Glaucoma Guidelines and Clinical Glaucoma Care
R.N. Weinreb, MD
La Jolla

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.

It 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 management.