(IGR 10-2 September, 2008)
Glaucoma Guidelines and Clinical Glaucoma Care
R.N. Weinreb, MD
With an increasing number of new drugs and their combinations, and new surgical
procedures along with the more conventional ones, I have been struck by how difficult
it must be for a clinician to manage effectively their glaucoma patients. Most of
us have learned the nuances of glaucoma care during a residency, and some of us
have been fortunate to have had dedicated time to do so during a glaucoma fellowship
under experienced glaucoma mentoring. And all of us, hopefully, have continued to
improve our clinical skills with post-training continuing medical education by reading
journals or periodicals, and attending lectures or conferences. But sales representatives
for pharmaceutical companies and instrument manufacturers line up at our clinics
for an opportunity to tout the benefits of their respective products. Even though
our choices may be limited by the economics or politics of healthcare, we often
still have a plethora of choices and the ability to prescribe or recommend one or
the other diagnostic test or therapy. If you are like me, you probably wonder
how to sort through the evidence and decide if a claim is valid and important
before applying it to our individual patients.
Individual trials usually do not
provide the best evidence for learning about the efficacy of a particular therapy.
The patient population in the trial may be different than that of the individual
to be treated, and the specific methods of treatment and follow-up may also be different
than what might be planned. Moreover, a clear understanding of the trade-offs between
the benefits and harms of the intervention often is not possible with a single clinical
trial. Instead, it seems preferable to seek an overview that systematically
searches for and combines evidence from a series of relevant trials, perhaps
even all of them, to have a more reliable assessment of treatment efficacy. But
most of us probably do not have the time or the inclination during the course of
our hectic clinical schedule to be systematically searching, reading and critically
analyzing appropriate literature.
For this reason, among others, glaucoma guidelines
for clinical practice have emerged throughout the world during the past decade.
As examples, there are guidelines in Europe and Asia, and preferred practice patterns
in the United States. Whether they are overtly called guidelines or cloaked under
another name, all such documents seek to provide a rational basis for clinical glaucoma
care that has an evidence-base. They are systematically developed statements to
help clinicians and patients with decisions about appropriate glaucoma care.
seems that we cannot scan a journal or open our mail without finding information
about a new clinical practice guideline being promulgated by a professional organization
or a manufacturer who assembles a group of experts to opine on a particular topic.
It was in Berlin in June at the biannual meeting of the European Glaucoma Society
that I had my first glimpse of the latest version of the EGS Glaucoma Guidelines.
Authored under the auspices of Carlo Traverso, the Editor, and his team of glaucoma
pundits, these excellent guidelines are more comprehensive and focused than earlier
ones. They also are didactic, a nice touch for the clinician who is not a glaucoma
expert. As with other appropriate and meaningful guidelines, substantial amounts
of time and money must have been invested in their production, application, and
dissemination. And as with any guidelines, however, there is the potential for some
of the information to be conflicting, irrelevant or biased, and even for some of
the authors to be conflicted. How should a clinician decide whether a specific set
of guidelines should be used?
There is no straightforward and objective answer to
this question, but two general principles should be considered. In general, one
should first look for a concise summary of the evidence and ensure that all
the relevant evidence has been evaluated and graded for its validity and freshness.
Some information may be more relevant than other information and some may be more
liable to error, but clinical decisions still need to be made even though the evidence
might not always be strong or timely. All guidelines also should describe explicitly
the methods used to search, grade and synthesize the evidence. The strength of the
recommendations should be graded on the quality of the identified evidence.
Such systematic validation is a formidable task as it is tedious, time consuming
and costly. This may be, in large part, why there are so few worthy guidelines.
Secondly, there should be practical information about how to trans-late this
information to clinical practice. On this particular point, the general relevance
of regional guidelines often fails as the conditions are often only those of the
originating region. The applicability of a guideline depends on the extent to which
it is in harmony or conflict with local factors such as the health economics, societal
values, prevalence, and other potential barriers.
Glaucoma guidelines provide the
promise of providing valid and practical information to busy clinicians. However,
much of glaucoma clinical care is still based on weak or no evidence. Therefore,
it also should be clear that there is a compelling need for more and higher
quality clinical investigation to enhance our evidence-based knowledge base of glaucoma