Effects of brinzolamide vs timolol as an adjunctive medication to latanoprost on circadian intraocular pressure control in primary open-angle glaucoma Japanese patients

The relationship between intraocular pressure and glaucoma: An evolving concept

Intraocular pressure (IOP) is the most important modifiable risk factor for glaucoma and fluctuates considerably within patients over short and long time periods. Our field's understanding of IOP has evolved considerably in recent years, driven by tonometric technologies with increasing accuracy, reproducibility, and temporal resolution that have refined our knowledge regarding the relationship between IOP and glaucoma risk and pathogenesis. The goal of this article is to review the published literature pertinent to the following points: 1) the factors that determine IOP in physiologic and pathologic states; 2) technologies for measuring IOP; 3) scientific and clinical rationale for measuring diverse IOP metrics in patients with glaucoma; 4) the impact and shortcomings of current standard-of-care IOP monitoring approaches; 5) recommendations for approaches to IOP monitoring that could improve patient outcomes; and 6) research questions that must be answered to improve our understanding of how IOP contributes to disease progression. Retrospective and prospective data, including that from landmark clinical trials, document greater IOP fluctuations in glaucomatous than healthy eyes, tendencies for maximal daily IOP to occur outside of office hours, and, in addition to mean and maximal IOP, an association between IOP fluctuation and glaucoma progression that is independent of mean in-office IOP. Ambulatory IOP monitoring, measuring IOP outside of office hours and at different times of day and night, provides clinicians with discrete data that could improve patient outcomes. Eye care clinicians treating glaucoma based on isolated in-office IOP measurements may make treatment decisions without fully capturing the entire IOP profile of an individual. Data linking home blood pressure monitors and home glucose sensors to dramatically improved outcomes for patients with systemic hypertension and diabetes and will be reviewed as they pertain to the question of whether ambulatory tonometry is positioned to do the same for glaucoma management. Prospective randomized controlled studies are warranted to determine whether remote tonometry-based glaucoma management might reduce vision loss and improve patient outcomes.

Combination of brinzolamide and brimonidine for glaucoma and ocular hypertension: critical appraisal and patient focus

Glaucoma is one of the leading causes of blindness and is characterized by optic nerve damage that results in visual field loss. Elevated intraocular pressure (IOP) has been associated with glaucoma progression; thus, IOP-lowering medications are the standard of care for glaucoma. Guidelines suggest monotherapy with IOP-lowering agents such as β-blockers (eg, timolol), prostaglandin analogs, carbonic anhydrase inhibitors (eg, brinzolamide), and α2-receptor agonists (eg, brimonidine). However, monotherapy may provide insufficient IOP reduction in some patients, thereby necessitating the use of multiple IOP-lowering medications. Multidrug regimens may be complex, may increase the risk of preservative-related ocular symptoms, and may potentially reduce overall drug exposure as a consequence of drug washout during closely timed sequential administrations; these difficulties may reduce overall drug efficacy and decrease patient persistence and adherence with multidrug treatment regimens. Fixed-combination medications that provide two IOP-lowering therapies within a single solution are available and may overcome some of these challenges. However, all currently available fixed combinations combine timolol with another IOP-lowering agent, indicating that additional fixed-combination alternatives would be beneficial. To meet this demand, a novel fixed combination of brinzolamide 1% and brimonidine 0.2% (BBFC) has recently been developed. In two randomized, double-masked, multinational clinical trials, BBFC had greater IOP-lowering efficacy than brinzolamide or brimonidine monotherapy after 3 months of treatment in patients with open-angle glaucoma or ocular hypertension. In both studies, the overall safety profile of BBFC was consistent with that of brinzolamide and brimonidine. Comparative studies with BBFC versus other IOP-lowering monotherapy and fixed-combination medications are not available, but the IOP reductions observed with BBFC are similar to or greater than those reported in the literature for other glaucoma treatments; thus, BBFC provides an additional fixed-combination therapeutic option for patients who require further efficacious IOP reduction and improved convenience and tolerability versus concomitant administration of two separate medications.

Intraocular pressure-lowering combination therapies with prostaglandin analogues

Intraocular pressure (IOP) reduction is currently the only therapeutic approach demonstrated to preserve visual function in patients with glaucoma. The first line of glaucoma treatment consists of topical IOP-lowering medications, usually initiated as monotherapy. A significant proportion of patients require more than one medication to reach a target IOP at which optic nerve damage will not progress. As prostaglandin analogues (PGAs) are the most effective class for reducing IOP, one of the other commonly used classes (β-adrenoceptor antagonist [β-blocker], carbonic anhydrase inhibitor or α(2)-adrenoceptor agonist) is frequently combined with a PGA. In the last decade, the use of fixed combinations containing two medications in a single bottle has steadily increased. Fixed combinations have the potential to simplify the dosing regimen, increase patient adherence, avoid the washout effect of the second drop on the first medication instilled, decrease exposure to preservatives and, sometimes, reduce the cost of treatment. Clinical trials have evaluated PGA-based fixed combinations versus unfixed combinations (individual components administered concomitantly) or versus individual monotherapies; however, any advantage that the fixed combinations may have in terms of IOP-lowering efficacy is still debated. For these reasons, the PGA-based fixed combinations are not approved by regulatory authorities in some countries, such as the US. We review the published studies evaluating the efficacy and tolerability of the IOP-lowering unfixed and fixed combination therapies with PGAs. Regarding unfixed combinations, the review shows that α(2)-adrenergic agonists-PGA and carbonic anhydrase inhibitor-PGA combinations seem to be at least as effective at reducing IOP as the β-blocker-PGA combinations. As for the fixed combinations, the review shows that the three PGA-timolol fixed combinations are more effective than their component medications used separately as monotherapy and are better tolerated than the three respective prostaglandins. The three PGA-timolol fixed combinations are less effective at reducing IOP than the unfixed combinations but are better tolerated. The advantage of the fixed combinations in terms of patient adherence and persistence is supported by a very small number of studies and remains to be more accurately determined. Most studies, but not all, seem to show that PGA-timolol fixed combinations are more effective than other available β-blocker fixed combinations (dorzolamide-timolol fixed combinations) at reducing IOP and are similarly tolerated.