Researchers develop risk assessment model for advanced age-related macular degeneration

August 8, 2011, JAMA and Archives Journals

A new risk assessment model may help predict development of advanced age-related macular degeneration, according to a report published Online First by Archives of Ophthalmology, one of the JAMA/Archives journals.

Age-related () is a leading cause of blindness in the United States and the Western world, according to background information in the article. "As progress in designing better preventive measures and earlier accelerates and new gene associations are identified that add to currently known risk factors, the desirability of having a reliable risk assessment model has become of considerable interest and potential value," write the authors. The model, they explain, should identify individuals with early AMD who are at greatest risk to progress to advanced AMD and should be able to predict when that progression might occur.

Michael L. Klein, M.D., from the Casey Eye Institute, Oregon Health & Science University, Portland, and colleagues sought to design a risk assessment model for development of advanced AMD that included phenotypic (related to observable physical characteristics), demographic, environmental and genetic risk factors. They used longitudinal data from the Age-Related Eye Disease Study, including participants' DNA samples, ocular and medical histories and examinations. The researchers identified two endpoints: development of advanced AMD in either eye by participants who did not have this condition at baseline, and advanced AMD in a second eye by participants who, at baseline, had it in one eye. Patients were followed for an average of 9.3 years.

The variables included in the final model included simple scale score (a sum of clinical in both eyes), two genotypes, very large drusen (deposits on the retina associated with AMD), smoking, family history, advanced AMD in one eye and age. The complete model appeared to perform well and to discriminate an individual's risk of advanced AMD. Of the 2,602 participants in the final model who, at baseline, had no advanced AMD, 24 percent (n = 635) developed advanced AMD during follow-up. Of those with advanced AMD at baseline, 82 percent who had the geographic atrophy (gradual deterioration of retinal cells, called "dry AMD") type and 56 percent who had the neovascular type (new blood vessel formation and leakage, called "wet AMD") developed advanced AMD in the other eye.

The results "can be of potential value in clinical practice by helping determine the frequency of follow-up examinations, the use of home monitoring of central vision, and the advisability of initiating including beneficial lifestyle changes such as dietary alterations and nutritional supplement use," the authors note. "The short-term end points (e.g., 2 years) may be helpful in planning clinical trials." They add that the model performed well on measures of discrimination, calibration and overall performance. "We believe our current model is of substantial value in assessing AMD risk, and we expect that future advances will further improve its accuracy," they write.

More information: Arch Ophthalmol. August 8, 2011. doi:10.1001/archophthalmol.2011.216

Related Stories

Recommended for you

Creation of synthetic horsepox virus could lead to more effective smallpox vaccine

January 19, 2018
UAlberta researchers created a new synthetic virus that could lead to the development of a more effective vaccine against smallpox. The discovery demonstrates how techniques based on the use of synthetic DNA can be used to ...

Study ends debate over role of steroids in treating septic shock

January 19, 2018
The results from the largest ever study of septic shock could improve treatment for critically ill patients and save health systems worldwide hundreds of millions of dollars each year.

Flu may be spread just by breathing, new study shows; coughing and sneezing not required

January 18, 2018
It is easier to spread the influenza virus (flu) than previously thought, according to a new University of Maryland-led study released today. People commonly believe that they can catch the flu by exposure to droplets from ...

New approach could help curtail hospitalizations due to influenza infection

January 18, 2018
More than 700,000 Americans were hospitalized due to illnesses associated with the seasonal flu during the 2014-15 flu season, according to federal estimates. A radical new approach to vaccine development at UCLA may help ...

Zika virus damages placenta, which may explain malformed babies

January 18, 2018
Though the Zika virus is widely known for a recent outbreak that caused children to be born with microencephaly, or having a small head, and other malformations, scientists have struggled to explain how the virus affects ...

Certain flu virus mutations may compensate for fitness costs of other mutations

January 18, 2018
Seasonal flu viruses continually undergo mutations that help them evade the human immune system, but some of these mutations can reduce a virus's potency. According to new research published in PLOS Pathogens, certain mutations ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.