Ultra-widefield angiography gaining ground for detecting retinal vascular pathology

The technology provides more clinical information, which can aid patient classification and treatment planning.

Improved retinal visualization may influence treatment of patients with diabetic retinopathy, according to a study.

Compared with conventional seven standard fields (7SF) stereoscopic imaging, the Optos Optomap 200Tx imaging system allowed for significantly more clinical information to be obtained in a retrospective study of 218 eyes of 188 patients with diabetes. More clinical information translates into more accurate patient classification, as well as better treatment and follow-up plans.

The relatively newer technology combines an ellipsoid mirror with a scanning laser ophthalmoscope.

“We have been looking mainly at the posterior retina for many, many years,” study co-author Szilárd Kiss, MD, told OSN Retina. “However, it is turning out that there is more to life than just what we see in the posterior retina, especially for diseases like diabetes.”

Over the past 4 years, Dr. Kiss has used the ultra-widefield imaging system as a diagnostic tool in more than 1,000 patients.

“We use this machine exclusively for our angiography, especially in the diabetic setting,” he said.

Study findings

The study, published in Retina, found that 3.2 times more total retinal surface area could be evaluated with ultra-widefield fluorescein angiography than with 7SF. The disease burden was also magnified, with 3.9 times more nonperfusion, 1.9 times more neovascularization and 3.8 times more panretinal photocoagulation detected.

“In 10% of the eyes, we went from having absolutely no signs of diabetic retinopathy detected with conventional imaging to diabetic retinopathy that may require treatment and close follow-up detected with the Optos ultra-widefield imaging,” Dr. Kiss said.

The study results were somewhat surprising to the authors, he noted.

“There is a lot of pathology that goes on beyond what we have been conventionally imaging, such as areas of ischemia and areas of neovascularization,” Dr. Kiss said. “For someone with proliferative disease, you will treat with laser or even anti-VEGF injections.”

A patient with no detected proliferative disease will be sent home and told to return for a repeated evaluation many months or even years later.

Adoption of new technology

Dr. Kiss estimated that fewer than 20% of clinicians are currently using ultra-widefield imaging and angiography.

“As more and more studies demonstrate the important role of the peripheral retina, I think the technology will become more widely accepted,” he said. “In the next several years, I can envision this becoming the standard imaging modality. Ultimately, hopefully, there will be improved patient outcomes that will follow.”

The ultra-widefield imaging system is easier to use than conventional imaging because it does not entail steering the eye, according to Dr. Kiss.

“Patients no longer have to look in a certain direction. They can simply look straight ahead. There is just one image taken vs. seven images put together with conventional imaging. Overall, it is easier for both the technician and patient,” he said.

The retrospective nature of the study was a positive aspect, Dr. Kiss noted, because the images were not obtained with the intention of being included in a study.

“Often, people conduct prospective studies with these spectacular images, and they make sure the technician achieves the best image quality possible. In contrast, we used images that one would take in everyday practice,” he said.

A follow-up study that was published in the British Journal of Ophthalmology attempted to quantify the disease burden in addition to considering pathogenesis.

“In that paper, we showed that peripheral areas of ischemia correlate with diabetic macular edema,” Dr. Kiss said. – by Bob Kronemyer

References:

Wessel, MM, Aaker GD, Parlitsis G, Cho M, D’Amico DJ, Kiss S. Ultra-wide-field angiography improves the detection and classification of diabetic retinopathy. Retina. 2012;32(4):785-791.
Wessel MM, Nair N, Aaker GD, Ehrlich JR, D’Amico DJ, Kiss S. Peripheral retinal ischaemia, as evaluated by ultra-widefield fluorescein angiography, is associated with diabetic macular oedema. Br J Ophthalmol. 2012;96(5):694-698.

For more information:

Szilárd Kiss, MD, can be reached at Department of Ophthalmology, Weill Cornell Medical College, 1305 York Avenue, 11th Floor, New York, NY 10021; 646-962-2217; email: szk7001@med.cornell.edu.
Disclosure: Dr. Kiss is a paid consultant to Optos.