New glaucoma research from the University of California, San Diego, has measured the amount and rate of change in glaucoma-related visual field loss and combined that information with data from the National Eye Institute’s Visual Function Questionnaire (explained below) to gather quality-of-life self-reports from study participants with glaucoma.
The study results indicate that vision-related function incorporating patient self-assessment and perspectives can help glaucoma physicians (a) better identify patients who may experience significant declines in quality of life (QoL) and (b) determine more appropriate treatment options for those individuals.
Ophthalmology: the Journal
The research, entitled Longitudinal Changes in Quality of Life and Rates of Progressive Visual Field Loss in Glaucoma Patients, has been published online ahead-of-print on October 15, 2014 in Ophthalmology, the official journal of the American Academy of Ophthalmology. Ophthalmology publishes original, peer-reviewed research in ophthalmology, including new diagnostic and surgical techniques, new drug findings, and results of clinical trials.
The authors are Felipe A. Medeiros, Carolina P.B. Gracitelli, Erwin R. Boer, Robert N. Weinreb, Linda M. Zangwill, and Peter N. Rosen, from the Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego.
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.
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.
About the Visual Function Questionnaire (VFQ-25)
The National Eye Institute’s Visual Function Questionnaire (VFQ-25) consists of 25 self-reported vision-related questions plus an additional health self-rating question. The health-related question has been shown to be a strong predictor of future health and mortality. The 25 questions address the following vision-related areas:
- self-rating of general vision
- difficulty with near vision activities
- difficulty with distance vision activities
- limitations in social functioning due to vision
- role limitations due to vision
- dependency on others due to vision
- mental health symptoms due to vision
- driving difficulties
- limitations with peripheral and color vision
- ocular pain
Here is more about the VFQ-25 from The Rand Corporation (in PDF format):
The National Eye Institute (NEI) sponsored the development of the VFQ-25, with the goal of creating a survey that would measure the dimensions of self-reported, vision-targeted health status that are most important for persons who have chronic eye diseases.
Because of that goal, the survey measures the influence of visual disability and visual symptoms on generic health domains, such as emotional well-being and social functioning, in addition to task-oriented domains related to visual functioning.
About the Research
Excerpted from Visual Field Loss Tied to Quality of Life (QoL) Decline in Those with Glaucoma from Medscape (registration required):
Felipe A. Medeiros, MD, PhD, from the Hamilton Glaucoma Center and Department of Ophthalmology, University of California at San Diego, and colleagues conducted a longitudinal observational study involving 322 eyes in 161 people. Study participants had a mean age of 69.5 years, 53% were men, 71% were white, 29% were black, and 4% identified themselves as Hispanic.
[Editor’s note: A longitudinal study follows, and gathers information about, the same individuals or group of people over an extended period of time – sometimes for decades.]
To be enrolled in the study, participants had to have taken the National Eye Institute Visual Function Questionnaire 25 (NEI VFQ-25) at least for two years and had to have had standard automated perimetry [also called visual field testing] at six-month intervals.
The researchers followed participants for an average of 3.5 years. Overall, the researchers found a significant correlation between change in NEI VFQ-25 … scores and change in binocular [visual field] sensitivity.
One of the things this article shows, for the first time, is that there is a direct relationship between the rate of visual field loss and decline in QoL, said senior author Peter Rosen, MD. “The first question we typically ask the patient is how [she or he] is doing. A lot of clinicians over the years have been bothered by that, because it’s not a consistent way of evaluating things,” he said.
The NEI VFQ-25 “really teases down to vision-related function. It incorporates the patient perspective in a very structured way,” he added. “I think that will be something that will be useful if incorporated into clinical decision making, as we begin to look at ways of detecting progression much earlier on.”
“I think this is a first step in helping us understand when and how our glaucoma patients experience decreasing [QoL],” Michael V. Boland, MD, PhD, assistant professor at the Wilmer Eye Institute at Johns Hopkins University School of Medicine. “Future research could focus on how treatments and depression may affect QoL, he added. “I think this is an important study because it’s the first to look at the longitudinal effect on [QoL] in glaucoma patients. The rate of loss is a key advance.”
More about the Study from Ophthalmology
From the article abstract:
Participants: We recruited 322 eyes of 161 patients with glaucomatous visual field loss from the Diagnostic Innovations in Glaucoma Study followed for an average of 3.5 … years.
Results: There was a significant correlation between change in the NEI VFQ-25 … scores during follow-up and change in binocular [visual field] sensitivity.
Eyes with more severe disease at baseline were also more likely to have a decrease in NEI VFQ-25 scores during follow-up. For subjects with the same amount of change in [binocular visual field sensitivity measurements], those with shorter follow-up times had larger changes in NEI VFQ-25 scores.
Conclusions: Baseline severity, magnitude, and rates of change in [binocular visual field] sensitivity were associated with longitudinal changes in QoL of glaucoma patients. Assessment of longitudinal visual field changes may help to identify patients at greater risk for developing disability from the disease.
Additional Information about Glaucoma Studies
- Maintaining a Glaucoma Medication Regimen: What Factors Do – or Don’t – Promote Adherence?
- Do People with Glaucoma Read Less and Engage Less with Reading Tasks? New Research Says Yes
- The VisionAware “Getting Started” kit provides tip sheets on specialized services and products that can assist with everyday life after vision loss.