NHMRC Glaucoma Guidelines - ANZGIG

NHMRC GUIDELINES FOR THE SCREENING, PROGNOSIS, DIAGNOSIS, MANAGEMENT AND PREVENTION OF GLAUCOMA
Chapter 9 – Medication
Point of note
In the majority of cases, medication is the first choice of management for patients with glaucoma.
There is an ever-increasing range of medication options and regimens that can be tailored to individual
needs. The selection will depend upon glaucoma subtype, stage of disease and personal situation.
Starting medication regimens
Health care providers and patients should choose medications based on the greatest chance of
achieving target IOP, the best safety profiles, the most convenient delivery method and most
affordable (South-East Asia Glaucoma Interest Group [SEAGIG] 2003). To facilitate adherence
to medication regimens, health care providers should start with the simplest, most appropriate
medication. Particularly for OAG, treatment should be initiated at the lowest effective concentration
of medication, preferably administered once daily (Royal College of Ophthalmologists [RCO] 2004).
There is general consensus that topical preparations are the first choice management for most
glaucoma patients. When patients cannot tolerate prostaglandin analogues or topical beta-blockers,
they should be offered one of the other topical medications first, prior to being offered a systemic
medication. This is due to their improved efficacy, ease of instillation (once daily dosing), lower
incidence of side effects, relatively limited contraindications or precautions to use and lack of
significant interactions with other medications. Hierarchies of use are outlined in Table 9.1.
Combination eye drops are becoming a more popular medication management choice. Anti-glaucoma
eye drops can be combined with each other, as well as offered in conjunction with laser therapy and
surgical management. Combination eye drops are preferred to two separate instillations of individual
medications for improving patient adherence and reducing inconvenience.
Currently all available fixed combination eye drops contain timolol with a prostaglandin analogue,
carbonic anhydrase inhibitor or alpha2-agonist. It is essential that the components of combination
products are carefully considered before prescribing to ensure all precautions and contraindications
to use are taken into account. Also, as medications from the same class should not be used in
conjunction with each other, it is important that the choice of a combination product does not
duplicate existing medication management (i.e. timolol or betaxolol should not be used along with
any of the current fixed dose combinations, all of which already contain timolol). The effect of
combined topical medications should be measured in terms of IOP reduction, as for single medication
preparations. Currently no specific combination of medications has been identified as preferable, in
terms of visual field (VF) preservation or ocular nerve head (optic nerve head) health.
Systemic administration of acetazolamide may be indicated when patients cannot tolerate topical
medications, are unable to safely and effectively instill the medications topically, or are failing to
achieve IOP targets and glaucomatous stability. This form of delivery however, is associated with
a significantly increased risk of developing side effects. For instance up to 50% of patients treated
with acetazolamide do not tolerate it. Therefore laser therapy or surgery is often considered as an
alternative at this stage.
110 National Health and Medical Research Council