Subscribe to Newsletter
Subspecialties Retina

Choroid Cartography

Part of the pathology of age-related macular degeneration (AMD) – and many other posterior segment diseases – is inflammation of the choroid and the accompanying retinal pigment epithelium (RPE). But it’s a patchy pathology; some regions are more susceptible to inflammation than others. North American researchers Jessica Skeie and Vinit Mahajan wanted to know why.

Skeie and Mahajan are based in the Department of Ophthalmology and Visual Sciences’ “Omics” laboratory at the University of Iowa Carver College of Medicine. They had the means to identify the proteins across multiple regions of the choroid-RPE regions, the bioinformatical know-how to process the information, and three non-diseased eyes from the Iowa Lions Eye Bank. The plan was simple: take tissue samples from multiple regions of the choroid-RPE complex – the fovea, macula and the periphery Figure 1) – and create a map. So what map did they draw?

0814-202-upfront-fig1

Figure 1. A schematic of the three sampled choroidal regions, in relation to the entire eye (left) and as regions (F, fovea; M, macula and P, periphery).

A molecular map that catalogued more than 4,000 unique proteins in each of the three areas examined, with differential regional expression patterns for almost 700 proteins that had previously been identified as risk factors for retinal diseases related to oxidative stress (1). Of note, the peripheral region contained unique antioxidant activity proteins, whereas many inflammation-related proteins and complement cascade activators were predominantly expressed in the fovea and macula regions sampled. One highlight was complement factor H (CFH). Certain CFH gene mutations can accelerate the development of AMD, and the study protein expression map revealed that CFH is most abundant in the fovea – the authors suggest that monitoring CFH expression in that region might act a marker of AMD disease status in certain experimental models.

“This molecular map now gives us clues why certain areas of the choroid are more sensitive to certain diseases, as well as where to target therapies and why,” explained Mahajan. “Before this, we just didn’t know what was where. Now you can see all those differences that you couldn’t see before.”

Previous studies have compared the abundance of single proteins in the fovea, macula, and periphery. The UI choroid-RPE map corroborates findings from these studies, but has also identified a treasure-trove of thousands more proteins that may be involved in vision loss. Mahajan likens it to a leap from the first topological drawings of a landscape to the detailed satellite images we have now.

Receive content, products, events as well as relevant industry updates from The Ophthalmologist and its sponsors.

When you click “Subscribe” we will email you a link, which you must click to verify the email address above and activate your subscription. If you do not receive this email, please contact us at [email protected].
If you wish to unsubscribe, you can update your preferences at any point.

  1. J.M. Skeie, V.B. Mahajan, “Proteomic Landscape of the Human Choroid-Retinal Pigment Epithelial Complex”, JAMA Ophthalmol. (2014) Epub ahead of print. doi: 10.1001/jamaophthalmol.2014.2065.
About the Author
Mark Hillen

I spent seven years as a medical writer, writing primary and review manuscripts, congress presentations and marketing materials for numerous – and mostly German – pharmaceutical companies. Prior to my adventures in medical communications, I was a Wellcome Trust PhD student at the University of Edinburgh.

Related Product Profiles
Uncover the Unique DNA of SPECTRALIS®

| Contributed by Heidelberg Engineering

Subspecialties Retina
ForeseeHome® – remote monitoring to help detect wet AMD earlier and improve outcomes

| Contributed by Notal Vision

Product Profiles

Access our product directory to see the latest products and services from our industry partners

Here
Register to The Ophthalmologist

Register to access our FREE online portfolio, request the magazine in print and manage your preferences.

You will benefit from:
  • Unlimited access to ALL articles
  • News, interviews & opinions from leading industry experts
  • Receive print (and PDF) copies of The Ophthalmologist magazine

Register

Disclaimer

The Ophthalmologist website is intended solely for the eyes of healthcare professionals. Please confirm below: