NHMRC Glaucoma Guidelines - ANZGIG
NHMRC Glaucoma Guidelines - ANZGIG
NHMRC Glaucoma Guidelines - ANZGIG
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<strong>NHMRC</strong> GUIDELINES FOR THE SCREENING, PROGNOSIS, DIAGNOSIS, MANAGEMENT AND PREVENTION OF GLAUCOMA<br />
Chapter 9 – Medication<br />
associated with a greatly increased risk of developing side effects and, up to 50% of patients treated<br />
with acetazolamide do not tolerate it. Systemic use of beta-blockers is not as effective in reducing<br />
IOP as topical medications and the concurrent use of topical and systemic beta-blockers should<br />
be avoided.<br />
Point of note<br />
This text is only a general guide to medications. It does not claim to contain all the medications,<br />
side effects and contraindications related to the treatment of glaucoma, and only the most common<br />
and relevant are discussed. Medication discovery and design is constantly evolving, therefore the<br />
information in this guideline has been updated since the publication of the associated systematic<br />
review. Before a health care provider commences a patient on a course of medication, it is advised<br />
that the product information sheet is carefully read and, if required, an expert opinion sought.<br />
Medication families<br />
Medications used for the long-term management of glaucoma fall into five classes: beta-blockers,<br />
prostaglandin analogues, alpha 2<br />
-agonists, carbonic anhydrase inhibitors and cholinergic agonists.<br />
Hyperosmotic medications such as mannitol are given to lower IOP in emergency situations,<br />
however as they are not used for long-term management, they are not completely described in<br />
this chapter. <strong>Glaucoma</strong> medications reduce IOP by increasing aqueous outflow and/or decreasing<br />
aqueous production. Each medication family has a different method of action, and can have<br />
significant side effects.<br />
The time taken to achieve maximal reduction in IOP is dependent on both the individual and<br />
the type of medication used. Initial reduction in IOP typically occurs within minutes to hours<br />
after administration, while maximal reduction in IOP can take weeks to months. For example, the<br />
known maximum IOP-lowering effect of prostaglandin analogues occurs after three to five weeks<br />
(EGS 2003). Therefore, response to newly initiated medications should be assessed after two to<br />
four weeks.<br />
When medications are ceased, it is important to note that they may have some continued effect<br />
on reducing IOP. The approximate time it takes for IOP to return to baseline levels after ceasing<br />
medications, also known as the wash-out period, is listed in Table 9.1. Table 9.1 also provides<br />
information on medications available in Australia, their mechanism of action, daily dosage<br />
requirements, efficacy, order of treatment choices and wash-out periods.<br />
Hierarchies of intervention<br />
There is general consensus that medications should be the first choice of management for almost<br />
all patients with glaucoma. Even when patients present in emergency situations with acute<br />
angle closure, medication is used to reduce IOP, to clear corneal oedema and to reduce pain, in<br />
preparation for laser therapy or surgery. There is increasing interest in using laser techniques earlier<br />
in the glaucoma management hierarchy. Evidence supports the use of laser therapy as first choice<br />
intervention in angle closure and for specific patient groups with open angle glaucoma (OAG) who<br />
are at-risk of visual loss within their lifetime. Further details are provided in Chapter 10.<br />
The most appropriate point-in-time medication should be prescribed for individuals relevant to<br />
their specific disease state. As disease states change, and/or as patients become less (or more) able<br />
to manage the administration of a particular medication type, other treatment choices can be made.<br />
A wide range of anti-glaucoma medications are available. The literature highlights that the type<br />
108 National Health and Medical Research Council