There are many medical treatment options available for glaucoma. When selecting a treatment, it is important to take into account efﬁcacy, mode of action, safety, tolerability, contraindications, quality of life, adherence and cost.
- Assess each eye individually when selecting therapy
- After diagnosis measure untreated intraocular pressure (IOP) more than once before initiating IOP-lowering treatment
- If feasible, a therapeutic trial on one eye first may be useful to determine IOP lowering efficacy (unless very high IOP or advanced disease)
- Always aim for the lowest possible dose
- Involve patients in decision-making
- Prostaglandins/prostamides have been approved as ﬁrst line treatment for several years. In spite of their cost, they are increasingly used as ﬁrst choice treatment; reasons include:
a) fewer instillations (once a day vs. twice daily)
b) lack of relevant systemic side-effects
c) IOP lowering efﬁcacy
- If the ﬁrst choice monotherapy does not appear to lower the IOP satisfactory or is not tolerated, it is preferable to switch to any of th eother topical agents that can be initiated as monotherapy before adding a second drug (see algorithm).
|First choice treatment A drug that a physician prefers to use as initial IOP lowering therapy (see algorithm for first and second choice treatments).
First line treatment: A drug that has been approved by an ofﬁcial controlling body (i.e. EMEA) for initial IOP lowering therapy.
- Meta-analyses are available for most of the drugs used for glaucoma (see Table 1 for comparative IOP reductions)
Table 1: lowering effect of topical IOP-lowering medications as determined by meta-analysis*
|Active ingredient||%IOP difference from baseline|
* These meta-analyses do not include combination products or adjunctive therapy. Moreover, while meta-analyses focus on IOP reduction, other aspects like patient characteristics, quality of life, side effects, convenience/compliance and cost effectiveness should be taken into consideration in making a drug therapy choice – particularly when IOP differences between the compounds are small.
Rationale for adjunctive drug therapy
Evidence shows that monotherapy fails to achieve a satisfactory IOP reduction in 40-75% of glaucoma patients after more than two years of therapy. While switching monotherapy should be attempted first, there are cases in which one drug is inadequate to lower a patient´s IOP to a desirable target pressure and add-on therapy is then required. Antiglaucoma eye drops can then be combined with each other, as well as added to laser and surgical treatments.
- If the ﬁrst selected monotherapy is well tolerated and effective, but not sufﬁcient to reach the target IOP, or there is evidence of progression and the target IOP is being reconsidered, adjunctive therapy with any other topical agent can be initiated.
- Use of β-blocker preparations with either a prostaglandin/prostamide, a carbonic anhydrase inhibitor, pilocarpine or with brimonidine have been shown to be more effective at IOP lowering than the use of one of these drugs separately.
- Drugs which belong to the same pharmacological group should not be used in combination (e.g. do not combine two prostaglandin derivatives or two beta-blockers) (see Table 2).
- When available, ﬁxed-combined drugs preparations may be preferable than two separate instillations of the same agents. A fixed combination may improve compliance and may reduce the daily amount of preservatives to which the eyes are exposed.
Table 2: Drug combinations – Additive effects
|CURRENT DRUG||α2 agonists||β blockers||topical CAIs||Cholinergic||Prostaglandin/Prostamides|
CAI: Carbonic anhydrase inhibitor