Addressing the burden of undiagnosed glaucoma

Data from a variety of studies highlighting the high prevalence of undiagnosed glaucoma point to a need for devising screening strategies that will enable affected individuals to receive treatment and, looking optimistically into the future, even be cured.

“Ophthalmologists, who are already busy seeing patients with glaucoma, may not fully appreciate the magnitude of the problem of undiagnosed disease,” said Anne L. Coleman, MD, PhD. “However, according to worldwide population-based studies, at least 50% of people with glaucoma do not know they are affected.”

Dr. Coleman is the Fran and Ray Stark Professor of Ophthalmology, Jules Stein Eye Institute, University of California Los Angeles.

A variety of studies have helped to identify variables associated with an increased likelihood of having undiagnosed glaucoma. The risk factors include male gender and younger age, having a smaller vertical cup-to-disc ratio, unilateral disease, or early visual field loss, and absence of myopia, family history of glaucoma, or history of cataract surgery.

People who have limited access into the health care system are also at increased risk for undiagnosed glaucoma, and included in this category are individuals with lower socioeconomic status, less language proficiency, and those residing in rural areas.

“The population of people with undiagnosed glaucoma includes those without reasons to see an eye-care practitioner and those who underestimate their personal risk, perhaps because they have no family history of the disease or are younger,” said Dr. Coleman. “However, even though glaucoma prevalence is age-related, it affects a lot of people in their 30s, 40s, and 50s, especially within certain ethnic groups.”

Strategies for screening

There are multiple issues to consider in designing screening programs for undiagnosed glaucoma. Keeping in mind that the overall prevalence of glaucoma is only about 2%, it seems reasonable to focus on higher risk groups.

For example, in the United States, African Americans and Hispanics might be targeted. However, this methodology overlooks the fact that while Caucasians may be at lower risk for having undiagnosed disease, they represent the largest affected subgroup in terms of actual numbers, Dr. Coleman added.

Another consideration relates to what tools should be used. The possible methods can include patient history, visual acuity, IOP measurement, structural evaluations, and visual field testing.

The next question that arises revolves around deciding how to intervene. Persons with glaucoma or glaucoma suspects may be offered disease education and an opportunity for care, or the program can be designed to be more active in assuring care is received.

An effective model

In 2010, the American Academy of Ophthalmology (AAO) announced its EyeSmart EyeCheck screening initiative to address the problem of undiagnosed eye disease among at-risk populations in the United States. The program, designed to screen for other eye diseases along with glaucoma in the general population, focuses on detecting moderate visual impairment (BCVA of 20/40 or worse) and uses the screening as a triage system for prioritizing individuals at immediate risk for blindness or significant vision loss.

“We were interested in first taking care of people with moderate visual impairment, and then will think of strategies to take care of those with early disease,” said Dr. Coleman, who directs the AAO H Dunbar Hoskins, Jr., MD Center for Quality Eye Care and is Secretary of Quality of Care for the AAO.

In pilot efforts, the program engaged the participation of local ophthalmologists and ophthalmology fellows to perform the screening. They used “low-tech” tools (visual acuity and optic nerve examination) to detect evidence of glaucomatous optic nerve damage, visually significant cataract, age-related macular degeneration, or other eye conditions that need to be treated and can be identified without a slit-lamp.

 “Low tech is better in this pilot program because we are using experienced ophthalmologists and do not need to use expensive imaging devices or to do detailed slit lamp exams to determine who needs to be evaluated further,” said Dr. Coleman.

Patients with positive findings were educated and referred for more definitive care. However, delivery of affordable care was another issue that had to be confronted since many of the individuals needing follow-up were uninsured and too young for Medicare.

“We had to investigate what resources were available in the community to take care of these patients and get them information on affordable or free care,” Dr. Coleman said.

“We were fortunate to be able to refer them to county hospitals, but it was also gratifying that quite a few ophthalmologists in the community were willing to see some patients for free.”

The first screening under the EyeSmart EyeCheck program was held in Los Angeles. Almost 500 individuals were screened over a 4.5-hour period, and 99% of the participants were Mexican Americans. The screening identified 22 individuals with definite glaucoma (4.4%), 138 (27.7%) with uncorrected refractive error, 4 (0.8%) with retinitis pigmentosa, and 13 (2.6%) with untreated diabetic retinopathy. Additionally, some patients were referred for further examination as media opacity precluded posterior segment examination.

“The screening program was a very positive experience for all involved. Not only did it identify patients needing follow-up care, but it was very informative to the participants, many of who had never heard of or seen an ophthalmologist,” said Dr. Coleman.

“It was also rewarding for the participating physicians, and the state society benefited as well because we were able to get those who were not yet members to join us in this community outreach program.”

FYI

Anne L. Coleman, MD, PhD, has no relevant financial interests to disclose.

e. colemana@ucla.edu

CALLOUT

‘Ophthalmologists . . . may not fully appreciate the magnitude of the problem of undiagnosed disease.’

Anne L. Coleman, MD, PhD.

TAKE HOME MESSAGE

With evidence that at least 50% of glaucoma is undiagnosed, strategies are needed to identify these individuals and assure they receive proper care. Experience so far with the American Academy of Ophthalmology’s EyeSmart EyeCheck screening initiative indicates it is a successful model for approaching the problem of undiagnosed eye disease among at-risk populations in the United States.

Caption:

Anne L. Coleman, MD, interviews a patient during a EyeSmart EyeCheck screening in Los Angeles. The program, designed to screen for other eye diseases along with glaucoma in the general population, focuses on detecting moderate visual impairment and uses the screening as a triage system for prioritizing individuals at immediate risk for blindness or significant vision loss.