Early Experience with the Paul Glaucoma Implant in Childhood Glaucoma: A Case Series.

Purpose: The Paul glaucoma implant (PGI, Advanced Ophthalmic Innovations, Singapore, Republic of Singapore) is a recently developed novel non-valved glaucoma drainage device (GDD) designed to effectively reduce the intraocular pressure (IOP) in glaucoma patients with a theoretically reduced risk of postoperative complications such as hypotony, endothelial cell loss, strabismus, and diplopia. Limited literature has evaluated its use in adult glaucoma; however, its use in pediatric glaucoma has not been reported to date. We present our early experience with PGI in refractory childhood glaucoma. Patients and Methods: This study was retrospective single-surgeon case series in a single tertiary center. Results: Three eyes of 3 patients with childhood glaucoma were enrolled in the study. During nine months of follow-up, postoperative IOP and number of glaucoma medications were significantly lower than preoperative values in all the enrolled patients. None of the patients developed postoperative complications including postoperative hypotony, choroidal detachment, endophthalmitis, or corneal decompensation. Conclusion: PGI is an efficient and relatively safe surgical treatment option in patients with refractory childhood glaucoma. Further studies with larger number of participants and longer follow-up period are required to confirm our encouraging results.

Ahmed and Baerveldt Glaucoma Drainage Devices in Childhood Glaucoma: A Meta-Analysis.

PRCIS: The effectiveness of Ahmed glaucoma valve (AGV) and Baerveldt glaucoma implant (BGI) was comparable in the management of childhood glaucoma over the long term despite initial better success rate with BGI. There were higher tube block and retraction rates in the BGI group and higher tube exposure rates in the AGV group. PURPOSE: To evaluate the outcomes and safety of AGV and BGI in childhood glaucoma. MATERIALS AND METHODS: We performed a systematic literature review of publications from 1990 to 2022 in PubMed, EMBASE, ClinicalTrials.gov, Ovid MEDLINE, Cochrane CENTRAL, and google scholar for studies evaluating AGV and BGI in childhood glaucoma. Primary outcome measures were intraocular pressure (IOP) reduction and glaucoma medication reduction. The secondary outcome measures were the success rates and incidence of postoperative complications. We conducted a meta-analysis using a random effects model. RESULTS: Thirty-two studies met the inclusion criteria. A total of 1480 eyes were included. The mean IOP reduction was 15.08 mm Hg ( P < 0.00001) for AGV and 14.62 ( P < 0.00001) for the BGI group. The mean difference between pre and postoperative glaucoma medications was 1 ( P < 0.00001) fewer medications in the AGV group and 0.95 ( P < 0.0001) fewer medications in the BGI group. There was a lower success rate in the AGV versus BGI groups at 2 years [63% vs 83%, respectively ( P < 0.0001) and 3 years (43% vs 79%, respectively ( P < 0.0001)]; however, the success was higher for AGV at 5 years (63% vs 56% in the BGI group, P < 0.001). The incidence of postoperative complications was comparable in the AGV and BGI groups, with rates of 28% and 27%, respectively. CONCLUSIONS: The IOP and glaucoma medication reduction, success rates, and incidence of postoperative complications were comparable in Ahmed and Baerveldt groups. Most literature comes from retrospective low-quality studies on refractory childhood glaucoma. Further larger cohort studies are needed.

Safety and Effectiveness of the PRESERFLO® MicroShunt in Primary Open-Angle Glaucoma: Results from a 2-Year Multicenter Study.

PURPOSE: To assess the safety and effectiveness of the PRESERFLO® MicroShunt (formerly InnFocus MicroShunt) in patients with primary open-angle glaucoma (POAG). DESIGN: The MicroShunt, a controlled ab externo glaucoma filtration surgery device, was investigated in a 2-year, multicenter, single-arm study. PARTICIPANTS: Eligible patients were aged 18-85 years with POAG inadequately controlled on maximal tolerated medical therapy with intraocular pressure (IOP) ≥18 and ≤35 mmHg or when glaucoma progression warranted surgery. METHODS: The MicroShunt was implanted as a stand-alone procedure with adjunctive use of topical mitomycin C (MMC; 0.2-0.4 mg/ml) for 2-3 minutes. MAIN OUTCOME MEASURES: The primary effectiveness outcome was IOP reduction and success (not requiring reoperation or pressure failures [IOP > 21 mmHg and < 20% reduction in IOP]) at year 1. Additional end points at year 2 included IOP reduction, success, glaucoma medications, adverse events (AEs), and reoperations. Results are reported in the overall population and subgroups of patients receiving 0.2 or 0.4 mg/ml MMC. RESULTS: In 81 patients, mean (± standard deviation [SD]) IOP decreased from 21.7 ± 3.4 mmHg at baseline to 14.5 ± 4.6 mmHg at year 1 and 14.1 ± 3.2 mmHg at year 2 (P < 0.0001). Overall success (with and without supplemental glaucoma medication use) at year 1 was 74.1%. Mean (± SD) number of medications decreased from 2.1 ± 1.3 at baseline to 0.5 ± 0.9 at year 2 (P < 0.0001), and 73.8% of patients were medication free. Most common nonserious AEs were increased IOP requiring medication or selective laser trabeculoplasty (25.9%) and mild-to-moderate keratitis (11.1%). There were 6 (7.4%) reoperations and 5 (6.2%) needlings by year 2. In an analysis (post hoc) according to MMC concentration, overall success was 78.1% (0.2 mg/ml) and 74.4% (0.4 mg/ml; P = 0.710). In the 0.2 and 0.4 mg/ml MMC groups, 51.9% and 90.3% of patients were medication free, respectively (P = 0.001). There was a trend toward lower IOP and higher medication reduction in the 0.4 mg/ml MMC subgroup. CONCLUSIONS: In this study, mean IOP and glaucoma medication reductions were significant and sustained over 2 years postsurgery. No long-term, sight-threatening AEs were reported. Further studies may confirm potential risk/benefits of higher MMC concentration.

Deep Sclerectomy With Intrascleral Versus Suprachoroidal Collagen Implant: A Randomized Control Trial.

PRCIS: Deep sclerectomy with intrascleral collagen implant (DSCI) was less effective in lowering intraocular pressure (IOP) than with suprachoroidal implantation. Further studies are needed to establish the potency and safety of deep sclerectomy with suprachoroidal collagen implant (DSSCI). PURPOSE: The purpose of this study was to analyze the safety and IOP-lowering effect of DSSCI in comparison with DSCI. SETTING: Geneva University Hospitals, Geneva, Switzerland. METHODS: This is a prospective, randomized, controlled study involving 13 patients (26 phakic eyes) with bilateral medically uncontrolled primary or secondary open-angle glaucoma. Bilateral deep sclerectomy was performed with each patient being randomly assigned to receive a collagen implant in the intrascleral space in one eye, and a suprachoroidal collagen implant in the other. Follow-up visits were performed at day 1; at week 1; and at months 6, 9, 12, 18, 30, 48, 54, and 60. RESULTS: Mean preoperative IOP was 24.1±4.2 mm Hg for DSCI group and 25.3±5.3 mm Hg for DSSCI group (P=0.1). The mean postoperative IOP was 14.8±4.0 mm Hg (DSCI) versus 9.8±3.7 mm Hg (DSSCI) at month 60 (P=0.01). Mean preoperative best-corrected visual acuity for the DSCI group was 0.76±0.22 and 0.74±0.23 for the DSSCI group (P=0.001), while the mean postoperative best-corrected visual acuity was 0.82±0.17 (DSCI) and 0.80±0.17 (DSSCI) at month 60 (P=0.004). CONCLUSIONS: DSSCI demonstrated a greater IOP-lowering effect than deep sclerectomy with intrascleral implantation. The safety profile of both methods was similar. More patients with a longer follow-up are required to comprehensively assess the safety and efficacy of this new approach.

Revisiting Results of Conventional Surgery: Trabeculectomy, Glaucoma Drainage Devices, and Deep Sclerectomy in the Era of MIGS.

How to cite this article: Bhartiya S, Dhingra D, et al. Revisiting Results of Conventional Surgery: Trabeculectomy, Glaucoma Drainage Devices, and Deep Sclerectomy in the Era of MIGS. J Curr Glaucoma Pract 2019;13(2):45-49.

The Quest for the Holy Grail of Glaucoma Surgery: Does Cypass Herald the End?

How to cite this article: Bhartiya S, Shaarawy T. The Quest for the Holy Grail of Glaucoma Surgery: Does Cypass Herald the End?. J Curr Glaucoma Pract 2018;12(3):99-101.

Comparing pattern scanning laser trabeculoplasty to selective laser trabeculoplasty: A randomized controlled trial.

PURPOSE: To compare safety, tolerability and intraocular pressure (IOP)-lowering efficacy of pattern scanning laser trabeculoplasty (PSLT) with selective laser trabeculoplasty (SLT) in fellow eyes of untreated patients with glaucoma. DESIGN: Randomized controlled trial. PARTICIPANTS: Twenty-nine patients (58 eyes) with primary and secondary open angle glaucoma (OAG) were randomized to undergo PSLT or SLT in each eye. METHODS: Pattern scanning laser trabeculoplasty was performed using the Pascal laser (Pascal Streamline 577; Topcon Inc., Tokyo, Japan). Patients' comfort level to treatment was assessed using a visual analogue scale (VAS). Follow-up visits were at week 1, month 1, 3 and 6. Success was defined as IOP reduction ≥20%. MAIN OUTCOME MEASURES: Safety, tolerability and IOP reduction. RESULTS: The mean age of patients was 54.1 ± 15.5 years. Baseline IOP was similar between both groups (PSLT, 17.3 ± 4.0 mmHg; SLT, 16.8 ± 3.6 mmHg, p > 0.05). In the PSLT group, the mean IOP at 1, 3 and 6 months was 14.2 ± 3.5, 13.9 ± 2.6 and 14.0 ± 2.7 mmHg, respectively. In the SLT group, the mean IOP at 1, 3 and 6 months was 14.4 ± 4.1, 13.7 ± 3.2 and 13.7 ± 3.1 mmHg, respectively. The IOP reduction in the PSLT group was greater than the SLT group at 1 month (p < 0.01) and 3 months (p < 0.01). VAS score was better in PSLT eyes: 23.9 ± 20.5 (range, 0-82) than in SLT eyes: 50.4 ± 25.3 (range, 0-98) (p < 0.001). No serious adverse events were recorded. CONCLUSIONS: Both laser modalities had similar safety and efficacy profiles while PSLT was better tolerated by patients.

The Suprachoroidal Route in Glaucoma Surgery.

Glaucoma surgeries targeting the uveoscleral drainage pathways have been drawing more attention lately. Among all the available techniques, procedures focusing on the supra-choroidal space seem particularly promising, by making use of a presumably efficient and secure outflow route and avoiding subconjunctival filtration blebs. The purpose of this review is to assess the efficacy and the security of the different suprachoroidal drainage implants, namely the CyPass Micro-Stent, the iStent Supra, the SOLX Gold Shunt, the Aquashunt, and the STARflo Glaucoma Implant. Most clinical studies seem to currently point toward the direction that there are actual benefits in suprachoroidal surgeries by avoiding bleb-related complications. Nevertheless, even suprachoroidal implants may be subject to scarring and failure. More data are still needed, especially concerning long-term effects, although the approach does seem appealing. How to cite this article: Gigon A, Shaarawy T. The Suprachoroidal Route in Glaucoma Surgery. J Curr Glaucoma Pract 2016;10(1): 13-20.

24-h Efficacy of Glaucoma Treatment Options.

Current management of glaucoma entails the medical, laser, or surgical reduction of intraocular pressure (IOP) to a predetermined level of target IOP, which is commensurate with either stability or delayed progression of visual loss. In the published literature, the hypothesis is often made that IOP control implies a single IOP measurement over time. Although the follow-up of glaucoma patients with single IOP measurements is quick and convenient, such measurements often do not adequately reflect the untreated IOP characteristics, or indeed the quality of treated IOP control during the 24-h cycle. Since glaucoma is a 24-h disease and the damaging effect of elevated IOP is continuous, it is logical that we should aim to understand the efficacy of all treatment options throughout the 24-h period. This article first reviews the concept and value of diurnal and 24-h IOP monitoring. It then critically evaluates selected available evidence on the 24-h efficacy of medical, laser and surgical therapy options. During the past decade several controlled trials have significantly enhanced our understanding on the 24-h efficacy of all glaucoma therapy options. Nevertheless, more long-term evidence is needed to better evaluate the 24-h efficacy of glaucoma therapy and the precise impact of IOP characteristics on glaucomatous progression and visual prognosis.

EX-PRESS glaucoma filtration device: Review of clinical experience and comparison with trabeculectomy.

Glaucoma filtration surgery is performed to reduce intraocular pressure (IOP) in patients for whom maximal tolerable pharmacologic IOP-lowering therapy and/or laser surgery fail to lower IOP sufficiently and/or fail to prevent optic nerve damage or visual field deterioration. For decades, the most widely utilized procedure for glaucoma filtration surgery has been trabeculectomy. Although this approach reliably provides long-term IOP reduction in many patients, the postoperative complication rate is high. This has driven the development of alternative approaches to reduce IOP surgically. The EX-PRESS glaucoma filtration device was developed to mimic IOP control by trabeculectomy and to have a better safety profile. This non-valved, medical-grade stainless steel device diverts aqueous humor from the anterior chamber to an intrascleral space. Despite the widespread use of the EX-PRESS device, only a few studies compare its efficacy and safety with that of trabeculectomy. We analyze available data regarding the safety and efficacy of the EX-PRESS device, particularly in comparison with trabeculectomy.

Supraciliary Micro-stent Implantation for Open-Angle Glaucoma Failing Topical Therapy: 1-Year Results of a Multicenter Study.

PURPOSE: To evaluate the safety and efficacy of a supraciliary micro-stent (CyPass Micro-Stent; Transcend Medical, Menlo Park, California, USA) for surgical treatment of glaucoma in patients refractory to topical medications. DESIGN: Multicenter, single-arm interventional study. METHODS: Patients with open-angle glaucoma (Shaffer Grade 3 and 4) and uncontrolled medicated intraocular pressure (IOP) >21 mm Hg at baseline and candidates for conventional glaucoma surgery were enrolled. Glaucoma medications were discontinued at surgery and resumed at investigator discretion. CyPass Micro-Stent implantation was completed in all patients using a standard clear corneal approach. Adverse events, postoperative IOP changes, and need for IOP-lowering medications during the first 12 postoperative months (12M) were monitored. RESULTS: Sixty-five eyes were enrolled, and 55 were available at 12M, accounting for loss to follow-up and early termination. Baseline IOP was 24.5 ± 2.8 mm Hg, and the mean number of medications recorded was 2.2 ± 1.1. There were no serious intraoperative events or major adverse events (eg, retinal or choroidal detachment, persistent uveitis, persistent hyphema, hypotony maculopathy). The most common adverse events included IOP increases >30 mm Hg beyond 1 month (11%, 7/65), transient hyphema (6%, 4/65), and cataract progression (12%, 5/41 phakic eyes). Mean IOP was 16.4 ± 5.5 mm Hg at 12 months-a 34.7% reduction (P < .0001). Mean medication usage also decreased from baseline to a mean of 1.4 ± 1.3 medications at 12M (P = .002). In eyes originally indicated for conventional glaucoma surgery, no secondary surgery was performed in 83% (53/64). CONCLUSION: Supraciliary stenting with the CyPass Micro-Stent effectively lowers IOP as a surgical treatment for glaucoma, precluding the need for more invasive glaucoma surgery in >80% of patients at 1 year, thereby reducing postoperative glaucoma surgical complications.

Determination of bleb capsule porosity with an experimental glaucoma drainage device and measurement system.

IMPORTANCE: Control of intraocular pressure after implantation of a glaucoma drainage device (GDD) depends on the porosity of the capsule that forms around the plate of the GDD. OBJECTIVE: To compare capsular porosity after insertion of 2 different GDDs using a novel implant and measurement system. DESIGN, SETTING, AND SUBJECTS: We performed an experimental interventional study at an eye research facility in a tertiary eye care center. Testing was performed on 22 adult New Zealand white rabbits that received the experimental GDD or an existing GDD. INTERVENTIONS: A new experimental GDD, the Center for Eye Research Australia (CERA) implant, was created using computer-aided design and a 3-dimensional printer. The CERA GDDs were implanted in the eyes of rabbits randomized into 1 of the following 3 groups: with no connection to the anterior chamber (n = 7), with connection to the anterior chamber for 1 week (n = 5), and with connection to the anterior chamber for 4 weeks (n = 5). In a control group (n = 5), a pediatric GDD was implanted without connection to the anterior chamber. We measured the capsular porosity using a pressure-gated picoliter pump at a driving pressure of 12 mm Hg. The animals were killed humanely for histologic study. MAIN OUTCOMES AND MEASURES: Porosity of the fibrous capsule around the implant. RESULTS: We found no difference in mean (SEM) capsular porosity between the CERA (3.39 [0.76; 95% CI, 1.43-5.48] µL/min) and pediatric (4.52 [0.52; 95% CI, 3.19-5.95] µL/min) GDDs (P = .28, unpaired t test) at 4 weeks without aqueous exposure. Mean (SEM) capsular porosity of CERA GDDs connected to the anterior chamber at 1 week was 2.46 (0.36; 95% CI, 1.55-3.44) µL/min but decreased to 0.67 (0.07; 95% CI, 0.49-0.86) µL/min at 4 weeks (P = .001, unpaired t test). CONCLUSIONS AND RELEVANCE: Our experimental method permits direct measurement of capsular porosity of an in situ GDD. In a comparison between an experimental (CERA) and an existing GDD, no differences were identified in capsular porosity or histologic reaction between the implants. These results suggest that the CERA GDD model can be used to test key components of glaucoma surgery and implant design.

Update on Schlemm's canal based procedures.

Surgical options for glaucoma have expanded in recent years. This article provides an evidence-based update on the novel or emerging surgical techniques for the treatment of open-angle glaucoma that are based on the Schlemm's canal (SC). Canaloplasty is an ab externo approach and was developed as an alternative to traditional filtering surgeries. The Hydrus microstent (Ivantis Inc., Irvine, CA) is a so-called SC scaffold that directly bypasses the trabecular meshwork to drain aqueous humor into the SC, which it keeps dilated over approximately one quadrant. Canaloplasty has also been shown to lower intraocular pressure (IOP) by up to 40% and combined with cataract surgery. IOP was lowered 44% at 24 months while maintaining a favorable safety profile. The Hydrus device has been proposed as an adjunct to cataract extraction surgery. To date, no published evidence from clinical trials is available on its in vivo safety and efficacy. Schlemm's canal based glaucoma procedures show promise as alternative treatments to traditional glaucoma surgery. Surgeons must be comfortable with angle anatomy. A prerequisite for functionality of these techniques is the integrity of the distal outflow system. At present, however, it is not possible to conclude whether these novel procedures will be viable alternatives to standard filtering surgery over the long-term.

Glaucoma surgery: taking the sub-conjunctival route.

We are currently in the midst of a surge in interest in glaucoma surgery. Novel pathways for reducing intraocular pressure (IOP) have been tried with various levels of success over the last few years. While the trabecular bypass and suprachoroidal approaches have captured much of the attention, filtering aqueous into the sub-conjunctival space remains the gold standard for lowering IOP. This review attempts to focus on current research in surgical methods to enhance filtration by potentially improving on tried and tested methods like the trabeculectomy, deep sclerectomy, and tube surgeries.