Fluorescein angiography, OCT both useful technologies in retinal disease management

April 15, 2006

Miami?Is it time to retire fluorescein angiography in light of the commercial availability of optical coherence tomography (OCT)? Certainly not, because they are complementary technologies that are integral to the management and treatment of retinal diseases, explained Carmen A. Puliafito, MD, MBA.

Miami-Is it time to retire fluorescein angiography in light of the commercial availability of optical coherence tomography (OCT)? Certainly not, because they are complementary technologies that are integral to the management and treatment of retinal diseases, explained Carmen A. Puliafito, MD, MBA.

"Both fluorescein angiography and OCT are necessary. Advances in therapy and technology, however, have altered the relative importance of both technologies in everyday life," Dr. Puliafito stated.

The reason clinicians still need both, he explained, is that fluorescein angiography may not be sufficient to pinpoint the problem. In assessing the vitreoretinal interface, OCT is superior to fluorescein angiography. This was the case of a patient who presented with a cataract and some macular degeneration. One month later, the patient was examined for a visual disturbance with only fluorescein angiography. If OCT had been done, the macular hole could have been identified immediately, said Dr. Puliafito. He is the Kathleen and Stanley Glaser Professor of Ophthalmology, Miller School of Medicine, University of Miami, and chair, Bascom Palmer Eye Institute, Miami.

A third patient with a visual acuity disturbance in the left eye was about to undergo a cataract extraction. The patient had focal vitreomacular traction, which was well documented on spectral OCT maps, which Dr. Puliafito demonstrated.

"The unique capabilities of fluorescein angiography are topographic localization, assessment of retinal capillary perfusion, and the potential usefulness of wide-field angiography," he said. Dr. Puliafito demonstrated how valuable fluorescein angiography is in showing the localization of neovascularization on the disc and elsewhere. A wide-field angiogram of a patient showed the evolution of the neovascularization and the extensive capillary nonperfusion. "The midperiphery remains an unknown in retinal vascular disease, and wide-field fluorescein angiography may provide better visualization," he said.

Fluorescein angiography, he pointed out, is also very effective in, for example, a patient with poor vision and central vein occlusion who was treated with intravitreal triamcinolone. The OCT showed thinning. "In this case, the OCT is not the full story in explaining visual acuity. The preoperative fluorescein angiogram of central retinal vein occlusion showed a suggestion of capillary nonperfusion. In this setting, in which the retinal circulation is involved, fluorescein angiography is indispensable," Dr. Puliafito said.

The management of choroidal neovascularization is an area that is changing rapidly. "I believe that fluorescein angiography should always be used in making the initial diagnosis," he said.

OCT advantages

"However, with the advent of anti-vascular endothelial growth factor (VEGF) therapy, angiographic subtype classification is declining in importance and most treatment decisions can be made using OCT. OCT shows why patients do not see well because of macular edema, subretinal fluid, and pigment epithelial detachment (PED)," he commented.

At Bascom Palmer, Dr. Puliafito and colleagues use visual acuity measurement and OCT for longitudinal follow-up for patients taking anti-VEGF therapy. He provided an example of a patient who appeared to have occult disease, but the OCT revealed retinal angiomatous proliferation. When treated with an anti-VEGF agent, the PED collapsed, but later recurred along with edema. Re-treatment was followed by restoration of the normal anatomy, improved vision, but then recurrence 2 months later. "We use OCT interactively," he said.

"OCT is continuing to develop and improve. We can obtain 30,000 A scans from a scan of a 6-mm box. The technology shows clinically relevant anatomy, it is quantitative, and it will guide retinal pharmacology therapy," Dr. Puliafito said. "At Bascom Palmer, we have a strategy to develop three-dimensional maps that can be used in a realistic way. This technology provides a much more precise story of the clinical picture. The images are perfectly registered and provide precise measurements of the retinal structures. Volume measurements are also available and can be easily obtained; these values can be continually used to monitor the patient's clinical situation. We are going to use these measurements to help make treatment decisions.