Clinical efficacy of topical nipradilol and timolol on visual field performance in normal-tension glaucoma: a multicenter, randomized, double-masked comparative study

Comparative analysis of medical treatments for long-term control of normal tension glaucoma: A systematic review and model-based network meta-analysis

BACKGROUND

To evaluate and compare the long-term efficacy of medical treatments for normal tension glaucoma (NTG) in controlling intraocular pressure (IOP), and establish a hierarchical ranking based on their effectiveness. 'Long-term' is defined as a treatment duration of over 12 weeks in randomised controlled trials (RCTs).

METHODS

This systematic review and model-based network meta-analysis (MBNMA) collected data of 795 patients with 997 eyes from RCTs. Patients with NTG were selected based on strict inclusion/exclusion criteria, with randomsation procedures and masking as reported in the individual trials. Eight different medications were compared, including prostaglandin analogues, beta-blockers, brimonidine, unoprostone isopropyl, brovincamine, and palmitoylethanolamide (PEA). Notably, PEA is an oral medication, while other drugs are topical agents.

RESULTS

Primary outcome is the long-term efficacy of IOP control across medications with different follow-up durations. Among the eight medications, PEA demonstrates the highest efficacy (Surface under the cumulative ranking, SUCRA = 7.46%), followed by two prostaglandin analogues: travoprost (SUCRA = 6.86%) and latanoprost (SUCRA = 6.76%), then two beta-blockers: nipradilol (SUCRA = 4.90%) and timolol (SUCRA = 4.89%). Both brimonidine and unoprostone isopropyl have SUCRA scores below 4.0%, indicating modest but limited efficacy. Brovincamine has the lowest SUCRA score (1.32%), reflecting minimal effectiveness.

CONCLUSIONS

This study revealed PEA as a promising agent for long-term IOP control in NTG patients, suggesting potential use as primary or adjunctive therapy. The outcomes call for PEA's consideration in clinical practice and highlight the need for further research into its long-term efficacy and safety for NTG.

The nitric oxide-guanylate cyclase pathway and glaucoma

Glaucoma is a prevalent optic neuropathy characterized by the progressive dysfunction and loss of retinal ganglion cells (RGCs) and their optic nerve axons, which leads to irreversible visual field loss. Multiple risk factors for the disease have been identified, but elevated intraocular pressure (IOP) remains the primary risk factor amenable to treatment. Reducing IOP however does not always prevent glaucomatous neurodegeneration, and many patients progress with the disease despite having IOP in the normal range. There is increasing evidence that nitric oxide (NO) is a direct regulator of IOP and that dysfunction of the NO-Guanylate Cyclase (GC) pathway is associated with glaucoma incidence. NO has shown promise as a novel therapeutic with targeted effects that: 1) lower IOP; 2) increase ocular blood flow; and 3) confer neuroprotection. The various effects of NO in the eye appear to be mediated through the activation of the GC- guanosine 3:5'-cyclic monophosphate (cGMP) pathway and its effect on downstream targets, such as protein kinases and Ca²⁺ channels. Although NO-donor compounds are promising as therapeutics for IOP regulation, they may not be ideal to harness the neuroprotective potential of NO signaling. Here we review evidence that supports direct targeting of GC as a novel pleiotrophic treatment for the disease, without the need for direct NO application. The identification and targeting of other factors that contribute to glaucoma would be beneficial to patients, particularly those that do not respond well to IOP-dependent interventions.

Visual Subfield Progression in Glaucoma Subtypes

Purpose

To investigate visual field progression pattern and factors associated with progression in patients with primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), and chronic angle-closure glaucoma (CACG).

Methods

The raw data of the 30-2 Humphrey Field Analyzer from glaucoma patients with definite visual field progression were processed with pointwise linear regression (PLR) analysis. The rate of change of retinal threshold sensitivity in the ten glaucoma hemifield test (GHT) zones, the upper and the lower hemifields, and the whole field was evaluated and was correlated with patients' basic demographic data.

Results

An average follow-up of 6.94 ± 2.69 years that showed the rate of change of visual field threshold sensitivity was correlated with the peak posttreatment intraocular pressure (IOP) and the long-term IOP fluctuations in all GHT zones except in the inferior arcuate area. The baseline IOP, the trough posttreatment IOP, the refractive status, and the CCT were not correlated with VF progression.

Conclusion

The rate of visual field progression was correlated with the peak posttreatment IOP and the long-term IOP fluctuation but with subfield differences.

Novel Therapeutics in Glaucoma Management

BACKGROUND

Glaucoma is a progressive optic neuropathy characterized by retinal ganglion cell death and alterations of visual field. Elevated intraocular pressure (IOP) is considered the main risk factor of glaucoma, even though other factors cannot be ruled out, such as epigenetic mechanisms.

OBJECTIVE

An overview of the ultimate promising experimental drugs to manage glaucoma has been provided.

RESULTS

In particular, we have focused on purinergic ligands, KATP channel activators, gases (nitric oxide, carbon monoxide and hydrogen sulfide), non-glucocorticoid steroidal compounds, neurotrophic factors, PI3K/Akt activators, citicoline, histone deacetylase inhibitors, cannabinoids, dopamine and serotonin receptors ligands, small interference RNA, and Rho kinase inhibitors.

CONCLUSIONS

The review has been also endowed of a brief chapter on last reports about potential neuroprotective benefits of anti-glaucoma drugs already present in the market.

Progression of primary open angle glaucoma in asymmetrically myopic eyes

PURPOSE

To compare progression of primary open angle glaucoma (POAG) in asymmetrically myopic eyes within the same subject and evaluate whether the degree of myopia is related to glaucoma progression.

METHODS

POAG patients with asymmetric myopia (axial length [AXL] ≥24 mm in both eyes, and the AXL difference between the right and left eyes to be ≥0.5 mm) were included. Glaucoma progression was determined either by optic disc/retinal nerve fiber layer (RNFL) photographs or by serial visual field (VF) data. The progression rates of VF mean deviation (dB/year) and spectral domain optical coherence tomography measured RNFL thickness (μm/year) were compared between the more myopic eye (MME) and the less myopic eye (LME) within the same subject.

RESULTS

A total of 55 patients (mean follow up period; 4.5 ± 1.0 years) were included. The mean AXL demonstrated a significant difference between MME and LME (26.3 ± 1.7 vs. 25.6 ± 1.7 mm; p = 0.036). The mean baseline VF MD (-3.8 ± 5.4 vs. -2.6 ± 4.7 dB; p = 0.21) and average RNFL thickness (77.5 ± 10.6 vs. 79.9 ± 12.3 μm; p = 0.36) did not differ between the MME and LME. Among the 55 patients, optic disc/RNFL photographic progression was noted in the MME in 15 patients, in the LME in 19 patients, and in both eyes in seven patients. VF progression was noted in the MME in seven patients, in the LME in seven patients, and in both eyes in four patients. The VF MD progression rates were -0.25 ± 0.34 dB/year in MME and -0.26 ± 0.34 dB/year in LME cases (p = 0.91). The mean progression rate of the average RNFL thickness also did not differ between the MME and LME (-0.59 ± 0.67 vs. -0.66 ± 0.72 μm/year, p = 0.68).

CONCLUSIONS

The degree of myopia was not associated with glaucoma progression when assessing the same patient using either the VF or optic disc/RNFL criteria in asymmetrically myopic patients.

Long Term Results of Visual Field Progression Analysis in Open Angle Glaucoma Patients Under Treatment

Purpose :

To evaluate visual field progression with trend and event analysis in open angle glaucoma patients under treatment.

Materials and Methods :

Fifteen year follow-up results of 408 eyes of 217 glaucoma patients who were followed at Adnan Menderes University, Department of Ophthalmology between 1998 and 2013 were analyzed retrospectively. Visual field data were collected for Mean Deviation (MD), Visual Field Index (VFI), and event occurrence.

Results :

There were 146 primary open-angle glaucoma (POAG), 123 pseudoexfoliative glaucoma (XFG) and 139 normal tension glaucoma (NTG) eyes. MD showed significant change in all diagnostic groups (p<0.001). The difference of VFI between first and last examinations were significantly different in POAG (p<0.001), and XFG (p<0.003) but not in NTG. VFI progression rates were -0.3, -0.43, and -0.2 % loss/year in treated POAG, XFG, and NTG, respectively. The number of empty triangles were statistically different between POAG-NTG (p=0.001), and XFG-NTG (p=0.002) groups. The number of half-filled (p=0.002), and full-filled (p=0.010) triangles were significantly different between XFG-NTG groups.

Conclusion :

Functional long-term follow-up of glaucoma patients can be monitored with visual field indices. We herein report our fifteen year follow-up results in open angle glaucoma.

Significance of corneal biomechanical properties in patients with progressive normal-tension glaucoma

AIM

To investigate the clinical significance of corneal biomechanical properties assessed using an ocular response analyser in patients with progressing normal-tension glaucoma (NTG).

METHODS

In this retrospective study, we included 82 eyes of 82 NTG patients who had been receiving topical anti-glaucoma medications. Patients were allocated to two groups based on the mean value of corneal hysteresis (CH) and the status of progression. The assessment of progression was based on the trend analysis using mean deviation slope. Uni- and multivariable logistic analyses were constructed to identify factors associated with increased odds of progression, including CH, central corneal thickness (CCT), and retinal nerve fibre layer (RNFL) thickness.

RESULTS

Forty-six eyes (56.1%) reached the progression criteria. Eyes with progression had lower CCT (530.2±38.6 vs 549.4±38.3 μm, p=0.03), thinner average RNFL thickness (70.6±16.1 vs 82.8±17.4 μm, p<0.01), lower CH (9.4±1.3 vs 10.8±1.4 mm Hg, p<0.01), and lower corneal resistance factor (9.3±1.3 vs 10.4±1.8 mm Hg, p<0.01) than eyes without progression. CH and CCT were significantly correlated (r=0.44, p<0.01). Upon multivariable analysis, CH (β (B)=0.32 per mm Hg lower, p<0.01) and average RNFL thickness (β=0.96 per μm lower, p=0.04) remained statistically significant.

CONCLUSIONS

Corneal biomechanical properties are correlated and associated with the progression of visual field damage in NTG patients. These findings suggest that CH can be used as one of the prognostic factors for progression, independent of corneal thickness or intraocular pressure.

Contributing factors for progression of visual field loss in normal-tension glaucoma patients with medical treatment

PURPOSE

To investigate the prognostic factors responsible for the progression of visual field defects (VFDs) in patients with normal-tension glaucoma (NTG) treated with topical antiglaucoma medications.

PATIENTS AND METHODS

A total of 92 eyes in 92 NTG patients treated with only topical antiglaucoma medications for ≥ 5 years were retrospectively analyzed. To identify subfield-based prognostic factors, the central 30-degree visual field (Humphrey Field Analyzer) was divided into 6 subfields: upper and lower arcuate, paracentral, and cecocentral subfields. Factors related to subfield-based progression (age, refraction, mean intraocular pressure (IOP), IOP variability, central corneal thickness, and disc hemorrhage) were evaluated using a linear mixed model.

RESULTS

Ninety-two eyes in 92 NTG patients were included in this study. The mean observation period was 7.7 ± 2.7 (5.0 to 15.5) years, and the estimated rate of change in the mean deviation value was -0.16 ± 0.31 dB/y (P<0.001). A subfield-based linear mixed model analysis of the time course of changes in the mean of total deviation identified a greater extent of myopia as a significant positive prognostic factor for VFD progression in the upper paracentral area (P=0.016). The mean IOP, central corneal thickness, disc hemorrhage, age, and IOP variation showed no significant contribution in any of the subfields.

CONCLUSIONS

The extent of myopia was found to be a significant positive prognostic factor for VFD progression in the upper paracentral subfield for non-high-myopic NTG eyes with an average IOP of 14.2 mm Hg under topical antiglaucoma medication.

Risk factors for progression of normal-tension glaucoma under β-blocker monotherapy

PURPOSE

To prospectively study prognostic factors for normal-tension glaucoma (NTG) under treatment with topical β-blocker.

METHODS

One hundred and forty-six eyes of 146 patients with NTG with a mean untreated intraocular pressure (IOP) of 14 mmHg, mild to moderate visual field damage and mean spherical equivalent refraction of -3.5 (-8.0 to +2.0) dioptre were randomized to topical nipradilol or timolol and followed for 3 years. The Humphrey full threshold 30-2 visual field test was performed every 6 months, and optic disc photographs were obtained every 12 months. Progression was defined as visual field progression, optic disc and/or peripapillary nerve fibre layer change, and factors relating to progression were evaluated using Cox proportional hazards models.

RESULTS

IOP decreased by 1.0 mmHg over the 3-year period, during which 35% showed progression according to the aforementioned criteria. Optic disc haemorrhage (hazard ratio [HR] 4.00, p < 0.001) and less extent of myopia (per dioptre, HR 1.15, p = 0.013) were significant risk factors. When progression was defined by visual field progression only, less extent of myopia was again a significant risk factor (HR 1.17, p = 0.038).

CONCLUSION

Beside optic disc haemorrhage, less extent of myopia was a risk factor for progression in the current NTG population where most patients were mildly myopic and IOP during follow-up averaged 13.2 mmHg under topical β-blocker.

Retrobulbar hemodynamic effects of nipradilol in normal and normal-tension glaucoma eyes

Purpose. To investigate the effects of nipradilol on retrobulbar hemodynamics. Methods. We investigated normal and normal-tension glaucoma (NTG) eyes. Topical nipradilol (one eye) and placebo eye drops (fellow eye) were instilled for 1 week in volunteers. Nipradilol was also instilled in NTG patients. Ultrasound color Doppler imaging for the posterior vessels was performed before, 2 hr, 1 week (for normal), and at 4 weeks (for NTG). Results. In normal eyes, there were significant decreases in the resistance index (RI) for the temporal short posterior ciliary arteries (PCA) at 2 hr and for the ophthalmic arteries at 1 week. There were no significant changes in the placebo-treated eyes. In the NTG eyes, there was a significant decrease in the RI for the central retinal artery, nasal, and temporal PCA at 2 hr and 4 weeks. Conclusion. Short-term observations found that nipradilol increased the ocular blood flow in normal and NTG eyes.

Effect of five years of treatment with nipradilol eye drops in patients with normal tension glaucoma

Background

The purpose of this study was to evaluate the effects of topical nipradilol monotherapy for 5 years on intraocular pressure, visual field performance, and optic disk topography.

Methods

Thirty patients with normal tension glaucoma were monitored for intraocular pressure every 1–3 months. A Humphrey visual field test and measurement of optic disk configuration using the Heidelberg retina tomograph II was done after every year of treatment and the results compared with those before treatment. Visual field performance was also evaluated by trend and event analysis.

Results

The mean intraocular pressure ± standard deviation after 3 years of nipradilol treatment (14.1 ± 2.0 mmHg) and after 5 years of nipradilol treatment (13.7 ± 2.1 mmHg) was significantly lower than that before treatment (17.0 ± 1.8 mmHg, P < 0.0001). Heidelberg retina tomograph II parameters, such as mean cup depth and height variation contour after treatment, were significantly increased compared with those before treatment. Visual field performance worsened in eight eyes by trend analysis and eight eyes by event analysis.

Conclusion

Nipradilol monotherapy was effective in reducing intraocular pressure over at least 5 years without worsening of optic disk topography. Furthermore, mean cup depth and height variation contour were also significantly improved. However, visual field performance worsened in 16.0% of patients with normal tension glaucoma.

Visual field loss in patients with normal-tension glaucoma under topical nipradilol or timolol: subgroup and subfield analyses of the nipradilol-timolol study

PURPOSE

To estimate the deterioration rates of visual field loss in Japanese normal-tension glaucoma (NTG) patients under either topical nipradilol or timolol, and to explore intergroup differences in the treatment results.

METHODS

A total of 146 NTG patients with mild to moderate damage were randomized to either nipradilol or timolol and followed for 3 years with a periodic comprehensive ophthalmological visual field examination (30-2 Humphrey perimeter program) every 6 months (the Nipradilol-Timolol Study). The time course of mean deviation (MD), the average total deviation (TD(mean)) in four subfields, and the corrected pattern standard deviation (CPSD) were compared between the two groups using regression analysis with a linear mixed effect model.

RESULTS

The estimated slope for MD (dB/year) was -0.03 in the nipradilol and -0.05 in the timolol group (P > 0.4). In both groups, TD(mean) in the superior-central subfield and CPSD showed significant changes (-0.3 and 0.2-0.3, P <or= 0.001). In the patients with early visual field loss or those younger than 40 years, deterioration of some visual field parameters tended to be slower in the nipradilol group than in the timolol group.

CONCLUSION

During 3 years of monotherapy with either nipradilol or timolol in NTG patients, only TD(mean) in the superior-central subfield and the CPSD changed significantly without any intergroup differences.