New Macular Degeneration Research from the Los Angeles Latino Eye Study

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Photograph of a retina with wet age-related macular degeneration

New results from the Los Angeles Latino Eye Study indicate that early – as opposed to later and more severe – vision changes resulting from macular degeneration (AMD) are associated with a lower self-reported vision-specific health-related quality of life.

According to study co-author Dr. Rohit Varma, "The study results are a wake-up call for both ophthalmologists and those in the Latino community to avoid a quality of life decline due to ocular conditions, especially in earlier stages of eye diseases such as AMD. More importantly, the lower level of health care access and utilization among this group is likely to impact follow-up care of these patients and may also make them more susceptible to diminished quality of life."

From JAMA Ophthalmology

The research, entitled Age-Related Macular Degeneration and Quality of Life in Latinos: The Los Angeles Latino Eye Study, has been published "online first" in the April 28, 2016 edition of JAMA Ophthalmology (formerly Archives of Ophthalmology). JAMA Ophthalmology is an international peer-reviewed journal published monthly by the American Medical Association.

The authors are Farzana Choudhury, MBBS, MS, PhD; Rohit Varma, MD, MPH; Ronald Klein, MD, MPH; W. James Gauderman, PhD; Stanley P. Azen, PhD; and Roberta McKean-Cowdin, PhD, all part of the Los Angeles Latino Eye Study Group, who represent the following institutions: the University of Southern California, Los Angeles and the University of Wisconsin School of Medicine and Public Health, Madison.

The Los Angeles Latino Eye Study

The Los Angeles Latino Eye Study (LALES) is a major research project in Los Angeles County, California, designed to gain a greater understanding of the prevalence and incidence of eye disease among Latinos. Because so little is known about the visual health needs of this segment of the population, the data collected from this study will be instrumental in determining the prevalence of cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy among Latinos in this community. The study will also determine the proportion of blindness and visual impairment that is caused by these diseases, and will explore the association of various risk factors, such as smoking or sun exposure with ocular disease.

The LALES is supported by the National Eye Institute and the National Center of Minority Health and Health Disparities, which are two components of the National Institutes of Health. You can read more about the range of research studies that have been produced by the Los Angeles Latino Eye Study at the LALES home page.

About the Research

Excerpted from Los Angeles Latino Eye Study (LALES) looks at age-related macular degeneration (AMD) and quality of life impact at Science Daily:

Researchers have published results of the largest population-based study of adult Latinos and age-related macular degeneration (AMD) in the National Eye Institute-funded Los Angeles Latino Eye Study (LALES), the first to analyze the risk and prevalence of early and late stage AMD and its impact on quality of life for older Latinos.

The LALES study, conducted among 4,876 Latinos in Los Angeles with a mean age of 54.8 years old, indicates that Latinos diagnosed with bilateral [i.e., both eyes] AMD with large drusen (explained below) and depigmentation as well as a more severe AMD had a substantially lower health-related quality of life as compared to those with AMD lesions in only one eye. In addition, the findings point to a more significant health-related quality of life decline beginning in early rather than later stages of the disease.

For instance … 91.6 percent of early AMD participants reported vision-related social function impact and 74.4 percent had near vision problems as compared to 67.7 percent and 46.9 percent respectively of late AMD participants who reported the same. The researchers also found that while participants may not have a measurable decrease in their visual acuity, their reported reduced visual function may possibly be the result of reduced contrast sensitivity associated with early-stage AMD.

"The study results are a wake-up call for both ophthalmologists and those in the Latino community to avoid a quality of life decline due to ocular conditions, especially in earlier stages of eye diseases such as AMD," said [study co-author] Rohit Varma, MD, MPH. "What was significant but not intuitively obvious was that Latinos diagnosed with AMD in both eyes or more severe AMD had a markedly diminished vision-specific quality of life requiring us to shift our clinical focus from treating advanced stages of AMD to finding earlier stage interventions and treatment options."

"Previous studies on Latinos have found this population to have a different pattern of AMD prevalence, incidence, progression and risk factors," said Dr. Varma. "More importantly, the lower level of health care access and utilization among this group is likely to impact follow-up care of these patients and may make them more susceptible to diminished quality of life."

"The LALES findings unexpectedly demonstrate that even the earliest stages of AMD may impair eyesight enough to interfere with daily activities. People with early AMD affecting both eyes appear to be especially vulnerable to declines in their vision-related quality of life, and might benefit from any early referral to a low vision specialist," said Maryann Redford, MPH, program director at the National Eye Institute.

About Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is a gradual, progressive, painless deterioration of the macula, the small sensitive area in the center of the retina that provides clear central vision. Damage to the macula impairs the central (or "detail") vision that helps with essential everyday activities, such as reading, preparing meals, watching television, playing card and board games, and sewing.

AMD is the leading cause of vision loss for people aged 60 and older in the United States. According to the American Academy of Ophthalmology, 10-15 million individuals have AMD and about 10% of people who are affected have the "wet" type of AMD.

Wet (Neovascular) Macular Degeneration

In wet, or exudative, macular degeneration (AMD), the choroid (a part of the eye containing blood vessels that nourish the retina) begins to sprout abnormal new blood vessels that develop into a cluster under the macula, called choroidal neovascularization (neo = new; vascular = blood vessels).

Because these new blood vessels are abnormal, they tend to break, bleed, and leak fluid under the macula, causing it to lift up and pull away from its base. This damages the fragile photoreceptor cells, which sense and receive light, resulting in a rapid and severe loss of central vision.

Dry Macular Degeneration

The dry (also called atrophic) type of AMD affects approximately 80-90% of individuals with AMD. Its cause is unknown, it tends to progress more slowly than the wet type, and there is not – as of yet – an approved treatment or cure. "Atrophy" refers to the degeneration of cells in a portion of the body; in this case, the cell degeneration occurs in the retina.

In dry age-related macular degeneration, small white or yellowish deposits, called drusen, form on the retina, in the macula, causing it to deteriorate or degenerate over time.

Photograph of a retina with drusen

A retina with drusen

Drusen are the hallmark of dry AMD. These small yellow deposits beneath the retina are a buildup of waste materials, composed of cholesterol, protein, and fats. Typically, when drusen first form, they do not cause vision loss. However, they are a risk factor for progressing to vision loss.

Risk Factors for Macular Degeneration

The primary risk factors for AMD include the following:

  1. Smoking: Current smokers have a 2-3 times higher risk for developing AMD than do people who never smoked. It's best to avoid second-hand smoke as well.
  2. Sunlight: Ultraviolet (UV) light is not visible to the human eye, but can damage the lens and retina. Blue light waves that make the sky, or any object, appear blue, are visible to the human eye and can also damage the lens and retina. Avoid UV light and blue/violet light as much as possible by wearing sunglasses with an amber, brown, or orange tint that blocks both blue and UV light.
  3. Uncontrolled hypertension: The National Eye Institute (NEI) reports that persons with hypertension were 1.5 times more likely to develop wet macular degeneration than persons without hypertension. It's important to keep your blood pressure controlled within normal limits.
  4. A diet high in packaged, processed food and low in fresh vegetables: NEI suggests that eating antioxidant-rich foods, such as fresh fruits and dark green leafy vegetables (kale, collard greens, and spinach) may delay the onset or reduce the severity of AMD. Eating at least one serving of fatty fish (salmon, tuna, or trout) per week may also delay the onset or reduce the severity of AMD.
  5. Race: According to NEI, Whites/Caucasians are more likely to have AMD than people of African descent.
  6. Family history: NEI reports that individuals with a parent or sibling with AMD have a 3-4 times higher risk of developing AMD.

You can read more about the full range of AMD risk factors at Risk Factors for Age-Related Macular Degeneration on the VisionAware website.

More about the Study from JAMA Ophthalmology

Edited and excerpted from the study abstract:

Importance: This study found evidence of a threshold effect [i.e., reaching a level or point at which something starts to change] in which the presence of bilateral [i.e., occurring in both eyes] drusen (explained above) and depigmentation of retinal pigment epithelium was associated with substantially low health-related quality of life in adult Latinos from the United States.

[Editor's note: Retinal pigment epithelium (RPE) cells are the deepest cells of the retina. The RPE helps to maintain the health of the retinal photoreceptor cells, called rods and cones. These photoreceptor cells are triggered by light to set off a series of electrical and chemical reactions that helps brain to interpret what the eye sees. Degeneration of the RPE cells also leads to the death of the rods and cones and, ultimately, to loss of vision.]

Objective: To assess the association of general and vision-specific health-related quality of life with age-related macular degeneration (AMD), overall and by bilaterality [i.e., occurring in both eyes] and severity, in adult Latinos.

Design, Setting, and Participants: The study included 4,876 participants from the general urban community in six US Census tracts in La Puente, California. The data for these analyses were collected as part of a population-based study of ocular diseases in adult Latinos in the Los Angeles Latino Eye Study from February 1, 2000 through May 31, 2003. The analysis was performed from November 2010 to February 2011. Additional analyses were performed in June 2014.

Results: Of the 4,876 participants included in the analysis, 4,402 (90.3%) had no AMD, and 474 (9.7%) had any AMD, with 453 having early (9.3%) and 21 (0.4%) having late stages of the disease. The mean age was 54.8 years. Of the 4,876 participants, 2,001 (41.0%) were male and 2,875 (59.0%) were female. In this [research group] of Latinos, participants with AMD had lower vision-specific health-related quality of life scores.

General health-related quality of life was assessed by the Medical Outcomes Study 12-Item Short-Form Health Survey and self-reported vision-related health-related quality of life by the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25).

Conclusions and Relevance: In this study of adult Latinos, early AMD lesions are associated with lower self-reported vision-specific health-related quality of life, but not general health-related quality of life. Severity and bilaterality of AMD are associated with measurably lower health-related quality of life, with the largest difference in scores occurring for individuals with both eyes affected.

Additional Information


Topics:
Cultural Diversity
Health
Low Vision
Macular Degeneration
Medical Updates

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