The Los Angeles Latino Eye Study (LALES) is the largest population-based study of eye disease in any minority population living in the United States. The study has provided significant new information on the prevalence and associated risk factors for eye disorders among Hispanics living in Los Angeles, a population consisting of people of predominantly Mexican origin. Previous reports from LALES have shown high rates of blindness and visual impairment, glaucoma, cataract, and diabetic retinopathy in this population; these rates were higher than those reported in US non-Hispanic whites. Most of the people with eye disorders were unaware and their eye conditions had not been diagnosed previously. It has been estimated that this community bears a disproportionate amount of eye disease burden compared to other ethnic groups in the United States.
In this month’s issue of the Journal , Varma and associates have completed a longitudinal follow-up of the LALES population and have reported the incidence and progression of diabetic retinopathy (DR) and macular edema (ME). The study found that the 4-year incidence of DR, ME, and clinically significant ME was 34%, 5.4%, and 7.2% respectively. Younger people and those with a longer duration of diabetes had higher risk of incident DR. These results are important as there are currently limited data regarding the incidence and natural history of DR. The high incidence and progression rates found are alarming, as many studies have reported a high prevalence of diabetes mellitus in Latinos. Nearly 1 in 5 Latinos has diabetes, and among those with diabetes, the prevalence of DR ranges from 30% to 50% and ME from 10% to 15%. Close to 20% are unaware that they have diabetes and yet they have moderate to severe ocular changes. Those who are unaware are more likely to report lower family income. Furthermore, diabetic people with lower incomes are more likely to have DR. Without public health interventions for both the diagnosis of diabetes and monitoring for DR, visual impairment and blindness rates will increase dramatically, given the aging of the Latino population. Interventions targeting at-risk lower-income Latino populations in particular need to be implemented to maintain the visual health of this community.
The many publications from the LALES have provided unique insights into eye diseases among Latinos. The LALES study population consists mainly of people of Mexican origin and it would be interesting to know if a similar disease profile is present among Latinos who are descendants from other countries, such as Cuba or countries in South America. The reasons for the high prevalence of eye diseases in Latinos are unclear. While this prevalence could be attributable to genetic differences, environmental factors are likely to be important. Many of the leading causes of low vision and blindness found in the LALES are actually potentially preventable and treatable diseases. This emphasizes the need for more frequent health examinations, better education, and increased public awareness of eye diseases. Consideration needs to be given to other modifiable risk factors such as the lack of insurance or poor access to care, especially among those with financial limitations. It is likely that there are even more vulnerable subgroups in this community, such as those who are not legal residents in the United States. Identifying an effective approach to screening and treating these individuals should also be part of any public health efforts to reduce visual impairment and blindness.
While the LALES has been very successful in documenting the extent of eye diseases among Latinos, there is a need for future studies examining the role and cost-effectiveness of new screening strategies for early detection of potentially treatable eye diseases. Thoughtful and effective approaches can result in better visual outcomes, in particular for those with diabetes and DR; these approaches are clearly needed in at-risk Latino populations.