07 Nov Age-Related Macular Degeneration: SD-OCT Imaging Predicts Dry To Wet Progression

MedicalResearch.com Interview with:
Theodore Leng, MD, MS , one of the article’s senior authors
Byers Eye Institute at Stanford
Stanford University School of Medicine
Palo Alto, CA 94303

Dr. Leng: What is the background for this study? What are the main findings?

Medical Research: Age-related macular degeneration (AMD) is the leading cause of blindness and central vision loss among adults older than 65 years. 80-85% of patients have the dry, non-exudative, form of the disease, but the wet, exudative, form of advanced AMD is of primary concern as it accounts for a majority of severe vision loss in Age-related macular degeneration. In wet AMD, abnormal blood vessels grow under the retina and can leak blood and fluid.

Until now, there has been no effective way to tell which patients with dry AMD are likely to progress to the wet stage. In our recent Investigative Ophthalmology & Visual Science article, we describe a new mathematical model that can predict which patients are likely to progress.

The predictive model identifies likely progressors by analyzing 3D spectral domain optical coherence tomography (SD-OCT) retinal imaging data that’s routinely obtained during retinal encounters.

We analyzed data from 2,146 SD-OCT scans of 330 eyes in 244 patients seen at The Byers Eye Institute at Stanford over a five-year period. We found that the area and height of drusen, the amount of reflectivity at the macular surface and the degree of change in these features over time, could be weighted to generate a patient’s risk score. Predictions from the model were compared with cases where patients actually progressed to wet Age-related macular degeneration. Our model accurately predicted every occurrence of progression within a year. There was a false positive rate of around 40%, but we thought this was a good tradeoff because we would not miss any potential progressors by using this sensitivity threshold.

Medical Research: What should clinicians and patients take away from your report?

Dr. Leng: Previously proposed predictive models have shown some accuracy over long periods of time, but 3 and 5 year predictions about Age-related macular degeneration progression are not clinically useful when you are trying to schedule a follow up visit for a patient in front of you in clinic. Our model allows the clinician to know with great accuracy, which patients within one year will progress. That will allow retina specialists to better schedule follow up and monitoring visits for their dry Age-related macular degeneration patients.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Leng: This was a proof-of-principle study using retrospective data. It will need to be validated by a larger prospective study. We are currently in the planning stages of such a study.

Citation:

Quantitative SD-OCT Imaging Biomarkers as Indicators of Age-Related Macular Degeneration Progression
de Sisternes L, Simon N, Tibshirani R, Leng T, Rubin DL
Invest Ophthalmol Vis Sci. 2014 Oct 9. pii: IOVS-14-14918. doi: 10.1167/iovs.14-14918. [Epub ahead of print]

Last Updated on November 7, 2014 by Marie Benz MD FAAD