Medical treatment of normal tension glaucoma

Pharmaceutical Approaches to Normal Tension Glaucoma

Normal tension glaucoma (NTG) is defined as a subtype of primary open-angle glaucoma (POAG) in which the intraocular pressure (IOP) values are constantly within the statistically normal range without treatment and represents approximately the 30-40% of all glaucomatous cases. The pathophysiology of this condition is multifactorial and is still not completely well known. Several theories have been proposed to explain the onset and progression of this disease, which can be divided into IOP-dependent and IOP-independent factors, suggesting different therapeutic strategies. The current literature strongly supports the fundamental role of IOP in NTG. The gold standard treatment for NTG tends to be based on the lowering IOP even if "statistically normal". Numerous studies have shown, however, that the IOP reduction alone is not enough to slow down or stop the disease progression in all cases, suggesting that other IOP-independent risk factors may contribute to the NTG pathogenesis. In addition to IOP-lowering strategies, several different therapeutic approaches for NTG have been proposed, based on vaso-active, antioxidant, anti-inflammatory and/or neuroprotective substances. To date, unfortunately, there are no standardized or proven treatment alternatives for NTG when compared to traditional IOP reduction treatment regimes. The efficacy of the IOP-independent strategies in decreasing the risk or treating NTG still remains inconclusive. The aim of this review is to highlight strategies reported in the current literature to treat NTG. The paper also describes the challenges in finding appropriate and pertinent treatments for this potentially vision-threatening disease. Further comprehension of NTG pathophysiology can help clinicians determine when to use IOP-lowering treatments alone and when to consider additional or alternatively individualized therapies focused on particular risk factors, on a case-by-case basis.

Impact of cerebral hypoperfusion-reperfusion on optic nerve integrity and visual function in the DBA/2J mouse model of glaucoma

Objective

One of the most important risk factors for developing a glaucomatous optic neuropathy is elevated intraocular pressure. Moreover, mechanisms such as altered perfusion have been postulated to injure the optical path. In a mouse model, we compare first negative effects of cerebral perfusion/reperfusion on the optic nerve structure versus alterations by elevated intraocular pressure. Second, we compare the alterations by isolated hypoperfusion-reperfusion and isolated intraocular pressure to the combination of both.

Methods and analysis

Mice were divided in four groups: (1) controls; (2) perfusion altered mice that underwent transient bi-common carotid artery occlusion (BCCAO) for 40 min; (3) glaucoma group (DBA/2J mice); (4) combined glaucoma and altered perfusion (DBA/2J mice with transient BCCAO). Optic nerve sections were stereologically examined 10–12 weeks after intervention.

Results

All experimental groups showed a decreased total axon number per optic nerve compared with controls. In DBA/2J and combined DBA/2J & BCCAO mice the significant decrease was roughly 50%, while BCCAO leaded to a 23% reduction of axon number, however reaching significance only in the direct t-test. The difference in axon number between BCCAO and both DBA/2J mice was almost 30%, lacking statistical significance due to a remarkably high variation in both DBA/2J groups.

Conclusion

Elevated intraocular pressure in the DBA/2J mouse model of glaucoma leads to a much more pronounced optic nerve atrophy compared with transient forebrain hypoperfusion and reperfusion by BCCAO. A supposed worsening effect of an altered perfusion added to the pressure-related damage could not be detected.

Travoprost- and Tafluprost-induced Changes in Intraocular Pressure and Ocular Pulse Amplitude

Purpose: To compare the intraocular pressure reduction and changes in ocular pulse amplitude of travoprost 0.003% and tafluprost 0.0015%. Methods: We assessed patients who were diagnosed with open-angle glaucoma from January 2017 to July 2019 for the first time at our hospital. Forty-two eyes were assigned to the travoprost group (23 patients) and 26 eyes were assigned to the tafluprost group (14 patients). Changes in intraocular pressure were measured by Goldmann applanation tonometry (GAT), and corrected ocular pulse amplitude (cOPA) was measured using dynamic contour tonometry. Changes in these parameters were observed and compared for 1 year. Results: No significant differences were observed between the GAT measurements and the cOPA of patients treated with travoprost and tafluprost for 1 year (<i>p</i> = 0.512, <i>p</i> = 0.105). The change in initial intraocular pressure on GAT observed after 1 week was -5.32 ± 2.63 mmHg for travoprost and -3.79 ± 3.19 mmHg for tafluprost (<i>p</i> = 0.0457). The initial change in cOPA was +0.04 ± 0.9 mmHg in the travoprost group and -0.76 ± 0.97 mmHg in the tafluprost group (<i>p</i> = 0.0028). Conclusions: Travoprost and tafluprost reached the targeted intraocular pressure with no difference in the long-term effects of reduced intraocular pressure. However, travoprost was initially better at lowering intraocular pressure faster, and tafluprost had a greater effect on lowering OPA. Prostaglandin analogs can be selected individually by considering the aforementioned factors.

Potential Therapeutic Benefit of NAD+ Supplementation for Glaucoma and Age-Related Macular Degeneration

Glaucoma and age-related macular degeneration are leading causes of irreversible blindness worldwide with significant health and societal burdens. To date, no clinical cures are available and treatments target only the manageable symptoms and risk factors (but do not remediate the underlying pathology of the disease). Both diseases are neurodegenerative in their pathology of the retina and as such many of the events that trigger cell dysfunction, degeneration, and eventual loss are due to mitochondrial dysfunction, inflammation, and oxidative stress. Here, we critically review how a decreased bioavailability of nicotinamide adenine dinucleotide (NAD; a crucial metabolite in healthy and disease states) may underpin many of these aberrant mechanisms. We propose how exogenous sources of NAD may become a therapeutic standard for the treatment of these conditions.

Effects of Consumption of Alcohol on Intraocular Pressure: Korea National Health and Nutrition Examination Survey 2010 to 2011

This study researched the association between alcohol consumption, intraocular pressure (IOP), and risk of open-angle glaucoma (OAG) using nationwide population-based cross-sectional data from the Korean population based survey. Information on alcohol intake was obtained by questionnaire and comprehensive ophthalmic examinations were performed. Among a total of 6057 participants, the prevalence of OAG was 4.4% (6.0% for men and 3.0% for women). Multivariate adjusted models showed that alcohol consumption showed significant relationship with changes in IOP. In sex-stratified analyses, alcohol consumption more than 2 times per week was associated with increased IOP in men without OAG, while in women with OAG drinking alcohol more than 4 times per week was associated with increased IOP. This study showed significant differences between men and women without glaucoma who consumed alcohol more than four times per week (p-value: 0.03). Our results suggest that alcohol consumption is associated with risk of elevated IOP depending on sex and presence of glaucoma in Koreans. Therefore, patients who need to control IOP should consider the effects of alcohol consumption.

The evaluation of short- and long-term stability studies for brimonidine in aqueous humor by DPV/BDDE method-possible application for direct assay in native samples

A novel voltammetric method was developed for brimonidine (BRIM) determination in deproteinized aqueous humor, simplifying preparation of biological samples for analysis for stability studies. The differential pulse voltammetric (DPV) method using boron doped diamond electrode (BDDE), based on characteristic oxidation peaks, was proposed and successfully applied. The linearity range was within 5.0 × 10^-6 to 5.0 × 10^-5 M of brimonidine, and limit of detection and limit of quantitation were 1.94 × 10^-6 M and 6.46 × 10^-6 M, respectively. Intra-day and inter-day precision and accuracy were evaluated and all results were in accordance with validation ICH guidelines. The best short-term stability study results were obtained for a concentration level of 3.0 × 10^-5 M expressed by deviation of + 1.86% between initial and post storage concentrations. A long-term stability study was performed for two concentrations of 3.0 × 10^-5 M and 5.0 × 10^-5 M and resulted in deviations of + 1.63% and + 3.56%, respectively. A freeze and thaw stability study indicated that samples might be frozen only once. The enhancement of DPV/BDDE method sensitivity gained by modification, for the analysis of immeasurable BRIM quantities in native, untreated aqueous humor, was reached for quantities of 6 or 12 nmol/0.1 mL aqueous humor with acceptable accuracy (up to + 7.5%). The nature of the process-the irreversible one electron oxidation voltammetric peak of BRIM-limited the sensitivity. Only electrochemical pre-treatment of the BDD electrode before each measurement significantly speeded up the whole procedure. The advantages of the proposed method are simplicity, short-time performance, and good specificity/selectivity, as well as satisfactory accuracy, and no chemical modification of BDDE was necessary.

Combination Products for Glaucoma: An Overview of Treatment Principles

Glaucoma is a leading cause of blindness and visual impairment. Treatments that lower intraocular pressure (IOP) tend to delay progression of the condition. However, the target IOP cannot be achieved with monotherapy in many patients. If monotherapy adequately controls IOP and is well tolerated, it should not be changed, but if the therapy is only partially effective, a combination may be used. Combination therapy is eventually needed in many cases of glaucoma. Combinations may be given as adjunctive or preferably as fixed therapies. The mechanism of action and contraindications of the constituent agents should be taken into account when prescribing combinations, for optimal safety and efficacy. As treatment choice expands, prescribing patterns are changing worldwide. Fixed combination therapies are increasingly prescribed in Europe in particular for the treatment of glaucoma. They should be administered according to the current evidence-based guidelines.

Neuroprotection: A Valuable Goal in Glaucoma Management?

Glaucoma is characterized by an accelerated loss of retinal ganglion cells, as a result of damage to optic nerve axons. One factor involved in the disease process is elevated intraocular pressure (IOP) and this is the current focus of therapies. However, up to 45% of patients experience glaucoma progression despite good IOP control and partly as a result, the treatment principle of direct neuroprotection has been developed, which consists of treating optic nerve degeneration in glaucoma independently of IOP lowering. Animal models have shown the potential of this approach but there are limited clinical trial data. Brimonidine and memantine currently show promise, in terms of efficacy and side effects, among the compounds entering clinical trials. Brimonidine has been shown to have a neuroprotective effect independent of IOP lowering in humans with glaucoma, and data from a large clinical trial are being analyzed. Memantine has shown neuroprotective effects in animal models of glaucoma, and data from a clinical trial in humans are awaited.

Neuroprotection for treatment of glaucoma in adults

BACKGROUND

Glaucoma is a heterogeneous group of conditions involving progressive damage to the optic nerve, deterioration of retinal ganglion cells, and ultimately visual field loss. It is a leading cause of blindness worldwide. Open angle glaucoma (OAG), the most common form of glaucoma, is a chronic condition that may or may not present with increased intraocular pressure (IOP). Neuroprotection for glaucoma refers to any intervention intended to prevent optic nerve damage or cell death.

OBJECTIVES

The objective of this review was to systematically examine the evidence regarding the effectiveness of neuroprotective agents for slowing the progression of OAG in adults compared with no neuroprotective agent, placebo, or other glaucoma treatment.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 7), Ovid MEDLINE, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Ovid MEDLINE Daily (January 1946 to August 2016), Embase (January 1980 to August 2016), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to August 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov), and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 16 August 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) in which topical or oral treatments were used for neuroprotection in adults with OAG. Minimum follow-up time was four years.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed titles and abstracts from the literature searches. We obtained full-text copies of potentially relevant studies and re-evaluated for inclusion. Two review authors independently extracted data related to study characteristics, risk of bias, and outcomes. We identified one trial for this review, thus we performed no meta-analysis. Two studies comparing memantine to placebo are currently awaiting classification until study investigators provide additional study details. We documented reasons for excluding studies from the review.

MAIN RESULTS

We included one multicenter RCT of adults with low-pressure glaucoma (Low-pressure Glaucoma Treatment Study, LoGTS) conducted in the USA. The primary outcome was progression of visual field loss after four years of treatment with either brimonidine or timolol. Of the 190 adults enrolled in the study, the investigators excluded 12 (6.3%) after randomization; 77 participants (40.5%) did not complete four years of follow-up. The rate of attrition was unbalanced between groups with more participants dropping out of the brimonidine group (55%) than the timolol group (29%).Of those remaining in the study at four years, participants assigned to brimonidine showed less progression of visual field loss than participants assigned to timolol (risk ratio (RR) 0.35, 95% confidence interval (CI) 0.14 to 0.86; 101 participants). Because of high risk of attrition bias and potential selective outcome reporting, we graded the certainty of evidence for this outcome as very low. At the four-year follow-up, the mean IOP was similar in both groups among those for whom data were available (mean difference 0.20 mmHg, 95% CI -0.73 to 1.13; 91 participants; very low-certainty evidence). The study authors did not report analyzable data for visual acuity or any data related to vertical cup-disc ratio, quality of life, or economic outcomes. The most frequent adverse event was ocular allergy to the study drug, which affected more participants in the brimonidine group than the timolol group (RR 5.32, 95% CI 1.64 to 17.26; 178 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Although the only trial we included in this review found less visual field loss in the brimonidine-treated group, the evidence was of such low certainty that we can draw no conclusions from this finding. Further clinical research is needed to determine whether neuroprotective agents may be beneficial for individuals with OAG. Such research should focus on outcomes important to patients, such as preservation of vision, and how these outcomes relate to cell death and optic nerve damage. As OAG is a chronic, progressive disease with variability in symptoms, RCTs designed to measure the effectiveness of neuroprotective agents require a long-term follow-up of five years or longer to detect clinically meaningful effects.

Change in Central Corneal Thickness After the Discontinuation of Latanoprost in Normal Tension Glaucoma-Change in Central Corneal Thickness After Stop of Latanoprost

PURPOSE

To assess the impact of latanoprost on central corneal thickness (CCT) after ceasing medication in patients with normal tension glaucoma (NTG).

METHODS

A total of 46 eyes from 46 NTG patients, and 44 eyes from 44 individuals with glaucoma suspect (controls), were included in this retrospective study. Newly diagnosed early NTG patients (visual field mean deviation >-6.00) were administered latanoprost 0.005% monotherapy once a day. CCTs were measured by ultrasound pachymetry before treatment, for 5 years during treatment, and for 2 years after ceasing treatment.

RESULTS

Mean CCT was reduced significantly in the NTG group during treatment [544.4 ± 35.8 μm vs. 531.4 ± 32.5 μm (n = 46), P < 0.001]. After ceasing latanoprost treatment, mean CCT increased [531.4 ± 32.5 μm vs. 544.6 ± 37.1 μm (n = 46), P < 0.01] over the course of 2 years. In the control group, however, mean CCT was not significantly different [553.5 ± 27.5 μm vs. 561.8 ± 24.7 μm (n = 44), P = 0.06] at the 7-year follow-up.

CONCLUSIONS

Latanoprost significantly reduced CCT in NTG patients after 5 years of treatment; however, the reduction was reversed 2 years after discontinuation of treatment.

Neuroprotection for treatment of glaucoma in adults

BACKGROUND

Glaucoma is a heterogeneous group of conditions involving progressive damage to the optic nerve, deterioration of retinal ganglion cells and ultimately visual field loss. It is a leading cause of blindness worldwide. Open angle glaucoma (OAG), the commonest form of glaucoma, is a chronic condition that may or may not present with increased intraocular pressure (IOP). Neuroprotection for glaucoma refers to any intervention intended to prevent optic nerve damage or cell death.

OBJECTIVES

The objective of this review was to systematically examine the evidence regarding the effectiveness of neuroprotective agents for slowing the progression of OAG in adults.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 9), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to October 2012), EMBASE (January 1980 to October 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 16 October 2012.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in which topical or oral treatments were used for neuroprotection in adults with OAG. Minimum follow up time was four years.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed titles and abstracts from the literature searches. Full-text copies of potentially relevant studies were obtained and re-evaluated for inclusion. Two review authors independently extracted data related study characteristics, risk of bias, and outcome data. One trial was identified for this review, thus we performed no meta-analysis. Two studies comparing memantine to placebo are currently awaiting classification until additional study details are provided. We documented reasons for excluding studies from the review.

MAIN RESULTS

We included one multi-center RCT of adults with low-pressure glaucoma (Low-pressure Glaucoma Treatment Study, LoGTS) conducted in the USA. The primary outcome was visual field progression after four years of treatment with either brimonidine or timolol. Of the 190 adults enrolled in the study, 12 (6.3%) were excluded after randomization and 77 (40.5%) did not complete four years of follow up. The rate of attrition was unbalanced between groups with more participants dropping out of the brimonidine group (55%) than the timolol group (29%). Of those remaining in the study at four years, participants assigned to brimonidine showed less visual field progression than participants assigned to timolol (5/45 participants in the brimonidine group compared with 18/56 participants in the timolol group). Since no information was available for the 12 participants excluded from the study, or the 77 participants who dropped out of the study, we cannot draw any conclusions from these results as the participants for whom data are missing may or may not have progressed. The mean IOP was similar in both groups at the four-year follow up among those for whom data were available: 14.2 mmHg (standard deviation (SD) = 1.9) among the 43 participants in the brimonidine group and 14.0 mmHg (SD = 2.6) among the 48 participants in the timolol group. Among the participants who developed progressive visual field loss, IOP reduction of 20% or greater was not significantly different between groups: 4/9 participants in the brimonidine group and 12/31 participants in the timolol group. The study authors did not report data for visual acuity or vertical cup-disc ratio. The most frequent adverse event was ocular allergy to study drug, which occurred more frequently in the brimonidine group (20/99 participants) than the timolol group (3/79 participants).

AUTHORS' CONCLUSIONS

Although neuroprotective agents are intended to act as pharmacological antagonists to prevent cell death, this trial did not provide evidence that they are effective in preventing retinal ganglion cell death, and thus preserving vision in people with OAG. Further clinical research is needed to determine whether neuroprotective agents may be beneficial for individuals with OAG. Such research should focus outcomes important to patients, such as preservation of vision, and how these outcomes relate to cell death and optic nerve damage. Since OAG is a chronic, progressive disease with variability in symptoms, RCTs designed to measure the effectiveness of neuroprotective agents would require long-term follow up (more than four years) in order to detect clinically meaningful effects.

Effect of latanoprost on central corneal thickness in unilateral normal-tension glaucoma

PURPOSE

To evaluate the effect of latanoprost on central corneal thickness (CCT) in patients with unilateral normal-tension glaucoma (NTG).

METHODS

A total of 38 patients, with unilateral NTG, who were being treated in our glaucoma clinic and were receiving 0.005% latanoprost monotherapy over 24 months, were included in this study. The data were collected, retrospectively, with reviewing of the charts. The mean CCT and the CCT reduction from the baseline were assessed before the treatment, and at 3, 6, 9, 12, and 24 months after the initiation of the treatment. An unaffected eye was also evaluated for the control group. All the measurements were performed with a commercially available ultrasound pachymeter.

RESULTS

There were no significant differences between the eyes for the baseline intraocular pressure and CCT. The mean CCT trend decreased, except at 9 months after the treatment in the latanoprost group (affected eye), but only statistically significant after 24 months of treatment by using paired-sample t-test [544.6±38.4 vs. 540.3±37.8 μm (P=0.013)]. There was no statistically significant changes of CCT between the groups with repeated measures analysis of variance (P=0.635).

CONCLUSION

Topical therapy with latanoprost may decrease the CCT, over a period of 24 months, in patients with NTG. These data should be taken into consideration in a long-standing latanoprost treatment of NTG.

Clinical options for the reduction of elevated intraocular pressure

Elevated IOP in clinical practice is usually seen in glaucoma or ocular hypertension. Glaucoma affects 60 million people worldwide and 8.4 million are bilaterally blind from this chronic disease.1 Options for reducing IOP rely on pharmacological agents, laser treatments and surgery which may be penetrating or non-penetrating. The last twenty years has seen significant changes in all of these strategies. This review aims to cover these clinical options and introduce some of the new technologies currently in development for the clinical lowering of IOP.

Cellular and molecular biology of optineurin

Optineurin is a gene linked to glaucoma, amyotrophic lateral sclerosis, other neurodegenerative diseases, and Paget's disease of bone. This review describes the characteristics of optineurin and summarizes the cellular and molecular biology investigations conducted so far on optineurin. Data from a number of laboratories indicate that optineurin is a cytosolic protein containing 577 amino acid residues. Interacting with proteins such as myosin VI, Rab8, huntingtin, transferrin receptor, and TANK-binding kinase 1, optineurin is involved in basic cellular functions including protein trafficking, maintenance of the Golgi apparatus, as well as NF-κB pathway, antiviral, and antibacteria signaling. Mutation or alteration of homeostasis of optineurin (such as overexpression or knockdown) results in adverse consequences in the cells, leading to the development of neurodegenerative diseases including glaucoma.

Update on the role of alpha-agonists in glaucoma management

Glaucoma is the second most common cause of world blindness (following cataract) with estimated cases reaching 79.6 million by 2020. Although the etiology of glaucoma is multi-factorial, intraocular pressure (IOP) is the only modifiable factor in glaucoma management proven to alter the natural course of the disease. Among various classes of IOP-lowering medications currently available, alpha-adrenergic receptor agonists are used either as monotherapy, as second-line therapy, or in fixed combination with beta-blockers. Non-selective adrenergic agonists such as epinephrine and dipivefrin are infrequently used today for the treatment of glaucoma or ocular hypertension, and have been replaced by the alpha-2-selective agonists. The use of apraclonidine for IOP reduction in glaucoma or OHT is limited due to a high rate of follicular conjunctivitis. The alpha-2-selective agonist in use today is brimonidine. The brimonidine-purite formulations are preferred to brimonidine-benzalkonium chloride (BAC) formulations due better tolerability while maintaining similar efficacy. Brimonidine is also effective when used in combination with a beta-blocker. Using brimonidine-timolol fixed combination (BTFC) as first-line therapy has an added potential for neuroprotection. This would be a valuable strategy for glaucoma treatment, for patients who are intolerant of prostaglandin analogs, or for patients where prostaglandin analogues are contraindicated as first-line therapy, such as in patients with inflammatory glaucoma.

Neuroprotection for treatment of glaucoma in adults

BACKGROUND

Glaucoma is a heterogeneous group of conditions involving progressive damage to the optic nerve, deterioration of retinal ganglion cells and ultimately visual field loss. It is a leading cause of blindness worldwide. Open angle glaucoma (OAG), the commonest form of glaucoma, is a chronic condition that may or may not present with increased intraocular pressure (IOP). Neuroprotection for glaucoma refers to any intervention intended to prevent optic nerve damage or cell death. The treatment can target extracellular factors such as reducing IOP, or cellular factors derived from the optic nerve itself such as blocking intracellular death signals.

OBJECTIVES

The objective of this review was to systematically examine the evidence regarding the effectiveness of neuroprotective agents, either topical or oral, for slowing the progression of OAG in adults.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library, Issue 4, 2009), MEDLINE (January 1960 to January 2010), EMBASE (January 1980 to January 2010), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2010) and ClinicalTrials.gov (http://clinicaltrials.gov). (5 January 2010). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 5 January 2010.

SELECTION CRITERIA

This review was limited to randomized controlled trials (RCTs) in which topical or oral treatments were used to prevent retinal ganglion cell death. Our population of interest was adults with OAG. As the primary outcome for this review was the proportion of participants who developed any progression of visual field loss at five years post intervention, only trials with at least five years of follow-up were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed titles and abstracts from the literature searches. Full text copies of relevant or potentially relevant studies were obtained and re-evaluated for inclusion. There were no trials identified for this review, thus we performed no data extraction or meta-analysis. Two studies comparing memantine to placebo are currently awaiting classification until additional study details are provided. Reasons for excluding studies from the review were documented.

MAIN RESULTS

In accordance with the selection criteria for inclusion, we identified no studies relevant for this review. The results of short-term trials and other studies are discussed in this review.

AUTHORS' CONCLUSIONS

Although neuroprotective agents are intended to act as pharmacological antagonists to prevent cell death, the evidence that they are effective in preventing retinal ganglion cell death, and thus preserving vision in patients with OAG, has not been demonstrated. Long-term RCTs are needed to determine whether or not neuroprotective agents may be beneficial for individuals with OAG.

Effect of travoprost on intraocular pressure during 12 months of treatment for normal-tension glaucoma

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering effect of travoprost in normal-tension glaucoma (NTG) over a 12-month follow-up.

METHODS

Forty-five eyes of 45 patients with unilateral NTG were treated with travoprost (0.004%) once a day for 12 months. Mean IOP and the IOP reduction from baseline were assessed at 0.5, 1, 3, 6, 9, and 12 months after the initiation of the treatment. Adverse ocular event frequency and the frequency of discontinuation of treatment due to adverse events were evaluated.

RESULTS

Mean IOP during 12 months of travoprost treatment ranged from 11.17 to 11.82 mmHg, and the mean IOP reduction in relation to baseline IOP from -2.71 to -3.71 mmHg (-18.3% to -25.1%). Mean IOP and IOP changes in the travoprost-treated and control groups were significantly different at every follow-up (P < 0.05 in each case). Both the magnitude (r = 0.6992) and percentage (r = 0.5464) of IOP reductions correlated positively with baseline IOP values. Ocular adverse events were usually mild to moderate and resolved without treatment.

CONCLUSIONS

Travoprost was well tolerated and significantly reduced IOP in NTG patients. In addition, initial IOP reductions were maintained throughout follow-up. Travoprost was found to be more effective in patients with greater baseline IOP.

Effects of Cyclooxygenase Inhibitors on Apoptotic Neuroretinal Cells

Glaucoma is characterized by a loss of retinal ganglion cells (RGC) which is associated with a decrease of visual function. Neuroprotective agents as a new therapeutic strategy could prevent the remaining neurons from apoptotic cell death. Previous studies have shown the involvement of the Cyclooxygenase (COX)-2 signalling in the apoptotic death of neurons. Herein we investigated the neuroprotective effect of COX-1/COX-2- and selective COX-2- inhibitors on apoptotic. R28, a neuroretinal cell line and determined the PGE(2) levels by ELISA. Furthermore we investigated differences in protein expression in the cells after exposure to elevated pressure compared to untreated cells by ProteinChip analysis.In addition, a protein profiling study of the cells after exposure to elevated pressure was performed. The protein expression profiles were measured by SELDI-TOF (Surface Enhanced Laser Desorption/Ionization-time of flight) Protein Chips. The protein identification was performed by mass spectrometry (MS).It could be shown that COX-2 inhibition significantly prevented the cells from apoptosis and reduced the PGE(2) concentrations. Selective COX-2 inhibitors were significant more potent than non-selective inhibitors or COX-1 inhibitors. We found differently expressed protein patterns in neuroretinal cells cultured at atmospheric pressure compared to those cells exposed to elevated pressure with or without celecoxib respectively. We identified three biomarkers, ubiquitin, HSP10 and NDKB, which were differently expressed in the groups. However, our data indicates a distinct neuroprotective effect of COX-2 inhibition. The local treatment with selective COX-2 inhibitors might provide an innovative strategy of therapeutic intervention for glaucoma.

Studies of optineurin, a glaucoma gene: Golgi fragmentation and cell death from overexpression of wild-type and mutant optineurin in two ocular cell types

Optineurin (OPTN) has recently been linked to glaucoma, a major cause of blindness worldwide. Mutations in OPTN such as Glu50-->Lys (E50K) have been reported in patients, particularly those with normal pressure glaucoma. Here, we show that the endogenous OPTN was not secreted in two ocular cell types, human trabecular meshwork and retinal pigment epithelial cells. It localized instead in the cytoplasm in a diffuse pattern without a distinct association with the Golgi apparatus. When overexpressed, however, wild-type OPTN-green fluorescent protein (GFP) formed foci especially around the Golgi, colocalizing partially with the common endocytic pathway marker transferrin receptor in both cell types. Fragmentation of the Golgi was also observed. On nocodazole treatment, the OPTN foci were dispersed into the cytoplasm. Overexpression of mutant OPTNE50K-GFP resulted in a greater number (P<0.0055) and size of the foci, compared with the wild type, and the Golgi alteration was potentiated. Cell loss observed in OPTN-expressing cultures was also more pronounced in OPTNE50K-GFP compared with that of wild-type OPTN-GFP counterparts (P<0.01). This study highlights a possible role of OPTN in vesicle trafficking and Golgi integrity. It also provides in-sights into the possible mechanisms why E50K would exhibit a propensity toward the development of glaucoma.

The effect of latanoprost on intraocular pressure during 12 months of treatment for normal-tension glaucoma

PURPOSE

To evaluate the intraocular pressure (IOP)-lowering efficacy of latanoprost in normal-tension glaucoma (NTG).

METHODS

One-hundred and seventeen eyes of 63 NTG patients treated with 0.005% latanoprost once a day were enrolled in this study. Of these, 85 eyes of 47 patients were treated for 12 months. Mean IOPs were analyzed, and the mean IOP reductions from the untreated baseline were assessed after two weeks and after 1, 3, 6, 9, and 12 months of treatment.

RESULTS

The mean untreated baseline IOP was 15.0 +/- 2.7 mmHg. After two weeks of latanoprost treatment, the mean IOP reduction from the baseline value was 2.6 +/- 0.2 mmHg (17.3%, p<0.05), and after 6 and 12 months, the reduction was 2.4 +/- 0.2 mmHg (16.0%, p<0.05) and 2.4 +/- 0.2 mmHg (16.0%, p<0.05), respectively. Patients with a baseline IOP of > or = 15 mmHg achieved significantly higher IOP reductions than those with a baseline IOP of <15 mmHg at all follow-ups (p<0.05).

CONCLUSIONS

Latanoprost was found to be well tolerated and to significantly reduce IOP in NTG patients.

Safe trabeculectomy technique: long term outcome

AIM

To assess the long term outcome of a new trabeculectomy technique.

METHODS

Trabeculectomy was performed using a fornix based conjunctival flap, an anterior chamber maintainer, a standardised punch technique, and a combination of adjustable and releasable sutures in 56 eyes of 53 patients. The main outcome measures were the postoperative intraocular pressure (IOP) and the frequency of early postoperative complications. The mean follow up time was 15.7 (range 12-21) months.

RESULTS

The mean preoperative and postoperative IOP at 12 months were 21.2 (SD 6) and 12.8 (3.0) mm Hg, respectively. All patients had an IOP of <21 mm Hg, 90.9% had an IOP <18 mm Hg, and 61.4% had an IOP <14 mm Hg. Postoperative complications were infrequent: flat anterior chamber (1.8%), bleb leakage (0%), or hypotony (1.5%) beyond 3 weeks, or choroidal detachment at any time point (8.9%).

CONCLUSIONS

This novel trabeculectomy method offers the possibility to tailor the IOP postoperatively with a minimum of postoperative complications and excellent IOP control at the long term follow up.

Therapeutic Strategies for Normal-Tension Glaucoma

Treatment of normal-tension glaucoma has been a subject of debate for several years. Glaucomatous damage cannot be influenced directly, and current treatment modalities in normal-tension glaucoma are aimed at the control of risk factors. Intraocular pressure is a widely accepted risk factor and its reduction can improve the prognosis in normal-tension glaucoma patients. The repeated demonstration of the importance of hemodynamic factors in normal-tension glaucoma has, however, not been paralleled by a comparable progress in the development of therapeutic modalities capable of influencing favorably ocular blood flow. Today, calcium channel blockers seem to be the most promising adjunctive treatment to be considered in patients with glaucomatous optic neuropathy without increased intraocular pressure.

Effects of glaucoma drugs on ocular hemodynamics in normal tension glaucoma: a randomized trial comparing bimatoprost and latanoprost with dorzolamide [ISRCTN18873428]

Background

Reduced choroidal perfusion is hypothesized to play a role in the pathogenesis of normal tension glaucoma. Thus the impact of antiglaucomatous eye drops on ocular perfusion has been the focus of recent research and the subject of intensive investigations. The present study investigates whether topically applied latanoprost or bimatoprost influence ocular perfusion in patients with normal tension glaucoma and compares these effects with that changes detected after the treatment with dorzolamide.

Methods

Ocular hemodynamics were assessed by color Doppler imaging (CDI) shortly before and after a one-month treatment with either latanoprost, bimatoprost or dorzolamide. Primary end-points of the study were peak systolic and end-diastolic blood flow velocities in the short posterior ciliary artery (SPCA) under the new therapy. Intraocular pressure (IOP) and additional perfusion parameters in the SPCA and other retrobulbar vessels were tracked as observational parameters. n = 42 patients with normal tension glaucoma were enrolled in the study.

Results

Systolic and diastolic blood flow velocities in the SPCA showed no significant alteration after the treatment with latanoprost or bimatoprost. Dorzolamide lead to increase of peak systolic velocity. IOP was reduced by all three agents in a range reported in the literature.

Conclusion

Topically applied latanoprost and bimatoprost act in a hemodynamically neutral manner and have the capability to lower IOP even in patients with normal tension glaucoma and low initial IOP level. Dorzolamide accelerates blood flow in systole. None of the tested compounds has a negative impact on hemodynamics in the short posterior ciliary arteries.

The Comparative Cardiovascular, Pulmonary, Ocular Blood Flow, and Ocular Hypotensive Effects of Topical Travoprost, Bimatoprost, Brimonidine, and Betaxolol

OBJECTIVE

This study evaluated systemic and ocular acute safety and intraocular pressure (IOP)-lowering efficacy of travoprost 0.004% and bimatoprost 0.03%, compared to brimonidine 0.2% and betaxolol 0.25% in healthy subjects.

PATIENTS AND METHOD

Nineteen (19) young men, ages between 24 and 42, were enrolled in a single-center, institutional randomized, double-masked, crossover clinical trial. Baseline IOP, heart rate, blood pressure, and respiratory rate were recorded at hour 0. At minute 30, heart rate, blood pressure, respiratory rate, and spirometry were measured. At hour 1, color Doppler imaging of retrobulbar vessels was performed. At hour 2, heart rate, blood pressure, and respiratory rate were measured; spirometry and a 15-minute treadmill test were performed. The same protocol was applied after one drop of a study medication was instilled into each eye on four subsequent visits at 5-day intervals.

RESULTS

Travoprost and bimatoprost did not cause significant reductions in systolic blood pressure during exercise and recovery. The mean respiratory rate and forced expiratory volume in 1 second were not significantly altered by any study medication. Travoprost reduced the resistive index and increased blood velocities in the ophthalmic artery and its branches. Bimatoprost caused a significant increase in end diastolic velocity of the ophthalmic artery. At hour 6, all medications reduced IOP significantly (p < 0.05). The most frequent ocular side effect of travoprost and bimatoprost was conjunctival hyperemia.

CONCLUSION

Travoprost and bimatoprost were found to be systemically safe and caused an increase in blood-flow velocities of the retrobulbar vessels after a single-dose application. Their ocular hypotensive effect was comparable to that of brimonidine and greater than that of betaxolol in healthy subjects.