Glaucoma surveillance essential for optimizing patient outcomes

Glaucoma progression occurs slowly in the vast majority of patients, and in the United States, most patients with glaucoma who are less than optimally treated, or even undiagnosed, will not go blind from the disease. 

These facts, however, should not diminish the importance of early diagnosis, treatment when indicated, and, most importantly, ongoing surveillance, said Kuldev Singh, MD, MPH during the Glaucoma Symposium CME at the 2016 Glaucoma 360 meeting.

Kuldev Singh, MD, said the combination of high risk and lack of diagnosis/surveillance creates a perfect storm for severe visual disability.

“Studies suggest that if we identified 20 individuals residing in the United States with primary open-angle glaucoma, about half would know that they have the disease and only half of those would be receiving optimal care including appropriate compliance and surveillance,” said Dr. Singh, professor of ophthalmology and director, Glaucoma Service, Stanford University, Stanford, CA. “Two or three of those undiagnosed and/or untreated would represent individuals who are at very high risk of glaucomatous vision loss.”

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Dr. Singh pointed out that the combination of high risk based upon genetic factors and lack of diagnosis/surveillance creates the “perfect,” or more fittingly “imperfect surveillance-related storm” for developing severe visual disability from the disease.

While large clinical trials have provided tremendous information relating to individual risk factors for the development and progression of disease, ophthalmologists still are unable to accurately predict, in a prospective manner, which patients are going to demonstrate rapid- versus slow-disease progression. Family history and ethnicity are helpful in making predictions regarding disease course, but each individual is unique and only time will reveal their true individualized risk, Dr. Singh said.

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“With that in mind, it is desirable to find glaucoma early in every patient, but tailor the treatment approach to what happens over time rather than simply using an approach that assumes all patients represent the average from clinical trials,” he commented.

Careful surveillance

Careful surveillance

Data from studies conducted as part of a collaboration between Shan Lin, MD, and colleagues at the University of California, San Francisco and San Francisco General Hospital, along with Dr. Singh and colleagues from Stanford University, have shed light on factors related to compliance with glaucoma therapy and supported the importance of appropriate glaucoma surveillance as a possible risk factor for disease progression.

For example, in a study investigating medication adherence based on prescription refill data, they found disease severity was the only factor that was independently associated with medication possession–such that patients with more severe disease were more likely to refill their medications than their counterparts with milder disease [Ophthalmology. 2013;120(6):1150-7].

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“It would make sense to think that patients with more severe glaucoma and thus, all other things being equal, greater disease symptoms, would be relatively more likely to refill their medication prescriptions than those who have no visual complaints,” said Dr. Singh. “The study confirmed this hypothesis, while demonstrating that other factors, such as age, race, gender, education, and even the number of medications, were relatively less important determinants of compliance.”

Results of another study showed that greater glaucoma disease severity was associated with a lesser likelihood of having returned for regular follow-up visits in preceding years [Am J Ophthalmol. 2013;156(2):362-9]. Somewhat surprisingly, it also found that patients who were refilling their medications were not more likely to have kept their follow-up appointments.

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“The data suggested that perhaps those who were using their medications religiously had a false sense of security that they did not need to return for follow-up; while those who were noncompliant with therapy were more likely to return to make sure they were okay,” said Singh. “It may be that patients who simply call the office asking for glaucoma medication refill authorizations in lieu of returning for follow-up at appropriate intervals may be at high risk of losing vision from the disease because taking medications provides no certainty that the disease will not get worse.”

He added that surgical therapy could not be offered to the patient who is rapidly progressing on medical therapy if they don’t return for an assessment.

Barriers fo surveillance

Barriers of surveillance

A study looking at barriers to surveillance identified long wait times, difficulties with appointment scheduling, language interpretation, and other medical or physical conditions as leading reasons why patients failed to keep clinic visits [Invest Ophthalmol Vis Sci. 2013;54(10):6542-8].

Another investigation found African American or Hispanic patients, unfamiliarity with duration of treatment, lack of knowledge about the permanence of disease, and the perception that follow-up is not important to be predictors of poor adherence to follow-up visits at San Francisco General Hospital.  [Arch Ophthalmol. 20133;129(7):872-8].

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“While one cannot conclude that these same factors are equally important in all clinic settings, the ability to measure predictors of poor follow-up adherence provides an opportunity to intervene and make things better with regard to clinic scheduling, interpretation, etc.,” said Dr. Singh.

Quoting Woody Allen, Dr. Singh stated that 80% of success is just showing up.

“If over 80% of our patients with glaucoma showed up over 80% of the time, we would be doing much better with regards to preventing glaucoma-related blindness than we are today,” Dr. Singh said. “Almost three decades of clinical practice have taught me that patients who are at greatest risk of vision loss from glaucoma are those who present with severe disease due to a late diagnosis as well as those who may have been diagnosed early but were lost to follow up for large periods of time.

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“While regular follow-up does not absolutely guarantee good results, we have numerous treatment options for glaucoma, and the combination of early diagnosis and appropriate surveillance with advancement of therapy, including medications, laser, and surgery as needed, is a winning treatment strategy for the overwhelming majority of those afflicted with the disease,” he concluded.

Caveats to consider

Caveats to consider

Although Dr. Singh emphasized the importance of follow-up, he also reinforced the need to individualize care, providing appropriately aggressive therapy for patients with faster-progressing glaucoma and avoiding overtreatment of low-risk patients with mild glaucoma.

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“One should consider early surgery for high-risk patients who have demonstrated fast disease progression, and, in contrast, remember that when managing low-risk patients, it is important to avoid doing harm from overly aggressive therapy,” he said. “The treatment should not be worse than the disease.”

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Finally, while Dr. Singh advocated for early detection and regular follow-up for glaucoma patients, he anticipated a manpower shortage in the workforce for the treatment of all those requiring care for this disease.

“We have to think of better models for diagnosis and surveillance, perhaps integrating co-management and telemedicine to reach the majority of afflicted Americans who are currently not receiving appropriate glaucoma care,” Dr. Singh concluded. “The solutions, from a public health perspective, will come when we align all stakeholders who want to make a difference so that we can collaborate to create models that work.”

Kuldev Singh, MD, MPH

Dr. Singh has no direct financial conflicts to disclose that are relevant to his presentation.