Efficacy of the Ahmed S2 Glaucoma Valve Compared with the Baerveldt 250-mm2 Glaucoma Implant

Efficacy and Safety of an Adjustable Glaucoma Drainage Device (eyeWatch System) for Refractory Glaucoma: A 2-Year Prospective Study

PRCIS

In this study, we report a 2-year follow-up after implantation of an adjustable glaucoma drainage device combined with a novel orbital filtering plate. The IOP was efficiently controlled postoperatively with limited complications and an excellent safety profile.

PURPOSE

To report the clinical results at 2 years after implantation of an eyeWatch (eW) system, which comprises an adjustable glaucoma drainage device (eW implant) combined with a novel orbital filtering plate (eyePlate), in refractory glaucoma.

PATIENTS AND METHODS

Monocentric, prospective, noncomparative clinical trial. Patients suffering from refractory glaucoma after several failed surgeries were operated using the eW system. The primary outcome was the success rate, defined as an IOP ≤18 mm Hg and reduction of more than 20% from baseline, IOP ≥6 mm Hg. Secondary outcomes were mean IOP, visual acuity, the number of antiglaucoma medications, and the number and type of complications.

RESULTS

Forty-two eyes from 42 patients were included. The mean follow-up time was 22.0±4.0 months. The mean baseline IOP decreased from 23.2±7.2 mm Hg before surgery to 11.9±4.4 mm Hg at 12 months ( P <0.001) and 11.5±3.0 at 24 months. The mean number of glaucoma medications decreased from 2.9±0.9 before surgery to 0.7±0.9 at 12 months ( P <0.001) and 1.0±0.9 at 24 months. The qualified success rate was 93% at 12 months and 90% at 24 months whereas the complete success rate was 46% and 40% at 12 and 24 months, respectively. Complications occurred in 7 patients.

CONCLUSIONS

Implantation of the eW system effectively lowered IOP and reduced glaucoma medications for a 2-year period in patients who had previously failed glaucoma surgery. Persistent hypotony was not observed and the number of complications was low.

Surgical safety and efficacy of a multi-stent system, the comet stent, in Baerveldt glaucoma implant surgery: a prospective pilot study

PURPOSE

This study aimed to introduce a new technique for lowering intraocular pressure (IOP) using a multi-stent system after the implantation of a Baerveldt glaucoma implant (BGI) and evaluate its clinical effectiveness.

STUDY DESIGN

Prospective case series.

METHODS

Six patients with uncontrolled refractory glaucoma were enrolled between December 2021 and May 2022. Six 6-0 nylon sutures were preoperatively inserted into the tube of a BGI. These sutures were named "comet stents" (CSs). BGI implantation was performed, and the CSs were removed one-by-one whenever the IOP rose during the follow-up period. IOP was measured 30-60 min after the removal of each CS, and the reduction in IOP was recorded to assess the effect of CS removal. IOP reduction and the effect of CS removal on IOP reduction were evaluated for 6 months. The cut and trimmed stented tubes were examined with scanning electron microscopy, and the ratio of the patent cross-sectional area to the total luminal area (PCSA, %) and the luminal area occupation rate per stent (%) were calculated.

RESULTS

The mean (±standard deviation) IOP decreased from 31.5 ± 2.8 mmHg at the baseline to 14.8 ± 8.3 mmHg at 1 month, 8.8 ± 4.7 mmHg at 3 months, and 9.2 ± 3.4 mmHg at 6 months. The IOP reduction induced by CS removal ranged from 0 to 19 mmHg. The mean PCSA was 52.7 ± 1.7%, and the mean luminal area occupation rate per stent was 7.9 ± 0.3%.

CONCLUSION

The use of CSs is an effective technique for controlling IOP in a step-by-step manner after BGI surgery.

[Real-world outcomes of glaucoma surgical procedures for open-angle glaucoma]

This article provides an overview of real-world outcomes in glaucoma surgical procedures. While randomized clinical trials provide valuable insights, they do not fully reflect real-world clinical practice. Real-world studies enable the evaluation of outcomes in uncontrolled settings and play a crucial role in counselling and decision-making for glaucoma treatment. By examining real-world data the article aims to identify rare adverse events that may go unnoticed in controlled clinical trials. The focus is on assessing the effectiveness and safety of glaucoma surgical procedures beyond the controlled trial setting.

Comparing Ahmed-FP7 to Baerveldt-250 and Baerveldt-350 surgical outcomes: 1-year results from a retrospective cohort study leveraging the electronic health record

OBJECTIVE

To compare outcomes following Ahmed-FP7 (AGI-FP7), Baerveldt-250mm2 (BGI-250), or Baerveldt-350mm2 (BGI-350) implantation.

METHODS AND ANALYSIS

Retrospective cohort study comprising 800 eyes from 800 individuals who underwent surgery 1 January 2016-31 December 2020 at a tertiary-care institution. Data were extracted from standardised fields in the electronic health record. Primary outcome was failure (defined as intraocular pressure (IOP) ≤5 mm Hg or >18 mm Hg or reduction <20% at two consecutive visits from month 3 onwards; or visual acuity (VA) loss ≥3 lines; or return to the operating room (OR)). Secondary outcomes were IOP, VA, number of follow-up visits and return to the OR.

RESULTS

A total of 523 AGI-FP7, 133 BGI-250 and 144 BGI-350 cases were analysed. The AGI-FP7 group was more likely to be younger and diagnosed with secondary glaucoma, with a higher mean baseline IOP (28.5±12.2 vs 22.0±7.7 mm Hg in BGI-250 and 23.4±9.0 in BGI-350, p<0.001). Cumulative failure rate at month 12 was 30% (AGI-FP7) vs 39% (BGI-250) vs 33% (BGI-350, p=0.159). Mean IOP at month 12 was lower in the BGI-350 group compared with AGI-FP7 (12.4±4.4 vs 14.8±5.6 mm Hg, p=0.003) but not BGI-250 (vs 13.1±4.6, p=0.710). Target IOP was achieved in 71% of AGI-FP7, 66% BGI-250, and 76% BGI-350. VA loss and rates of return to the OR did not differ between groups. Both BGI-250 and BGI-350 had more follow-up visits than AGI-FP7 (p<0.001).

CONCLUSION

These three glaucoma drainage devices performed similarly within 1 year, with no difference in failure rates despite differing baseline patient characteristics.

Comparing Surgical and Clinical Success Rates of Ahmed FP7, and Baerveldt 250 and Baerveldt 350 Glaucoma Drainage Devices

PRCIS

Surgical and clinical success rates were similar among Ahmed FP7, and Baerveldt 250 and 350 glaucoma drainage devices at three years.

PURPOSE

To compare rates of surgical and clinical success in patients with Ahmed FP7 (FP7), Baerveldt 250 (B250), or Baerveldt 350 (B350) glaucoma drainage devices (GDDs).

DESIGN

A retrospective cohort study.

METHODS

A total of 157 eyes of 129 adult patients with FP7, B250, B350 GDDs, and 190 eyes of 99 medically controlled glaucoma patients were enrolled at a tertiary care institution from August 2017 through July 2019. They were followed through April 2020. The main outcome measures included surgical and clinical failure. Surgical failure was defined as intraocular pressure (IOP) outside 5-21 mm Hg, IOP reduced <20% below baseline, additional glaucoma surgery, GDD removal, or no light perception. Eyes that did not meet their goal IOP ranges or required secondary glaucoma interventions were deemed clinical failures.

RESULTS

A total of 43 (12.4%) FP7, 36 (10.4%) B250, 78 (22.5%) B350, and 190 (54.8%) medically treated control eyes were enrolled. By the postoperative year 3 visit, 10 (23.2%) FP7, 11 (30.6%) B250, and 32 (41.0%) B350 eyes had met a surgical failure criterion ( P =0.127). There were no significant differences in the numbers of eyes meeting their IOP target ranges ( P =0.510), and rates of secondary glaucoma surgeries ( P =0.270). Overall clinical success was attained among 83.3% FP7, 81.8% B250, and 68.0% B350 eyes ( P =0.447).

CONCLUSIONS

The GDD groups were similar in their rates of success, based on both the surgical and clinical success definitions.

Racial Disparities Affecting Black Patients in Glaucoma Diagnosis and Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Racial Disparities Affecting Black Patients In Glaucoma Diagnosis And Management

Black patients are more affected by glaucoma and suffer from more advanced disease. Diagnostic challenges among black patients with glaucoma include lower rates of diagnostic testing and thinner average central corneal thickness, the latter of which affects intraocular pressure measurement. Treatment challenges include poor follow-up, medication adherence, and trust in providers. Black patients undergoing trabeculectomy have higher rates of failure compared to white patients. Race is not a definitive factor affecting success for tube shunts, laser trabeculoplasty, cyclophotocoagulation, and micro-invasive glaucoma surgeries, but the body of evidence is limited by low inclusion of black patients in these studies. Future steps should include increased attention toward improving trust between patients and providers, improving access to care, and increased representation of black patients in glaucoma research to better understand factors affecting racial disparities in glaucoma management and outcomes in this population disproportionately affected by the disease.

Real-World Outcomes of Glaucoma Filtration Surgery Using Electronic Health Records: An Informatics Study

PRCIS

Utilizing an automated pipeline for data extraction from electronic health records provides real-world information on the success of various glaucoma procedures, with tube shunt implantation associated with increased failure rates compared with trabeculectomy.

BACKGROUND

We aimed to evaluate the long-term survival of glaucoma surgeries using an automated pipeline for extraction of outcomes from electronic health records.

METHODS

A retrospective observational study from a single academic center. Patients undergoing trabeculectomy, Ex-PRESS shunt, Baerveldt, and Ahmed tube shunt insertion from 2009 to 2018 were identified from electronic health record procedure codes. Patient characteristics were identified from structured and unstructured fields using a previously validated natural language processing pipeline.

RESULTS

Five hundred twelve patients underwent 711 glaucoma surgeries: 287 trabeculectomies, 47 Ex-PRESS shunts, 274 Baerveldt and 103 Ahmed tube implantations. The Median follow-up was 359 days. The mean baseline IOP was 24.4 mm Hg (SD 10.9), and 73.1% were on ≥3 medications. Compared with trabeculectomy, tube shunt surgery had a higher risk of failure (Baerveldt: Hazard Ratio (HR) 1.44, 95% CI 1.02 to 2.02; Ahmed: HR 2.01, 95% CI 1.28 to 3.17). Previous glaucoma surgery was associated with increased failure (≥2 previous surgeries: HR 2.74, 95% CI 1.62 to 4.64), as were fewer baseline medications (<3 medications: HR 2.96, 95% CI 2.12 to 4.13) and male sex (HR 1.40, 95% CI 1.03 to 1.90). At 1 year, tube shunt patients had a 2.53 mm Hg ( P =0.002) higher IOP compared with trabeculectomy patients.

CONCLUSIONS

Baerveldt and Ahmed tube shunt implantation was associated with increased failure compared with trabeculectomy. Fewer baseline medications, previous glaucoma surgeries, and male sex were also risk factors for failure. These results demonstrate the utility of applying an informatics pipeline to electronic health records to investigate key clinical questions using real-world evidence.

Factors associated with vision loss in Black or Hispanic patients 1 year after standalone or combined Ahmed glaucoma valve surgery

PURPOSE

To determine factors associated with vision loss 1 year after Ahmed glaucoma valve (AGV) surgery in Black or Hispanic patients, who bear disproportionate glaucoma burdens yet have been underrepresented in pivotal trials.

METHODS

This retrospective study included Black or Hispanic patients who received AGVs standalone or combined with phacoemulsification and/or cyclodestructive lasers. Univariate and multivariate generalized estimating equations evaluated the effects of baseline, surgical, and postoperative factors on vision loss of two Snellen lines or more at the 1-year follow-up visit. The primary term was the hypertensive phase (HP), which signified an intraocular pressure (IOP) reading > 21 mmHg within the first 3 postoperative months after reduction below 22 in the first week, without other tube malfunction.

RESULTS

Of 241 eyes from 186 patients, vision loss of ≥ 2 lines at the 1-year follow-up visit occurred in 21.6% (N = 52). Vision loss of ≥ 2 lines occurred in 52.5% of eyes at week 1, 36.9% of eyes at month 1, and 27.0% of eyes at month 3. Between 6 months and 1 year, vision loss frequencies stabilized. In the multivariate model, HP (OR = 4.71 (2.14, 10.38)), total quadrants with split fixation (1.47 (1.20, 1.81)), follow-up non-glaucomatous eye pathology (2.89 (1.44, 5.80)), and concurrent cataract surgery (0.42 (0.22, 0.82)) each met significance (p < 0.05).

CONCLUSION

Post-AGV vision loss in the early follow-up period among Black or Hispanic patients was often transient. Hypertensive phase and split fixation each increased the odds of vision loss at 1 year, while concurrent cataract surgery decreased the odds.

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.

Biocompatibility and feasibility of VisiPlate, a novel ultrathin, multichannel glaucoma drainage device

BACKGROUND

Glaucoma is the leading cause of blindness worldwide. Glaucoma drainage devices and minimally invasive glaucoma surgeries (MIGS) often present with tradeoffs in safety and durability of efficacy. Using a rabbit model, we examined the biocompatibility and feasibility of VisiPlate, a novel, ultrathin, tubeless subconjunctival shunt comprised of a network of microchannels.

METHODS

Six naive female New Zealand White rabbits received implants (three only in the right eye with contralateral eye untreated and three in both eyes) composed of a 400-nm-thick aluminum oxide core coated with 2 µm of parylene-C, manufactured with microelectromechanical systems (MEMS) techniques. Tonometry, slit lamp exam, clinical exam, fluorescein patency testing, and histopathology were performed.

RESULTS

VisiPlate demonstrated IOP-lowering of 20-40% compared to baseline at each time point over the course of 3 months in the nine implanted eyes. All eyes developed blebs over the implant, and fluorescein testing demonstrated fluid patency at 22 days post-implantation. Slit lamp and clinical observations showed that VisiPlate was well tolerated, with low levels of conjunctival congestion, conjunctival swelling, aqueous flare, hyphema, and iris involvement from surgery that resolved over time. At sacrifice time points of 93 days and 180 days, the only notable observations were mild levels of conjunctival congestion in implanted eyes. Histopathology showed minimal tissue response and no obvious inflammation, fibrosis, or necrosis around the implant.

CONCLUSIONS

The results of this in vivo study demonstrate the biocompatibility and IOP-lowering effect of a multichannel, ultrathin subconjunctival shunt in a rabbit model. The data suggest that VisiPlate may safely enhance aqueous outflow and significantly reduce intraocular pressure.

Absence of lymphatic vessels in non-functioning bleb capsules of glaucoma drainage devices

PURPOSE

To evaluate the presence and appearance of blood and lymphatic vessels in non-functioning bleb capsules of glaucoma drainage devices (GDD).

MATERIALS AND METHODS

Non-functioning (n=14) GDD-bleb capsules of 12 patients were analyzed by immunohistochemistry for blood vessels (CD31, vascular endothelium), lymphatic vessels (lymphatic vessel endothelial hyaluronan receptor-1 [LYVE-1] and podoplanin) and macrophages (CD68).

RESULTS

CD31+++ blood vessels and CD68+ macrophages were detected in the outer layer of all specimens. LYVE-1 immunoreactivity was registered in single non-endothelial cells in 8 out of 14 (57%) bleb capsule specimens. Podoplanin-immunoreactivity was detected in all cases, located in cells and profiles of the collagen tissue network of the outer and/or the inner capsule layer. However, a colocalization of LYVE-1 and podoplanin as evidence for lymphatic vessels was not detected.

CONCLUSIONS

We demonstrate the presence of blood-vessels but absence of lymphatic vessels in non-functioning bleb capsules after GDD-implantation. While the absence of lymphatic vessels might indicate a possible reason for drainage device failure, this needs to be confirmed in upcoming studies, including animal experiments.

The ahmed versus Baerveldt study at King Khaled Eye Specialist Hospital: Three-year treatment outcomes

PURPOSE:

The purpose of this study was to analyze the outcomes of two frequently used surgical valves in treating refractory glaucoma.

METHODS:

This was a retrospective and nonrandomized study comparing patients aged 18 years or older who underwent implantation using standardized surgical techniques.

RESULTS:

A total of 86 patients were included in the study, 48 in the Ahmed group and 38 in the Baerveldt group. The overall success rate was 63.1% in both the groups. At the 3-year follow-up, the Ahmed group had a mean intraocular pressure (IOP) of 14.0 ± 4.8 mmHg (60% reduction) compared with 15.8 ± 6.2 mmHg (53.3% reduction) in the Baerveldt group (0.536). The Ahmed group required an average of 1.6 ± 1.3 medications (59% reduction) compared with 2.1 ± 1.7 (40% reduction) in the Baerveldt group (P < 0.001).

CONCLUSION:

Despite a high failure rate, both devices were effective in lowering IOP and the need for medications. Lower IOP and medications were needed in the Ahmed group.

Surgical Outcomes of a Second Ahmed Glaucoma Valve Implant for the Treatment of Refractory Glaucoma

PRéCIS:: In this article, the authors concluded that an additional Ahmed glaucoma valve (AGV) implantation after the failure of an initial AGV, even with the addition of glaucoma medications, maybe a good surgical treatment option for refractory glaucoma.

PURPOSE

To evaluate the surgical outcomes of a second AGV implant in Hispanic patients with refractory glaucoma.

MATERIALS AND METHODS

The medical records of patients who underwent a second AGV implant were reviewed retrospectively. Clinical outcome measures including intraocular pressure (IOP), visual acuity, and glaucoma medication use were collected from the preoperative visit and all follow-up visits up to 18 months after surgery. Failure was defined as one of the following: loss of light perception, sustained IOP >21 or <6 mm Hg, an IOP reduction of <20% from baseline, need for additional glaucoma surgery, including needling revision with subconjunctival adjuvant therapy, or valve extrusion.

RESULTS

A total of 48 patients were included. In all cases, an S-2 model was implanted in the superonasal quadrant. Mean preoperative IOP was 24.3±7.9 mm Hg and was significantly reduced to 13.9±4.8 at 6 months (P<0.05), 15.4±7.2 at 12 months (P<0.05), and 12.9±2.0 at 18 months (P<0.05). Mean glaucoma medications were reduced from 2.8±1.1 preoperatively to 1.9±1.2 at 6 months (P<0.05), 2.4±1.2 at 12 months, and 2.2±1.1 at 18 months; however, the difference was no longer statistically significant after 6 months, and the success rate was 60% at the mean for survival time of 15 months (13.7 to 16.5).

CONCLUSION

The findings of this study demonstrate that a second AGV can achieve a significant reduction in IOP for up to 18 months postoperatively.

Initial Clinical Results of the eyeWatch: a New Adjustable Glaucoma Drainage Device Used in Refractory Glaucoma Surgery

PRéCIS:: In this study, we report clinical results after implantation of an adjustable glaucoma drainage device. The intraocular pressure (IOP) profile was efficiently controlled postoperatively as the resistance to aqueous humor outflow was finely adjusted.

PURPOSE

The main purpose of this study was to evaluate the safety and efficacy of the new adjustable glaucoma drainage device eyeWatch used in conjunction with a Baerveldt glaucoma implant in refractory glaucoma.

PATIENTS AND METHODS

This was a multicentric, prospective, noncomparative clinical trial. Patients older than 18 years of age suffering from refractory glaucoma after failed surgeries, with IOP of ≥20 mm Hg, in whom a further glaucoma procedure using an aqueous shunt was planned, were enrolled in this study. The primary outcome was the success rate, defined as an IOP≤18 mm Hg and reduction of >20% from baseline, IOP≥6 mm Hg. Secondary outcomes were mean IOP, visual acuity, number of antiglaucoma medications, number, and type of complications.

RESULTS

Fifteen patients were included. The mean follow-up time was 15.6±3.5 months. The mean baseline IOP decreased from 26.2±6.8 mm Hg before surgery to 11.9±2.8 mm Hg at 12 months (P<0.001). The mean number of glaucoma medications decreased from 3.0±0.7 before surgery to 0.8±0.9 at last visit (P<0.001). The success rate was 40% for complete success and 93% for overall success at last follow-up. Complication rate was 7%.

CONCLUSIONS

The novel glaucoma device allows for perioperative and postoperative noninvasive adjustments of the resistance to aqueous humor outflow. This leads to better management of IOP during the early postoperative period, preventing ocular hypotony and eliminating the need for obstructive elements and reinterventions. The rate of complications was low, IOP was adequately controlled and lowered, with a substantial reduction in the number of antiglaucoma medication.

Encapsulated Bleb Excision with Collagen Matrix Implantation Following Failed Ahmed Glaucoma Valve Implantation

Purpose

To investigate the clinical features and surgical outcomes of encapsulated bleb excision with collagen matrix implantation performed in patients with failed Ahmed glaucoma valve (AGV) implantation.

Methods

Eighteen eyes of 18 patients underwent encapsulated bleb excision and collagen matrix implantation. Patients were divided into two groups by reference to intraocular pressure (IOP) after preoperative ocular massage: group 1, patients who exhibited substantial IOP reductions; and group 2, patients who did not show substantial changes in IOP. Needling was conducted in group 2. The clinical features of the two groups were compared, including IOP changes after ocular massage and needling, AGV status, and surgical outcomes 6 months after surgery.

Results

The mean preoperative IOP among the 18 patients was 30.6 ± 5.7 mmHg. After ocular massage, the IOPs decreased by 22 and 26 mmHg in the two patients in group 1 and the 16 patients in group 2 showed a mean IOP reduction of 1.6 ± 2.2 mmHg (p = 0.013). IOPs decreased after needling in group 2 (range, 6 to 30 mmHg; p < 0.001). Fibrovascular tissue ingrowth into the AGV was observed in the two patients in group 1 and the same ingrowth was observed in 10 of the 16 patients in group 2. Six months after surgery the mean IOP among the 18 patients decreased significantly (19.1 ± 3.2 mmHg, p < 0.001). There was no significant difference in the mean postoperative IOP at 6 months between group 1 (14.0 ± 2.8 mmHg) and group 2 (19.8 ± 2.6 mmHg, p = 0.052).

Conclusions

Encapsulated bleb excision with collagen matrix implantation resulted in a significant IOP-lowering effect 6 months after surgery. Fibrovascular ingrowth into the AGV was common but did not seem to be a major cause of AGV implantation failure.

Glaucoma Drainage Device Coated with Mitomycin C Loaded Opal Shale Microparticles to Inhibit Bleb Fibrosis

Excessive fibrosis is the topmost factor for the defeat of surgical glaucoma drainage device (GDD) implantation. Adjuvant drug approaches are promising to help reduce the scar formation and excessive fibrosis. Opal shale (OS), as a natural state and noncrystalline silica substance with poriferous nature and strong adsorbability, is highly likely to undertake drug loading and delivery. Here, we employed OS microparticles (MPs) by ultrasound and centrifugation and presented an innovative and improved GDD coated with OS MPs, which were loaded with mitomycin C (MMC). MMC-loaded OS MPs were physically absorbed on the Ahmed glaucoma valve surface through OS' adsorbability. About 5.51 μg of MMC was loaded on the modified Ahmed glaucoma valve and can be released for 18 days in vitro. MMC-loaded OS MPs inhibited fibroblast proliferation and showed low toxicity to primary Tenon's fibroblasts. The ameliorated drainage device was well tolerated and effective in reducing the fibrous reaction in vivo. Hence, our study constructed an improved Ahmed glaucoma valve using OS MPs without disturbing aqueous humor drainage pattern over the valve surface. The modified Ahmed glaucoma valve successfully alleviated scar tissue formation after GDD implantation surgery.

Efficacy of Ologen matrix implant in Ahmed Glaucoma Valve Implantation

To determine the efficacy and safety of the Ologen collagen matrix adjunctive to Ahmed valve surgery. A randomized prospective multicentre clinical trial involving 58 patients that were followed for one year. Conventional surgery with Ahmed valve was performed in 31 eyes (Control group/CG) and in 27 Ologen (Ologen group/OG) was placed over the valve's plate. Baseline data: age, corneal thickness, intraocular pressure(IOP) and antiglaucoma medications.Postoperative data (days 1, 7 and months 1, 3, 6 and 12): IOP, antiglaucoma medications, visual acuity and complications were recorded. Frequency of hypertensive phase, complete and qualified success and survival rate were studied. No differences were found between CG and OG in the baseline data. The only difference between groups was a significantly lower IOP at day 1. No other differences were found in the follow-up between groups. Hypertensive phase (56%CG and 55%OG, p = 0,947), complete success 28,6%CG and 30,4%OG (p = 0,88) and qualified success 96,4% and 95,9%(p = 0,794). Survival rates at 1 year were 76,7%(CG) and 69,2%(OG)(p = 0,531). 38,7% of patients in the CG suffered some complication during follow-up and 61,5% in OG(p = 0,086). Ologen does not increase safety or efficacy in Ahmed valve surgery at one-year follow-up. This is the first study that shows no benefit of Ologen adjunctive to this surgery.

Is Ahmed valve superior to Baerveldt implant as an aqueous shunt for the treatment of glaucoma?

INTRODUCTION

Aqueous shunt has emerged as an alternative technique to trabeculectomy, considered the standard for glaucoma surgery. Currently, it is mainly indicated after failure of trabeculectomy or in glaucoma with high risk of failure. The Ahmed valve and the Baerveldt implant are the most commonly used aqueous shunts. However, it is not clear whether there are differences between them.

METHODS

To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach.

RESULTS AND CONCLUSIONS

We identified five systematic reviews including 10 studies overall, of which two were randomized trials. We concluded the Ahmed valve probably achieves a lower decrease in intraocular pressure, might lead to less qualified success and probably needs more reinterventions than the Baerveldt implant. Regarding safety profile, the Ahmed valve is not clearly superior or inferior to the Baerveldt implant.

Surgical outcomes of a new affordable non-valved glaucoma drainage device and Ahmed glaucoma valve: comparison in the first year

BACKGROUND

A new low-cost, indigenously manufactured, non-valved glaucoma drainage device (GDD) has been introduced and its design is based on the Baerveldt Glaucoma Device. We aim to demonstrate the efficacy and safety of this GDD (Aurolab aqueous drainage implant, AADI) vis-à-vis the valved device, Ahmed glaucoma valve (AGV), in the management of refractory glaucomas.

DESIGN

Retrospective, comparative, interventional.

PARTICIPANTS

Case review of consecutive patients who underwent GDD surgery by a single fellowship-trained surgeon at a Tertiary Centre between January 2014 and November 2016.

PRIMARY OUTCOME MEASURE

Intraocular pressure (IOP).

SECONDARY

Antiglaucoma medication (AGM), LogMAR best-corrected visual acuity (BCVA), complications.

RESULTS

A total of 88 eyes of 83 patients were included; 36 eyes received AGV and 52 AADI. Preoperative parameters were similar between groups. Median follow-up was 13 and 12 months for AADI and AGV, respectively. Overall success rate was higher in AADI (92.3%) vs AGV (80.5%) (p<0.001). The median IOP in mm Hg (Quartiles; IQR) (AADI 14 (10,15;5) vs AGV 16 (14,20;6)) and AGM (AADI: 0 (0,1;1) vs AGV 2 (1,2.75;1.75)) was significantly lower in the AADI group at last follow-up (p<0.001). LogMAR BCVA improved in both groups; complication rates (AADI 44.2% vs AGV 52.7%) were comparable (p=0.59).

CONCLUSIONS

Both procedures were effective in reduction of IOP and need for AGM. Nevertheless, overall success rate was higher in the AADI group and IOP and number of AGM required was significantly lower in the AADI group; this affordable GDD could have a tremendous impact in the management of refractory glaucomas in low-income to middle-income countries.

Comparison of the Ahmed and Baerveldt glaucoma shunts with combined cataract extraction

OBJECTIVE

To compare the surgical outcomes of combined phacoemulsification with either Ahmed glaucoma valve (AGV) or Baerveldt glaucoma implant (BGI).

DESIGN

Retrospective cohort study.

PARTICIPANTS

A total of 104 eyes that underwent combined phacoemulsification with either AGV (PhacoAGV; n = 57) or BGI (PhacoBGI; n = 47) implantation.

METHODS

Failure was defined as uncontrolled intraocular pressure (IOP; <5 mm Hg, ≥18 mm Hg, or <20% reduction), additional glaucoma surgery, vision-threatening complications, or progression to no-light-perception vision.

RESULTS

The PhacoAGV group was older (p = 0.03), had poorer baseline visual acuity (VA; p = 0.001), and had fewer previous glaucoma surgeries (p = 0.04). Both groups had similar baseline IOP (PhacoAGV: 26.4 ± 8.3 mm Hg; PhacoBGI: 25.7 ± 7.3; p = 0.66) and glaucoma medications (PhacoAGV: 3.8 ± 1.0; PhacoBGI: 3.6 ± 1.5; p = 0.54). At 2 years, failure rates were 44% in the PhacoAGV group and 23% in the PhacoBGI group (p = 0.02). Both groups had similar mean IOP reduction (PhacoAGV: 45%; PhacoBGI: 47%, p = 0.67) and medication use reduction (PhacoAGV: 47%; PhacoBGI: 58%, p = 0.38). The PhacoBGI group had higher IOP and medication use up to 1 month (p < 0.05). Both groups improved in VA from baseline (p < 0.05) and had similar overall complication rates (p = 0.31). The PhacoBGI group required more overall interventions (p < 0.0005).

CONCLUSIONS

This comparative study found no difference in IOP, glaucoma medications, or complication rates between PhacoAGV and PhacoBGI at 2 years, despite BGIs being implanted in patients at higher risk for failure. The PhacoAGV group had higher failure rates at 2 years. Both groups had significant improvements in VA due to removal of their cataracts. The PhacoBGI group required more interventions, but most of these were minor slit-lamp procedures.

Conjunctival repair after glaucoma drainage device exposure using collagen-glycosaminoglycane matrices

Background

To report the results of the repair of conjunctival erosions resulting from glaucoma drainage device surgery using collagen-glycosaminoglycane matrices (CGM).

Methods

Case series of 8 patients who underwent revision surgery due to conjunctival defects with exposed tubes through necrosis of the overlying scleral flap and conjunctiva after Baerveldt drainage device surgery. The defects were repaired by lateral displacement of the tube towards the sclera, with a slice of a CGM as a patch, covered by adjacent conjunctiva.

Result

Successful, lasting closure (follow-up of 12 to 42 months) of the conjunctival defects was achieved without any side-effects or complications in all eight cases.

Conclusions

Erosion of the drainage tube, creating buttonholes in the conjunctiva after implantation of glaucoma drainage devices, is a potentially serious problem. It can be managed successfully using a biodegradable CGM as a patch.

Long-term Outcomes of a Modified Technique Using the Baerveldt Glaucoma Implant for the Treatment of Refractory Glaucoma

PURPOSE OF THE STUDY

The purpose of the study was to evaluate the long-term effectiveness and safety profile of Baerveldt glaucoma implant (BGI) in patients with refractory glaucoma operated using a modified technique to avoid postoperative complications.

PATIENTS AND METHODS

A total of 160 eyes from 147 glaucomatous patients were enrolled in a consecutive interventional noncomparative case series. All the patients were treated with a 350-mm BGI using a modified technique. Intraocular pressure (IOP), the number of medications, the complications, and the postoperative interventions were reported preoperatively and during the follow-up. Postoperative IOP and the rate of complications were the primary outcome measures. The complete and qualified surgical success was the second endpoint.

RESULTS

BGI obtained a mean IOP reduction from 31.8±6.4 mm Hg (baseline) to 14.4±3.5 mm Hg after a mean follow-up period of 38.4±9.6 months. The mean number of medications reduced between preoperative (n=3.17±1.03) and postoperative period (n=0.58±0.83) (P<0.0001). Cumulative probability of maintaining an IOP between 5 and 21 mm Hg and/or a 25% or greater reduction in IOP was 78.7% at 1 year and 72.1% at 4 years, including 39 eyes (24.4%) in which postoperative interventions were required (qualified success). If we exclude those eyes from the analysis, the probability of complete success was 93.4% at 1 year and 91.4% at 4 years in 75.4% of the eyes.

CONCLUSIONS

This modified technique achieved a high percentage of surgical success during the whole follow-up time and was effective in preventing the most serious immediate complications of nonvalved tube shunts.

Aqueous shunts for glaucoma

BACKGROUND

Aqueous shunts are employed to control intraocular pressure (IOP) for people with primary or secondary glaucomas who fail or are not candidates for standard surgery.

OBJECTIVES

To assess the effectiveness and safety of aqueous shunts for reducing IOP in glaucoma compared with standard surgery, another type of aqueous shunt, or modification to the aqueous shunt procedure.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 8), MEDLINE Ovid (1946 to August 2016), Embase.com (1947 to August 2016), PubMed (1948 to August 2016), LILACS (Latin American and Caribbean Health Sciences Literature Database) (1982 to August 2016), ClinicalTrials.gov (www.clinicaltrials.gov); searched 15 August 2016, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 15 August 2016. We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 15 August 2016. We also searched the reference lists of identified trial reports and the Science Citation Index to find additional trials.

SELECTION CRITERIA

We included randomized controlled trials that compared various types of aqueous shunts with standard surgery or to each other in eyes with glaucoma.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened search results for eligibility, assessed the risk of bias, and extracted data from included trials. We contacted trial investigators when data were unclear or not reported. We graded the certainty of the evidence using the GRADE approach. We followed standard methods as recommended by Cochrane.

MAIN RESULTS

We included 27 trials with a total of 2099 participants with mixed diagnoses and comparisons of interventions. Seventeen studies reported adequate methods of randomization, and seven reported adequate allocation concealment. Data collection and follow-up times varied.Four trials compared an aqueous shunt (Ahmed or Baerveldt) with trabeculectomy, of which three reported one-year outcomes. At one-year, the difference in IOP between aqueous shunt groups and trabeculectomy groups was uncertain (mean difference (MD) 2.55 mmHg, 95% confidence interval (CI) -0.78 to 5.87; 380 participants; very low-certainty evidence). The difference in logMAR visual acuity was also uncertain (MD 0.12 units, 95% CI -0.07 to 0.31; 380 participants; very low-certainty evidence). In two trials, the difference in visual field score was uncertain (MD -0.25, 95% CI -1.91 to 1.40; 196 participants; very low-certainty evidence). The mean number of antiglaucoma medications was higher in the aqueous shunt group than the trabeculectomy group in one trial (MD 0.80, 95% CI 0.48 to 1.12; 184 participants; low-certainty evidence). The effect on needing additional glaucoma surgery was uncertain between groups in two trials (risk ratio (RR) 0.24, 95% CI 0.04 to 1.36; 329 participants; very low-certainty evidence). In one trial, fewer total adverse events were reported in the aqueous shunt group than the trabeculectomy group (RR 0.59, 95% CI 0.43 to 0.81; 212 participants; very low-certainty evidence). No trial reported quality-of-life outcomes at one-year follow-up.Two trials that compared the Ahmed implant with the Baerveldt implant for glaucoma found higher mean IOP in the Ahmed group at one-year follow-up (MD 2.60 mmHg, 95% CI 1.58 to 3.62; 464 participants; moderate-certainty evidence). The difference in logMAR visual acuity was uncertain between groups (MD -0.07 units, 95% CI -0.27 to 0.13; 501 participants; low-certainty evidence). The MD in number of antiglaucoma medications was within one between groups (MD 0.35, 95% CI 0.11 to 0.59; 464 participants; moderate-certainty evidence). More participants in the Ahmed group required additional glaucoma surgery than the Baerveldt group (RR 2.77, 95% CI 1.02 to 7.54; 514 participants; moderate-certainty evidence). The two trials reported specific adverse events but not overall number of adverse events. Neither trial reported visual field or quality-of-life outcomes at one-year follow-up.One trial compared the Ahmed implant with the Molteno implant for glaucoma over two-year follow-up. Mean IOP was higher in the Ahmed group than the Molteno group (MD 1.64 mmHg, 95% CI 0.85 to 2.43; 57 participants; low-certainty evidence). The differences in logMAR visual acuity (MD 0.08 units, 95% CI -0.24 to 0.40; 57 participants; very low-certainty evidence) and mean deviation in visual field (MD -0.18 dB, 95% CI -3.13 to 2.77; 57 participants; very low-certainty evidence) were uncertain between groups. The mean number of antiglaucoma medications was also uncertain between groups (MD -0.38, 95% CI -1.03 to 0.27; 57 participants; low-certainty evidence). The trial did not report the proportion needing additional glaucoma surgery, total adverse events, or quality-of-life outcomes.Two trials compared the double-plate Molteno implant with the Schocket shunt for glaucoma; one trial reported outcomes only at six-month follow-up, and the other did not specify the follow-up time. At six-months, mean IOP was lower in the Molteno group than the Schocket group (MD -2.50 mmHg, 95% CI -4.60 to -0.40; 115 participants; low-certainty evidence). Neither trial reported the proportion needing additional glaucoma surgery, total adverse events, or visual acuity, visual field, or quality-of-life outcomes.The remaining 18 trials evaluated modifications to aqueous shunts, including 14 trials of Ahmed implants (early aqueous suppression versus standard medication regimen, 2 trials; anti-vascular endothelial growth factor agent versus none, 4 trials; corticosteroids versus none, 2 trials; shunt augmentation versus none, 3 trials; partial tube ligation versus none, 1 trial; pars plana implantation versus conventional implantation, 1 trial; and model M4 versus model S2,1 trial); 1 trial of 500 mm² Baerveldt versus 350 mm² Baerveldt; and 3 trials of Molteno implants (single-plate with oral corticosteroids versus single-plate without oral corticosteroids, 1 trial; double-plate versus single-plate, 1 trial; and pressure-ridge versus double-plate with tube ligation, 1 trial).

AUTHORS' CONCLUSIONS

Information was insufficient to conclude whether there are differences between aqueous shunts and trabeculectomy for glaucoma treatment. While the Baerveldt implant may lower IOP more than the Ahmed implant, the evidence was of moderate-certainty and it is unclear whether the difference in IOP reduction is clinically significant. Overall, methodology and data quality among existing randomized controlled trials of aqueous shunts was heterogeneous across studies, and there are no well-justified or widely accepted generalizations about the superiority of one surgical procedure or device over another.

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.

Ahmed Versus Baerveldt Glaucoma Drainage Implantation in Patients With Markedly Elevated Intraocular Pressure (≥30 mm Hg)

PURPOSE

Glaucoma patients with markedly elevated intraocular pressure (IOP) are at risk for developing severe hypotony-related complications. The goal of this study was to compare the surgical outcomes of the Ahmed Glaucoma Valve (AGV) and the Baerveldt Glaucoma Implant (BGI) in this patient population.

METHODS

Patients with preoperative IOP≥30 mm Hg were included. Outcome measures were: (1) surgical failure (IOP>21 mm Hg or <30% reduction from baseline or IOP≤5 mm Hg on 2 consecutive follow-up visits after 3 mo, or additional glaucoma surgery, or loss of light perception) and (2) surgical complications.

RESULTS

A total of 75 patients were included: 37 in the AGV group and 38 in the BGI group. The mean±SD follow-up was 2.3±1.6 years for the AGV group and 2.4±1.7 years for the BGI group (P=0.643). Mean preoperative IOP was 38.7±6.5 mm Hg for the AGV group and 40.8±7.6 mm Hg for the BGI group. At the last follow-up, 10 (27.0%) patients failed in the AGV group compared with 6 (15.8%) patients in the BGI group (P=0.379). The BGI group had higher rate of flat or shallow anterior chamber (n=4, 10%) compared with the AGV group (n=0, 0%) (P=0.043).

CONCLUSIONS

Failure rates of AGV and BGI in patients with IOP≥30 mm Hg were comparable. There were more early hypotony-related complications in the BGI group; however, none were vision threatening. Both glaucoma drainage implants were effective in treating patients with uncontrolled glaucoma in an emergency setting.

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.

The Ahmed shunt versus the Baerveldt shunt for refractory glaucoma: a meta-analysis

Background

The purpose of this study was to compare the efficacy and tolerability of the Ahmed glaucoma valve (AGV) implant and the Baerveldt implant for the treatment of refractory glaucoma.

Methods

We comprehensively searched four databases, including PubMed, EMBASE, Web of Science, and the Cochrane Library databases, selecting the relevant studies. The continuous variables, namely, intraocular pressure reduction (IOPR) and a reduction in glaucoma medication, were pooled by the weighted mean differences (WMDs), and the dichotomous outcomes, including success rates and tolerability estimates, were pooled by the odds ratio (ORs).

Results

A total of 929 patients from six studies were included. The WMDs of the IOPR between the AGV implant and the Baerveldt implant were 1.58 [95 % confidence interval (CI): −2.99 to 6.15] at 6 months, −1.01 (95 % CI: −3.40 to 1.98) at 12 months, −0.54 (95 % CI: −4.89 to 3.82) at 24 months, and −0.47 (95 % CI: −3.29 to 2.35) at 36 months. No significant difference was detected between the two groups at any point in time. The pooled ORs comparing the AGV implant with the Baerveldt implant were 0.51 (95 % CI: 0.33 to 0.80) for the complete success rate and 0.67 (95 % CI: 0.50 to 0.91) for qualified success rate. The Baerveldt implant was associated with a reduction in glaucoma medication at −0.51 (95 % CI: −0.90 to −0.12). There were no significant differences between the AGV implant and the Baerveldt implant on the rates of adverse events.

Conclusions

The Baerveldt implant is more effective in both its surgical success rate and reducing glaucoma medication, but it is comparable to the AGV implant in lowering IOP. Both implants may have comparable incidences of adverse events.

Postoperative Complications in the Ahmed Baerveldt Comparison Study During Five Years of Follow-up

PURPOSE

To compare the late complications in the Ahmed Baerveldt Comparison Study during 5 years of follow-up.

DESIGN

Multicenter, prospective randomized clinical trial.

METHODS

setting: Sixteen international clinical centers.

STUDY POPULATION

Two hundred seventy-six subjects aged 18-85 years with previous intraocular surgery or refractory glaucoma with intraocular pressure of >18 mm Hg.

INTERVENTIONS

Ahmed Glaucoma Valve FP7 or Baerveldt Glaucoma Implant BG 101-350.

MAIN OUTCOME MEASURES

Late postoperative complications (beyond 3 months), reoperations for complications, and decreased vision from complications.

RESULTS

Late complications developed in 56 subjects (46.8 ± 4.8 5-year cumulative % ± SE) in the Ahmed Glaucoma Valve group and 67 (56.3 ± 4.7 5-year cumulative % ± SE) in the Baerveldt Glaucoma Implant group (P = .082). The cumulative rates of serious complications were 15.9% and 24.7% in the Ahmed Glaucoma Valve and Baerveldt Glaucoma Implant groups, respectively (P = .034), although this was largely driven by subjects who had tube occlusions in the 2 groups (0.8% in the Ahmed Glaucoma Valve group and 5.7% in the Baerveldt Glaucoma Implant group, P = .037). Both groups had a relatively high incidence of persistent diplopia (12%) and corneal edema (20%), although half of the corneal edema cases were likely due to pre-existing causes other than the aqueous shunt. The incidence of tube erosion was 1% and 3% in the Ahmed Glaucoma Valve and Baerveldt Glaucoma Implant groups, respectively (P = .04).

CONCLUSIONS

Long-term rates of vision-threatening complications and complications resulting in reoperation were higher in the Baerveldt Glaucoma Implant than in the Ahmed Glaucoma Valve group over 5 years of follow-up.

Comparison of the Ahmed glaucoma valve with the Baerveldt glaucoma implant: a meta-analysis

BACKGROUND

This study aims to compare the efficacy and safety of the Ahmed glaucoma valve (AGV) with the Baerveldt glaucoma implant (BGI) in glaucoma patients.

METHODS

Databases were searched to identify studies that met pre-stated inclusion criteria, involving randomized controlled clinical trials (RCTs) and non-randomized controlled clinical trials. Treatment effect was analyzed using a random-effect model.

RESULTS

Ten controlled clinical trials (1048 eyes) were analyzed, involving two RCTs and eight retrospective comparative studies. Short-term results (6-18 months) and long-term results (>18 months) were analyzed separately. There was no significant difference in the success rate for short-term follow-up between the AGV and BGI groups (5 studies, 714 eyes, odds ratio [OR]: 0.97; 95 % confidence interval [CI]: 0.56, 1.66; P = 0.90). For long-term pooled results (7 studies, 835 eyes), the success rate of AGVs was lower than that of BGIs (OR: 0.73; 95 % CI: 0.54, 0.99, P = 0.04), However, subgroup and sensitivity analyses did not show a significant difference in the success rate between the two groups (P ≥0.05). The AGV group had a higher mean intraocular pressure than the BGI group in short-term (6 studies, 685 eyes, weighted mean difference [WMD]: 2.12 mmHg; 95 % CI: 0.72-3.52; P <0.05) and long-term pooled results (7 studies, 659 eyes, WMD: 1.85 mmHg; 95 % CI: 0.43, 3.28; P = 0.01). The BGI group required fewer glaucoma medications after implantation than the AGV group in two follow-up periods (all P <0.05). The AGV was found to be associated with a significantly lower frequency of total complications (8 studies, 971 eyes, OR: 0.67; 95 % CI: 0.50-0.90; P = 0.007) and severe complications (8 studies, 971 eyes, OR: 0.57; 95 % CI: 0.36-0.91; P = 0.02) than the BGI.

CONCLUSIONS

The study showed no significant difference in success rate between the two groups. The BGI was more effective for control of intraocular pressure and required fewer medications than the AGV, but the AGV had lower incidence of total and severe complications than the BGI.

Five-year treatment outcomes in the Ahmed Baerveldt comparison study

PURPOSE

To compare the 5-year outcomes of the Ahmed FP7 Glaucoma Valve (AGV) (New World Medical, Cucamonga, CA) and the Baerveldt 101-350 Glaucoma Implant (BGI) (Abbott Medical Optics, Abbott Park, IL) for the treatment of refractory glaucoma.

DESIGN

Multicenter, randomized, controlled clinical trial.

PARTICIPANTS

A total of 276 patients, including 143 in the AGV group and 133 in the BGI group.

METHODS

Patients aged 18 to 85 years with previous intraocular surgery or refractory glaucoma and intraocular pressure (IOP) of ≥18 mmHg in whom glaucoma drainage implant (GDI) surgery was planned were randomized to implantation of an AGV or a BGI.

MAIN OUTCOME MEASURES

Surgical failure, IOP, visual acuity (VA), use of glaucoma medications, and complications.

RESULTS

At 5 years, IOP (mean ± standard deviation [SD]) was 14.7±4.4 mmHg in the AGV group and 12.7±4.5 mmHg in the BGI group (P = 0.015). The number of glaucoma medications in use at 5 years (mean ± SD) was 2.2±1.4 in the AGV group and 1.8±1.5 in the BGI group (P = 0.28). The cumulative probability of failure during 5 years of follow-up was 44.7% in the AGV group and 39.4% in the BGI group (P = 0.65). The number of subjects failing because of inadequately controlled IOP or reoperation for glaucoma was 46 in the AGV group (80% of AGV failures) and 25 in the BGI group (53% of BGI failures; P = 0.003). Eleven eyes in the AGV group (20% of AGV failures) experienced persistent hypotony, explantation of implant, or loss of light perception compared with 22 eyes (47% of failures) in the BGI group. Change in logarithm of the minimum angle of resolution VA (mean ± SD) at 5 years was 0.42±0.99 in the AGV group and 0.43±0.84 in the BGI group (P = 0.97).

CONCLUSIONS

Similar rates of surgical success were observed with both implants at 5 years. The BGI produced greater IOP reduction and a lower rate of glaucoma reoperation than the AGV, but the BGI was associated with twice as many failures because of safety issues.

Three-year treatment outcomes in the Ahmed Baerveldt comparison study

PURPOSE

To compare 3-year outcomes and complications of the Ahmed FP7 Glaucoma Valve (AGV) (New World Medical, Cucamonga, CA) and the Baerveldt Glaucoma Implant (BGI) 101-350 (Abbott Medical Optics, Abbott Park, IL) for the treatment of refractory glaucoma.

DESIGN

Multicenter, randomized, controlled clinical trial.

PARTICIPANTS

A total of 276 patients: 143 in the AGV group and 133 in the BGI group.

METHODS

Patients aged 18 to 85 years with refractory glaucoma and intraocular pressures (IOPs) ≥ 18 mmHg in whom an aqueous shunt was planned were randomized to an AGV or a BGI.

MAIN OUTCOME MEASURES

The IOP, visual acuity (VA), supplemental medical therapy, complications, and failure (IOP >21 mmHg or not reduced by 20% from baseline, IOP <5 mmHg, reoperation for glaucoma or removal of implant, or loss of light perception vision).

RESULTS

At 3 years, IOP (mean ± standard deviation) was 14.3 ± ± 4.7 mmHg (AGV group) and 13.1 ± 4.5 mmHg (BGI group) (P = 0.086) on 2.0 ± 1.4 and 1.5 ± 1.4 glaucoma medications, respectively (P = 0.020). The cumulative probabilities of failure were 31.3% (standard error [SE], 4.0%) (AGV) and 32.3% (4.2%) (BGI) (P = 0.99). Postoperative complications associated with reoperation or vision loss of >2 Snellen lines occurred in 24 patients (22%) (AGV) and 38 patients (36%) (BGI) (P = 0.035). The mean change in the logarithm of the minimum angle of resolution VA at 3 years was similar (AGV: 0.21 ± 0.88, BGI: 0.26 ± 0.74) in the 2 treatment groups at 3 years (P = 0.66). The cumulative proportion of patients (SE) undergoing reoperation for glaucoma before the 3-year postoperative time point was 14.5% (3.0%) in the AGV group compared with 7.6% (2.4%) in the BGI group (P = 0.053, log rank). The relative risk of reoperation for glaucoma in the AGV group was 2.1 times that of the BGI group (95% confidence interval, 1.0-4.8; P = 0.045, Cox proportional hazards regression).

CONCLUSIONS

Implantation of the AGV was associated with the need for significantly greater adjunctive medication to achieve equal success relative to implantation of the BGI and resulted in a greater relative risk of reoperation for glaucoma. More subjects experienced serious postoperative complications in the BGI group than in the AGV group.

The Ahmed versus Baerveldt study: three-year treatment outcomes

OBJECTIVE

To compare 2 commonly used aqueous drainage devices for the treatment of refractory glaucoma.

DESIGN

International, multicenter, randomized trial.

PARTICIPANTS

Patients aged 18 years or older with uncontrolled or high-risk glaucoma refractory to maximum medical therapy, many of whom had failed trabeculoplasty and trabeculectomy.

METHODS

Eligible patients were randomized to 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 of the target range (5-18 mmHg, with ≥20% reduction from baseline) for 2 consecutive visits after 3 months, vision-threatening complications, de novo glaucoma procedures, or loss of light perception. Secondary outcome measures include IOP, medication use, visual acuity, complications, and interventions.

RESULTS

A total of 238 patients were enrolled and randomized; 124 received the Ahmed implant and 114 received the Baerveldt implant. Baseline characteristics were similar in both groups. Half the study group had secondary glaucoma, and 37% had previously failed trabeculectomy. The mean preoperative IOP was 31.4±10.8 mmHg on 3.1±1.0 glaucoma medications. Median baseline Snellen visual acuity was 20/100. At 3 years, the cumulative probability of failure was 51% in the Ahmed group and 34% in the Baerveldt group (P = 0.03). Mean IOP was 15.7±4.8 mmHg in the Ahmed group (49% reduction) and 14.4±5.1 mmHg in the Baerveldt group (55% reduction; P = 0.09). Mean number of glaucoma medications was 1.8±1.4 in the Ahmed group (42% reduction) and 1.1±1.3 in the Baerveldt group (65% reduction; P = 0.002). There was a moderate but similar decrease in visual acuity in both groups (P< 0.001). The 2 groups had similar complication rates (52% Ahmed, 62% Baerveldt; P = 0.12); however, the Baerveldt group had a higher rate of hypotony-related vision-threatening complications (0% Ahmed, 6% Baerveldt; P = 0.005). More interventions were required in the Baerveldt group, although the difference did not reach statistical significance (38% Ahmed, 50% Baerveldt; P = 0.07). Most complications were transient, and most interventions were slit-lamp procedures.

CONCLUSIONS

Both devices were effective in reducing IOP and glaucoma medications. The Baerveldt group had a lower failure rate and required fewer medications than the Ahmed group after 3 years, but it experienced more hypotony-related vision-threatening complications.

Recent clinical pearls from clinical trials in glaucoma

PURPOSE OF REVIEW

Over the past several years, numerous clinical trials in glaucoma have contributed to our understanding of the medical and surgical treatment of the disease. The goal of this review is to summarize the findings and conclusions of what the authors feel are the key clinical trials in glaucoma.

RECENT FINDINGS

One of the major findings of Low-Pressure Glaucoma Treatment study was that patients randomized to the brimonidine group were statistically less likely to have progressive visual field loss than those randomized to the timolol group, even though there was no significant difference between the intraocular pressure (IOP)-lowering effect of these two drugs. The Ocular Hypertension Treatment Study has effectively demonstrated that patients with ocular hypertension should be risk stratified prior to initiation of treatment and that it appears to be relatively safe to delay treatment in low-risk patients. The 3-year canaloplasty study demonstrates the long-term safety and efficacy of this surgery. However, it also demonstrates that canaloplasty can deliver a modest IOP reduction and therefore is likely more suited for patients with mild damage and a higher target IOP. The 1-year results from the Ahmed Baerveldt Comparison Study do not demonstrate a clear superiority of one implant over the other. These findings are consistent with prior retrospective studies in the literature.

SUMMARY

These four studies have furthered our understanding of the field of glaucoma and provided key insights into the medical and surgical management of patients with this complex disease.

Previous cyclodestruction is a risk factor for late-onset hypotony and suprachoroidal haemorrhage after glaucoma drainage device surgery

AIM

To investigate whether previous cyclodestructive (eg, cyclophotocoagulation and cyclocryodestruction) procedures have any influence on the general outcome and pressure level after glaucoma drainage device (GDD) surgery.

METHODS

Retrospective analysis of 110 consecutive patients who had undergone GDD (Baerveldt 250 mm(2) and 350 mm(2) implant, AMO, USA) surgery with a minimum follow-up of 3 months. The patients were divided into patients with previous cyclodestructive surgery before GDD surgery (I; 47 patients) and patients without previous cyclodestructive surgery (II; 63 patients). Intraocular pressure (IOP), medication score, best-corrected visual acuity and surgical treatments were recorded before and after drainage device implantation.

RESULTS

Patients of group I had a mean preoperative IOP of 32.1 mm Hg and a mean medication score of 4.8; patients of group II had a mean preoperative IOP of 29.2 mm Hg (p=0.18) and a mean medication score of 4.9 (p=0.84). All patients who developed suprachoroidal haemorrhage (six cases) belonged to group I (6/47=12.8%), no patient of group II (0/63=0%) developed suprachoroidal haemorrhage (Fisher's test: p=0.01). Twelve patients developed late-onset (>6 weeks after GDD surgery) hypotony, nine of them belonging to group I (9/47=19.1%) and three of them to group II (3/63=4.8%) (Fisher's test: p=0.03).

CONCLUSIONS

While taking potential bias arising from the retrospective nature of the study into consideration, a history of previous cyclodestructive procedures before GDD surgery seems to be a major risk factor for suprachoroidal haemorrhage and for late-onset postoperative hypotony.

Intermediate term safety and efficacy of transscleral cyclophotocoagulation after tube shunt failure

PURPOSE

To determine the efficacy and safety of diode transscleral cyclophotocoagulation (TSCPC) after tube shunt failure.

PATIENTS AND METHODS

The patient population consisted of 32 eyes of 31 patients with uncontrolled glaucoma. Each eye had a previously implanted aqueous tube shunt and was currently on maximally tolerated medication. Each eye also underwent TSCPC treatment using the Iridex (Mountain View, CA) diode laser with a maximum of 360 degrees of treatment. All 31 charts were reviewed for data pertaining to demographics, treatment, ocular history, and follow-up clinical examinations. Safety was evaluated by complication data. Efficacy was evaluated in terms of TSCPC treatment parameters (number of laser applications, laser power, application duration, and degrees of ciliary body treated), intraocular pressure, number of hypotensive medications, and any further treatment required.

RESULTS

With a mean (SD) follow-up of 17.1 (16.3) (median=11.7) months from the last treatment, the mean intraocular pressure decreased from 28.6 (10.2) mm Hg to 16.8 (7.5) mm Hg (35% reduction) at 3 months (n=30, P<0.0001) and to 14.7 (7.9) mm Hg (43% reduction) at 1 year (n=13, P<0.0001). Complications included hypotony (n=4), hyphema (n=2), failed corneal transplant (n=1), and loss of light perception (n=5).

CONCLUSIONS

TSCPC has a significant ocular hypotensive effect on glaucoma refractory to both tube shunt and medical therapy. The safety of this intervention remains unclear in this high risk patient population and warrants further study.

Glaucoma associated with Boston type I keratoprosthesis

PURPOSE

To evaluate outcomes of the Boston type I keratoprosthesis (KPro) and associated incidence of glaucoma.

DESIGN

Retrospective cohort study.

PARTICIPANTS

All patients who underwent KPro surgery at 1 institution from 2003 to 2009 with at least 3 months of follow-up.

METHODS

Preoperative visual acuity, diagnosis, history of glaucoma, and intraoperative and postoperative parameters were recorded. Statistical analysis was performed to identify factors that may influence increase in intraocular pressure (IOP) and glaucoma development or progression after surgery.

MAIN OUTCOME MEASURES

Best-corrected visual acuity (BCVA), IOP, postoperative medical and surgical treatments for glaucoma, and KPro retention and complications.

RESULTS

Thirty-six KPro procedures were performed in 30 eyes of 29 patients with a mean (±SD) follow-up of 17 ± 19 months (range, 3-67 months). The main indication for KPro implantation was corneal graft failure (77%). Primary KPro procedures were performed in 23% of eyes for limbal stem cell deficiency secondary to chemical burns and aniridia and for herpetic disease. Median preoperative BCVA was hand motions with an overall improvement to 20/330 (range, 20/20 to hand motions) at 9 months postoperatively; mean BCVA was 20/600 (range, 20/40 to NLP) at the last follow-up. Twenty eyes (67%) had a preoperative history of glaucoma, with 8 of those eyes (40%) having undergone previous glaucoma surgery. Twenty-one eyes (70%) underwent concomitant glaucoma surgery. Postoperative increased IOP (22 mm Hg or higher) was noted in 15 eyes (50%), although definite glaucoma development or progression was noted in 7 of those 15 eyes (23% of total eyes). Mean BCVA at the last follow-up in eyes with glaucoma development or progression was 3/200 compared with 20/563 in the remaining 23 eyes. Six patients (20%) required repeat KPro implantation, and retroprosthetic membranes developed in 23 eyes (77%). No patient had vitritis or infectious endophthalmitis develop.

CONCLUSIONS

The Boston type I KPro is an effective option for management of eyes with poor prognosis for primary or repeat penetrating keratoplasty. Visual potential is limited by preoperative comorbidities; however, glaucoma development or progression of preexisting glaucoma is a significant cause of postoperative visual loss. Rigorous perioperative management of elevated IOP is essential for long-term success of KPro surgery.