300 after a single glaucoma consultation between February 2020 and April 2021, with at least 12 months of documented post-op follow-up. Results: A total of 16 eyes from 15 patients were included. Complete success was observed in 47% of patients and overall success in 83%. The mean IOP decreased from 31.5 mm Hg to 10.7 mm Hg (67% reduction from baseline), and the number of IOP-lowering drops was reduced from 3.1 to 0.7 at one year. The mean BCVA remained stable. No additional IOP-lowering surgeries were required, and no severe sight-threatening complications were noted. Conclusions: The initial one-year results suggest that the eyePlate could be a safe and effective device for reducing IOP in an ethnically diverse refractory glaucoma population. Further follow-up is necessary to determine the long-term safety and efficacy.

Long-term outcome of surgical management in neovascular glaucoma: A retrospective, multicentric study.

This study aimed to evaluate and compare surgical outcomes among neovascular glaucoma patients undergoing trabeculectomy (Trab), glaucoma drainage device (GDD) implantation, or trans-scleral cyclophotocoagulation (TSCPC). This study analyzed the records of 176 neovascular glaucoma cases treated surgically between January 2017 and December 2021 at four Indian centers. Procedures included trabeculectomy with MMC in 80 eyes, GDD implantation in 25 eyes, and TSCPC in 71 eyes. Outcome measures comprised intraocular pressure (IOP) reduction, antiglaucoma medication (AGM) usage, complications, and best-corrected visual acuity (BCVA). Following surgery, all groups exhibited a significant reduction in IOP. One year postoperatively, complete success rates were 42.9% for the implant group, 54.3% for the Trab group, and 33.3% for the TSCPC group, with corresponding qualified success rates of 57.1%, 36.7%, and 58.9%, respectively. Improvement in postoperative vision was noted, with an increase of 0.24 LogMAR in the Trab group, 0.11 in the GDD group, and a decrease of 0.35 in the TSCPC group. Complications occurred in 27% of Trab and 14% of TSCPC cases, while the GDD group experienced a hypertensive phase in 40% of eyes. In managing neovascular glaucoma, trabeculectomy, GDD, and TSCPC provide comparable IOP control, with GDD showing a higher medication dependency. Trabeculectomy yields superior vision outcomes but carries a higher risk of postoperative complications, emphasizing the importance of individualized treatment selection and vigilant postoperative care.

Intraoperative OCT to check the correct postimplant position of PreserfloTM.

This study was designed to examine the capacity of intraoperative optical coherence tomography (OCT) to predict the postimplant position of the glaucoma drainage device PreserfloTM. 13 eyes (mean age 65.42 (14.89) years) underwent PreserfloTM (Santen, Osaka, Japan) placement. Before surgery, participants were subjected to a comprehensive ophthalmic examination (intraocular pressure (IOP), cup to disk ratio (C/D), visual field, OCT, endothelial cell count). Anterior segment OCT scans were obtained intraoperatively using a Rescan 700 OCT system (Carl Zeiss Meditec, Inc., Oberkochen, Germany). One day postsurgery, anterior segment OCT using the Spectralis OCT (Heidelberg Engineering GmbH) was performed in a sitting position to capture the same chamber cross-section as before. The main outcome variables were tube-endothelium distance (T-E) and tube length (TL) in the anterior chamber measured using both OCT systems. Correlation between intraoperative and office measurements was examined through Pearson correlation (r) and intraclass correlation coefficients (ICC). Mean intraoperative and in-office T-E were 625.26 (SD 366.60) versus 561.16 (SD 364.62) µm respectively (p = 0.540). Intraoperative and in-office anterior chamber TL were 1386 (SD 701.82) and 1433.91 (SD 713.55) µm, respectively (p = 0.029). Excellent correlation was observed between both sets of T-E (r = 0.992; p = 0.008) and TL (r = 0.984; p = 0.016) values. Both OCT systems showed good agreement yielding ICCs of 0.992 (p < 0.001) for T-E and 0.995 (p = 0.001) for TL. Excellent correlation was observed between our intraoperative and postoperative OCT measurements. These results support the usefulness of intraoperative OCT to confirm the correct position of an implanted PreserfloTM microshunt.

Complications Following XEN45 Gel Stent and Glaucoma Drainage Device Implantation During Glaucoma Fellowship.

Purpose XEN45 Gel Stent and glaucoma drainage device (GDD) implantation is safe and effective for glaucoma treatment and should be taught during glaucoma fellowship training. However, complications may still occur, with potentially sight-threatening consequences. The purpose of this study is to describe the management of complications following a series of XEN45 Gel Stent and GDDsurgeries performed over the course of glaucoma fellowship training. Methods This is a retrospective case series of XEN45 Gel Stent surgeries performed on 16 eyes and GDD surgeries performed on seven eyes. Patient demographics, disease characteristics, and complications are reviewed. The intra- and postoperative course of five select cases with complications are described in detail. Results The most frequent complications following XEN45 implantation were transient hypotony (10 eyes, 63%), reduced visual acuity (VA) (five eyes, 31%), choroidal effusion (three eyes, 19%), hyphema (two eyes, 13%), and intraocular pressure (IOP) spike (two eyes, 13%). Thirteen eyes (81%) required bleb needling, and three eyes (19%) required XEN45 replacement. Complications following GDD implantation included hypotony (three eyes, 43%), reduced VA (two eyes, 29%), choroidal effusion (two eyes, 29%), IOP spike (two eyes, 29%), implant exposure (two eyes, 29%), and shallow anterior chamber (one eye, 14%). Three eyes (43%) required revision or explantation with a secondary glaucoma surgery. One choroidal effusion following XEN45 surgery and one following GDD surgery were hemorrhagic choroidal effusions requiring surgical drainage. Conclusion Significant and potentially sight-threatening complications may occur following XEN45 Gel Stent and GDD implantation performed over the course of fellowship training. Glaucoma fellows should be ably equipped to recognize, diagnose, and manage these complications both intra- and postoperatively.

Secondary ab interno stenting to manage early tube-related hypotony.

Trabeculectomy is the gold standard procedure to achieve control of intraocular pressure surgically. However, glaucoma drainage devices have their place in certain refractory glaucomas not amenable to control by the standard trabeculectomy. These devices come with their own set of complications, cognizance of which is critical to anticipate and manage appropriately. With the nonvalved devices, hypotony is one difficult problem to deal with. Several modifications have been described to manage refractory hypotony after tubes. We present here a simple, less invasive surgical technique of secondary ab interno suture stenting to manage tube-related early hypotony.

3-year safety and efficacy results of PreserFlo™ Microshunt in glaucoma patients: A multicentre European cohort study

PurposeTo report three-year outcomes of a multicenter cohort undergoing Preserflo Microshunt surgery (PFMS). DesignRetrospective cohort study MethodsRetrospective review of 100 consecutive eyes (91 patients) undergoing PFMS from four tertiary-referral glaucoma centers. Primary outcome were success rates. Secondary outcomes included: intraocular pressure (IOP), best-corrected visual acuity, medication, complications and postoperative interventions. Results100 eyes of 91 patients were included. Qualified and complete success rates (95 % CI) were 80 % (72–87 %) and 56 % (47–65 %) for Criterion A (IOP≤21 mmHg), 75 % (67–83 %) and 55 % (46–65 %) for Criterion B (IOP≤18 mmHg), 44 % (31–50 %) and 39 % (30–49 %) for Criterion C (IOP≤15 mmHg) and 10 % (5–16 %) and 10 % (5–16 %) for Criterion D (IOP≤12 mmHg) respectively. Mean IOP decreased from 23.8 mmHg to 14.1 mmHg (reduction of 35.3 %) after 36 months with a reduction of IOP-lowering agents from 2.52 (0 – 4) to 0.69 (0 – 3). 7 eyes (7 %) needed additional glaucoma surgery. Of these, 3 eyes underwent a glaucoma drainage device and 4 eyes had a trabeculectomy.36 eyes received additional procedures after PFMS implantation. Of these, 14 eyes (14 %) underwent a surgical revision and 12 eyes (12 %) a bleb needling procedure.The complication rate was low: 1 eye developed corneal decompensation and underwent a DMEK after 24 months. 1 eye had a conjunctival erosion requiring a revision surgery. 2 eyes developed a postoperative uveitis that was treated with topical steroids and resolved without further damage. There were no hypotony-related complications. ConclusionsPFMS surgery is a safe and effective procedure for reducing IOP and pressure-lowering therapy.

Intraocular pressure control efficacy and safety of HA-Mg glaucoma drainage plate implantation in the anterior chamber of rabbit eyes

The current clinical application of glaucoma drainage devices is made of non-degradable materials. These non-degradable drainage devices often trigger inflammatory responses and scar proliferation, possibly leading to surgical failure. We developed a biodegradable material hydroxyapatite-coated magnesium (HA-Mg) as a glaucoma drainage device. Twelve New Zealand white rabbits were randomly assigned to three groups: HA-Mg drainage plate group (6 right eyes), trabeculectomy group (6 right eyes), and control group (12 left eyes). Results showed that all HA-Mg drainage plates were completely degraded ~4 months postoperatively. At the 5th month postoperatively, there was no statistical difference in the corneal endothelium density between the HA-Mg drainage plate group and the control group (p = 0.857). The intraocular pressure (IOP) level in the HA-Mg drainage plate implantation group was lower than in the other two groups. The trypan blue dye still drained from the anterior chamber to the subconjunctiva 5 months after HA-Mg drainage plate implantation. HE staining revealed the scleral linear aqueous humor drainage channel and anterior synechia were observed after drainage plate completely degraded, with no obvious infiltration with the inflammatory cells. This study showed the safety and efficacy of HA-Mg glaucoma drainage plate in controlling IOP after implantation into the anterior chamber of rabbit eyes.Graphical abstractWe developed a biodegradable material hydroxyapatite-coated magnesium (HA-Mg) as a glaucoma drainage device. This study evaluated the safety and efficacy of HA-Mg glaucoma drainage plate in controlling intraocular pressure after implantation into the anterior chamber of rabbit eyes.