Treatment outcomes in the Tube Versus Trabeculectomy (TVT) study after five years of follow-up

24-Month Outcomes of Ahmed ClearPath® Glaucoma Drainage Device for Refractory Glaucoma

Purpose

To describe the safety and efficacy of the Ahmed ClearPath^® (ACP) 250 mm² glaucoma drainage device (GDD) in the treatment of refractory primary open-angle glaucoma (POAG).

Patients and methods

This was a retrospective, noncomparative, single-surgeon, interventional case series of adult patients with medically ± surgically refractory POAG undergoing ACP implantation. Intraocular pressure (IOP), the number of glaucoma medications, and complications were recorded over 24 months of follow-up. Primary outcomes included mean reductions in both IOP and medication use through 24 months, and secondary outcomes included the proportion of eyes achieving an IOP between 6 and 19 mmHg, IOP reduction by ≥20%, and reduction by ≥1 medication at last mean follow-up.

Results

Twelve eyes of 11 patients (mean age 71.3 ± 14.1 years) fit inclusion criteria and were enrolled. Most patients were Caucasian (n = 8), female (n = 10), and all had severe POAG (n = 11). The mean last follow-up was 18 months, at which time the mean (standard deviation) baseline IOP of 29.0 (7.6) mmHg was reduced to 12.2 (4.0) mmHg (58% reduction). 91.7% of eyes achieved an IOP between 6 and 19 mmHg, and 100% of eyes met an IOP reduction of ≥20%. Mean baseline number of glaucoma medications was 3.0 (0.9) and was reduced to 0.5 (0.7) at last mean follow-up (83.3% reduction), with 91.7% of eyes using ≥1 fewer medications. No long-term complications were observed, and short-term complications (mild hyphema, inflammation, and pain) were resolved by month 3.

Conclusion

To our knowledge, this is the second long-term study evaluating the efficacy of the Ahmed ClearPath drainage device in adult patients, and the first study with 24-months follow-up. The ACP device is safe and effective at reducing both IOP and medication burdens in patients with severe POAG. Additionally, minimal short-term complications were noted with no long-term adverse effects, increasing comfort for both the surgeon and the patient.

Short-term Efficacy and Safety of Open Conjunctiva ab Externo XEN45 Gel Stent Implantation in Glaucoma Patients

PRCIS

We examined the safety and efficacy of the open conjunctiva ab externo approach for XEN45 gel stent implantation. There was a significant reduction in intraocular pressure and number of glaucoma medications at 12 months follow-up.

PURPOSE

This study aims to determine the safety and efficacy of the open conjunctiva ab externo approach to XEN45 stent implantation.

METHODS

Retrospective chart review of all patients between July 2018 and March 2020 who underwent XEN implantation. IOP and number of glaucoma medications were measured at the preoperative, 1 day, 1 week, 1-, 3-, 6-, and 12 months postoperative appointments. The primary outcome of this study is the number of cases achieving complete success at 12 months postoperative.

RESULTS

44 eyes of 44 patients were included. Mean preoperative IOP was 26.2±8.7 mmHg on 3.2±0.7 IOP-lowering medications. At 12 months postoperative, mean IOP was 18.9±9.1 mmHg (n=35, P<0.0001; mean reduction of 27.9%) on 0.9±1.4 (n=35, P<0.0001) IOP-lowering medications. Postoperative needling was performed in 5 cases (11.4%). Of the 35 cases with a postoperative visit at 12 months, complete success was achieved in 14 cases (40.0%) and qualified success in 3 cases (8.6%). Eighteen cases (51.4%) were recorded as failures at 12 months, comprised of 4 cases requiring reoperation for glaucoma (2 XEN implants, 1 trabeculectomy, and 1 Baerveldt implant), and 14 cases that did not meet the IOP-lowering criteria for success. During the postoperative course, there was one case of self-limited hypotony, two self-resolving choroidal effusions, and three cases of bleb leakage.

CONCLUSIONS

The open conjunctiva ab externo approach to XEN45 implantation achieved successful levels of IOP reduction in 48.6% of glaucoma cases within the first year. The most common adverse events included the need for additional glaucoma surgery (excluding needling procedures), transient hypotony, and bleb leak.

The effect of the hypertensive phase on the long-term outcomes of Ahmed glaucoma valve (AGV) implantation

BACKGROUND

To investigate the long-term effect of hypertensive phase (HP) on the clinical outcomes of Ahmed glaucoma valve (AGV) implantation.

METHOD

The records of patients with different etiologies of glaucoma who underwent AGV implantation with at least 3 years of follow-up were retrospectively reviewed. HP was defined as the IOP > 21 mm Hg during the first three months after surgery. The main outcome measure was cumulative success defined as 5 < IOP ≤ 21 mmHg and 20% reduction from the baseline with or without IOP lowering medications. Results that do not achieve cumulative success or undergo glaucoma reoperation during the follow-up period are considered failures. The secondary outcome measures were intraocular pressure (IOP) and the number of glaucoma medications.

RESULTS

A total of 120 patients (28 patients of HP, 92 patients without HP) with an average age (± SD) of 48.9 ± 19.6 years and a mean follow-up of 4.5 ± 1.4 years were enrolled. The mean duration of survival was 5.3 ± 0.5 years in HP which was significantly shorter than 6.4 ± 0.2 years in non-HP (log rank = 4.2, P = 0.04). Mean IOP and number of IOP lowering agents were higher in postoperative visits at 1,2, 3, and 4 years in HP patients compared with non-HP (all Ps < 0.01). Higher baseline IOP was significantly associated with higher rates of surgical failure.

CONCLUSION

In the long-term follow-up, the duration of survival was significantly longer in the non-HP group. In the non-HP group, the failure rate was significantly lower than the HP group.

Six-month outcomes of combined conventional needle goniotomy and phacoemulsification in eyes with early to moderate primary open-angle and pseudoexfoliation glaucoma and ocular hypertension

Purpose:

Angle-based surgeries for the treatment of open-angle glaucoma have gained popularity in recent years. This study aimed to evaluate the efficacy of combined phacoemulsification and goniotomy in primary open-angle and pseudoexfoliation glaucoma (POAG and PXG) and ocular hypertension (OHTN).

Methods:

In this interventional case series in the setting of the Glaucoma Service at the Farabi Eye Hospital, 32 eyes of 30 patients with early-to-moderate POAG and PXG and OHTN were enrolled. All eyes underwent combined phacoemulsification and needle goniotomy. Intraocular pressure (IOP) and the number of antiglaucoma medications as well as demographic data were recorded at baseline and one day, one week, one month, three months, and six months after the surgery. Generalized Estimating Equation (GEE) was used to compare the values of IOP and the number of medications at different time points. Kaplan–Meier graph was used to demonstrate the survival status of the eyes.

Results:

Mean IOP at baseline was 21.8 ± 4.6 mmHg on mean 1.2 ± 1.5 topical medications. There was a 25.2% (16.3 ± 4.5 mmHg) and 32.1% (14.8 ± 3.9 mmHg) reduction in IOP at three and six months after procedure, respectively (P < 0.001). Meanwhile, the decline in medications was 66.7% (0.4 ± 0.9) and 50.0% (0.6 ± 1.1) at the same time points (P = 0.002 and P = 0.048, respectively). Post-operative complications were clot hyphema (n = 1, 3.1%), fibrinous inflammation (n = 1, 3.1%) and distorted pupil (n = 2, 6.3%).

Conclusion:

Combined phacoemulsification and needle goniotomy as a procedure for mild and moderate POAG and PXG and OHTN is as effective as other modified goniotomies in the setting of minimally invasive glaucoma surgeries (MIGS).

Corneal Edema and Keratoplasty: Risk Factors in Eyes With Previous Glaucoma Drainage Devices

PURPOSE

To assess risk factors contributing to corneal decompensation following glaucoma drainage device (GDD) implantation.

DESIGN

Retrospective case control study.

METHODS

Records of 1610 eyes that underwent GDD implantation between June 1, 2009, and April 1, 2020, at the Johns Hopkins Wilmer Eye Institute were reviewed. Seventy-nine eyes (5%) developed corneal decompensation, of which 46 underwent keratoplasty. These 79 cases were matched with 220 controls. Cox proportional hazard models with robust standard error estimates to account for clustering at the matched-pair level were used to assess risk factors for corneal decompensation. Kaplan-Meier survival analysis analyzed time to corneal decompensation.

RESULTS

The mean (SD) age of cases and controls was 68 (12.3) and 60.5 (15.9) years, respectively. The mean time from GDD implantation to corneal decompensation was 32 months, and the cumulative probability of developing decompensation at 3, 6, and 9 years was 4.7%, 9.2%, and 14.8%, respectively. Final visual outcomes in cases were worse, with a final mean ± SD visual acuity (logMAR) of 1.96±1.25 relative to a mean±SD visual acuity of 1.11±1.36 in controls (P < .001). In the multivariable model, significant risk factors for corneal decompensation were increased age (adjusted hazard ratio [AHR] 1.39, 95% CI 1.18, 1.63; P ≤ .001), history of Fuchs dystrophy or iridocorneal endothelial syndrome (AHR 9.18, 95% CI 5.35, 15.74; P ≤ .001), and postoperative complications such as hypotony (AHR 3.25, 95% CI 1.85, 5.72; P ≤ .001) and tube-cornea touch (AHR 6.37, 95% CI 3.77, 10.75; P ≤ .001).

CONCLUSIONS

The risk of postoperative corneal decompensation is persistent over time. Patients receiving GDDs, particularly those with advanced age, preexisting corneal pathology, and postoperative complications, should be counseled regarding their increased risk for corneal decompensation.

Cost Utility of Schlemm's Canal Microstent Injection With Cataract Surgery for Open-angle Glaucoma in the US Medicare System

PRCIS

Hydrus microstent (HMS) implantation at the time of cataract surgery appears to be cost-effective in mild-to-moderate glaucoma. However, long-term follow-up is essential for a full assessment of device performance, safety and cost-effectiveness.

PURPOSE

The aim was to assess the societal cost-utility to the US Medicare system of implanting HMS with cataract surgery versus cataract surgery alone in patients with open-angle glaucoma.

PATIENTS

Markov model cohort of patients with mild-to-moderate open-angle glaucoma and visually significant cataract.

METHODS

Patients received HMS during cataract surgery versus cataract surgery alone, in a deterministic model over a 2-year horizon using TreeAge software. Both arms received additional ocular hypotensive agents to control intraocular pressure. Treatment effect of HMS was measured as mean number of ocular hypotensive medications and intraocular pressure, which directly impacted transition probabilities. Health states included the Hodapp-Parrish-Anderson glaucoma stages (mild, moderate, advanced, blind) and death. One-way sensitivity and probabilistic sensitivity analyses were conducted on device efficacy and longer time horizons.

RESULTS

At 2 years, HMS with cataract surgery in mild glaucoma had an incremental cost-utility ratio of USD 38,346.43 per utility gained, compared with cataract surgery alone. Probabilistic sensitivity analysis was cost-effective in 61.4% of iterations for HMS+cataract surgery. The probability of side-effects with eye drops, utility decrement with side-effects, cost of the HMS and real-world efficacy rate had the greatest impact on model outcomes. HMS must be 85.60% as effective as published data to maintain cost-effectiveness at a willingness-to-pay threshold of USD 50,000. The incremental cost-utility ratio of HMS with cataract surgery in moderate glaucoma was USD 42,895.38.

CONCLUSIONS

HMS implantation during cataract surgery appears to be cost-effective for patients with mild-to-moderate glaucoma. Nevertheless, more long-term safety and efficacy data are required.

Outcomes of Baerveldt Glaucoma Drainage Devices in Pediatric Eyes

PRCIS

In children, Baerveldt implants showed 84% success at 1 year, but decreased to 32% at 8 years. Age, race, and glaucoma type were not risk factors for failure. Concurrent intraocular surgery was associated with complications.

PURPOSE

Evaluate success and risk factors for failure and complications of Baerveldt glaucoma implants in children.

METHODS

Retrospective case series of children who underwent Baerveldt implant placement (2012-2019 by single surgeon) with ≥1 year follow-up. Ocular examination and surgical details were collected. Failure defined as intraocular pressure (IOP) <5 mm Hg or >21 mm Hg for 2 consecutive visits, need for IOP related surgery, or visually significant complication.

RESULTS

One hundred-six eyes of 76 patients underwent 110 Baerveldt placement at median 6.4 years. Baerveldt placement was combined with additional procedures in 49% with vitrectomy most common (30%). Success of first Baerveldt (per patient) was 64% at final follow-up (median 4.7 y). One-, 5-, and 8-year survival rates were 84%, 60%, and 32%, respectively. There was no difference (P=0.97) in survival between first Baerveldt and all Baerveldt surgeries. Failure of first Baerveldt was not associated with sex, age, ethnicity, prior IOP-lowering surgery, concurrent intraocular surgery, or glaucoma type. Complications occurred in 14% and were associated with concurrent surgery. Twenty-six percent required additional IOP-lowering surgery. At final follow-up, IOP and glaucoma medications were significantly decreased (P<0.0001). Eyes underwent an average of 3.8±2.3 ocular surgeries and 3.0±2.0 glaucoma surgeries.

CONCLUSIONS

Baerveldt implants showed good success initially, but survival rates declined over time. No risk factors for failure of first implanted Baerveldt were identified. Concurrent surgery was associated with complications. Majority of eyes required multiple surgeries to achieve IOP control and preserve vision.

Survey of glaucoma surgical preferences among glaucoma specialists in Spain

PURPOSE

To evaluate the spectrum of glaucoma surgery undertaken among members of the Spanish Glaucoma Society (SEG).

METHODS

A 10 question web-based anonimous survey was mailed through the Annals of the Spanish Glaucoma Society to all its members on January, February and July 2019 to determine their preferred surgical approach.

MAIN OUTCOME MEASURES

Age, type of Glaucoma, surgery undertaken, type of anti-scarring strategy and prothesis introduced for the last 10 surgeries since the survey was received. The surgeon experience was registered in years of practice.

RESULTS

A total of 97 SEG members across the country answered the survey. Sixty-two (63.4%) responders had more than 10 years of experience. Primary open angle glaucoma was the most frequent type of glaucoma (60.6%). The most popular surgery was deep-sclerectomy (37.3%) followed by trabeculectomy (17,6%) and the collagen microshunt (XEN® Allergan Inc., Irvine, CA) (14.1%). Glaucoma drainage device (GDD) was used in 10.5% of the cases. Up to 21.7% of surgeries were reinterventions, where GDD was used in 27.3% and trabeculectomy in 20.3% of the cases. Glaucoma surgery was combined with phacoemulsification in 47.3% of the eyes. Mitomycin C (MMC) was used in 54,8% of the cases, collagen matrix (Ologen®, Aeon Astron Corporation, Taipei, Taiwan) was used alone in 8.2% of the cases and in 13,7% combined with MMC. MMC was used in a soaked sponge in 79% of cases (concentrations of 0.02% in 99% and 0.04% in 1%) and in 21% of cases MMC was injected subconjunctivally (concentrations of 0,01% in 81% and 0.02% in 19%).

CONCLUSIONS

Although the glaucoma surgeon performs a wide range of surgical techniques, deep sclerectomy remains the most widely used surgical technique in Spain. Combined cataract and glaucoma surgery is performed almost in half of the patients and MMC is the most frequently selected antifibrotic agent, alone or combined with collagen matrix. The new minimal invasive surgical techniques represent the 20% of the total.

Analysis of risk factors and ocular hypotony characteristics in choroidal detachment after penetrating glaucoma surgery

PURPOSE

To analyze the risk factors and ocular hypotony characteristics of choroidal detachment (CD) after penetrating glaucoma surgery and to compare between eyes with and without CD.

METHODS

This retrospective study enrolled 173 eyes of 168 patients. Patients who underwent trabeculectomy or Ahmed glaucoma valve implantation due to medically uncontrolled glaucoma and who had intraocular pressure (IOP) < 9 mmHg at any time during the first postoperative week were included.

RESULTS

The study population consisted of 61 (36.3%) females and 107 (63.7%) males with a mean age of 60.7 ± 14.2 years. The postoperative median follow-up time was 24 months (range, 12-40 months). Postoperatively, CD developed in 47 (27.1%) eyes. Multivariate analyses demonstrated that eyes with high preoperative IOP (> 40 mmHg) were 12.1 times more likely to develop CD (p = 0.000) and that presence of IOP < 9 mmHg on the first day of surgery increased the CD risk 3.8 times (p = 0.002); male gender raised the risk 2.7 times (p = 0.028). The mean preoperative IOP in CD eyes was significantly higher than in non-CD eyes (p = 0.000). The mean IOP change between preoperative and lowest IOP was significantly greater in those with CD than in those without CD (p = 0.000). The mean lowest IOP in the CD eyes was significantly lower than in the non-CD eyes (p = 0.037). For the surgical failure rate, no significant difference was found between the CD and the non-CD groups (p = 0.14).

CONCLUSIONS

The present study demonstrated that high preoperative IOP, presence of IOP < 9 mmHg on the first postoperative day, and male gender were significantly associated with CD after penetrating glaucoma surgery. Choroidal detachment accompanied by hypotony did not affect the final outcome negatively.

Glaucoma control after phacoemulsification in eyes with functioning glaucoma filtration surgeries: trabeculectomies versus glaucoma drainage devices

PURPOSE

Several studies have demonstrated decompensation of intraocular pressure (IOP) control following phacoemulsification in eyes with a functioning trabeculectomy. Limited evidence base suggests that this effect is minimal in eyes with functioning glaucoma drainage devices (GDD). The aim of this study was to report on glaucoma control after phacoemulsification in eyes with a functioning GDD compared to eyes with a functioning trabeculectomy.

METHODS

Single-centre retrospective comparative study of patients with a functioning non-valved GDD (Baerveldt 350; Johnson & Johnson Surgical Vision) or trabeculectomy undergoing phacoemulsification. Glaucoma outcomes including IOP, cup:disc ratio (CDR), global retinal nerve fibre layer (RNFL) thickness and visual field mean deviation (MD) are reported. Failure was defined as IOP rise > 20% from baseline.

RESULTS

Fifteen eyes with a functioning trabeculectomy and twenty-three eyes with a functioning GDD with 24-month post-phacoemulsification data were identified. Mean IOPs were significantly lower in the trabeculectomy group at month 24 compared to the GDD group, 9.5 and 15.9 mmHg (p = 0.001) respectively. At month 12, there was significant worsening on MD in GDD group compared to trabeculectomy group, - 20.0 dB and - 11.3 dB respectively (p = 0.03). A greater proportion of eyes failed in the GDD group compared to the trabeculectomy group, N = 15 (65%) and n = 7 (47%), p = 0.26.

CONCLUSION

As with functioning trabeculectomies, phacoemulsification should be approached with similar caution in eyes with functioning GDD. An existing GDD is at least as likely to fail following clear corneal phacoemulsification as an existing trabeculectomy and non-augmented GDDs may be at greater risk.

How Can We Quantify and Compare Harm in Surgical Trials?

PURPOSE

To describe methods that can be used to quantify and compare harm caused by surgical interventions in ophthalmology trials.

DESIGN

Perspective study.

METHODS

A published landmark glaucoma trial was used as an exemplar. A consensus-derived classification system of severity of complications was applied to published data of the Tube Versus Trabeculectomy glaucoma trial. The severity grade of each complication was multiplied to the number of patients who incurred that complication to estimate a total harm score for each intervention. Graphical tools were also used to display the differences in complications between trial arms. A review of literature on best practice for reporting harm data was also conducted.

RESULTS

Analyzing treatment harm is challenging with the relatively small number of events and sample sizes used in randomized controlled trials. However, quantification and graphical representation of harm after surgery is possible. Reframing the research question to one for detecting signals of adverse reactions and use of Bayesian analyses can be useful.

CONCLUSIONS

Analysis of harm data in clinical trials needs further attention. A severity classification system and a total harm score can be used to quantify harm after glaucoma surgery. Graphical tools can also help interpret complication data.

Trabeculectomy Efficacy in a Latin American Ophthalmology Training Institution

Aim

To report trabeculectomy efficacy in a Latin American Ophthalmology Training Institution.

Materials and methods

Retrospective study between March 2015 and March 2019, Medical records of 77 patients (96 eyes) that underwent trabeculectomy were reviewed. Collected data included glaucoma type, pre- and post-trabeculectomy intraocular pressure (IOP) and glaucoma therapy and assigned surgeon. Data analysis included descriptive statistics, Paired T student double tailed, and Welch-Satterthwaite test.

Results

Ninety-six eyes (77 patients) that underwent trabeculectomy were included in the analysis. 44.79% were male and 55.20% female. Median age was 54.04 ± 18.92 years. Median IOP pretrabeculectomy was 27.86 ± 10 mm Hg. More commonly found diagnoses were narrow angle glaucoma (36.46%), primary open-angle glaucoma (18.75%), and secondary to chronic steroid use glaucoma (14.58%). Median IOP reduction from basal IOP at 6 weeks, 6 months, and 12 months after trabeculectomy was 15.87 mm Hg, 14.42 mm Hg and 14.55 mm Hg, respectively, p < 0.05. Cumulative success was 66.66% at 12 months follow-up. General decrease of antiglaucomatous topical therapy was 1.9 ± 1.09 (p > 0.05) eye drops. Trabeculectomy success rate was 69.23% for attendants and 65.71% for residents (p = 0.85).

Conclusion

Trabeculectomy continues to be a successful and effective therapy to obtain significant and stable IOP decrease. Success trabeculectomy rates are comparable between residents and attendants.

How to cite this article

López RAG, Castillo NLO. Trabeculectomy Efficacy in a Latin American Ophthalmology Training Institution. J Curr Glaucoma Pract 2022;16(1):17-19.

Anterior segment imaging in minimally invasive glaucoma surgery - A systematic review

Minimally invasive glaucoma surgery (MIGS) has grown in popularity over the past decade. This systematic review explores the peri-operative and intraoperative application of anterior segment imaging to maximize the efficacy and safety of MIGS. A review of the PubMed, EMBASE and CINAHL databases was conducted, with inclusion criteria restricted to MIGS that had received United States Food and Drug Administration (FDA) premarket approval, FDA 510(K) premarket notification, or were listed as a class 1 device exempt from FDA approval or notification. 21 manuscripts from 21 unique studies were identified pertaining to MIGS devices including the XEN Gel Stent, Trabectome, iStent Inject, 1st-generation iStent and the Kahook Dual Blade (KDB). Anterior segment imaging modalities included anterior segment optical coherence tomography (AS-OCT), ultrasound biomicroscopy (UBM), aqueous angiography, OCT volumetric scans and in vivo confocal microscopy. Identification and evaluation of aqueous outflow pathways before and after MIGS have potential for improving patient preoperative patient selection and postoperative outcomes. Intraoperative imaging potentially provides the resolution needed for good visualization of angle anatomy and accurate evaluation of surgical endpoints in angle-based MIGS. Anterior segment imaging has been used to identify procedural complications, provide objective information on implant location in relation to surrounding anatomy, assess the post-implantation structural impact of MIGS devices and manage bleb failure and scarring. Technical difficulties in incorporating imaging modalities into the surgical microscope, variable quality of images and optical interference from ocular structures or surgical instruments are remaining barriers, which discourage the widespread clinical use of this technology.

PRESERFLO™ MicroShunt versus trabeculectomy: first results on efficacy and safety

PURPOSE

To report efficacy and safety outcomes of the PRESERFLO™ MicroShunt compared with trabeculectomy, the current gold-standard treatment for advanced glaucoma, in the early and intermediate postoperative period.

METHODS

Institutional prospective interventional cohort study of primary open-angle glaucoma (POAG) patients scheduled for the PRESERFLO™ MicroShunt. The comparison group were POAG patients who had had received trabeculectomy and were matched for age, known duration of disease, number and classes of intraocular pressure (IOP)-lowering medications to ensure a similar conjunctival condition. The study is part of the Dresden Glaucoma and Treatment Study (DGTS), was not randomized, but used a uniform study design, with the same inclusion and exclusion criteria as well as standardized definitions of success and failure.

MAIN OUTCOME MEASURES

mean diurnal IOP (mdIOP, mean of 6 measurements), diurnal peak IOP, diurnal IOP fluctuations, glaucoma medical therapy, success rates, visual acuity, visual fields, surgical complications and interventions, and severe adverse events.

RESULTS

Fifty-two eyes of 52 patients, 26 in each group, were analysed. At 6 months, median [Q25, Q75] mdIOP was 10.8 [9.5-12.2] mmHg in the microshunt and 10.3 [7.6-11.8] mmHg in the trabeculectomy group. Reduction in mdIOP (p = 0.458), peak diurnal IOP (p = 0.539), and median diurnal fluctuation (p = 0.693) was not statistically significantly different between groups. The rate of interventions was statistically significantly higher in the trabeculectomy compared with the microshunt group (p = 0.004). None of the patients experienced severe adverse events.

CONCLUSION

Both procedures are equally effective and safe in lowering mdIOP in patients with POAG. Because the microshunt is less invasive with less follow-up and interventions needed postoperatively, it might be recommended earlier in the treatment of glaucoma.

Reintervention rate in glaucoma filtering surgery: A systematic review and meta-analysis

PURPOSE

Reintervention rate is an important factor impacting on patients, surgeons, and society. To date, only a few studies have focused on this topic. For this reason, a systematic review and meta-analysis was undertaken to assess the reintervention rate after glaucoma filtering surgery.

MATERIALS AND METHODS

Prospective studies reporting the reintervention rate after glaucoma filtering surgery and with at least 12 months of follow-up were systematically searched on PubMed, Medline and Embase databases. The primary outcome was the total reintervention rate following surgery. Secondary outcomes were: the rate of manipulation, in-clinic and in-operating room reintervention; the reintervention rate for intraocular pressure (IOP) control and for complications; demographic, clinical and surgical variables associated with reintervention rate.

RESULTS

Ninety-three studies with a total of 8345 eyes were eligible. The total reintervention rate was 1.84 (95% CI 1.57-2.13), with a lower rate for Baerveldt (0.53, 95% CI 0.29-0.83) and Preserflo (0.60, 95% CI 0.15-1.29), and a higher rate for Xen (4.26, 95% CI 2.59-6.31). The manipulation rate was 0.99 (95% CI 0.77-1.23), the in-clinic reintervention rate was 0.08 (95% CI 0.05-0.12) and the in-operating room reintervention rate was 0.28 (95% CI 0.22-0.35). The reintervention rate for IOP control was 1.26 (95% CI 1.04-1.51) and the reintervention rate for complications was 0.27 (95% CI 0.21-0.35).

CONCLUSIONS

All types of surgery presented a total reintervention rate similar to the overall findings, except studies on Baerveldt and Preserflo Microshunt, with a lower rate, and Xen, with a higher rate. None of the variables evaluated were found to be directly associated with the explored outcomes.

Emerging Evidence of Noncoding RNAs in Bleb Scarring after Glaucoma Filtration Surgery

PURPOSE

To conduct a narrative review of research articles on the potential anti- and pro-fibrotic mechanisms of noncoding RNAs following glaucoma filtration surgery.

METHODS

Keyword searches of PubMed, and Medline databases were conducted for articles discussing post-glaucoma filtration surgeries and noncoding RNA. Additional manual searches of reference lists of primary articles were performed.

RESULTS

Fifteen primary research articles were identified. Four of the included papers used microarrays and qRT-PCR to identify up- or down-regulated microRNA (miRNA, miR) profiles and direct further study, with the remainder focusing on miRNAs or long noncoding RNAs (lncRNAs) based on previous work in other organs or disease processes. The results of the reviewed papers identified miR-26a, -29b, -139, -155, and -200a as having anti-fibrotic effects. In contrast, miRs-200b and -216b may play pro-fibrotic roles in filtration surgery fibrosis. lncRNAs including H19, NR003923, and 00028 have demonstrated pro-fibrotic effects.

CONCLUSIONS

Noncoding RNAs including miRNAs and lncRNAs are emerging and promising therapeutic targets in the prevention of post-glaucoma filtration surgery fibrosis.

Tissue Reactivity to, and Stability of, Glaucoma Drainage Device Materials Placed Under Rabbit Conjunctiva

Purpose

To evaluate tissue reactivity to, and the stability of, glaucoma drainage device materials placed under rabbit conjunctiva in vivo.

Methods

Disks (diameter, 3 mm; thickness, ∼0.3 mm) fabricated from poly(styrene-block-isobutylene-block-styrene) (SIBS), silicone, stainless-steel, or glutaraldehyde cross-linked collagen (GACLC) were inserted under rabbit conjunctiva. Conjunctival and scleral sections obtained at 4, 8, and 12 weeks after surgery were immunostained for α-smooth muscle actin (SMA). The ratio of the maximum thickness of the α-SMA-positive conjunctiva to the scleral thickness (α-SMA/S ratio) was calculated. The in vivo stability of the drainage devices at 12 weeks after insertion was evaluated.

Results

The mean α-SMA/S ratios of the SIBS and silicone groups were lower than that of the stainless-steel group at 4 weeks after surgery (P < 0.05), and that of the SIBS group was lower than that of the GACLC group (P < 0.05). The ratios at 8 weeks after surgery were lower in the SIBS and silicone groups than in the GACLC group (P < 0.01). The ratios at 12 weeks after surgery were lower in the SIBS and silicone groups than in the GACLC group (P < 0.05). The surface areas of GACLC disks explanted from conjunctivae were significantly lower than that of intact disks (P < 0.01).

Conclusions

SIBS and silicon were highly biostable and exhibited less tissue reactivity than GACLC in vivo.

Translational Relevance

Comparisons of materials using animal models can predict the clinical stability and safety of such materials in humans.

Surgical Outcomes of Ahmed Glaucoma Valve Implantation with Postoperative Use of Prednisolone Acetate Versus Difluprednate

PURPOSE

To evaluate the effect of postoperative topical prednisolone acetate and difluprednate on surgical outcomes of Ahmed Glaucoma Valve (AGV) implantation.

DESIGN

Retrospective comparative case series PARTICIPANTS: The study population consisted of 102 eyes of 90 patients, including 52 eyes that received prednisolone acetate 1% (PF group) and 50 eyes that received difluprednate 0.05% (DZ group).

METHODS

The medical records of consecutive patients who underwent AGV implantation at the University of California San Francisco were retrospectively reviewed. Patients in the PF group received prednisolone acetate 1% 6-8 times per day tapered over 5-6 months, and patients in the DZ group received difluprednate 0.05% 4 times daily tapered over 4 months postoperatively.

MAIN OUTCOME MEASURES

Intraocular pressure (IOP), number of glaucoma medications, visual acuity (VA), postoperative complications, and rate of treatment success.

RESULTS

At 1 year, IOP (mean ± standard deviation) was 12.4 ± 3.7 mmHg in the DZ group and 13.0 ± 4.0 mmHg in the PF group (P = 0.49). The number of glaucoma medications was 0.72 ± 0.71 in the DZ group and 1.09 ± 0.91 in the PF group (P = 0.04), with a reduction from baseline of 2.5 ± 1.0 glaucoma medications in the DZ group and 1.8 ± 1.6 medications in the PF group (P = 0.01). LogMAR VA (mean ± SD) was 0.55 ± 0.80 in the DZ group and 0.59 ± 0.65 in the DZ group after 1 year of follow-up (P = 0.81). The cumulative probability of success was 95.8% in the DZ group and 93.5% in the PF group at 1 year (P = 0.61). Postoperative complications occurred in 4 eyes (7.7%) in the DZ group and 6 eyes (12%) in the PF group (P = 0.52).

CONCLUSIONS

After 1 year, postoperative treatment with difluprednate 0.05% following AGV implantation resulted in similar IOP with use of fewer glaucoma medications compared with prednisolone acetate 1%. The rates of treatment success and surgical complications were comparable between the two groups during the first year of follow-up.

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.

Minimally Invasive Micro Sclerostomy (MIMS) Procedure: A Novel Glaucoma Filtration Procedure

PRCIS

Intermediate-term results suggest that ab interno Minimally Invasive Micro Sclerostomy (MIMS) stent-less subconjunctival filtration procedure is a promising treatment option for patients with open-angle glaucoma (OAG).

PURPOSE

MIMS is a novel ab interno, stent-less, subconjunctival filtration procedure. This study set to investigate the safety, performance, and efficacy of MIMS in OAG patients.

METHODS

Prospective, open-label, single arm clinical trial with intrasubject comparisons. Study participants were adults with OAG who were candidates for a filtration procedure. Patients were operated by a single surgeon (A.A.) in Chennai, India. Following mitomycin-C pretreatment, ab interno MIMS procedure was performed alone or combined with phacoemulsification surgery. Procedure-related complications and adverse events were assessed. Primary outcomes: patients (%) achieving an intraocular pressure (IOP) ≥5 mm Hg and ≤18 mm Hg, and an IOP reduction of >20% as compared with baseline, with or without hypotensive medications, with no need for recurrent surgery.

RESULTS

Twenty-one phacoemulsification-MIMS and 10 standalone MIMS procedures were performed. Mean age was 63.94±6.33 years. Mean duration of MIMS was 1:58±0:25 (min:s). Scleral tunnels were achieved in all cases. No device malfunctions, intraoperative complications, or serious adverse events were reported. Five (16.12%) patients presented with iris clogging 1 to 24 weeks following procedure. Two were treated with laser and 3 required trabeculectomy. Mean IOP change from baseline at 24 weeks was 47.4% (31.2 to 16.4 mm Hg, P<0.0001, n=23). The mean difference was -14.8 mm Hg (95% confidence interval: -17.6, -11.9) with no statistically significant differences between groups. Qualified success was achieved in 21 (84%), 17 (74%), and 13 (93%) after 12, 24, and 52 weeks, respectively. Complete success was achieved in 17 (68%), 13 (57%), and 8 (57%) after 12, 24, and 52 weeks, respectively.

CONCLUSIONS

The interim results suggest that MIMS procedure may be a simple and effective surgical option for early OAG patients requiring target IOP in high teens although iris clogging of incision site is the major concern with this procedure.

The surgical management of glaucoma: A review

After a long period of little change, glaucoma surgery has experienced a dramatic rise in the number of possible procedures in the last two decades. Glaucoma filtering surgeries with mitomycin C and glaucoma drainage devices remain the standard of surgical care. Other newer surgeries, some of which are minimally or microinvasive glaucoma surgeries, target existing trabecular outflow, enhance suprachoroidal outflow, create subconjunctival blebs, or reduce aqueous production. Some require the implantation of a device such as the iStent, Hydrus, Ex-PRESS, XEN and PRESERFLO, whilst others do not-Trabectome, Kahook dual blade, Ab interno canaloplasty, gonioscopy-assisted transluminal trabeculotomy, OMNI and excimer laser trabeculotomy. Others are a less destructive variation of an established procedure, such as micropulse transscleral cyclophotocoagulation, endoscopic cyclophotocoagulation and ultrasound cycloplasty. Cataract surgery alone can be a significant glaucoma operation. These older and newer glaucoma surgeries, their mechanism of action, efficacy and complications are the subject of this review.

Posterior segment complications of Ahmed valve implantation

BACKGROUND

To assess the time, incidence, and outcome of posterior segment complications of Ahmed valve implantation (AVI).

METHODS

248 eyes that underwent AVI were reviewed retrospectively. Visual acuity, preoperative characteristics, and postoperative posterior segment complications were assessed.

RESULTS

The incidence of posterior segment complications of AVI was 31.4% (78/248). The mean follow-up period was 97.4 ± 53.5 months. The mean time to occur posterior segment complication was 1.5 months. The most common posterior segment complication was choroidal detachment (17.7%) and others included ocular decompression retinopathy (3.2%), hypotonic maculopathy (2.8%), vitreous hemorrhage (2.0%), retinal detachment (1.2%), endophthalmitis (1.2%), suprachoroidal hemorrhage (1.2%), epiretinal membrane (0.8%), cystoid macular edema (0.8%), and proliferative vitreoretinopathy (0.4%). Older age, hypertension, and postoperative hypotony had an increased risk of posterior segment complications of AVI.

CONCLUSIONS

The overall incidence of posterior segment complications of AVI was 31.4%. Older age, hypertension, and postoperative hypotony were significantly associated with posterior segment complications of AVI.

Evaluation of machine learning algorithms for trabeculectomy outcome prediction in patients with glaucoma

The purpose of this study was to evaluate the performance of machine learning algorithms to predict trabeculectomy surgical outcomes. Preoperative systemic, demographic and ocular data from consecutive trabeculectomy surgeries from a single academic institution between January 2014 and December 2018 were incorporated into models using random forest, support vector machine, artificial neural networks and multivariable logistic regression. Mean area under the receiver operating characteristic curve (AUC) and accuracy were used to evaluate the discrimination of each model to predict complete success of trabeculectomy surgery at 1 year. The top performing model was optimized using recursive feature selection and hyperparameter tuning. Calibration and net benefit of the final models were assessed. Among the 230 trabeculectomy surgeries performed on 184 patients, 104 (45.2%) were classified as complete success. Random forest was found to be the top performing model with an accuracy of 0.68 and AUC of 0.74 using 5-fold cross-validation to evaluate the final optimized model. These results provide evidence that machine learning models offer value in predicting trabeculectomy outcomes in patients with refractory glaucoma.

PreserFlo® MicroShunt: An Overview of This Minimally Invasive Device for Open-Angle Glaucoma

For moderate-to-severe glaucoma, trabeculectomy remains the “gold standard” intraocular pressure (IOP)-lowering treatment; nonetheless, this method requires extensive post-operative maintenance. Microinvasive glaucoma surgery (MIGS) treatments are designed to lessen intra- and post-operative care burden while offering an acceptable IOP decrease for individuals with mild to moderate glaucoma. The PreserFlo® MicroShunt (previously InnFocus MicroShunt) is an 8.5 mm glaucoma drainage device manufactured from poly(styrene-block-isobutylene-block-styrene) (SIBS), an extremely biocompatible and bioinert material. The lumen is narrow enough to prevent hypotony, but big enough to avoid being obstructed by sloughed cells or pigment. The device is implanted ab externo, as a stand-alone procedure or in conjunction with cataract surgery, with intraoperative mitomycin C, and a bleb is produced under the conjunctiva and Tenon’s capsule. The MicroShunt was CE-marked in 2012 and designed for primary open-angle glaucoma, the IOP of which remains uncontrolled after maximally tolerated topical treatment. Several clinical trials evaluating the MicroShunt’s long-term safety and effectiveness have been conducted, highlighting the effectiveness of the device over time, along with a tolerable safety profile. The present review aims to gather evidence of PreserFlo’s effectiveness and safety results almost 10 years after its introduction, and furthermore, to compare it with other MIGS and with the gold-standard trabeculectomy for glaucoma management.

Malignant glaucoma following gonioscopy-assisted transluminal trabeculotomy: a case report

BACKGROUND

To report a case of malignant glaucoma that developed after gonioscopy-assisted transluminal trabeculotomy (GATT).

CASE PRESENTATION

An 85-year-old male pseudophakic patient affected by pseudoexfoliative glaucoma (PEXG), unresponsive to medical glaucoma treatment, underwent uneventful GATT surgery. On the first day after surgery, the eye showed a shallow central and peripheral anterior chamber (AC) with a raised intraocular pressure (IOP) measured at 55 mmHg. Optical coherence tomography and ultrasound biomicroscopy confirmed the diagnosis of malignant glaucoma. Laser iridotomy, posterior capsulotomy and hyaloidotomy were performed, and the patient was treated with atropine sulphate 1%, maximum topical and systemic ocular hypotensive drugs with no improvement in the IOP. Subsequently, the patient underwent pars plana anterior vitrectomy, resulting in deepening of the AC with opening of the iridocorneal angle and decrease of the IOP. No further postoperative complications were recorded, and the IOP remained controlled 12 months after surgery without antiglaucoma medications.

CONCLUSIONS

Despite the minimally invasive profile of GATT, malignant glaucoma may develop after this procedure. Early recognition and prompt treatment are mandatory for preventing permanent visual loss.

The Outcomes of XEN Gel Stent Implantation: A Systematic Review and Meta-Analysis

Purpose

XEN gel stents are used for the treatment of open-angle glaucoma (OAG), including primary and secondary glaucoma that are uncontrolled by previous medical therapy and cases with previous failed surgery. Our aim was to systematically review of the clinical data of currently published ab-interno XEN gel stents with an emphasis on intraocular pressure (IOP), antiglaucoma medication outcomes, and safety profiles.

Methods

We analyzed all of the publications (MEDLINE, EMBASE, Cochrane Library) on the ab-interno XEN gel stent to evaluate the reduction in IOP and antiglaucoma medications following the procedure. The primary outcomes measured for the meta-analysis were reduction in IOP and anti-glaucoma medications. The secondary outcome were adverse events. For each study, we used a random effects analysis model to calculate the mean difference and 95% confidence intervals for the continuous results (reduction in IOP and antiglaucoma medications) using the inverse variance statistical method.

Results

Five hundred twenty-seven articles were checked and 56 studies were found to be relevant with a total of 4,410 eyes. There was a significant reduction in IOP as well as in the number of medications required in patients treated with ab-interno XEN implant either alone or combined with cataract surgery. This new treatment for various types of glaucoma reduced the IOP by 35% to a final average close to 15 mmHg. This reduction was accompanied by a decrease in the number of antiglaucoma medications in all the studies, approximately 2 classes of medication at the price of more needlings. The overall complete success rate was 21.0–70.8% after 2 years using strict criteria originally designed to record success rate in filtration surgery. The incidence of complications vision-threatening was low at <1%.

Conclusions

XEN gel stent was effective and safe for primary and secondary OAG. Further studies should be performed to investigate the impact of ethnicity on the success and failure rate after XEN implantation.

Bleb Analysis Using Anterior Segment Optical Coherence Tomography and Surgical Predictors of XEN Gel Stent

Purpose

To determine the early predictors of surgical success 6 months after XEN surgery among clinical parameters, including anterior segment optical coherence tomography (AS-OCT).

Methods

A total of 31 eyes with medically uncontrolled primary open-angle glaucoma or pseudoexfoliation glaucoma was enrolled retrospectively. Using AS-OCT, XEN tip location was categorized into intraconjunctival, intratenon, or uviform at day 1 and blebs were classified into no or low, high sparse, high thick, cystic, or mixed walls at month 6. Using slit-lamp photography, blebs were classified into no or low, localized avascular, diffuse avascular, localized vascular, or diffuse vascular blebs at month 6. Surgical success was defined as an intraocular pressure (IOP) of less than 14 mm Hg.

Results

Intraconjunctival and intratenon locations of the tip mostly created a high sparse wall, whereas the uviform type mostly created no or low wall and no or low bleb. The uviform type was linked to pseudoexfoliation glaucoma. A high sparse wall and diffuse avascular bleb showed a lower mean IOP than a high thick wall and localized vascular bleb. In the multivariate analysis, female sex and IOP at week 1 were early predictors of surgical success (8.45 times and 33.1% per 1 mm Hg-decrease, respectively).

Conclusions

Bleb evaluation using AS-OCT is valuable to correlate tip location and bleb morphology with clinical profiles, considering that a lower early postoperative IOP is linked to surgical success.

Translational Relevance

Bleb analysis using AS-OCT on day 1 could help to predict bleb morphology after 6 months, which is important to maintain the functioning bleb in the longer term.

Efficacy comparison of combined trabeculectomy with MMC and gonioscopy-assisted transluminal trabeculotomy

PURPOSE

To compare the efficacy of gonioscopy-assisted transluminal trabeculotomy combined with cataract surgery (PGATT) and trabeculectomy combined with cataract surgery (PTRAB) in open-angle glaucoma patients.

METHODS

A multi-centered, retrospective, non-randomized study included 67 PGATT patients and 70 PTRAB patients. We compared preoperative intraocular pressure (IOP), best-corrected visual acuity (BCVA) compared with early and final IOP, medication numbers, and BCVA levels. Success was determined as IOP reduction > 20% from baseline, IOP between 5 and 21 mmHg, preoperative IOP of higher than 21 mmHg with medication and postoperative IOP of less than 21 mmHg without medication for surgeries performed for intolerance to medication, postoperative IOP < 21 mmHg as well as < 18 mmHg separately without medications, and no need for further glaucoma surgery.

RESULTS

Preoperative IOP values were 28.61 ± 6.02 mmHg in PTRAB group and 23.99 ± 8.00 mmHg in PGATT group (P < 0.0001). Early postoperative IOP values were found lower in PTRAB group as 12.19 ± 3.41 mmHg and as 15.69 ± 4.67 mmHg in PGATT group (P < 0.0001). Last follow-up IOP reading were lower in PGATT group (P = 0.009). IOP difference values were found higher both in early and last postoperative periods in PTRAB group (respectively, P < 0.0001, P = 0.018). Success rates were found higher in both at lower than 21 and 18 mmHg levels in PGATT group (respectively, P = 0.014, P = 0.010).

CONCLUSION

We found the PGATT combined procedure to be a well-tolerated, effective procedure that can lower IOP both early and late in the postoperative period with different rates of IOP success compared with the combined PTRAB procedure.

Factors associated with the surgical outcomes of Baerveldt glaucoma implant for open-angle glaucoma, an age-related eye disease

To identify the factors associated with the surgical outcomes of Baerveldt glaucoma implant (BGI) for open-angle glaucoma (OAG), the medical records of 51 consecutive OAG patients (age, 43-91 years) who underwent BGI were retrospectively reviewed (median follow-up, 21.7 months). Surgical success was defined as the following postoperative intraocular pressures (IOPs, mmHg): (A) 6 ≤ IOP ≤ 21; (B) 6 ≤ IOP ≤ 18; and (C) 6 ≤ IOP ≤ 15 without loss of light perception or additional glaucoma surgery. Univariate analysis showed that age (all criteria), glaucoma type (criterion C), and preoperative IOP (criteria A and B) were the candidate factors (P < 0.20). When the patients were divided into two groups according to median age (72 years), the success probability was higher in the older group for criteria B (P = 0.047) and C (P = 0.02), and the postoperative IOP was lower in the older group 1-year post-surgery (P = 0.002). Furthermore, the multivariate Cox proportional hazards model revealed that older age was independently associated with surgical success for criteria B (relative risk [RR], 0.94; P = 0.02) and C (RR, 0.94; P = 0.01). In conclusion, older age is a factor associated with the surgical success of BGI for OAG.

Case report: Cataract extraction/lensectomy, excisional goniotomy and transscleral cyclophotocoagulation: Affordable combination MIGS for plateau iris glaucoma

We report the successful treatment of angle closure glaucoma and plateau iris with combined early cataract surgery/lensectomy, goniotomy, and transscleral cyclophotocoagulation. The underlying mechanism of angle closure and plateau iris was addressed with cataract extraction and goniosynechiolysis. Goniotomy was used to enhance trabecular meshwork outflow and lower intraocular pressure, and the "slow burn" transscleral cyclophotocoagulation was safely performed to reduce the size of the ciliary processes. The unique combinations of these procedures restored the iridocorneal angle anatomy to normalize IOP and prevent vision loss from glaucoma in patients with plateau iris. This is a cost-effective option with longer term efficacy.

Effects of Valproic Acid and Mitomycin C Combination Therapy in a Rabbit Model of Minimally Invasive Glaucoma Surgery

Purpose

This study aimed to compare the effectiveness of combination therapy consisting of low-dose mitomycin C (MMC) and valproic acid (VPA) against high-dose MMC for improving the scar phenotype in minimally invasive glaucoma surgery (MIGS).

Methods

A rabbit model of MIGS incorporating the PreserFlo MicroShunt was treated with high (0.4 mg/mL) or low (0.1 mg/mL) doses of MMC or with combination therapy consisting of low-dose (0.1 mg/mL) MMC and VPA. Operated eyes were examined by live ocular imaging, histochemical evaluation, multiphoton quantitation of collagen characteristics, and molecular analyses.

Results

Although high-dose MMC obliterated the vasculature, combination therapy vastly improved the postoperative tissue morphology by maintaining the vasculature without increased vascularization. Combination therapy also altered collagen morphology and reduced encapsulation of the MicroShunt distal end, which remained at risk with MMC treatment alone. Multiphoton quantitation indicated that the combination therapy significantly reduced collagen density and fiber dimensions compared with monotherapy. At the molecular level, combination therapy significantly reduced Vegfa, Vegfc, and Vegfd expression and inhibited Col1a1 upregulation from baseline levels, all of which low-dose MMC alone was unable to achieve. Notably, COL1A1 protein levels appeared more consistently suppressed by combination therapy compared with high-dose MMC alone.

Conclusions

Compared with high-dose MMC, combination therapy was less toxic by sparing the vasculature and potentially more effective in reducing scarring via the regulation of collagen content and organization.

Translational Relevance

VPA may be combined with low-dose MMC to replace high-dose MMC to deliver safe and effective anti-scarring outcomes.

Is canaloplasty with mitomycin c a safe procedure in myopic glaucoma?

PURPOSE

Myopic glaucoma patients display a considerable risk of complications following antiglaucomatous filtering surgery, e.g., trabeculectomy. Canaloplasty with mitomycin C may reduce this risk by avoiding massive overfiltration.

METHODS

We performed retrospective analysis of 31 eyes with myopia that underwent canaloplasty modified with mitomycin C in a consecutive single-surgeon case series. Annual data and success rates were analysed. Twenty-three myopic eyes that had received conventional trabeculectomy with mitomycin C were recorded as a comparison.

RESULTS

The 31 eyes with a follow-up of 40 ± 26 months after canaloplasty had a mean spherical equivalent of - 8.4 ± 4.5 dioptres. Intraocular pressure decreased from 32.3 ± 9.6 mmHg (range: 17 to 58) to 16.8 ± 8.1 mmHg (range: 5 to 44) 1 year after surgery (- 46%; p < 0.001) with a medication score reduction from 5 to 1.2 (p < 0.001). Qualified success rates (Criterion B: no revision surgery, IOP < 21 mmHg, IOP reduction > 20%) were 83% after 1 year and 61% at the 2nd and 3rd years. In 5 eyes (16%), early ocular hypotony (≤ 5 mmHg) was observed. Two eyes (7%) showed transient choroidal detachment and swelling. The 23 eyes that had received trabeculectomy had success rates (Criterion B) of 91% at the 1st and 86% at the 2nd and 3rd years. Hypotony occurred in 10 eyes (44%), and 4 eyes (17%) showed choroidal detachment or macular folds.

CONCLUSIONS

Postoperative complications related to overfiltration were less frequent after canaloplasty with mitomycin C. Midterm data proved good efficacy. Pressure reduction, success rates and rates of medication free patients were significantly higher in trabeculectomy compared to modified canaloplasty with mitomycin C.

Effect of prophylactic aqueous suppression on ahmed glaucoma valve surgery success

Purpose:

To evaluate the effect of prophylactic aqueous suppressants immediately post-Ahmed glaucoma valve (AGV) surgery on the rate of hypertensive phase and success.

Methods:

Retrospective case–control study of 80 eyes with refractory glaucoma undergoing AGV surgery. Forty eyes in the intervention group (preoperative aqueous suppressants continued postoperatively) and 40 in the control group (all glaucoma drops stopped after surgery and reintroduced as required) were included in this study. Patients were followed for 1 year. Data collected included intraocular pressure (IOP), number of glaucoma medications, and number of eyes requiring further IOP lowering surgery. The frequency of hypertensive phase and 1-year success was compared between the groups.

Results:

Hypertensive phase occurred in 22.5% of the intervention group compared to 42.5% of the control group; however, this difference was not statistically significant (P = 0.06). Success at 1 year (IOP ≤21 mmHg but ≥5 mmHg and 20% reduction from baseline without additional surgery) was similar in each group: 77.5% in the intervention group and 62.5% in the control group (P = 0.22). However, at 1 year, significantly more eyes in the intervention group had an IOP ≤17 mmHg (95% vs. 80%, P = 0.04). The mean time interval to a second IOP lowering procedure was significantly shorter in the control group (P < 0.005).

Conclusions:

With prophylactic preoperative aqueous suppressants, more eyes achieved an IOP of ≤17 mmHg. The time interval to repeat the glaucoma procedure was significantly shorter in the control group.

Outcomes of Resident Performed Hydrus, iStent, and Kahook Glaucoma Procedures in a Predominantly African American Population

PRCIS

This retrospective study characterized the efficacy and safety of 3 different microinvasive glaucoma surgery (MIGS) procedures in a predominantly African American population at the Philadelphia Veterans Affairs Hospital (Hydrus, Kahook, iStent), demonstrating no significant difference in intraocular pressure (IOP) and medication reduction between the 3 at long-term follow-up.

PURPOSE

To compare the efficacy and safety of 3 different MIGS procedures in a predominantly African American population.

METHODS

Retrospective cohort study of patients undergoing cataract extraction combined with 1 of 3 MIGS procedures (Hydrus, iStent, Kahook) at the Philadelphia Veterans Affairs Medical Center between January 1, 2015 and November 1, 2020. Analysis of variance and regression models were used to compare reduction in IOP and medication use among 3 MIGS types.

RESULTS

A total of 123 eyes of 112 patients were included, including 56 (45.5%) eyes for Hydrus, 40 (32.5%) eyes for iStent, and 27 (22.0%) eyes for Kahook. Adjusted mean IOP reduction was greater for Hydrus at postoperative day 1 (-4.49 vs. -1.76 for iStent and -1.69 for Kahook, P=0.05 and greater for Kahook at postoperative week 1 (-2.53 vs. +0.70 for iStent vs. -1.41 for Hydrus, P=0.02), but did not differ significantly between MIGS types at subsequent postoperative visits (all P>0.05). In multivariable analysis, MIGS type was not significantly associated with reduction in IOP or medication use at 9 to 12 months postoperatively. There were no significant differences in complication rates across MIGS types.

CONCLUSION

In this study, the difference in IOP lowering and medication reduction postoperatively between the Hydrus, iStent, and Kahook was not statistically significant after postoperative day 1. More studies are needed to evaluate outcomes of MIGS surgeries in glaucoma populations of different disease severity.

Evaluation of Adverse Effects of Topical Glaucoma Medications on Trabeculectomy Outcomes Using the Glaucoma Medications Intensity Index

Introduction

Trabeculectomy is commonly performed for glaucoma when medications are unable to control disease progression or have intolerable adverse effects. Previous studies have suggested that a higher number of and/or longer treatment duration with preoperative topical glaucoma medications are associated with a higher risk of trabeculectomy failure, but most of these studies lack quantification of exposure. The aim of this study was to investigate the relationship between preoperative exposure to topical glaucoma medications and trabeculectomy outcome, using a new method for quantifying accumulated exposure.

Methods

Consecutive patients with primary open-angle glaucoma (POAG) or normal-tension glaucoma (NTG) who underwent primary trabeculectomy between 2013 and 2017 were retrospectively reviewed. The Glaucoma Medications Intensity Index (GMII) was calculated for each eye by multiplying the number of drops per week by duration of use (in years). The relationship between the GMII and postoperative outcome in terms of 1- and 2-year success rates and survival time was analyzed.

Results

A total of 55 eyes from 40 subjects were analyzed, all with follow-up > 6 months (mean 2.72 ± 1.46 years). The GMII for eyes with successful (n = 41) and failed (n = 14) outcome at last visit was 111.71 ± 78.59 and 167.41 ± 85.04, respectively, and significantly higher in failed eyes (P = 0.03). Univariate regression analysis of age, gender, cup–disc ratio, previous phacoemulsification, diabetes, hypertension, dyslipidemia, preoperative number of glaucoma medications/treatment duration/intraocular pressure (IOP), and GMII showed age and GMII to be possible predictors of treatment failure. On subsequent multivariate analysis, only GMII was correlated with failure (odds ratio 1.021, 95% confidence interval 1.00–1.05; P = 0.05). When GMII ≥ 80, the postoperative survival time was shorter (P = 0.02), the 1-year IOP, number of glaucoma medications, and number of needlings performed were higher (P = 0.03, P  < 0.01, P  < 0.03, respectively), and reduction in glaucoma medication was less (P = 0.02).

Conclusion

The GMII can be used to predict eyes at higher risk for trabeculectomy that may benefit from additional perioperative intervention or treatment. It can also help the surgeon time the surgery before the GMII becomes too high, thereby optimizing the patient’s postoperative outcome.

Conventional glaucoma implants and the new MIGS devices: a comprehensive review of current options and future directions

Glaucoma is a progressive optic neuropathy that is the second leading cause of preventable blindness worldwide, after cataract formation. A rise in the intraocular pressure (IOP) is considered to be a major risk factor for glaucoma and is associated with an abnormal increase of resistance to aqueous humour outflow from the anterior chamber. Glaucoma drainage devices have been developed to provide an alternative pathway through which aqueous humour can effectively exit the anterior chamber, thereby reducing IOP. These devices include the traditional aqueous shunts with tube-plate design, as well as more recent implants, such as the trabeculectomy-modifying EX-PRESS^® implant and the new minimally invasive glaucoma surgery (MIGS) devices. In this review, we will describe each implant in detail, focusing on their efficacy in reducing IOP and safety profile. Additionally, a critical and evidence-based comparison between these implants will be provided. Finally, we will propose potential developments that may help to improve the performance of current devices.

Three-year outcome of sulcus fixation of Baerveldt glaucoma implant surgery

PURPOSE

The purpose of this study was to evaluate the 3-year surgical outcome of the sulcus fixation of Baerveldt glaucoma implant (BGI), focusing on corneal damage.

METHODS

This prospective observational study included 37 patients who underwent a median of two previous glaucoma surgeries and sulcus fixation of BGI for the first time. Each patient's intraocular pressure (IOP), glaucoma drug score, corneal endothelial cell density (ECD), and logMAR-converted best-corrected visual acuity (VA) were measured preoperatively and postoperatively until 36 months after surgery. Complete success was defined as reduced IOP (5-21 mmHg and >20% rate), without corneal damage (postoperative development of decompensation, unmeasurable ECD, or reduction in ECD of >20%), without loss of light perception, and without additional surgery requirement. Qualified success was defined by excluding the corneal criteria from complete success.

RESULTS

A total of 51% (19/37) patients experienced complete treatment success, whereas 86% (32/37) had qualified success. The median IOP (glaucoma drug score) decreased from 26 mmHg (5) to 15 mmHg (2) at three years postoperatively. The median postoperative ECD (reduction rate) decreased from 1838 cells/cm² preoperatively to 1587 cells/mm² (14%) at one year, 1358 cells/mm² (26%) at two years, and 1228 cells/mm² (33%) at three years postoperatively. One month after surgery, the VA was significantly reduced from preoperative values but did not decline after that.

CONCLUSION

Sulcus fixation of BGI was effective for IOP reduction. However, ECD decreased over time.

Analytical model for managing hypotony after implantation surgery of a glaucoma drainage device

The main aim of glaucoma treatment is to reduce the intraocular pressure (IOP). One of the most common surgical treatments of glaucoma is the implantation of a glaucoma drainage device to drain the aqueous humor from the anterior chamber to a filtration bleb, where the aqueous humor is absorbed. In some cases, the excess of drainage causes ocular hypotony, which constitutes a sight-threatening complication. To prevent hypotony after this intervention, surgeons frequently introduce a suture into the device tube, which increases the hydraulic resistance of the tube and, therefore, the IOP. This study aims to provide an analytical model to correct hypotony following implantation surgery of a glaucoma drainage device, which may help glaucoma surgeons decide on hypotony treatment. The results indicate that the IOP after implanting a cylindrical tube around 300 μm in diameter is essentially the same as that built up in the filtering bleb and can hardly be controlled by introducing a straight suture unless the suture diameter is slightly lower than that of the tube. On the contrary, when the tube diameter is smaller than, for example, 100 μm, significant reductions of the IOP can be obtained by introducing a thin suture into the tube.

Comparison of Outcomes Following Glaucoma Drainage Tube Surgery Between Primary and Secondary Glaucomas, and Between Phakic and Pseudophakic eyes

PURPOSE

To report outcomes of glaucoma drainage device (GDD) surgery based on primary or secondary glaucoma diagnosis and lens status.

DESIGN

Single-center, retrospective, consecutive cohort study.

METHODS

University of Florida patients aged 18 to 93 years who underwent nonvalved GDD surgery between 1996 and 2015 with a minimum of 1-year follow-up were examined. Of the 186 eyes of 186 patients enrolled, 108 had a primary glaucoma and 78 a secondary glaucoma diagnosis. Excluding 13 aphakic patients, 57 eyes were phakic and 116 pseudophakic. Mean intraocular pressure (IOP), mean number of medications, visual acuity (VA), surgical complications, and failure (IOP ≥18 mm Hg, IOP <6 mm Hg, reoperation for glaucoma, or loss of light perception) were the main outcome measures.

RESULTS

No significant difference was noted in mean IOP and mean medication use (12.8 ± 4.5 and 13.0 ± 6.6 mm Hg on 2.0 ± 1.2 and 1.5 ± 1.1 medication classes, respectively), mean VA (1.08 ± 0.98 and 0.94 ± 0.89, respectively), failure, or numbers of complications and reoperations (P > 0.05) between eyes with primary and secondary glaucomas at up to 5 years postoperatively. Comparison of phakic and pseudophakic eyes showed a statistically significant higher success rate for the pseudophakic patient group at the ≥18 mm Hg upper limit and <6 mm Hg lower limit (P = 0.01), and significantly fewer eyes required reoperation to lower IOP (6.9% vs 23%).

CONCLUSIONS

GDD surgery appears equally effective for secondary glaucomas as for primary glaucomas, and has a better outcome for pseudophakic eyes than phakic eyes.

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.

Efficient capture of high-quality real-world data on treatments for glaucoma: the Fight Glaucoma Blindness! Registry

Objective

To describe the development and implementation of a web-based high-quality data collection tool to track the outcomes of glaucoma treatments in routine practice.

Methods and analysis

This is a prospective observational registry study. An international steering committee undertook an iterative structured process to define a minimum, patient-centred data set designed to track outcomes of glaucoma treatment. The outcomes were coded into a web-based programme allowing easy access for rapid data entry. Clinicians receive personal reports enabling instant audit of their outcomes. Analyses of aggregated anonymised data on real-world outcomes are analysed and periodically reported with the goal of improving patient care.

Results

The minimum data set developed by the international steering committee includes the following: a baseline visit captures 13 mandatory fields in order to accurately phenotype each patient's subtype of glaucoma and to allow comparison between services, and a follow-up visit includes only four mandatory fields to allow completion within 30 s.Currently, there are 157 surgeons in 158 ophthalmology practices across Australia and New Zealand who are registered. These surgeons are tracking 5570 eyes of 3001 patients and have recorded 67 074 visits. The median number of eyes per surgeon is 22 eyes with a range of 1-575. The most common glaucoma procedure, excluding cataract surgery, is iStent inject, with 2316 cases.

Conclusion

This software tool effectively facilitates data collection on safety and efficacy outcomes of treatments for different subgroups of glaucoma within a real-world setting. It provides a template to evaluate new treatments as they are introduced into practice.

Evolution of a Glaucoma Fellow's Surgical Training: Improvements in Tube Shunt Case Times during the Academic Year

Purpose The aim of the study is to report changes in tube shunt placement surgical case times for glaucoma fellows during the course of the academic year.

Patients and Methods Electronic health records were retrospectively reviewed to determine patient demographics, surgical case times (defined as procedure start time to procedure end time), and glaucoma fellow involvement. Only cases with a glaucoma fellow as the primary surgeon were included. Operative case times were compared by first and second halves of the academic year (beginning in July and ending in June) using a two-tailed t-test.

Results Five hundred and seventy-three individual tube shunt surgeries (385 Ahmed, 188 Baerveldt) performed by 28 glaucoma fellows (17 females, 11 males) at Duke University Eye Center and University of North Carolina Medical Center were included. Overall, case times were significantly shorter in the second half of the academic year as compared with the first (55.3 ± 17.1 minutes vs. 61.0 ± 17.4 minutes, p <0.001). Both male (57.3 ± 16.8 minutes vs. 63.2 ± 18.6 minutes, p = 0.008) and female (53.5 ± 17.3 minutes vs. 59.3 ± 16.4 minutes, p = 0.003) fellows demonstrated shorter case times over the academic year; additionally, female fellows trended toward shorter case times than male fellows in both the first half (p = 0.072) and second half (p = 0.053) of the academic year. Fellows also exhibited shorter case times with both Ahmed implants (54.1 ± 16.2 minutes vs. 59.3 ± 15.8 minutes, p = 0.002) and Baerveldt implants (57.8 ± 18.9 minutes vs. 64.2 ± 20.0 minutes, p = 0.025) cases over the academic year. Baerveldt case times were significantly longer than Ahmed cases in the first half (p = 0.028) and trended toward being longer than Ahmed cases in the second half (p = 0.070).

Conclusion Across 5 years at two academic institutions, glaucoma fellows had shorter primary tube shunt surgical case times in the second half of the academic year. These findings reflect improvement in surgical efficiency throughout glaucoma fellowship. These findings should be taken into consideration when scheduling trainee surgeries at academic medical centers at different points in the academic year.