Aqueous Shunt Research Articles

New treatments for glaucoma.

This review highlights new Federal Drug Administration (FDA) approved glaucoma treatments to familiarize providers with immediately available options. New FDA-approved treatments include the bimatoprost implant, travoprost implant, direct selective laser trabeculoplasty (DSLT), and ocular pressure adjusting pump. The bimatoprost implant is approved for a single administration with effects lasting for about 1 year, as opposed to the nearly 3-year effect for the travoprost implant. Meanwhile, the DSLT lowers intraocular pressure (IOP) by applying a laser through the limbus within 2 s. Lastly, the ocular pressure adjusting pump is a noninvasive, nonpharmaceutical device that lowers IOP with negative pressure within a pair of goggles. Not only do these modalities lower IOP, but they also improve the patient experience by reducing drop burden, decreasing laser duration, or lowering side effects. Although the list of therapies still in development is extensive, another two promising devices under review include a supraciliary stent and an adjustable aqueous tube shunt. Glaucoma treatment has considerably evolved over the last decade with the introduction of novel topical medications, minimally invasive glaucoma surgeries, sustained-release drug delivery systems, and wearable devices. This expansion in glaucoma has enabled more patient-centric decision-making regarding treatment.

Long-term outcomes of aqueous shunt surgery in glaucoma secondary to congenital aniridia

Long-term outcomes of aqueous shunt surgery in glaucoma secondary to congenital aniridia

Abstract 4135239: Pausing Under Pressure: Ocular Hypertension as an Atypical Cause of Heart Block

A 67-year-old male with a history of hypertension presented to the emergency department with abnormal cardiac monitor results. Prior to this, he was diagnosed with primary open-angle glaucoma by ophthalmology and underwent left-sided aqueous tube shunt placement, which was complicated by hypotony requiring revision and holding of all topical glaucoma medications. Concurrently, he was noted to have an irregular heart rhythm during a routine physical. In office ECG showed normal sinus rhythm, but subsequent 14-day continuous ECG monitor showed sinus bradycardia with nadir heart rate of 21 beats-per-minute and 114 ventricular pauses (longest 4.8 seconds) primarily due to second-degree atrioventricular (AV) block, Mobitz type 1, but also periods of high-grade AV block. He was sent to the emergency department for expedited pacemaker evaluation. On further review, heart block and ventricular pauses occurred exclusively over a 12-hour period that temporally coincided with a hospitalization for acute ocular hypertension following shunt revision. His intraocular pressure peaked at 56 mmHg (normal range 10-21 mmHg), then normalized to 21 mmHg after acetazolamide and anterior chamber paracentesis. Bradycardia resolved following ophthalmic intervention. Bradyarrhythmias were attributed to excess vagal tone from acute ocular hypertension via an atypical but recognized cause of the oculocardiac reflex, and pacemaker placement was avoided. The oculocardiac reflex is a reflex bradycardia involving the trigeminal and vagus nerves. Cardiac effects are consistent with other vagally-mediated bradyarrhythmias, including sinus bradycardia, AV block, and even asystole. This reflex occurs commonly during traction on extraocular muscles during strabismus surgery, but can be seen in other orbital and ocular stimuli. To our knowledge, this is the first documented case of ocular hypertension leading to atrioventricular block through this mechanism. This case illustrates the importance of (1) clinical context of abnormal events during extended cardiac monitoring, (2) understanding the oculocardiac reflex as a cause of bradyarrhythmias, and (3) ruling out reversible medical causes of dysrhythmias prior to permanent device implantation.

Long-term surgical outcomes of combined Ahmed glaucoma valve implantation and phacoemulsification with intraocular lens implantation for patients with glaucoma secondary to iridocorneal endothelial syndrome

BackgroundTo assess the long-term outcomes of patients with glaucoma secondary to iridocorneal endothelial syndrome (GS-ICE) who underwent Ahmed glaucoma valve (AGV) implantation combined with phacoemulsification and intraocular lens (IOL) implantation surgery.MethodsIn this non-comparative retrospective case series study, twelve patients with uncontrolled GS-ICE and cataract underwent Ahmed aqueous shunt combined with phacoemulsification and IOL implantation surgery at Beijing Tongren Eye Center between June 2014 and June 2022. Main medical records included best-corrected visual acuity (BCVA), intraocular pressure (IOP), number of antiglaucoma medications (AGM), corneal status and further surgical interventions. Surgical success was defined as a postoperative IOP ≥ 6mmHg and ≤ 21mmHg without (complete success) or with/without (qualified success) topical AGM and vision of at least light perception during the follow-up period.ResultsTwelve eyes of twelve patients were reviewed. Preoperative IOP was decreased from a mean of 38.5 ± 6.7 mmHg on 3.3 ± 0.9 AGM to a mean of 16.3 ± 4.3 mmHg (P<0.001) on 0.6 ± 1.1 medications (P<0.001) at the last follow-up (47.0 ± 24.7 months). Eight eyes (66.7%) had stable vision or at least one line improvement than that before surgery. Eight eyes (66.7%) achieved qualified success and six eyes (50.0%) achieved complete success after surgery. The surgical procedure had a qualified survival of 91.7% at 1 year, 82.5% at 3 years, 72.2% at 5 years, and 48.1% at 7 years.ConclusionAGV implantation combined with phacoemulsification and IOL implantation seems to be an effective method in IOP control and vision maintain for patients with GS-ICE. The combined surgical procedure may be a reliable option for those GS-ICE patients with coexisting cataract.

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.

Association of Atopic Dermatitis and Risk of Glaucoma Surgery: A Global Population-Based Study

Précis: Severe atopic dermatitis (AD) in patients with glaucoma heightens the risk of requiring surgical intervention, necessitating prompt specialist care and strict surveillance. Objective: The impact of AD on the prognosis of patients with glaucoma is rarely studied. This study aims to assess the risk of requiring glaucoma surgery among patients with glaucoma with and without AD. Materials and Methods: In this retrospective cohort analysis, we assessed patients with glaucoma initially diagnosed from December 5, 2003 to December 3, 2018 using the TriNetX database, dividing them into AD and non-AD cohorts. 1:1 propensity-score matching created balanced groups for baseline traits and comorbidities. We compared the cohorts’ risk and cumulative incidence of needing glaucoma surgery (minimally invasive glaucoma surgery, trabeculectomy, aqueous shunt, or transscleral cyclophotocoagulation). A subgroup analysis was also conducted for patients with severe AD. Results: Out of 528,469 patients with glaucoma, 2624 were in the AD group. Among the AD group, 584 had severe AD. The AD group showed a comparable risk of requiring surgery to the non-AD group (hazard ratio: 1.03; 95% CI: 0.72, 1.47). In contrast, the severe AD group demonstrated a significantly greater risk and cumulative incidence of surgery (hazard ratio: 2.80; 95% CI: 1.37, 5.73; log-rank P = 0.003) compared with the non-AD group. Conclusion: Patients with glaucoma with severe AD are significantly more likely to need surgical intervention, with AD severity being a correlating factor for increased risk.

Aqueous shunt exposure repair: outcomes and risk factors for recurrence.

To investigate the outcomes of aqueous shunt exposure repair and to identify risk factors for recurrent exposure after surgical repair. This is a retrospective interventional case series of consecutive patients who underwent repair of an exposed aqueous shunt. Demographic and clinical data were extracted from the patients' records and survival analysis was employed to determine the probability of survival of the repair without further exposure. Cox proportional regression analysis was utilised to identify potential risk factors for failure of the repair surgery. Seventy-six eyes of 76 patients were included in the study. The probability of survival without further exposure was 76.2% (CI 66.9-86.8%), 72.7% (CI 62.8-84.1%) and 54.7% (40.5-73.7%) at 1,2 and 4 years, respectively. No eye in which the tube was repositioned in the anterior chamber or in the sulcus (n = 9; 11.8%) developed a recurrence of the exposure. A shorter interval from the time of tube insertion to the repair surgery (HR 2.87 [CI 1.11-7.39]; p = 0.03; reference longer interval), a history of previous surgical revision (HR 3.06 [1.15-8.12]; p = 0.02; reference no prior revision) and the use of a human pericardial donor patch at the time of revision (HR 3.43 [1.16-10.13]; p = 0.03; reference other than pericardium) was associated with an increased risk of exposure recurrence. Aqueous shunt exposure revision is associated with reasonable mid and long term success. A shorter interval from tube insertion to exposure revision, previous revisions and the use of a human pericardium patch were associated with increased risk of failure.

Droplet Laplace valve‐enabled glaucoma implant for intraocular pressure management

AbstractGlaucoma, the leading cause of irreversible blindness worldwide, is closely linked to aqueous overaccumulation and elevated intraocular pressure (IOP). For refractory glaucoma, aqueous shunts with valves are commonly implanted for effective aqueous drainage control and IOP stabilization. However, existing valved glaucoma implants have the disadvantages of inconsistent valve opening/closing pressures, poor long‐term repeatability due to their reliance on moving parts, and complex architectures and fabrication processes. Here, we propose a novel valving concept, the droplet Laplace valve (DLV), a three‐dimensional printable moving‐parts‐free microvalve with customizable and consistent threshold valving pressures. The DLV uses a flow discretization unit governed by capillarity, comprising a droplet‐forming nozzle, and a separated reservoir to digitize continuous flow into quantifiable droplets. Unlike the classic one‐time‐use Laplace valves, the DLV's unique design allows for its reusability. The opening pressure is adjustable by varying the nozzle size, like the classic Laplace valves (following the Young–Laplace equation), while the closing pressure can be modified by tuning the separation distance and the reservoir size. Various DLVs with customizable opening pressures from 5 to 11 mmHg have been demonstrated, with opening/closing pressure differences suppressed down to &lt;0.5 mmHg (&lt;0.15 mmHg under the best conditions). Thanks to its moving‐parts‐free nature and digitized flow properties, the DLV shows a highly repeatable valving performance (&lt;1.7%, 1000 cycles) and a predictable linear flow rate–pressure correlation (R2 &gt; 0.99). Preliminary ex vivo validation in an enucleated porcine eye confirms the DLV's efficiency in aqueous shunting and prompt IOP stabilization. The DLV technology holds great promise in glaucoma implants for IOP management and various microsystems for flow control.

Case study and pilot results: Stepwise approach to teach a resident tube shunt surgery

Case study and pilot results: Stepwise approach to teach a resident tube shunt surgery

Aqueous Shunts with Extraocular Reservoir for Open-Angle Adult Glaucoma: A Report by the American Academy of Ophthalmology

Aqueous Shunts with Extraocular Reservoir for Open-Angle Adult Glaucoma: A Report by the American Academy of Ophthalmology

Techniques and Preferences for Nonvalved Aqueous Shunts: A Survey of American Glaucoma Society Members

Techniques and Preferences for Nonvalved Aqueous Shunts: A Survey of American Glaucoma Society Members

Baerveldt-350 with 3-0 Prolene Ripcord to Minimize Hypotony-Associated Complications after Spontaneous Ligature Dissolution

Baerveldt-350 with 3-0 Prolene Ripcord to Minimize Hypotony-Associated Complications after Spontaneous Ligature Dissolution

Glaucoma Fellows-in-Training Recent Surgery Trends

Glaucoma Fellows-in-Training Recent Surgery Trends

Outcomes of microPulse transscleral laser therapy in eyes with prior glaucoma aqueous tube shunt.

To evaluate the outcomes of micropulse transscleral laser therapy (MP-TLT) in patients with uncontrolled glaucoma and prior glaucoma aqueous tube shunt. In this single‑center, retrospective, interventional case series, eyes that underwent MP-TLT and had prior glaucoma aqueous tube shunt surgeries were included. The Cyclo Glaucoma Laser System (IRIDEX Corporation, Mountain View, CA, USA) with the MicroPulse P3 probe (version 1) was used. Post‑operative data were collected at day 1, week 1, and months 1, 3, 6, 12, 18, 24, 30 and 36. A total of 84 eyes (84 patients) with mean age of 65.8 ± 15.2years and with advanced glaucoma (baseline mean deviation -16.25 ± 6.80dB and best-corrected visual acuity 0.82 ± 0.83 logMar) were included in the study. Baseline mean IOP was 19.95 ± 5.6mm Hg with a mean number of medications 3.39 ± 1.02. There were statistically significant differences in IOP between baseline and all follow-up visits (p < 0.01 for all). The mean percentage of IOP reduction between baseline and different follow-up visits ranged from 23.4% to 35.5% (p < 0.01). There was a significant reduction of visual acuity (≥ 2-lines) at 1year (30.3%) and 2years (76.78%). There was a statistically significant reduction in the number of glaucoma medications between baseline and all follow-up visits after postoperative week 1 (p < 0.05 for all). No severe complications including persistent hypotony and related complications were observed. At the last follow-up visit, only 24 (28%) eyes out of 84 eyes remained in the study. MP-TLT is an effective treatment for reducing IOP and decreasing the number of medications in patients with advanced glaucoma and prior glaucoma aqueous tube shunt.

Safety and Efficacy of Resident-Performed Gonioscopy-Assisted Transluminal Trabeculotomy.

GATT can be performed efficaciously and safely by PGY-3 and PGY-4 residents, with clinical outcomes and complication rates that mirror those of attending-performed GATT cohorts from the literature. Report outcomes of gonioscopy-assisted transluminal trabeculotomy (GATT) performed by PGY-3 and PGY-4 residents. A retrospective chart review was performed for patients undergoing resident-performed GATT. Eyes with previous traditional glaucoma surgery (trabeculectomy or aqueous shunt) or neovascular glaucoma were excluded from this analysis. The primary aim was to assess whether resident-performed GATTs demonstrated success rates comparable with the GATT literature. Surgical success was defined as intraocular pressure (IOP)<21mmHg, and an IOP reduction of 20% from baseline, and no subsequent IOP-lowering surgery. The secondary and tertiary aims were to describe complication rates and operating times for resident-performed GATTs, respectively. A total of 50 eyes from 40 patients with various types of glaucoma were included. Eyes either underwent resident-performed GATT-alone (N=9) or GATT+cataract extraction with intraocular lens implantation (CEIOL) (N=41). The surgical success rate at 6 months was 71% for GATT-alone and 42% for GATT+CEIOL. Three eyes required subsequent IOP-lowering surgery. The hyphema rate was 16% at postoperative week 1 and 6% at postoperative month 1. The IOP spike (>30mmHg) rate was 18%. Mean surgical time for both GATT-alone and GATT+CEIOL was longer for PGY-4s than for PGY-3s, attributable to less attending assistance during PGY-4 cases and more resident-performed cataracts in PGY-4 GATT+CEIOL cases (85%) compared with PGY-3 cases (35%). GATT can be performed efficaciously and safely by PGY-3 and PGY-4 residents, with clinical outcomes and complication rates that mirror those of attending-performed GATT cohorts from the literature.

Baerveldt Aqueous Shunt with or without Mitomycin C Augmentation: A Retrospective Comparison Study

Baerveldt Aqueous Shunt with or without Mitomycin C Augmentation: A Retrospective Comparison Study

Commentary: Retinal detachment in eyes treated with Aurolab aqueous drainage implant for refractory glaucoma - Incidence and outcomes

The principal indication for glaucoma drainage devices (GDDs) is usually glaucoma refractory to filtering surgery.[1] Currently, commonly available GDDs are either valved like the Ahmed glaucoma valve (AGV; New World Medical Inc., Rancho Cucamonga, CA, USA) or non-valved GDDs like the Baerveldt glaucoma implant (BGI; Abbott Medical Optics, Abbott Park, IL, USA) and Aurolab aqueous drainage implant (AADI; Aurolab, Aravind Eye Hospital, Madurai, India), which have been shown to be safe and effective in both pediatric and adult populations. AADI has certain advantages over AGV. Since it is indigenously manufactured, it is highly cost-effective when compared to AGV. Studies have shown that it has a higher success rate, achieves significantly lower intraocular pressure (IOP), and the patients require less number of anti-glaucoma medications postoperatively. Some studies also indicate that the long-term IOP control is better with AADI when compared to that with AGV.[123] Postoperative posterior segment complications that may arise after usage of GDDs are hypotony and its consequences like hypotony maculopathy, serous choroidal effusion, choroidal detachment, suprachoroidal hemorrhage, retinal detachment, and endophthalmitis.[45] Overall, retinal complications have been described in 14%-50% of eyes with GDD implantation and majority occur within 35 days after GDD implantation.[5] Rhegmatogenous retinal detachment (RRD) occurs in approximately 5% of eyes after aqueous humor shunt implantation, with most occurring within 4 months of surgery.[6] Khan et al.[7] reported the incidence of RRD after AADI and AGV implantation to be 5.4% and 4.3%, respectively. The present authors analyzed the outcomes of 10 cases of RRD/1158 (0.86%) cases after AADI implantation.[8] Few points are to be kept in mind in these cases. As has been pointed out by the authors, some predisposing factors for the development of retinal detachment may have been there, such as uveitis, vitreous incarceration, scleral perforation, and retinal dialysis after pars plana tube placement. Nowadays, vitrectomy is often the preferred mode of treatment than scleral buckling procedure. Intraoperative choroidal drainage is often required as these RRDs are frequently associated with choroidal detachment. Rarely, suprachoroidal hemorrhage (SCH) is also a concomitant complication and intraoperative drainage of SCH is sometimes required. Moreover, retinal detachment after appositional choroidal effusion or expulsive hemorrhage can result in retinal adhesions, which are to be tackled meticulously. Use of heavy fluid perfluorocarbon liquid is particularly beneficial for retinal reattachment. Silicone oil is the preferred mode of endotamponade and it is recommended to use it at the end of surgery. Postoperative visual prognosis is often compromised as the chance of recurrence of retinal detachment is high. The present authors have also highlighted that poor visual recovery is primarily due to recurrent RRD as well as preexisting glaucoma. Tube blockade by silicone oil droplets may result in rise of IOP postoperatively, further worsening the glaucoma status. Many times, migration of emulsified silicone oil particles into the subconjunctival space through both the valved and non-valved devices has been reported.[910] When a scleral buckle is to be placed in a case with a preexisting GDD, utmost care should be taken to avoid the displacement of the tube placed in the anterior chamber. Studies have also shown the occurrence of phthisis bulbi following aqueous humor shunt implantation.[11] So, as has been concluded by the authors, vitrectomy with silicone oil tamponade appears to be the preferred approach in the management of these eyes, with IOP being well controlled post-vitrectomy, but it should be kept in mind that the visual outcomes are largely unsatisfactory due to recurrent RRD and preexisting advanced glaucoma.

Early Intraocular Pressure Control Via Capsule Revision of a Failed Valved Aqueous Shunt During Concurrent Placement of a Nonvalved Aqueous Shunt

Early Intraocular Pressure Control Via Capsule Revision of a Failed Valved Aqueous Shunt During Concurrent Placement of a Nonvalved Aqueous Shunt

Glaucoma drainage devices implantation in uveitic glaucoma: a systematic review

Background: Uveitis is broadly defined as inflammation of the uvea. Glaucoma is the third most common complication of uveitis. Uveitic Glaucoma (UG) is known to be refractory, and multiple surgeries are often required for proper treatment. The purpose of this study is to determine the effectiveness of Glaucoma Drainage Device (GDD) implantation as a surgical procedure in UG patients.Method: We conducted a systematic search of electronic databases from PubMed, Science Direct, and SpringerLink using a combination of relevant keywords was performed by 5 independent reviewers. Various search terms, including 'glaucoma drainage device', 'glaucoma drainage implants', 'glaucoma filtration implants', 'aqueous shunts', 'uveitic glaucoma', 'inflammatory glaucoma'.Result: A total of 143 articles were retrieved, but only 14 articles were eligible for data extraction. There are 631 eyes from 583 patients who had UG, 442 eyes underwent GDD implantation. Overall, intraocular pressure and the use of glaucoma medication were reduced. Mean IOP preoperative is 31.57 mmHg, and IOP postoperative is 14.48 mmHg. There is a reduction in IOP of an average of 17.09 mmHg. The number of glaucoma medications has decreased from 3.24 to 1.29 postoperatively.Conclusion: UG has been shown to be managed successfully by GDD implantation. GDD implantation may be considered a long-term effective surgical option for patients with UG.

Aqueous Shunt Revision with Autologous Capsular Patch Graft: Surgical Technique Description and Preliminary Results

Aqueous Shunt Revision with Autologous Capsular Patch Graft: Surgical Technique Description and Preliminary Results