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C CLINICAL RESEARCH

advanced disease. In other words, functional loss is present in early glaucoma, but not detected by conventional
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AVF analysis. There appears to be a tipping point at an RNFL thickness of approximately 75μm at which time the
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detection of functional loss improves. 288
Clinical Recommendation for monitoring based upon stage of disease:
• SD-OCT is likely better at detecting glaucomatous progression in early disease while SAP is better at
detecting glaucomatous progression in later stages.

It has also been shown that SD-OCT might be superior at detecting progression after a shorter number of visits in
individuals unable to provide reliable fields. 289,302 The clinician should be aware that even in the presence of reliable
testing results, 2 to 3 years is typically required to detect progression, or the effect of treatment on slowing progres-
sion. 237,302 Further, this timeframe assumes ideal circumstances, when testing is frequent (every 3 to 4 months) and
results are reliable, two criteria that may not be replicated in day-to-day practice. 302

Clinical Recommendation for frequency of testing:
• Progression will be detected sooner with more frequent testing: once an initial rate of change has been
established over the first two years (requiring testing every 3 to 4 months), it is recommended that OCT
and SAP are done at least every 6 months.

MANAGEMENT

WHEN TO CONSIDER TREATMENT
Glaucoma management encompasses all of the steps culminating in the assessment of risk and diagnosis of glau-
coma (ideally at the pre-perimetric stage), followed by setting of target pressures and the initiation of treatment.
Periodic reassessments over the long-term are scheduled based on the severity of the disease, rate of progression,
risk for adverse effects and patient-specific factors such as concerns for non-adherence.

The conventional approach to management begins with topical medications, followed by selective laser trabeculo-
plasty and then surgery, although a strong case has been made for initiating treatment with trabeculoplasty. The
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ultimate decision of where to begin will depend on the individual patient’s needs, values and abilities, as well as
other factors such as access to care.

Clearly, management of any disease, particularly a chronic disease, requires careful consideration on many levels.
While the evidence available around disease diagnosis and the benefits and risks of treatment is in itself important
to keep up with, so too is the evidence around the rates of adherence to therapy, patient-reported outcome concerns,
and health-related quality of life measures. While these areas are pivotal to successful disease management, they are
beyond the scope of this review.

Other important considerations include the rate of ocular surface disease in the population affected by glaucoma.
Not only does adherence to topical treatment likely suffer as a result of the presence of ocular surface disease,
the IOP control may also suffer if the ocular surface disease is not appropriately managed. 305,306 Preservative-free
(at minimum, benzalkonium chloride-free) formulations should be considered early in the management plan to
reduce the exposure of the ocular surface and anterior chamber tissues to benzalkonium chloride (BAK). Fixed-
combination agents reduce the exposure to preservatives and help address wash-out related concerns, while having
a positive impact on adherence. At present, there remains no treatment for glaucoma, per se; rather the use of
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intraocular pressure reduction to facilitate a corresponding reduction in risk of progression.
Ultimately, the decision about treatment resides with the individual. Thorough counselling on the risks and benefits
of treatment versus carefully monitoring without treatment must be undertaken with each person. Take care to
ensure that a family member or care-giver can be present, especially in those patients for whom a decision like this
may be challenging. Detailed documentation of the counselling and informed consent procedure(s) is suggested.

46 CANADIAN JOURNAL of OPTOMETRY | REVUE CANADIENNE D’OPTOMÉTRIE VOL. 79 SUPPLEMENT 1, 2017