Optical coherence tomography (OCT) has so revolutionized the diagnosis and management of age-related macular degeneration (AMD) that it is now not only standard of care but also the foundation of personalized care for our patients.

Per our current diagnostic paradigm, we rely on OCT to detect and measure intraretinal and subretinal fluid and pigment epithelial detachments, i.e., all the markers of active choroidal neovascularization (CNV). OCT data informs treatment strategies and response to medications. It’s my firm opinion that the OCT-guided approach has led to earlier detection and better outcomes. Furthermore, as we choose from among an increasing array of anti-VEGF medication options and adopt today’s treatment protocols—primarily treat and extend—OCT allows us to evaluate the aggressiveness of each patient’s CNV, which guides us to more precise, personalized treatment plans.

What treatment interval we set, and when and by how much we can extend it, are questions we can only fully answer with OCT.

OCT IN PRACTICE

In my practice, ensuring I’m using this crucial technology to its fullest potential for the benefit of my patients means adhering to the following practices.

• OCT in both eyes, every visit. I order bilateral OCT scans at every visit for all AMD patients I’m monitoring, which are those with higher-risk dry AMD and those with CNV in at least one eye. This includes “injection-only” visits. This allows me to monitor incremental response to treatment and pick up any fellow-eye changes as soon as possible. I’m amazed by the number of patients I’m following who develop fellow-eye CNV early in the middle of a series of injections. For me, the goal is to find and treat any new or recurring lesions before symptom manifestation.
• Complete image review. It’s ideal to look at every slice that composes the OCT macular cube scan so that the entire macula is evaluated. Doing so commonly reveals lesions that are out of the central subfield, and which wouldn’t have been seen if only one or two cross-sections through the macula were viewed. Being aware of these lesions allows me to treat them before they extend into the fovea and cause vision loss.
  In today’s era of anti-VEGF therapy, I believe it’s substandard to view a printout of just one slice through the macula when evaluating a patient, although resources can sometimes dictate that. Also, OCT elevation maps often don’t pick up small changes that should be addressed.
• Treat until the macula is dry. In AMD, good visual acuity over time is an end goal. Tactically, complete resolution of fluid in the macula is most important for dictating my treatment plans. The expanding anti-VEGF medication armamentarium is making complete resolution more possible than ever. Some retina specialists may consider some amount of subretinal fluid to be acceptable and not detrimental to a patient’s current or future vision, but I only feel comfortable when the macula is dry, which is wholly guided by OCT.
• Use OCT to engage patients in their care. OCT is an amazing patient education tool. I show my patients images at every visit. It helps them to understand their condition and goes a long way toward convincing them they need treatment when they do. This is increasingly important as we follow the evidence that leads us toward recommending treatment earlier, often before patients are aware of any symptoms. Walking patients through their OCT images illustrates for them improvement over time, which eases their minds and nurtures trust, and usually makes them more amenable to injections.
• Use image management and analysis tools. By now the majority of retina specialists are using OCT imaging software to review images, which typically includes the ability to register images from two different timepoints. However, more powerful tools have emerged. For example, the platform from Zeiss includes Forum, which enables access to exam data from all DICOM-compliant diagnostic instruments in one place. The platform also includes Retina Workplace, which goes well beyond being an image repository to being a retinal data center, providing insights that can be used to improve patient care. Workplace automatically analyzes and overlays imaging data in new ways. For instance, aspects of OCT images, such as central subfield thickness, are graphed over time for at-a-glance trend recognition. Visit history charts allow visualization of the efficacy of different treatments over time. Images can be dragged and dropped to quickly compare OCT raster scans and cubes, fluorescein angiography and fundus images across multiple visits, and injection data can be annotated and integrated with OCT data.
• Get familiar with OCTA. As the newest application of OCT technology, OCT angiography (OCTA) has not taken root yet as the standard of care, but its potential importance in AMD diagnosis and management is large. OCTA gives us the ability to visualize and monitor the retina blood vessels directly, watching for changes that could be happening independently of changes in our surrogate markers of disease activity. As such it will add new, valuable information to our decision-making. The more we educate ourselves on a daily basis on the use case for OCTA, the better off we’ll be in the future.

In the meantime, by capturing structural OCT data frequently and making use of cutting-edge image management and analytics tools, we can make the most informed and personalized treatment decisions for each of our AMD patients.

Dr. Karth is a vitreoretinal surgeon with Oregon Eye Consultants, in Eugene, OR.