Five-Year Visual Field Outcomes of the HORIZON Trial

Cost-Effectiveness Analysis of Hydrus Microstent for Patients with Mild to Moderate Primary Open-Angle Glaucoma in Canada

OBJECTIVE

To assess the cost-effectiveness of Hydrus Microstent combined with cataract surgery (CS) vs. CS alone for treating patients with mild to moderate primary open-angle glaucoma (POAG).

DESIGN

Cost-utility analysis using efficacy and safety results of a pivotal randomized clinical trial.

SUBJECTS

Modeled cohort of patients with mild to moderate POAG and visually significant cataract.

METHODS

A semi-Markov model was developed to model effects and costs over a 15-year time horizon from the Canadian public health care payer perspective for patients with mild or moderate POAG receiving Hydrus Microstent during CS vs. CS alone. The model utilizes the Hydrus Microstent for Lowering IOP in Glaucoma Patients Undergoing Cataract Surgery (HORIZON) trial patient cohort. Progression was guided using the annualized rate of progression derived from a post hoc analysis of 5-year visual field loss data from the HORIZON trial. The amount of visual field lost was mapped on a sequential addition of medications used as a proxy for irreversible progression. Costs were derived from various publicly available sources and publications. Utility values were sourced from a published analysis that conducted a mapping exercise based on Health Utilities Index mark 3 using Canadian tariffs. We conducted deterministic and probabilistic sensitivity analyses to examine the uncertainty around alternative model input values. Scenario analyses explored structural uncertainty.

MAIN OUTCOME MEASURES

Total costs per patient, quality-adjusted life years (QALYs), and incremental cost-utility ratio.

RESULTS

Compared with CS alone, Hydrus + CS was a dominant strategy (greater benefits and lower costs). Although life years were equivalent between the 2 treatments (11.41 years), the Hydrus + CS arm was associated with higher benefits (9.351 vs. 9.040 in QALYs). This translated into an additional 0.311 QALYs for Hydrus + CS. Total costs were lower with Hydrus + CS (Can$ 26 770 vs. Can$ 27 145) resulting in a saving of Can$ 375. Results of scenario analyses showed robustness of the model. The cost-effectiveness acceptability curve shows a probability of 85.3% of Hydrus + CS being cost-effective compared with CS alone at a willingness-to-pay threshold of 50 000/QALY.

CONCLUSIONS

Hydrus Microstent combined with CS is a cost-effective long-term treatment for patients with POAG.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Visual Function After Schlemm's Canal-Based MIGS

Filtration surgery is highly effective in lowering intraocular pressure; however, it is associated with a higher risk of severe complications. Visual dysfunction may persist in relatively uneventful cases because of induced astigmatism or worsening optical aberrations. Therefore, for early- to moderate-stage glaucoma, an increasing number of surgeons are prioritizing surgical safety and preserving postoperative visual function by opting for minimally invasive glaucoma surgery (MIGS). Among the various MIGS techniques, canal-opening surgery-targeting aqueous outflow through the Schlemm's canal (Schlemm's canal-based MIGS, CB-MIGS)-has gained increasing popularity. Unlike filtration surgery, CB-MIGS does not require creating an aqueous outflow pathway between the intraocular and extraocular spaces. Consequently, it is considered a minimally invasive procedure with a reduced risk of severe complications and is increasingly being chosen for suitable cases. Although this surgical technique has limitations in lowering intraocular pressure, it avoids the manipulation of the conjunctiva or sclera and is primarily performed through a small corneal incision. Therefore, a minimal impact on induced astigmatism or postoperative refractive changes is expected. However, few reviews comprehensively summarize postoperative changes in visual function. Therefore, this study reviews the literature on visual function after CB-MIGS, focusing on changes in best-corrected visual acuity (BCVA), refraction, astigmatism, and the effectiveness of visual field preservation to assess the extent of these postoperative changes. Hyphema is the primary cause of early postoperative vision loss and is often transient in cases in which other complications would have led to visual impairment. Severe complications that threaten vision are rare. Additionally, compared with filtration surgery, postoperative visual recovery tends to be faster, and the degree of induced astigmatism is comparable to that of standalone cataract surgery. When combined with cataract surgery, the refractive error is at the same level as that of cataract surgery alone. However, in some cases, mild hyperopic shifts may occur because of axial length shortening, depending on the extent of intraocular pressure reduction. This possibility has been highlighted in several studies. Regarding the effectiveness of slowing the progression of visual field defects, most studies have focused on short- to medium-term postoperative outcomes. Many of these studies have reported the sufficient suppression of progression rates. However, studies with large sample sizes and long-term prospective designs are limited. To establish more robust evidence, future research should focus on conducting larger-scale, long-term investigations.

Association of Systemic Calcium Channel Blocker Use with Visual Field Progression in a Large Real-World Cohort from Glaucoma Clinics

PURPOSE

To test the association between use of calcium channel blocker (CCB) medications and the rate of visual field (VF) progression in a large cohort of patients from 5 glaucoma clinics.

DESIGN

Retrospective longitudinal case-control study.

SUBJECTS

Patients attending 5 glaucoma clinics in the United Kingdom using the same electronic medical record (EMR) system.

METHODS

For the main analysis, we selected 1 eye from patients with at least 5 reliable (false positive errors < 15%) VFs over a period of at least 4 years. The use of systemic medications was derived from the EMR system. Calcium channel blocker users were identified as cases. Propensity score matching (PSM) and multivariable analyses (MVAs) were used to adjust for confounders. A directed acyclic graph of the relevant variables guided the selection of covariates. Linear mixed-effect models (LMMs) were used to test the effect on the rate of VF mean deviation (MD) associated with CCB use and other covariates (for the MV analysis). Sensitivity analyses were conducted with different inclusion criteria and cutoffs on the estimated duration of CCB use.

MAIN OUTCOME MEASURES

The mean difference in the rate of VF MD progression between CCB users and controls.

RESULTS

The main analysis included 14 475 eyes (1942 from CCB users) that met the selection criteria (1 eye per patient). The median (interquartile range) VF series length was 8 (6, 11) tests, with a follow-up of 8.6 (6, 11.5) and 8.2 (5.9, 11.2) years in CCB users and controls, respectively. One-to-one PSM pairing with controls was achieved for all CCB users. The estimated rate of MD progression was -0.31 (-0.33 to -0.28) dB/year (mean [95% confidence intervals]) in the CCB users and -0.35 (-0.37 to -0.33) dB/year in the matched controls (P = 0.016). This significant difference was confirmed with the MV analysis including all controls (P = 0.020). All sensitivity analyses confirmed the main results.

CONCLUSIONS

Calcium channel blocker use was statistically significantly associated with a slower rate of VF deterioration after multivariable adjustment. The estimated difference was small and likely not clinically significant but may be influenced by the limited information on the duration of CCB exposure in this cohort.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Clinical pearls from glaucoma clinical trials: a case-based approach

Purpose of review

The purpose of this review is to summarize past and present findings of established clinical trials in glaucoma with a case-based approach. We provide a general overview of each major trial and provide recommendations for their implementation in clinical practice.

Recent findings

Summary

There have been several large glaucoma clinical trials performed over the last three decades. These trials have guided clinical decision making by helping risk stratify patients and guide medical and surgical management.

Validation of a Novel Low-Cost Glaucoma Risk Calculator for Community-Based Screening in High-Risk Populations

Purpose

To assess the validity of a novel, low-cost glaucoma screening calculator in determining glaucoma risk in high-risk New York communities.

Patients and Methods

This prognostic community-based study was conducted in New York City neighborhoods from 2022 to 2024 among participants aged 40 years and older. Glaucoma screenings were held at community gatherings including local fairs, senior citizen homes, places of worship, and in the lobby of medical offices. The screenings were conducted by trained non-physician medical personnel comprised medical students and medical assistants working under physician supervision. Participants' intraocular pressure (IOP) and central corneal thickness (CCT) were measured in both eyes with a handheld tonometer and pachymeter, respectively. Participants then completed a comprehensive eye exam by an ophthalmologist to confirm glaucoma status. Statistical analysis was completed using MedCalc version 22.023 (MedCalc Software Ltd. Ostend, Belgium) with 95% confidence intervals.

Results

Of the 823 study participants, 716 (mean age 62.9 ± 11.9 years) were eligible to participate and completed the comprehensive follow-up exam. 68% identified as Black, 6.7% identified as Hispanic/Latino, and 52.5% identified as female. The Laroche glaucoma calculator had a sensitivity of 93.5% (CI 89.1-96.5%), specificity of 91.3% (CI 88.5-93.6%), positive predictive value of 80.5% (CI 75.7-84.6%), negative predictive value of 97.3% (CI 95.5-98.4%) and accuracy of 91.9% (CI 89.6-93.8%).

Conclusion

The Laroche glaucoma calculator shows high sensitivity, specificity, positive predictive value, negative predictive value, and accuracy using affordable screening methods to determine glaucoma risk.

Combined Microinvasive Glaucoma Surgery With Phacoemulsification in Open-Angle Glaucoma: A Systematic Review and Meta-analysis

PURPOSE

To compare efficacies and safeties of combined phacoemulsification-microinvasive glaucoma surgeries (MIGS) to phacoemulsification only in eyes with open-angle glaucoma.

DESIGN

Systematic review and meta-analysis.

METHODS

A multidatabase literature search was conducted to capture MIGS articles published before April 19, 2024. Key exclusion criteria were inadequate follow-up, significant loss to follow-up, standalone MIGS surgery, or unreported primary outcomes. MIGS were grouped according to mechanisms of action: (1) trabecular meshwork (TM) bypass that improves aqueous drainage into Schlemm's canal, (2) non-gonioscopy-assisted transluminal trabeculotomy (non-GATT) goniotomies that remove TM with varying devices, and (3) GATT that removes TM with a catheter or suture placed into Schlemm's canal. Efficacy was measured by reductions in intraocular pressure (IOP) and medications, whereas safety was compared using incidence of sight-threatening and other adverse events.

RESULTS

A total of 95 studies were included, accounting for 9733 eyes followed up at 1-year. The control group had a baseline IOP of 16.9 (95% CI: 15.9-17.9) mm Hg on 1.43 (1.19-1.68) medications and a postoperative IOP of 15.2 (14.4-15.9) mm Hg on 0.80 (0.54-1.00) medications. The TM bypass baseline IOP was 18.2 (17.6-18.7) mm Hg on 1.89 (1.78-2.01) medications that lowered to an IOP of 14.8 (14.5-15.1) mm Hg on 0.80 (0.65-0.95) medications at 1 year after operation. The non-GATT goniotomy baseline IOP was 20.0 (19.2-20.8) mm Hg on 2.30 (2.09-2.53) medications, and at 1-year follow-up, the IOP was 14.6 (14.3-15.0) mm Hg on 1.41 (1.22-1.62) medications. Lastly, the GATT baseline IOP of 21.8 (19.5-24.1) mm Hg on 2.90 (2.36-3.44) medications was reduced to an IOP of 12.5 (10.0-15.0) mm Hg on 0.73 (0.37-1.09) medications at 1-year after operation. All MIGS groups had equal or lower rates of sight-threatening events and secondary glaucoma surgery when compared with control. GATT had the highest hyphema rate at 27.7% (13.5%-44.5%) followed by non-GATT goniotomy with 15.5% (7.8%-25.0%). These were both significantly higher than TM bypass and control groups, with hyphema rates of 3.5% (1.6%-5.9%) and 4% (only 1 study reporting hyphema rate), respectively.

CONCLUSIONS

Based on current peer-reviewed articles, there is strong evidence that when compared with phacoemulsification alone, combined phacoemulsification-MIGS is beneficial for patients with open-angle glaucoma and does not increase the incidence of vision-threatening events. Key limitations of our review stem from heterogeneities in protocol design or outcome reporting and a limited number of high-quality studies with long-term follow-up.

Minimally Invasive Glaucoma Surgery

BACKGROUND

Approximately 1.4 % of the German population aged 35 to 74 suffers from glaucoma, which is one of the more common causes of blindness. The only evidence-based treatment option at present is lowering the intraocular pressure. Modern minimally invasive surgical procedures hold out the prospect of lowering the intraocular pressure without the risk of serious complications.

METHODS

This is a selective review of pertinent publications retrieved by a search in PubMed, including randomized, controlled trials and meta-analyses.

RESULTS

The intraocular pressure can be lowered with eyedrops, laser procedures, and surgery. Trabeculectomy is the reference standard in glaucoma surgery but leads to complications in 3-15% of cases. In minimally invasive glaucoma surgery, very small stents can be implanted to lower the intraocular pressure. These proce - dures have a better safety profile but are only indicated for mild or moderate glaucoma. The Kahook Dual Blade, iStent inject, and Hydrus Microshunt procedures have been studied in randomized, controlled trials. An additional pressure-lowering effect beyond that of cataract surgery was demonstrated only for the latter two procedures (1.9 mmHg and 1.8 mmHg, respectively). Other procedures have only been investigated in cohort studies to date; a pressure-lowering effect was found for some of them. Moreover, iStent and Hydrus Microshunt have been found to slow the progression of visual field defects.

CONCLUSION

There are robust data documenting the effect of iStent and Hydrus Microshunt in lowering the intraocular pressure and lessening the need for eyedrops. High-quality controlled trials are still needed to test the efficacy of other procedures.

Relationship Between Intraocular Pressure and the True Rate of Functional and Structural Progression in the United Kingdom Glaucoma Treatment Study

Purpose

To investigate the effect of average intraocular pressure (IOP) on the true rate of glaucoma progression (RoP) in the United Kingdom Glaucoma Treatment Study (UKGTS).

Methods

UKGTS participants were randomized to placebo or Latanoprost drops and monitored for up to two years with visual field tests (VF, 24-2 SITA standard), IOP measurements, and optic nerve imaging. We included eyes with at least three structural or functional assessments (VF with <15% false-positive errors). Structural tests measured rim area (RA) with Heidelberg retina tomography (HRT) and average peripapillary retinal nerve fiber layer (pRNFL) thickness with optical coherence tomography (OCT). One eye of 436 patients (222 on Latanoprost) was analyzed. A Bayesian hierarchical model estimated the true RoP of VF and structural metrics, and their correlations, using sign-reversed multivariable exponential distribution. RA and pRNFL measurements were converted to a dB scale, matching the VF metric (mean deviation [MD]). The effect of average IOP on the true RoPs was estimated.

Results

True RoP at the mean average IOP (17 mm Hg) was faster (P < 0.001) for VF-MD (-0.59 [-0.73, -0.48] dB/year) than HRT-RA (-0.05 [-0.07, -0.03] dB/year) and OCT-pRNFL (-0.08 [-0.11, -0.06] dB/year). The proportional acceleration of RoP per mm Hg increase was, however, not significantly different (smallest P = 0.15). Accounting for the structural floor-effect largely eliminated the differences in RoPs (smallest P = 0.25).

Conclusions

VF appeared to deteriorate at a faster rate than structural measurements. However, this could be explained by the floor-effect from nonfunctional tissue. IOP induced a similar acceleration in RoP per mm Hg increase.

The effect of cataract surgery on lowering intraocular pressure

PURPOSE OF REVIEW

To review the literature evaluating the effectiveness of cataract surgery alone and cataract surgery in combination with other procedures and surgeries on intraocular pressure (IOP) in patients with ocular hypertension and glaucoma.

RECENT FINDINGS

Recent studies of large trials have shown the IOP-lowering effect of cataract surgery and the beneficial effect of minimally invasive glaucoma surgery (MIGS). More studies are being published on when to use cataract surgery alone, with MIGS, or with traditional glaucoma surgeries for both primary open angle glaucoma and primary angle closure glaucoma.

SUMMARY

Patients with ocular hypertension and visually significant cataracts would benefit from cataract surgery alone to lower intraocular pressure. Patients with mild to moderate glaucoma would likely benefit from cataract surgery and MIGS to achieve a lower IOP. Patients with more advanced glaucoma would benefit from cataract surgery combined with a traditional incisional glaucoma surgery. Clear lens extraction can be used in patients with primary angle closure and early primary angle closure glaucoma. In patients with more advanced disease, phacoemulsification and another glaucoma surgery is likely to be required to achieve IOP control. MIGS are starting to be used in angle closure glaucoma, although more research needs to be done to define its role.

Association Between Greater Social Vulnerability and Delayed Glaucoma Surgery

PURPOSE

Timing of surgical intervention in glaucoma is crucial to preserving sight. While ocular characteristics that increase surgical risk are known, the impact of neighborhood-level social risk factors such as the Social Vulnerability Index (SVI) and Area Deprivation Index (ADI) on time to glaucoma surgery is unknown. The objective of this study was to evaluate the association between SVI or ADI scores and the timing of glaucoma surgical intervention.

DESIGN

Retrospective cohort study.

METHODS

Adult subjects with open-angle glaucoma were identified from the Bascom Palmer Glaucoma Repository using International Classification of Disease-10 codes. Subject demographics, ocular characteristics, and standard automated perimetry data were extracted. Geocoded data were obtained using subject residences and American Community Survey data. Univariable and multivariable time-to-event survival analyses using accelerated failure time models were completed to evaluate whether geocoded SVI and ADI scores accelerated or delayed time to glaucoma surgery from initial glaucoma diagnosis in the electronic health record.

RESULTS

A total of 10,553 eyes from 6934 subjects were evaluated, of which 637 eyes (6.0%) from 568 subjects (8.2%) underwent glaucoma surgery. Mean age was 68.3 ± 13.5 years, with 57.9% female, 21.5% Black, and 34.5% Hispanic subjects. Mean follow-up time was 5.0 ± 2.1 years, with time to surgery of 3.2 ± 1.9 years. Multivariable accelerated failure time models demonstrated that higher mean intraocular pressure (time ratio [TR] 0.27 per 5 mm Hg higher; 95% confidence interval [CI]: 0.23-0.31, P < .001), faster standard automated perimetry rate of progression (TR 0.74 per 0.5 dB/year faster; 95% CI: 0.69-0.78, P < .001), moderate (TR 0.69; 95% CI: 0.56-0.85, P < .001) or severe baseline severity (TR 0.39; 95% CI: 0.32-0.47, P < .001), and thinner central corneal thickness (TR 0.85 per 50 µm thinner; 95% CI: 0.77-0.95, P = .003) all accelerated time to surgery. In contrast, overall SVI delayed surgery (TR 1.11 per 25% increase; 95% CI: 1.03-1.20, P = .006). Specifically, SVI Themes 1 (TR 1.08; 95% CI: 1.01-1.17, P = .037) and 4 (TR 1.11; 95% CI: 1.03-1.19, P = .006) were significant. Patients from the most deprived neighborhoods (highest national ADI quartile) had a 68% increase in time to surgery compared to the least deprived quartile (TR 1.68; 95% CI: 1.20-2.36, P = .002).

CONCLUSIONS

Residence in areas with higher SVI or ADI scores was associated with delayed glaucoma surgery after controlling for demographic and ocular parameters. Awareness of such disparities can guide initiatives aimed at achieving parity in health outcomes.

Impact of Social Vulnerability Index on the Development of Severe Visual Impairment or Blindness From Glaucoma

PURPOSE

To evaluate whether geocoded social risk factor data predict the development of severe visual impairment or blindness due to glaucoma during follow-up using a large electronic health record (EHR) database.

DESIGN

Cohort study.

METHODS

Patients diagnosed with open-angle glaucoma (OAG) at a tertiary care institution. All eyes had glaucomatous visual field defects at baseline. Sociodemographic and ocular data were extracted from the EHR, including age, gender, self-reported race and ethnicity, insurance status, OAG type, prior glaucoma laser or surgery, baseline disease severity using Hodapp-Anderson-Parrish criteria, mean intraocular pressure (IOP) during follow-up, and central corneal thickness. Social vulnerability index (SVIndex) data at the census tract level were obtained using geocoded patient residences. Mixed-effects Cox proportional hazard models were completed to assess for the development of severe visual impairment or blindness during follow-up, defined as BCVA ≤ 20/200 at least at the last two clinic visits or standard automated perimetry (SAP) mean deviation (MD) ≤ -22dB confirmed on two tests.

RESULTS

A total of 4,046 eyes from 2,826 patients met inclusion criteria and were followed for an average of 4.3 ± 2.2 years. Severe visual impairment or blindness developed in 79 eyes (2.0%) from 76 patients (2.7%) after an average of 3.4 ± 1.8 years, leading to an incidence rate of severe visual impairment or blindness of 0.5% per year. Older age (adjusted hazards ratio [HR] 1.36 per decade, P = .007), residence in areas with higher SVIndex (HR 1.56 per 25% increase, P < .001), higher IOP during follow-up (HR 3.01 per 5 mmHg increase, P < .001), and moderate or severe glaucoma at baseline (HR 7.31 and 26.87, P < .001) were risk factors for developing severe visual impairment or blindness. Concordance index of the model was 0.88. Socioeconomic, minority status/language, and housing type/transportation SVIndex themes were key contributors to developing severe visual impairment or blindness.

CONCLUSIONS

Risk factors for developing glaucoma-related severe visual impairment or blindness included older age, elevated IOP during follow-up, moderate or severe disease at baseline, and residence in areas associated with greater social vulnerability. In addition to ocular risk factors, geocoded EHR data regarding social risk factors could help identify patients at high risk of developing glaucoma-related visual impairment.

Combined Phacoemulsification and Hydrus Microstent Implantation in Asian Eyes With Moderate-to-Severe Normal Tension Glaucoma-12-Month Outcomes

PRCIS

This study reports 12-month outcomes of combined phacoemulsification and Hydrus Microstent implantation in Asian eyes with moderate-to-severe normal tension glaucoma (NTG), demonstrating a significant reduction in glaucoma medications with an excellent intra and postoperative safety profile.

OBJECTIVE

To evaluate the 12-month safety and efficacy outcomes of combined phacoemulsification and Hydrus Microstent (Ivantis Inc.) implantation in Asian eyes with moderate to severe NTG.

METHODS

Retrospective study of consecutive surgeries performed from August 2019 to August 2021 in a single tertiary eye centre in Singapore. Outcome measures included a reduction in intraocular pressure (IOP), number of glaucoma medications, and intra and postoperative complications.

RESULTS

Data from 21 eyes of 21 subjects were analyzed. All subjects were ethnic Chinese, and the majority were males (14, 66.7%). At baseline, the mean IOP was 13.3 (2.3) mm Hg, all eyes had a Humphrey visual field mean deviation of ≥-6 dB [mean: -13.9 (4.3) dB], and all eyes were on at least one glaucoma medication. There was no statistically significant reduction in IOP at all time points compared with baseline (all P > 0.05). However, the median number of medications was reduced from 2 to 0 at all time points, up to postoperative month (POM) 12 (all P < 0.001). There were no intraoperative complications. No eyes underwent secondary glaucoma procedures nor lost any Snellen line of visual acuity by POM12. One (4.8%) eye experienced numerical hypotony at postoperative day 1, which resolved conservatively. Two (9.5%) eyes underwent laser iridoplasty for stent occlusion by iris. There was no deterioration in Humphrey visual field mean deviation at POM12 compared with baseline (n = 20, P > 0.05).

CONCLUSION

Combined phacoemulsification and Hydrus Microstent implantation were effective in reducing medication burden in Asian eyes with moderate to severe NTG, up to 12 months postoperatively.

Two-Year Retrospective Study of Cataract Surgery and Schlemm Canal Hydrus Microstent in Black and Afro-Latino Patients

Background

The Hydrus Microstent has been shown to be efficacious in the treatment of Open-angle Glaucoma. We previously reported 1-year results of the Hydrus Microstent in Black and Afro-Latino patients.

Objective

Here we report two-year results of the Hydrus Microstent in Black and Afro-Latino patients with mild to moderate open-angle glaucoma.

Design

This was a retrospective, nonrandomized study that was carried out at two private practices in Harlem, NY and Queens, NY.

Methods

This study consisted of Black and Afro Latino patients who had a Hydrus Microstent implanted for the treatment of glaucoma. The evaluated parameters were intraocular pressure (IOP), reductions in the number of medications, mean deviation on visual field test and visual acuity. We excluded persons with advanced glaucoma and incomplete data. We included those with mild to moderate glaucoma and had complete two-year follow-up data.

Results

The study consisted of 86 patients and 86 eyes. The mean age was 69. The mean pre-op IOP was 14.1 on 2.17 medications. At two years the mean IOP was 14 (p = 0.651) on 0.42 medications (p = 0.000003); 88% of patients were medication free (p = 0.651), The MD on the visual field changed little from -5.73 preoperatively to -5.21 at two years. There were 3 intraocular pressure spikes and 1 case of hyphema that were treated and had complete resolution. No patients required secondary surgery.

Conclusion

Our results show that at two years the Hydrus Microstent can maintain low intraocular pressures, reduce medication burden and, in aggregate, experienced little change in visual field Mean Deviation in Black and Afro Latino patients with mild to moderate glaucoma.

Visual Field Outcomes in the Primary Tube Versus Trabeculectomy Study

PURPOSE

To describe visual field outcomes in the Primary Tube Versus Trabeculectomy (PTVT) Study.

DESIGN

Cohort analysis.

PARTICIPANTS

A total of 155 eyes (155 subjects) randomly assigned to treatment with tube shunt surgery (n = 84) or trabeculectomy with mitomycin C (n = 71).

METHODS

The PTVT Study was a multicenter randomized clinical trial comparing the safety and efficacy of trabeculectomy and tube shunt surgery in eyes without previous intraocular surgery. Subjects underwent standard automated perimetry (SAP) at baseline and annually for 5 years. Standard automated perimetry tests were deemed reliable if the false-positive rate was ≤ 15%. Tests were excluded if visual acuity was ≤ 20/400 or loss of ≥ 2 Snellen lines from baseline because of a nonglaucomatous etiology. Linear mixed-effects models were used to compare rates of change in SAP mean deviation (MD) between the 2 groups. Intraocular pressure (IOP) control was assessed by percentage of visits with IOP < 18 mmHg and mean IOP.

MAIN OUTCOME MEASURES

Rate of change in SAP MD during follow-up.

RESULTS

A total of 730 SAP tests were evaluated (average of 4.7 tests per eye). The average SAP MD at baseline was -12.8 ± 8.3 decibels (dB) in the tube group and -12.0 ± 8.4 dB in the trabeculectomy group (P = 0.57). The mean rate of change in SAP MD was -0.32 ± 0.39 dB/year in the trabeculectomy group and -0.47 ± 0.43 dB/year in the tube group (P = 0.23). Eyes with mean IOP 14 to 17.5 mmHg had significantly faster rates of SAP MD loss compared with eyes with mean IOP < 14 mmHg (-0.59 ± 0.13 vs. -0.27 ± 0.08 dB/year; P = 0.012), and eyes with only 50% to 75% of visits with IOP < 18 mmHg had faster rates than those with 100% of visits with IOP < 18 mmHg (-0.90 ± 0.16 vs. -0.29 ± 0.08 dB/year; P < 0.001). Multivariable analysis identified older age and worse IOP control as risk factors for faster progression in both treatment groups.

CONCLUSIONS

No statistically significant difference in mean rates of visual field change was observed between trabeculectomy and tube shunt surgery in the PTVT Study. Worse IOP control was significantly associated with faster rates of SAP MD loss during follow-up. Older patients were also at risk for faster progression.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Ocular Pharmacology

Treatment of ocular diseases presents unique challenges and opportunities for the clinician and for the clinical pharmacologist. Ophthalmic pharmaceuticals, typically given as liquids, require consideration of solubility, physiological pH, and osmolarity, as well as sterility and stability, which in turn requires optimal pharmaceutics. Ocular tissue levels are challenging to obtain in humans, and the clinical pharmacokinetics is typically blood levels, which are primarily related to safety, rather than efficacy. The eye is a closed compartment with multiple physiological barriers with esterases and transporters, but relatively little cytochrome oxidases. Delivery routes include topical, intravitreal, and systemic. Patient dosing involves not only adherence issues common to all chronic diseases, but also performance requirements on eye drop instillation. Therapeutically, ocular diseases and their pharmacological treatments include both those analogous to systemic diseases (e.g., inflammation, infection, and neuronal degeneration) and those unique to the eye (e.g., cataract and myopia).

Estimating the Distribution of True Rates of Visual Field Progression in Glaucoma

Purpose

The purpose of this study was to estimate the distribution of the true rates of progression (RoP) of visual field (VF) loss.

Methods

We analyzed the progression of mean deviation over time in series of ≥ 10 tests from 3352 eyes (one per patient) from 5 glaucoma clinics, using a novel Bayesian hierarchical Linear Mixed Model (LMM); this modeled the random-effect distribution of RoPs as the sum of 2 independent processes following, respectively, a negative exponential distribution (the "true" distribution of RoPs) and a Gaussian distribution (the "noise"), resulting in a skewed exGaussian distribution. The exGaussian-LMM was compared to a standard Gaussian-LMM using the Watanabe-Akaike Information Criterion (WAIC). The random-effect distributions were compared to the empirical cumulative distribution function (eCDF) of linear regression RoPs using a Kolmogorov-Smirnov test.

Results

The WAIC indicated a better fit with the exGaussian-LMM (estimate [standard error]: 192174.4 [721.2]) than with the Gaussian-LMM (192595 [697.4], with a difference of 157.2 [22.6]). There was a significant difference between the eCDF and the Gaussian-LMM distribution (P < 0.0001), but not with the exGaussian-LMM distribution (P = 0.108). The estimated mean (95% credible intervals, CIs) "true" RoP (-0.377, 95% CI = -0.396 to -0.359 dB/year) was more negative than the observed mean RoP (-0.283, 95% CI = -0.299 to -0.268 dB/year), indicating a bias likely due to learning in standard LMMs.

Conclusions

The distribution of "true" RoPs can be estimated with an exGaussian-LMM, improving model accuracy.

Translational Relevance

We used these results to develop a fast and accurate analytical approximation for sample-size calculations in clinical trials using standard LMMs, which was integrated in a freely available web application.

How much does cataract surgery contribute to intraocular pressure lowering?

PURPOSE OF REVIEW

To review the literature evaluating the effect of cataract surgery on intraocular pressure (IOP) in patients with glaucoma.

RECENT FINDINGS

Recent high-quality secondary analyses of large and primary trials continue to show IOP lowering following cataract surgery. Likewise, cataract surgery remains a key treatment for angle closure glaucoma. Some micro-invasive glaucoma surgeries (MIGS) have strong evidence to be performed at the time of cataract surgery. Data clarifying when these surgeries should be combined with cataract surgery is emerging. The mechanism underlying IOP lowering after cataract surgery remains unclear.

SUMMARY

Patients who are glaucoma suspects with visually significant cataracts would benefit from cataract surgery alone. Those with mild-moderate damage on 1-2 classes of medications would most likely benefit from additional MIGS. Patients with advanced disease would benefit from cataract surgery and a choice of additional surgery, which depends on disease status and patient factors. Clear lens extraction is becoming a more accepted practice as a primary procedure for patients with angle closure and high IOP or glaucoma. The role of additional MIGS in angle closure needs further study.

Trabecular Procedures Combined with Cataract Surgery for Open-Angle Glaucoma: A Report by the American Academy of Ophthalmology

PURPOSE

To determine the intraocular pressure (IOP) reduction of various trabecular procedures (a form of minimally invasive glaucoma surgery [MIGS]) combined with cataract surgery compared with cataract surgery alone, to compare the safety of the various trabecular procedures, and to highlight patient characteristics that may favor one trabecular procedure over another.

METHODS

A search of English-language peer-reviewed literature in the PubMed database was initially conducted in February 2021 and updated in April 2023. This yielded 279 articles. Twenty studies met initial inclusion and exclusion criteria and were assessed for quality by the panel methodologist. Of these, 10 were rated level I, 3 were rated level II, and 7 were rated level III. Only the 10 level I randomized controlled trials (RCTs) were included in this assessment, and all were subject to potential industry-sponsorship bias.

RESULTS

The current analysis focuses on the amount of IOP reduction (in studies that involved medication washout) and on IOP reduction with concurrent medication reduction (in studies that did not involve medication washout). Based on studies that performed a medication washout, adding a trabecular procedure to cataract surgery provided an additional 1.6 to 2.3 mmHg IOP reduction in subjects with hypertensive, mild to moderate open-angle glaucoma (OAG) at 2 years over cataract surgery alone, which itself provided approximately 5.4 to 7.6 mmHg IOP reduction. In other words, adding a trabecular procedure provided an additional 3.8% to 8.9% IOP reduction over cataract surgery alone, which itself provided 21% to 28% IOP reduction. There was no clear benefit of one trabecular procedure over another. Patient-specific considerations that can guide procedure selection include uveitis predisposition, bleeding risk, metal allergy, and narrowing of Schlemm's canal. There are no level I data on the efficacy of trabecular procedures in subjects with pretreatment IOP of 21 mmHg or less.

CONCLUSIONS

Trabecular procedures combined with cataract surgery provide an additional mild IOP reduction over cataract surgery alone in hypertensive OAG subjects. Additional research should standardize outcome definitions, avoid industry sponsorship bias, and study the efficacy of these procedures in normotensive OAG.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Short-term report of early glaucoma surgery with a clear lens extraction and an intraocular lens, OMNI canaloplasty, and a HYDRUS microstent: a case series in younger patients

Purpose

The purpose of this case series is to report the surgical outcomes from the combination of a clear lensectomy, OMNI® canaloplasty, and a HYDRUS® microstent with an adjacent goniotomy.

Methods

This is a retrospective non-comparative single-center case series of four black patients of African descent with glaucoma who were treated with a clear lensectomy, OMNI canaloplasty, and a HYDRUS microstent with an adjacent goniotomy. The surgeries were performed by an experienced cataract and glaucoma surgeon, Daniel Laroche, MD. The parameters investigated in this study were postoperative intraocular pressure (IOP) and the mean number of preoperative and postoperative medications needed.

Results

The mean age of the four patients was 44.5 years. All patients had a mean postoperative reduction in IOP of 17 mmHg to 12.7 mmHg. The mean number of preoperative medications was 2.2, while the mean number of postoperative medications was 0.3. Potential complications such as hyphema, IOP spikes, or corneal edema were not seen in this series. All patients achieved a lower IOP and stable vision with less refractive error. Patients also experienced improved visual fields, clearer vision, and more open angles.

Conclusion

Clear lensectomy and combined microinvasive glaucoma surgery (MIGS) in patients with primary open-angle glaucoma (POAG) and narrow-angle glaucoma (NAG) results in the safe lowering of IOP. The limitations of this study include the small series size and the retrospective potential for bias. Further research with a larger series and a prospective trial with follow-up should be performed.

European Glaucoma Society - A guide on surgical innovation for glaucoma

PROLOGUE: Glaucoma surgery has been, for many decades now, dominated by the universal gold standard which is trabeculectomy augmented with antimetabolites. Tubes also came into the scene to complement what we use to call conventional or traditional glaucoma surgery. More recently we experienced a changing glaucoma surgery environment with the "advent" of what we have become used to calling Minimally Invasive Glaucoma Surgery (MIGS). What is the unmet need, what is the gap that these newcomers aim to fill? Hippocrates taught us "bring benefit, not harm" and new glaucoma techniques and devices aim to provide safer surgery compared to conventional surgery. For the patient, but also for the clinician, safety is important. Is more safety achieved with new glaucoma surgery and, if so, is it associated with better, equivalent, or worse efficacy? Is new glaucoma surgery intended to replace conventional surgery or to complement it as an 'add-on' to what clinicians already have in their hands to manage glaucoma? Which surgery should be chosen for which patient? What are the options? Are they equivalent? These are too many questions for the clinician! What are the answers to the questions? What is the evidence to support answers? Do we need more evidence and how can we produce high-quality evidence? This EGS Guide explores the changing and challenging glaucoma surgery environment aiming to provide answers to these questions. The EGS uses four words to highlight a continuum: Innovation, Education, Communication, and Implementation. Translating innovation to successful implementation is crucially important and requires high-quality evidence to ensure steps forward to a positive impact on health care when it comes to implementation. The vision of EGS is to provide the best possible well-being and minimal glaucomainduced visual disability in individuals with glaucoma within an affordable healthcare system. In this regard, assessing the changes in glaucoma surgery is a pivotal contribution to better care. As mentioned, this Guide aims to provide answers to the crucial questions above. However, every clinician is aware that answers may differ for every person: an individualised approach is needed. Therefore, there will be no uniform answer for all situations and all patients. Clinicians would need, through the clinical method and possibly some algorithm, to reach answers and decisions at the individual level. In this regard, evidence is needed to support clinicians to make decisions. Of key importance in this Guide is to provide an overview of existing evidence on glaucoma surgery and specifically on recent innovations and novel devices, but also to set standards in surgical design and reporting for future studies on glaucoma surgical innovation. Designing studies in surgery is particularly challenging because of many subtle variations inherent to surgery and hence multiple factors involved in the outcome, but even more because one needs to define carefully outcomes relevant to the research question but also to the future translation into clinical practice. In addition this Guide aims to provide clinical recommendations on novel procedures already in use when insufficient evidence exists. EGS has a long tradition to provide guidance to the ophthalmic community in Europe and worldwide through the EGS Guidelines (now in their 5th Edition). The EGS leadership recognized that the changing environment in glaucoma surgery currently represents a major challenge for the clinician, needing specific guidance. Therefore, the decision was made to issue this Guide on Glaucoma Surgery in order to help clinicians to make appropriate decisions for their patients and also to provide the framework and guidance for researchers to improve the quality of evidence in future studies. Ultimately this Guide will support better Glaucoma Care in accordance with EGS's Vision and Mission. Fotis Topouzis EGS President

Challenging the "Topical Medications-First" Approach to Glaucoma: A Treatment Paradigm in Evolution

Topical glaucoma medications are effective and safe, but they have numerous well-documented limitations that diminish their long-term utility and sustainability. These limitations can include high rates of nonadherence (with associated glaucoma progression), concerning side effects, inconsistent circadian intraocular pressure (IOP) control, complex dosing regimens, difficulty with self-administration, costs, and decreased quality of life. Despite these limitations, topical medications traditionally have been first-line in the glaucoma treatment algorithm, as no other minimally invasive treatment alternatives existed. In recent years, however, novel interventional therapies-including sustained-release drug-delivery platforms, selective laser trabeculoplasty, and micro-invasive glaucoma surgery procedures-have made it possible to intervene earlier without relying on topical medications. As a result, the topical medication-first treatment approach is being reevaluated in an overall shift toward earlier more proactive interventions.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

Validating Trend-Based End Points for Neuroprotection Trials in Glaucoma

Purpose

The purpose of this study was to evaluate the power of trend-based visual field (VF) progression end points against long-term development of event-based end points accepted by the US Food and Drug Administration (FDA).

Methods

One eye from 3352 patients with ≥10 24-2 VFs (median = 11 years) follow-up were analyzed. Two FDA-compatible criteria were applied to these series to label "true-progressed" eyes: ≥5 locations changing from baseline by more than 7 dB (FDA-7) or by more than the expected test-retest variability (GPA-like) in 2 consecutive tests. Observed rates of progression (RoP) were used to simulate trial-like series (2 years) randomly assigned (1000 times) to a "placebo" or a "treatment" arm. We simulated neuroprotective "treatment" effects by changing the proportion of "true progressed" eyes in the two arms. Two trend-based methods for mean deviation (MD) were assessed: (1) linear mixed model (LMM), testing average difference in RoP between the two arms, and (2) time-to-progression (TTP), calculated by linear regression as time needed for MD to decline by predefined cutoffs from baseline. Power curves with 95% confidence intervals were calculated for trend and event-based methods on the simulated series.

Results

The FDA-7 and GPA-like progression was achieved by 45% and 55% of the eyes in the clinical database. LMM and TTP had similar power, significantly superior to the event-based methods, none of which reached 80% power. All methods had a 5% false-positive rate.

Conclusions

The trend-based methods can efficiently detect treatment effects defined by long-term FDA-compatible progression.

Translational Relevance

The assessment of the power of trend-based methods to detect clinically relevant progression end points.

Hydrus microstent for the treatment of primary open-angle glaucoma: overview of its safety and efficacy

INTRODUCTION

Minimally invasive glaucoma surgeries (MIGS) are now a consolidated reality in many surgical units. The Hydrus Microstent is one of several MIGS devices bypassing trabecular outflow and had excellent results over the years. This article aims to review the key features of the Hydrus Microstent in terms of design, efficacy, and safety.

AREAS COVERED

The present review analyses the main characteristics of the device by evaluating the technical and physical details of its functioning. The evidence that supports a clinical decision summarizes the most influential clinical trials and the most accurate systematic reviews.

EXPERT OPINION

The Hydrus device has been extensively studied regarding biocompatibility and outflow potential. The subsequent clinical studies have been well-built and proved that the device effectively reduces intraocular pressure (IOP) and the eyedrop load. The device covers almost a quarter of Schlemm's canal circumference, offering at least two advantages: cannulating the Schlemm's canal provides evidence that the device has been implanted correctly; covering a larger area potentially allows to target multiple collector channels or at least areas of active outflow. This scaffold may prove more effective in naïve patients or subjects who used antiglaucoma eyedrops for a limited period, as the prolonged use of hypotonic medications has been associated with the surgical failure of ab interno microhook trabeculotomy.

Spotlight on Schlemm's Canal MicroStent Injection in Patients with Glaucoma

Minimally invasive glaucoma surgery (MIGS) has revolutionized glaucoma care with its favorable safety profile and ability to delay or minimize the need for traditional, bleb-based procedures. Microstent device implantation is a type of angle-based MIGS, which reduces intraocular pressure (IOP) through bypass of the juxtacanalicular trabecular meshwork (TM) and facilitation of aqueous outflow into the Schlemm's canal. Although there are limited microstent devices on the market, multiple studies have evaluated the safety and efficacy of iStent^® (Glaukos Corp.), iStent Inject^® (Glaukos Corp.), and Hydrus^® Microstent (Alcon) in the treatment of mild-to-moderate open-angle glaucoma, with and without concurrent phacoemulsification. This review attempts to provide a comprehensive evaluation of injectable angle-based microstent MIGS devices in the treatment of glaucoma.