New Research: Results from the Philadelphia Glaucoma Detection and Treatment Project

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a view of the eye to check for glaucoma

New glaucoma research, initially presented at the American Glaucoma Society 24th Annual Meeting, concludes that targeting individuals at risk for glaucoma in underserved communities – in this case, Philadelphia – can yield a high detection rate of glaucoma-related diagnoses. The authors conclude that "providing examinations and offering treatment at community-based sites providing services to older adults are effective ways to improve access to eye care by underserved populations."

This new glaucoma detection research, entitled The Philadelphia Glaucoma Detection and Treatment Project: Detection Rates and Initial Management, has been published online ahead-of-print in the May 22, 2016 edition of Ophthalmology, the official journal of the American Academy of Ophthalmology. Ophthalmology publishes original, peer-reviewed research in ophthalmology, including new diagnostic and surgical techniques, the latest drug findings, and results of clinical trials.

The authors are Michael Waisbourd, MD; Noelle L. Pruzan, MD; Deiana Johnson, MPH; Angela Ugorets, BS; John E. Crews, DPA; Jinan B. Saaddine, MD; Jeffery D. Henderer, MD; Lisa A. Hark, PhD, RD; and L. Jay Katz, MD, who represent the following institutions: Wills Eye Hospital Glaucoma Research Center, Philadelphia, PA; Vision Health Initiative, Centers for Disease Control and Prevention, Atlanta, GA; and Lewis Katz School of Medicine at Temple University, Philadelphia, PA.

About the Philadelphia Glaucoma Detection and Treatment Project

Excerpted from Reducing Barriers to Glaucoma Screening: A community-based project in Philadelphia increased access to care in high-risk populations, an interview with Project principals L. Jay Katz, MD; Michael Waisbourd, MD; and Lisa A. Hark, PhD, RD, via eyetubeOD:

Sometimes the work we do in the interest of research affords us the opportunity to have tremendous impact on the communities we serve as physicians. Such is the case with the community-based mobile glaucoma program initiated by the Wills Eye Hospital Glaucoma Service and Glaucoma Research Center.

The program, called the Philadelphia Glaucoma Detection and Treatment Project, was a demonstration project designed to find out if it might be possible to bring the tools needed to diagnose and treat glaucoma to high-risk populations, rather than waiting for patients to come to us. Patients were educated, enrolled, examined, and, if a diagnosis was positive, offered a same-day, on-the-spot intervention, such as laser therapy.

Traditionally, screening programs have a significant problem with follow-up. For one reason or another, often despite the best intentions, many patients diagnosed with an eye disease through screenings get lost to follow-up, and, hence, an opportunity for treatment is lost. Glaucoma is particularly insidious on this account, as the disease burden is often highest among those who have suboptimal access to care. This is a big reason why almost half of all glaucoma cases go undetected.

This ongoing program has two objectives: (1) to establish community partners, such as senior centers, that can be used as sites to identify patients in need of glaucoma services, and (2) to conduct educational workshops and comprehensive eye examinations in these community sites, immediately connecting patients in need of treatment with care.

For the program, we sent a mobile unit staffed with an ophthalmologist and stocked with diagnostic [and treatment] equipment … to 43 program sites (senior centers, senior housing buildings, and community centers) in areas with a high population density of African American individuals in West Philadelphia, North Philadelphia, Northeast Philadelphia, and South Philadelphia. Our experts led awareness workshops to educate patients about glaucoma and recruit into the program.

Each patient who enrolled received a complete eye examination at no cost… More than 1,600 patients were enrolled; African American patients had to be older than 50 years, and others had to be older than 60 years. Patients who were positively diagnosed with any type of glaucoma were followed up at the community sites.

We received generous support … in the form of a donated [laser] so that we could offer patients on-the-spot treatment options, specifically selective laser trabeculoplasty (SLT) for individuals with open-angle glaucoma and laser peripheral iridotomy (LPI) procedures for those with anatomically narrow angles.

[Editor's note: You can learn more about laser peripheral iridotomy (LPI), selective laser trabeculoplasty (SLT), and eye drops to lower eye pressure at What Are the Different Treatments for Glaucoma? on the VisionAware website.]

We returned to each program site at least twice: 4 to 6 weeks after the initial visit to assess those who had glaucoma or who had received a laser treatment, and at 4 to 6 months after the initial examination. Through the program, we learned a lot more than we expected. A significant number of patients were diagnosed with glaucoma-related conditions, including glaucoma, glaucoma suspect, or narrow angle. Other eye diseases were also detected.

You can read the authors' interview in its entirety, including the project results, at Reducing Barriers to Glaucoma Screening: A community-based project in Philadelphia increased access to care in high-risk populations.

What Is Glaucoma?

The term "glaucoma" describes a group of eye diseases that can lead to blindness by damaging the optic nerve. It is one of the leading causes of vision loss and blindness. The human eye continuously produces a fluid, called the aqueous, that must drain from the eye to maintain healthy eye pressure.

Types of Glaucoma

In primary open-angle glaucoma, the most common type of glaucoma, the eye's drainage canals become blocked, and the fluid accumulation causes pressure to build within the eye. This increasing pressure can cause damage to the optic nerve, which transmits information from the eye to the brain. Vision loss is usually gradual and often there are no early warning signs.

In angle-closure glaucoma, also called "acute" glaucoma, the aqueous cannot drain properly because the entrance to the drainage canal is either too narrow or is closed completely. In this case, eye pressure can rise very quickly and cause an acute glaucoma attack. Symptoms can include sudden eye pain, nausea, headaches, and blurred vision. Acute glaucoma is a true ocular emergency and requires immediate treatment.

In normal-tension glaucoma, also called low-tension/low pressure glaucoma, individuals with the disease experience optic nerve damage and subsequent vision loss, despite having normal intraocular [i.e., within the eye] pressure (IOP).

Most eye care professionals define the range of normal IOP as between 10 and 21 mm Hg [i.e., millimeters of mercury, which is a pressure measurement]. Most persons with glaucoma have an IOP measurement of greater than 21 mm Hg; persons with normal-tension glaucoma, however, have an IOP measurement within the normal range.

Visual Field Loss

Glaucoma results in peripheral (or side) vision loss initially, and the effect as this field loss progresses is like looking through a tube or into a narrow tunnel. This constricted "tunnel vision" effect makes it difficult to walk without bumping into objects that are off to the side, near the head, or at foot level.

A living room viewed through a constricted visual field

A living room viewed through a constricted visual field.
Source: Making Life More Livable. Used with permission.

Glaucoma is an especially dangerous eye condition because most people do not experience any symptoms or early warning signs at the onset. Glaucoma can be treated, but it is not curable. The damage to the optic nerve from glaucoma cannot be reversed.

More about the Study from Ophthalmology

From the study summary and abstract:

Purpose; To evaluate the detection rates of glaucoma-related diagnoses and the initial treatments received in the Philadelphia Glaucoma Detection and Treatment Project, a community-based initiative aimed at improving the detection, treatment, and follow-up care of individuals at risk for glaucoma.

Participants: A total of 1,649 individuals at risk for glaucoma who were examined and treated in 43 community centers located in underserved communities of Philadelphia.

Methods: Individuals were enrolled if they were African American aged ≥ (greater than or equal to) 50 years, were any other adult aged ≥ (greater than or equal to) 60 years, or had a family history of glaucoma. After attending an informational glaucoma workshop, participants underwent a targeted glaucoma examination including an ocular, medical, and family history; visual acuity testing, intraocular [i.e., within the eye] pressure (IOP) measurement, and corneal pachymetry; slit-lamp and optic nerve examination; automated visual field testing; and fundus color photography.

[Editor's note: You can read more about all of these diagnostic tests for glaucoma at How Can I Detect Glaucoma if There Are No Initial Symptoms? on the VisionAware website.]

If indicated, treatments included selective laser trabeculoplasty (SLT), laser peripheral iridotomy (LPI), or IOP-lowering medications. Follow-up examinations were scheduled at the community sites after 4 to 6 weeks or 4 to 6 months, depending on the clinical scenario.

[Editor's note: You can learn more about laser peripheral iridotomy (LPI), selective laser trabeculoplasty (SLT), and eye drops to lower eye pressure at What Are the Different Treatments for Glaucoma? on the VisionAware website.]

Results: Of the 1,649 individuals enrolled, 645 (or 39.1%) received a glaucoma-related diagnosis; 20% were identified as open-angle glaucoma suspects, 9.2% were identified as having narrow angles (or as a primary angle closure/suspect), and 10.0% were diagnosed with glaucoma, including 9% with open-angle glaucoma and 1% with angle-closure glaucoma.

Overall, 39% of those diagnosed with glaucoma were unaware of their diagnosis. A total of 196 patients (11.9%) received glaucoma-related treatment, including 84 who underwent laser peripheral iridotomy (LPI), 13 who underwent selective laser trabeculoplasty (SLT), and 103 who were prescribed eye pressure-lowering medication.

Conclusions: Targeting individuals at risk for glaucoma in underserved communities in Philadelphia yielded a high detection rate (39.1%) of glaucoma-related diagnoses. Providing examinations and offering treatment, including first-line laser procedures, at community-based sites providing services to older adults are effective to improve access to eye care by underserved populations.

More about Glaucoma at VisionAware


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