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SPOTLIGHT ON TECHNOLOGY & TECHNIQUE

This fundus scanner is all about contrasting disease

The Eidon AF’s automated, built-in autofluorescence feature identifies and monitors retinal conditions.

When using an imaging device to help diagnose retinal disease or identify disease progression in ophthalmology, a factor is contrast, says SriniVas R. Sadda, MD, president and chief scientific officer, Doheny Eye Institute, University of California, Los Angeles.

CenterVue’s Eidon AF offers a built-in, automated fundus autofluorescence (AF) feature that improves accurate identification of disease characteristics in a noninvasive way.

CLEARING UP QUESTIONS

K. Bailey Freund MD, of Vitreous Retinal Macular Consultants of New York and clinical professor, Department of Ophthalmology, New York University School of Medicine, New York, notes the Eidon’s AF capability provides clinicians information with respect to disease duration and differentiation between disease states.

“In central serous chorioretinopathy, it gives you a sense of how chronic the disease has been and whether there were prior episodes of serous detachment,” Dr. Freund says. “It may identify areas of disease outside of the central macula that you may not have realized were present. In older patients, AF may help clarify whether subretinal fluid is due to CSC or to AMD.”

FEATURES

The Eidon AF system, an addition to the Eidon platform launched in September 2016, captures a 60-degree AF image with a single flash of light. This allows for high-fidelity images without the need for image averaging. Also, its mosaic function offers a panoramic, 110 degree view of the retina.

The Eidon AF features new automated stereo imaging and enhanced review capabilities. It’s remote viewer also has a registered flicker function to help monitor the slightest changes in retinal characteristics, says Dave MacLellan, CenterVue’s marketing director.

MANY USES

For AMD, the Eidon AF can track geographic atrophy and the loss of retina cells, and be used to detect inflammatory macular diseases such as white dot syndromes. “[It] can be useful in identifying areas where there has been disruption of the outer retina, which often appears bright in conditions such as multiple evanescent white dot syndrome or acute zonal occult outer retinopathy,” Dr. Freund says.

The fundus AF is designed to help differentiate inherited retinal diseases that have certain characteristic patterns like Stargardt disease, Best disease, pattern dystrophies and retinitis pigmentosa.

Further, better imaging of inherited retinal diseases has implications for genetic counseling, ordering genetic tests, and, ultimately, identifying possible gene therapy trial candidates according to Dr. Freund.

USER- AND PATIENT-FRIENDLY

The Eidon AF’s capabilities and user-friendly design make it a good fit for ophthalmology practices, says Dr. Sadda. “You do not need a [specially trained] person to acquire the images. It means a reduction in practice expenses.”

Dr. Freund echoes Dr. Sadda’s sentiment, saying lots of instruction is not needed for superior photos. Once acquired, the sharp images and contrast of AF can be a useful “educational tool” for patients and improve communication with the clinician.

“If you show a patient with AMD-related geographic atrophy their OCT images, it is hard for them to understand what all the different layers mean,” says Dr. Freund. “With [Eidon] AF, it is very clear to clinicians and patients. If there is a large, dark area in the central macula that represents atrophy which is responsible for their loss of vision, it is clear which area is missing vision. It is one of the best ways to explain to a patient why he or she is having symptoms. You can also show them progression when that black area is getting larger.”

The technology’s confocal nature offers advantages such as the enhanced contrast, Dr. Freund notes. “The excitation light source is not as bright as some of the other AF systems, so patients may experience less transient photo bleaching following image acquisition.”

A BONUS FOR RESEARCHERS

For Dr. Sadda, the technology’s shorter wavelength as compared to other AF technologies creates an opportunity to study additional molecules.

The advantage of the 450-nm wavelength is that it may excite other molecules, not just lipofuscin, a fluorescent pigment that accumulates in the RPE. Other AF technologies typically use a 488-nm or longer wavelength.

CONCLUSION

Eidon’s new AF capability allows ophthalmologists to see the progression of conditions like AMD and other hereditary macular dystrophies.

It is “a significant improvement in imaging for our ophthalmology customers,” says Mr. MacLellan. OM

Dr. Sadda is a consultant to, and receives research instruments from, CenterVue.