Wide-field imaging: ‘Big picture’ for quick, accurate diagnosis
Wide-field imaging has become an integral tool in the diagnosis and management of patients with retinal disease.
Take-home: Wide-field imaging has become an integral tool in the diagnosis and management of patients with retinal disease.
Reviewed by Srinivas R. Sadda, MD
Dr. SaddaLos Angeles–Wide-field imaging has become an important technology in the clinical practice that aids in disease characterization, documentation, and diagnosis and management.
Wide-angle imaging, which refers to visualization of the peripheral retina, must visualize at least 100º of the retina to be considered a wide-angle view. Some non-contact, wide-field imaging modalities capable of this are the Optos 200 Tx and the Heidelberg Spectralis instruments.
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“What is especially exciting is that the latest generation of technology has multi-modal capability on the wide-field platform that includes indocyanine green angiography in addition to color, red-free, autofluorescence, and fluorescein angiography images,” according to Srinivas Sadda, MD.
Importance of wide-field imaging
“Wide-field imaging matters because there is a lot of important information out there,” Dr. Sadda stated. That information might be overlooked without wide-field capabilities.
Dr. Sadda, president and CSO, Stephen J. Ryan–Arnold and Mabel Beckman Endowed Chair Professor of Ophthalmology, Doheny Eye Institute, University of California–Los Angeles, demonstrated this by citing findings reported by Aiello and colleagues that patients with diabetes can have lesions that are predominantly outside of the seven standard fields (Ophthalmology 2013; 120: 2587-95).
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“They demonstrated that patients who had predominantly peripheral disease had a dramatically higher risk for progression to proliferative diabetic retinopathy,” Dr. Sadda said. Specifically, these patients had a 4.7 times higher risk.
This finding, he pointed out, calls into question how the disease should be staged in the future. “We can certainly envision a future in which we use wide-field imaging, automated lesion detection, and perhaps a more quantitative approach to staging the disease,” Dr. Sadda added.
While areas of nonperfusion in a number of retinal diseases are visible clearly on wide-field angiography, Dr. Sadda is excited about the findings of clinical trials that will investigate peripheral nonperfusion. He and his colleagues have studied this in retinal vein occlusion and found that more peripheral nonperfusion seems to be associated with more macular edema.
Dr. Sadda mentioned a caveat in relation to peripheral nonperfusion, which some of this is actually normal, according to a recent study he and his colleagues conducted in association with Michal Singer, MD. “In that study we were able to define the area of normal perfused retina as 962mm2,” Dr. Sadda reported.
Representative case
A 52-year-old woman with diabetes and a history of glaucoma presented with recent rapid reduction in her superior visual field as well as rubeosis. A new inferior hemiretinal vein occlusion was noted on examination and panretinal photocoagulation (PRP) of the inferior peripheral retina was planned.
(All images courtesy of Srinivas Sadda, MD)
Ultra-wide-field fluorescein angiography, however, demonstrated that the areas of non-perfusion extended further superiorly on the nasal side than one might have expected. As a result of this finding, the PRP laser was extended into the additional areas of superonasal non-perfusion.
(All images courtesy of Srinivas Sadda, MD)
Wide-field imaging patterns
Patterns on wide-field imaging can facilitate rapid diagnosis, Dr. Sadda pointed out.
In the case of a 25-year-old Caucasian woman with decreased peripheral vision bilaterally as the result of pigmented paravenous retinochoroidal atrophy, he showed on wide-field imaging the striking appearance of the fluorescence with the abnormalities along the retinal vasculature.
(All images courtesy of Srinivas Sadda, MD)
Another case was that of a 35-year-old Caucasian woman with retinal degeneration who had a markedly depigmented fundus. However, the autofluorescence was relatively unremarkable, according to Dr. Sadda.
(All images courtesy of Srinivas Sadda, MD)
“When combined with the finding that there was no foveal depression on computed tomography, we were able to diagnose ocular cutaneous albinism in this patient,” he said
(All images courtesy of Srinivas Sadda, MD)
Wide-field imaging without pupillary dilation
An important capability of wide-field imaging is that pupillary dilation is not needed in patients in whom dilation is difficult.
A 42-year-old patient was referred to the oculoplastics service for ptosis repair for a superior visual field problem. Images obtained through undilated pupils showed an abnormality in the inferior peripheral retina–i.e., a sectoral retinal degeneration that caused the visual field abnormality.
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“Wide-field imaging has become an integral tool in our clinical practice,” Dr. Sadda summarized. “It provides a more complete characterization of retinal diseases. The big picture that wide-field imaging affords ophthalmologists facilitates a more rapid and accurate diagnosis.”
(All images courtesy of Srinivas Sadda, MD)
Srinivas R. Sadda, MD
Dr. Sadda is a consultant to Allergan, Genentech, Regeneron, and Optos Inc., and Roche and has received research grant support from Allergan, Genentech, Carl Zeiss Meditec, and Optos. He also has received research instruments from Optos, Heidelberg Engineering, Nidek, Topcon, CenterVue, Tomey, and Carl Zeiss Meditec.
