Once-daily versus twice-daily levobunolol (0.5%) therapy. A crossover study

A Cross-Over Trial Comparing Once Daily Levobunolol with Once and twice Daily Timolol

The intraocular pressure (IOP) lowering efficacy of once-daily levobunolol 0.5% was compared with timolol 0.5% twice-daily and timolol 0.5% once-daily in 20 chronic open angle glaucoma and 5 ocular hypertensive patients. The design used was a randomised double blind cross-over trial with three periods each of 8 weeks separated by 2 weeks of no treatment.

We found that following levobunolol a two week washout was not sufficient for the IOP to return to its original baseline level suggesting that levobunolol is a longer acting drug than timolol. Adjusting for this carryover effect, we found no significant difference in the IOP lowering effect among the three regimes (p=0.53). Reduced cost, less ocular discomfort and better compliance are the main potential advantages of the once daily treatments.

Effects of timolol maleate, levobunolol and apraclonidine on intraocular pressure, pupil size, blood pressure and heart rate in beagles

ABSTRACT The aim of this study was to evaluate changes in intraocular pressure (IOP), pupil size (PS), blood pressure (BP), heart rate (HR), and ECG variables (Pms wave PmV, PR interval, QRS complex, RMV wave and QT intervals) over time during the instillation of 0.5% timolol, 0.5% levobunolol and 0.5% apraclonidine in clinically normal dogs. Ten adult beagles were used. Baseline values were measured at 8a.m., 2p.m. and 8p.m., for three consecutive days. A waiting period of 10 days between the administrations of each drug was established. For 15 consecutive days, the drug being tested was instilled in one eye of each dog twice a day (7a.m. and 7p.m.). The parameters were evaluated at the aforementioned times on days 3, 6, 9, 12 and 15. Data were statistically compared using the Bonferroni test and one-way repeated measures analysis of variance (P<0.05). The Pearson test was used to evaluate any correlation between QT interval, HR and BP. The tested drugs did not find a decrease in IOP. A significant decreased in PS was observed in almost all dogs following levobunolol administration, relative to the control eye. A significant decrease in HR was observed on day 3 following levobunolol treatment, while apraclonidine induced an increase on day 15. Blood pressure was reduced in all measurement time points following apraclonidine treatment. A negative correlation between QT interval and HR was only observed in dogs treated with timolol. In conclusion, levobunolol was the only drug that induced significant alterations in PS. Apraclonidine was the only drug that induced systemic hypotension. Timolol was the only drug to that induced a negative correlation between QT and HR.

Bradyarrhythmias secondary to topical levobunolol hydrochloride solution

An 88-year-old man was admitted with fatigue, dizziness, and heart palpitations. Both the electrocardiogram and Holter confirmed the existence of sinus bradycardia and sinus arrest. One hour prior to the onset of symptoms, he received levobunolol hydrochloride solution topically. The levobunolol hydrochloride solution was discontinued and the bradycardia resolved. He was diagnosed as having intermittent sinus bradycardia and sinus arrest, induced by topical β-blocker therapy. Levobunolol hydrochloride solution is an effective therapy for ocular hypertension, probably by reducing aqueous fluid production. However, it can induce cardiac side effects such as bradyarrhythmia and should be used with caution in elderly patients or patients with cardiac disease.

Interventions for improving adherence to ocular hypotensive therapy

BACKGROUND

Poor adherence to therapy is a significant healthcare issue, particularly in patients with chronic disease such as open-angle glaucoma. Treatment failure may necessitate unwarranted changes of medications, increased healthcare expenditure and risk to the patient if surgical intervention is required. Simplifying eye drop regimes, providing adequate information, teaching drop instillation technique and ongoing support according to the patient need may have a positive effect on improving adherence.

OBJECTIVES

To summarise the effects of interventions for improving adherence to ocular hypotensive therapy in people with ocular hypertension (OHT) or glaucoma.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2012, Issue 6), MEDLINE (June 1946 to June 2012), EMBASE (June 1980 to June 2012), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (June 1937 to June 2012), PsycINFO (1806 to June 2012), PsycEXTRA (1908 to June 2012), Web of Science (1970 to June 2012), ZETOC (1993 to June 2012), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), 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 26 June 2012. We did not search the National Research Register (NNR) as this resource has now been now archived. We contacted pharmaceutical manufacturers to request unpublished data and searched conference proceedings for the Association for Research in Vision and Ophthalmology (ARVO), and the Annual Congress for the Royal College of Ophthalmologists (RCO).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs that compared interventions to improve adherence to ocular hypotensive therapy for patients with OHT or glaucoma.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed the search results for eligibility and extracted data for included trials onto specifically designed forms. We did not pool data due to clinical and methodological heterogeneity.

MAIN RESULTS

Sixteen trials (1565 participants) met the inclusion criteria. Seven studies investigated some form of patient education. In six of these studies this education was combined with other behavioural change interventions including tailoring daily routines to promote adherence to eye drops. Eight studies compared different drug regimens (one of these trials also compared open and masked monitoring) and one study investigated a reminder device. The studies were of variable quality and some were at considerable risk of bias; in general, the length of follow-up was short at less than six months with only two studies following up to 12 months. Different interventions and outcomes were reported and so it was not possible to produce an overall estimate of effect. There was some evidence from three studies that education combined with personalised interventions, that is, more complex interventions, improved adherence to ocular hypotensive therapy. There was less information on other outcomes such as persistence and intraocular pressure, and no information on visual field defects, quality of life and cost. There was weak evidence as to whether people on simpler drug regimens were more likely to adhere and persist with their ocular hypotensive therapy. A particular problem was the interpretation of cross-over studies, which in general were not reported correctly. One study investigated a reminder device and monitoring but the study was small and inconclusive.

AUTHORS' CONCLUSIONS

Although complex interventions consisting of patient education combined with personalised behavioural change interventions, including tailoring daily routines to promote adherence to eye drops, may improve adherence to glaucoma medication, overall there is insufficient evidence to recommend a particular intervention. The interventions varied between studies and none of the included studies reported on the cost of the intervention. Simplified drug regimens also could be of benefit but again the current published studies do not provide conclusive evidence. Future studies should follow up for at least one year, and could benefit from standardised outcomes.

Interventions for improving adherence to ocular hypotensive therapy

BACKGROUND

Poor adherence to therapy is a significant healthcare issue, particularly in patients with chronic disease such as open angle glaucoma. Treatment failure may necessitate unwarranted changes of medications, increased healthcare expenditure and risk to the patient if surgical intervention is required. Simplifying eye drop regimes, providing adequate information and ongoing support according to patient need, may have a positive effect on improving adherence.

OBJECTIVES

To summarise the effects of interventions for improving adherence to ocular hypotensive therapy in people with ocular hypertension (OHT) or glaucoma.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO, Web of Science, ZETOC and OpenSIGLE. In addition, we searched research registers of ongoing studies. We contacted pharmaceutical manufacturers to request unpublished data and searched conference proceedings for the Association for Research in Vision and Ophthalmology (ARVO), and the Annual Congress for the Royal College of Ophthalmologists (RCO). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 15 January 2009.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi RCTs that compared interventions to improve adherence to ocular hypotensive therapy for patients with OHT or glaucoma.

DATA COLLECTION AND ANALYSIS

At least two authors independently assessed the search results for eligibility and extracted data for included trials onto specifically designed forms. We calculated the mean difference for continuous data and relative risks for dichotomous data. Where appropriate, we pooled data using a fixed-effect model.

MAIN RESULTS

Eight trials met the inclusion criteria. There was considerable heterogeneity of interventions and reported outcome measures and therefore, meta-analysis was limited to two studies. Overall, studies were not of high quality due to small sample sizes, missing data and short term follow-up. Three of five drug comparison studies provided evidence that reducing the frequency of drops can improve adherence. However, the study that compared the least frequent regime with one of the most complicated, showed no difference in reported adherence. A small study of thirteen patients found a reminder device beneficial to adherence levels yet only one of two studies involving education and individualised care planning was found to be successful.

AUTHORS' CONCLUSIONS

Interventions involving simplified dosing regimes, reminder devices, education and individualised care planning, did show improvements in adherence rates. However, due to inadequate methodological quality and heterogeneity of study design we are unable to advocate any particular interventions at this time.

An in vivo confocal microscopy and impression cytology analysis of preserved and unpreserved levobunolol-induced conjunctival changes

PURPOSE

To provide an in vivo confocal microscopy (IVCM) and impression cytology analysis of preserved-and unpreserved levobunolol-induced changes of conjunctival epithelium.

METHODS

27 eyes of 27 patients were consecutively randomized to receive preserved or unpreserved levobunolol; all patients had a recent diagnosis of primary open angle glaucoma (POAG) or ocular hypertension and were not previously treated with topical medications. IVCM and impression cytology were performed before and after six months of therapy. Goblet cells density and a conjunctival epithelium regularity index were considered in the IVCM analysis, whereas impression cytology specimens were graded and scored in accordance with Nelson's method.

RESULTS

After six months of therapy, IVCM and impression cytology parameters showed significant differences with respect to baseline in both groups (p<0.001); significant differences were also found between the two groups (p<0.001). The IVCM analysis showed a goblet cells density reduction (61% and 17% from baseline, respectively in group 1 and 2) (p<0.001) and an higher index of epithelial regularity (p<0.001) in both groups; the impression cytology analysis showed an higher score in both groups (p<0.001).

CONCLUSIONS

All the IVCM and impression cytology parameters correlated well with the conjunctival modifications induced by the topical therapy, suggesting the less toxicity of unpreserved drugs.

Effects of topical levobunolol or fixed combination of dorzolamide-timolol or association of dorzolamide-levobunolol on intraocular pressure, pupil size, and heart rate in healthy cats

The effects of topical levobunolol with the fixed combination of 2% dorzolamide-0.5% timolol and the association of 2% dorzolamide with 0.5% levobunolol on intraocular pressure (IOP), pupil size (PS), heart rate (HR), and conjunctival hyperemia in eighteen halthy cats were investigated and compared. IOP, PS, HR, and conjuntival hyperemia were daily recorded at three times (9a.m., 2p.m., and 6p.m.). Three groups were formed (n=6), and one eye of each animal was randomly selected and treated with topical levobunolol (L), or commercial combination of dorzolamide-timolol (DT), or the association of dorzolamide with levobunolol (DL). The first day (0) consisted of recording of baseline values. On the next four consecutive days, drugs were instilled at 8a.m. and 8p.m. and measurements were taken at the same times fore cited. Comparing with the baseline values, all evaluated parameters significantly decreased (P<0.001). Conjuntival hyperemia was not seen. Levobunolol significantly declined IOP, PS, and HR in normal cats, and showed a stronger effect in lowering HR, when compared to dorzolamide-timolol effect. No synergistic effect in IOP declining was noted when levobunolol dorzolamide was added to levobunolol.

Cardiovascular and respiratory considerations with pharmacotherapy of glaucoma and ocular hypertension

Glaucoma and ocular hypertension are highly prevalent conditions in individuals over the age of 40 and are commonly seen together in patients with cardiovascular disease. Many of the antiglaucoma medications, when systemically absorbed, affect the sympathetic and parasympathetic nervous systems of patients and can cause cardiovascular toxicity. Such adverse effects are frequently associated with the long-term use of potentially toxic agents in elderly people, who are most prone to chronic eye disease. Moreover, patients may not associate their symptoms with the topical eye medications, and consequently may not report adverse drug effects. Drug-drug interactions can also occur when patients are taking medications for both cardiovascular disease and glaucoma. In this review, the systemic toxicity of these agents is reviewed, along with possible drug-drug interactions. Mention is made of other antiglaucoma medications used alone and in combination with topical beta-blockers. Identification of genetic loci-a bold new step toward glaucoma treatment-is mentioned briefly at the end of the article.

Management of glaucoma: focus on pharmacological therapy

Glaucoma represents a major cause of vision loss throughout the world. Primary open-angle glaucoma, the most common form of glaucoma, is a chronic, progressive disease often, though not always, accompanied by elevated intraocular pressure (IOP). In this disorder, retinal ganglion cell loss and excavation of the optic nerve head produce characteristic peripheral visual field deficits. Patients with normal-tension glaucoma present with typical visual field and optic nerve head changes, without a documented history of elevated IOP. A variety of secondary causes, such as pigment dispersion syndrome and ocular trauma, can result in glaucoma as well. Treatment of all forms of glaucoma consists of reducing IOP. With proper treatment, progression of this disease can often be delayed or prevented. Treatment options for glaucoma include medications, laser therapy and incisional surgery. Laser techniques for the reduction of IOP include argon laser trabeculoplasty and selective laser trabeculoplasty. Both techniques work by increasing outflow of aqueous humour through the trabecular meshwork. Surgical options for glaucoma treatment include trabeculectomy, glaucoma drainage tube implantation and ciliary body cyclodestruction. While each of these types of procedures is effective at lowering IOP, therapy usually begins with medications. Medications lower IOP either by reducing the production or by increasing the rate of outflow of aqueous humour within the eye. Currently, there are five major classes of drugs used for the treatment of glaucoma: (i) cholinergics (acetylcholine receptor agonists); (ii) adrenoceptor agonists; (iii) carbonic anhydrase inhibitors (CAIs); (iv) beta-adrenoceptor antagonists; and (v) prostaglandin analogues (PGAs). Treatment typically begins with the selection of an agent for IOP reduction. Although beta-adrenoceptor antagonists are still commonly used by many clinicians, the PGAs are playing an increasingly important role in the first-line therapy of glaucoma. Adjunctive agents, such as alpha-adrenoceptor agonists and CAIs are often effective at providing additional reduction in IOP for patients not controlled on monotherapy. As with any chronic disease, effective treatment depends on minimising the adverse effects of therapy and maximising patient compliance. The introduction of a variety of well tolerated and potent medications over the past few years now allows the clinician to choose a treatment regimen on an individual patient basis and thereby treat this disorder more effectively.

Comparison of the Effects of Topical Levobunolol and Timolol Solution on the Human Ocular Surface

PURPOSE

To compare the effects of levobunolol hydrochloride and timolol maleate on tear volume, precorneal tear film stability, and corneal epithelial barrier function in normal human eyes.

SUBJECTS AND METHODS

The study population consisted of 14 healthy volunteers. To obtain pretreatment baseline values, we determined the radius of the tear meniscus (RTM) by meniscometry; the noninvasive breakup time (NIBUT) of the precorneal tear film with a tear specular microscope; and corneal fluorescein uptake with a fluorophotometer. Levobunolol hydrochloride (0.5%) or timolol maleate solution (0.5%) was instilled twice daily for 4 weeks into 1 eye; the contralateral eye was treated with the other topical drug twice daily for the same period. At the end of the study period, the same tests were performed, and the pre- and posttreatment results were compared.

RESULTS

Timolol solution did, and levobunolol did not, significantly reduce NIBUT from the baseline values. RTM was significantly decreased by treatment with either timolol or levobunolol solution. Corneal fluorescein uptake was not significantly changed, although it was higher after treatment with both topical drugs.

CONCLUSIONS

Four-week treatment with timolol solution resulted in significant instability of the precorneal tear film. Both timolol and levobunolol solution significantly decreased tear volume on the ocular surface. These results indicate that levobunolol solution applied twice daily has equal effects on the tear volume and corneal epithelial barrier function as does timolol solution applied twice daily and that it affects precorneal tear film stability less than timolol solution.

Cardiovascular considerations in using topical, oral, and intravenous drugs for the treatment of glaucoma and ocular hypertension: focus on beta-adrenergic blockade

Glaucoma and ocular hypertension are highly prevalent conditions in individuals over the age of 40 and are commonly seen together in patients with cardiovascular disease. Many of the antiglaucoma medications, when systemically absorbed, affect the sympathetic and parasympathetic nervous systems of patients and can cause cardiovascular toxicity. Such adverse effects are frequently associated with the long-term use of potentially toxic agents in elderly people, who are most prone to chronic eye disease. Moreover, patients may not associate their symptoms with the topical eye medications, and consequently may not report adverse drug effects. Drug-drug interactions can also occur when patients are taking medications for both cardiovascular disease and glaucoma. This review focuses on beta-adrenergic blockers as topical antiglaucoma medications and other topical antiglaucoma drugs. The systemic toxicity of these agents is reviewed, along with the possible drug interactions. Brief mention is also made of other antiglaucoma medications used alone and in combination with topical beta-blockers.

Pharmacological therapy for glaucoma: a review

For some time the medical treatment of glaucoma has consisted of topical beta-blockers, adrenergic agents, miotics and oral carbonic anhydrase inhibitors (CAIs). However, the therapeutic arsenal available for the medical treatment of glaucoma has recently extended with new classes of ocular hypotensive agents i.e. prostaglandins, local CAIs and alpha2-adrenergic agents. Beta-blockers are still the mainstay in glaucoma treatment and are first line drugs. However, even if they are applied once daily, as with timolol in gel forming solution and levobunolol, the possible cardiopulmonary adverse effects of beta-blockers remain a cause for concern. When monotherapy with beta-blockers is ineffective in reducing intraocular pressure (IOP) or is hampered by adverse effects, a change of monotherapy to prostaglandins, local CAIs, alpha2-adrenergic agonists (brimonidine) or to dipivalyl epinephrine is advised. Prostaglandins, local CAIs and alpha2-adrenergic agonists, such as brimonidine, may in time become first line drugs because they reduce IOP effectively and until now systemic adverse effects have rarely been reported with these agents. The development of a pro-drug of either a local CAI or an alpha2-adrenergic agonist with a sustained and continuous effect on IOP level, which could be applied once a day is suggested. Because of these new developments, miotics, i.e. pilocarpine and carbachol, are recommended as second or third line drugs. The cholinesterase inhibitors are considered third line drugs as better agents with fewer local and systemic adverse effects have become available. Oral CAIs may be used temporarily in patients with elevated IOPs e.g. postsurgery or post-laser, or continuously in patients with glaucoma resistant to other treatment. Combining ocular hypotensive drugs is indicated when the target pressure for an individual patient cannot be reached with monotherapy. Combination therapy of beta-blockers is additive with prostaglandins, topical CAIs and miotics. Prostaglandins such as latanoprost can be combined with beta-blockers, adrenergic agents, local CAIs and miotics. Combinations with brimonidine or local CAIs need further investigation. Treatment of glaucoma with the new ocular hypotensive agents, either in monotherapy or combination therapy, may provide lower IOPs and delay or postpone the need for surgery.

Efficacy and adverse effects of medications used in the treatment of glaucoma

With the advent of several new topically active medications for glaucoma therapy, intraocular pressure (IOP) can be reduced to target levels in more patients before resorting to surgery. Some of these newer agents have a number of advantages over some of the older medications, several of which are seldom used now. The topically active carbonic anhydrase inhibitors are better tolerated than oral formulations, which are infrequently used despite their greater efficacy compared with the topical formulations. The alpha2-adrenergic agonists effectively reduce IOP with few systemic adverse effects. The prostaglandin analogues are even more effective and well tolerated when applied once daily without known systemic adverse effects. The variety of glaucoma medications forces the physician to be selective with various combinations before proceeding with surgery. This article critically reviews the literature pertaining to the newer glaucoma medications, thereby providing guidelines to make rational choices from among the available options.

Glaucoma associated with uveitis

Raised intraocular pressure is a common and frequently serious complication of anterior uveitis. The milieu of inflammatory cells, the mediators they release, and the corticosteroid therapy used to treat the uveitis can participate in the pathogenesis of uveitic glaucoma. These factors alter the normal anatomic structure of the anterior chamber and angle, influencing aqueous production and outflow. These changes act to disrupt the homeostatic mechanisms of intraocular pressure control. Structural changes in the angle can be acute, such as in secondary angle closure with pupillary block glaucoma, or chronic, such as combined steroid-induced and secondary open angle glaucoma. Management of uveitic glaucoma may be difficult because of the numerous mechanisms involved in its pathogenesis. Diagnostic and therapeutic decisions are guided by careful delineation of the pathophysiology of each individual case. The goal of treatment is to minimize permanent structural alteration of aqueous outflow and to prevent damage to the optic nerve head. This article reviews the pathogenesis of uveitic glaucoma, with specific attention to etiology. Medical and surgical therapies are also discussed, with emphasis on the more recent developments in each category.

Correlation of intraocular pressures in pairs of monozygotic and dizygotic twins

PURPOSE

Studies of twins may help to establish the importance of hereditary and environmental determinants of chronic diseases. Intraocular pressure (IOP) is a risk factor for glaucoma. The authors hypothesized that IOPs would be more highly correlated between monozygotic (MZ) than between dizygotic (DZ) twins.

METHODS

This was a concurrent, case-control study. Volunteer pairs of twins were recruited at a twins' festival. Zygosity was determined by a questionnaire that correlates well with blood-typing classification. Intraocular pressure was measured with a Tonopen six times within 5 minutes (3 times per eye) and averaged.

RESULTS

Mean IOP was 14.4 +/- 2.7 mmHg for 61 pairs of MZ twins and 13.9 +/- 2.6 mmHg for 32 pairs of DZ twins. The difference in IOP between the members of a pair was abbreviated delta IOP. The authors found a significant difference in median delta IOP between the MZ and DZ groups (1.2 versus 2.3 mmHg; P = 0.0014). Intraocular pressures were more highly correlated when considering right versus left eyes (intraclass correlation, r1 = 0.853; P < 0.001) than when considering the members of pairs of MZ twins (r1 = 0.735; P < 0.001), which in turn were more highly correlated than pressures of the members of pairs of DZ twins (r1 = 0.407; P = 0.006).

CONCLUSIONS

The intraclass correlation for IOP was greater for MZ than for DZ twins. In addition, the median intrapair difference (median delta IOP) was less for MZ than for DZ twins. These results suggest that hereditary factors may play some role in the determination of IOP.

Can the concentration of timolol or the frequency of its administration be reduced?

BACKGROUND

There is evidence that the ocular hypotensive effect of topical beta-blockers persists for at least 24 hours once beta-blockade has been achieved. In previous studies, the highest concentration of drug generally has been used for this purpose.

METHOD

Home tonometry was performed with a self-tonometer by 14 patients to study the intraocular pressure (IOP) reduction of 0.5% timolol administered once daily in the morning or in the evening and of 0.25% timolol administered in the morning. The study was masked and included washout periods before and between the different regimens. At the end of each treatment period, the IOP was monitored five times daily for 3 days.

RESULTS

No significant difference in mean reduction of IOP was found between the morning instillation of once daily 0.5% timolol compared with evening instillation of 0.5% timolol. In addition, there was no statistically significant difference in the mean IOP reduction between once daily administration of 0.25% versus 0.5% timolol.

CONCLUSION

This study indicates that a lower concentration of timolol maleate used once daily may achieve maximum IOP reduction. The time of the single administration appears not to make any difference.