How has the introduction of spectral-domain technology changed how ophthalmologists use OCT?

It has already changed our practice

Seenu M. Hariprasad

Spectral-domain OCT is already improving how we view the retina because the information we are getting is better. For one, the vitreomacular interface is so much better defined compared with time-domain OCT technology.

One of the clearest ways that spectral-domain has changed vitreoretinal clinical practice is in the management of diseases such as exudative AMD. I think we were missing intraretinal fluid with Stratus OCT and we were undertreating patients who we thought were dry based on this older technology. With spectral-domain OCT, we are picking up small slivers of fluid or pockets of macular edema so we can more accurately “treat and extend” with anti-VEGF therapy.

I am happy to see that anterior segment surgeons are more frequently using OCT, especially in the context of modern-day cataract surgery. I don’t think you should go into cataract surgery without clearly defining the anatomy of the macula or diagnosing macular pathology. A cataract surgeon needs to have an accurate assessment of the macula to advise that patient and try to predict postoperative outcome. Nothing will replace a good macular exam; however, OCT can be used to document or confirm findings.

We need normative databases to see how measurements compare from one device to another. Many of our seminal clinical trials — MARINA and ANCHOR, for instance — were done with Stratus OCT. Now we have spectral-domain OCT, which is clearly superior. We want to use them for future studies, but how will we compare results to past studies? We really need to figure how we are going to compare OCT data from new trials to those done even as recently as 5 years ago.

Seenu M. Hariprasad, MD, is Associate Professor of Ophthalmology and Chief, Vitreoretinal Service, at the University of Chicago, Department of Surgery.

Easier image acquisition facilitates patient flow

Andrew A. Moshfeghi

Spectral-domain OCT has allowed for more precise evaluation of the macula and the vitreoretinal interface. But it also allows for easier image acquisition. It is faster than previous-generation time-domain devices, and so it is changing practice flow positively.

It appears that more general ophthalmologists are now using OCT devices. It seems that before, there were a few vanguard practices that had them, but now after seven or eight iterations of spectral-domain OCT available at competitive price points, a lot of general and multispecialty practices are acquiring OCT devices, and many are getting spectral-domain.

We are referred a number of unhappy cataract patients after surgery. These are people who went into surgery thinking they would be 20/20, only to be diagnosed afterward with a retinal or macular disorder. The two most common findings are epiretinal membrane — or some sort of vitreoretinal traction — and AMD. So either the cataract precluded adequate visualization of the macula before cataract surgery, the ophthalmologist did not see it or the ophthalmologist did not do an OCT before cataract surgery, which would save them a lot of grief and heartache afterward. Careful preoperative evaluation is especially important for the patient who is paying out of pocket for premium lenses on top of their cataract surgery.

Right now, many of the spectral-domain devices have good interactive software that can be used to view OCT images on workstations throughout the clinic. But it is still a bit cumbersome to use. As we move into this era of electronic medical records, it should be more user-friendly, and perhaps even presented in a standardized DICOM format similar to what radiologists use.

There is novel research and development of OCT hardware that is very interesting. For instance, work is being done that could transfer OCT images directly to the microscope viewfinder that would be helpful so that the OCT image will register with what you are already looking at. If those kinds of innovations come to reality, we could be looking at a future of OCT-guided vitrectomy and OCT-guided epiretinal membrane peeling.

Andrew A. Moshfeghi, MD, MBA, is Assistant Professor of Ophthalmology at University of Miami Miller School of Medicine.