Infrared imaging is an aid for patient education about GA

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In sister publication Ophthalmology Times’ Case of the Quarter series, Katherine Talcott, MD, shares 2 cases of geographic atrophy (GA) and highlights the importance of multimodal imaging to diagnose and monitor GA progression. Talcott is an assistant professor of ophthalmology at the Cole Eye Institute at Cleveland Clinic Lerner College of Medicine in Ohio.

Case 1: Visual decline

A 64-year-old woman was referred by her optometrist with the complaint of worsening vision over the previous 6 months, more so in the left eye. She also reported blobs in her vision. The patient had age-related macular degeneration (AMD) and had been followed by the optometrist for the past 5 years. She took AREDS vitamins (Bausch + Lomb) and monitored her vision using the Amsler grid. Her family history was positive for AMD; her father and uncles developed AMD in their 70s. The patient resided in a rural area and traveled
2.5 hours to her examinations.

The visual acuities (VAs) in the right and left eyes, respectively, were 20/20 and 20/25. The color fundus photographs showed areas of GA, which were responsible for her current visual difficulties. The optical coherence tomography (OCT) images ruled out intraretinal/subretinal fluid in both eyes. However, according to Talcott, there was diffuse retinal pigment epithelium (RPE) and ellipsoidal zone loss.

Talcott mentions the usefulness of the infrared images. “These images highlight the areas of atrophy very well,” she says. “These areas are not as well defined on the color fundus photographs.”

Autofluorescence images of the retina are also very helpful to show patients why they are having visual difficulties. This patient had significant areas of hypoautofluorescence in both eyes. Autofluorescence imaging is also helpful to determine the patient’s candidacy for treatment or research studies, Talcott explains.

The presence of hyperautofluorescence at the edge of the atrophic areas may suggest that the disease is rapidly progressive.

Each of the imaging modalities in this case conveyed different information about the treatments needed. “OCT is critical to ascertain that the patient does not have exudative changes, and [it] can assess for atrophy,” she says.

Moreover, Talcott explains the infrared images obtained at baseline can help pinpoint any changes in the eye that occur over time and the disease pattern. “[Although] OCT is the mainstay of the evaluation, the infrared images can help patients understand what is happening in the retina,” she comments.

Talcott also emphasizes the importance of regular monitoring of patients. Before treatment starts, she evaluates patients with GA every 6 months to rule out exudative changes. She also points out the scheduling of examinations based on the patient’s circumstances; in this case, the patient can be seen by a local optometrist to help cut down on travel to examinations far from home.

Case 2: Low-vision options

A 76-year-old woman with GA had progressive worsening of vision in her eye that interfered with reading and sewing. The right and left eye VAs were 20/25 and counting fingers, respectively, and had been stable for 3 years. The patient had a history of a macular macrovessel in the right eye and a choroidal hemangioma in the left eye.

The infrared images showed the macrovessel and areas of atrophy in the right eye corresponding to areas of loss of RPE and outer retinal changes on the OCT images. Diffuse areas of outer retinal loss were seen in the left eye. Multimodal imaging provided a better understanding of why the patient was having increasing difficulty seeing. A review of past infrared images showed that the atrophic areas had been enlarging and coalescing over the past year. The images from 3 years previously showed almost no atrophy.

Following a discussion about future visual problems, Talcott referred the patient to a local optometrist who specialized in low vision and visual rehabilitation for assessment of functional deficits and any potential interventional options to improve functionality.

An important takeaway from this case is the ability to look at the past images, which can provide a sense of the tempo of the disease regarding how fast changes are occurring and to determine whether there is anything else occurring in the retina.

Talcott also emphasizes the importance of the optometric component of this patient’s care. “There are certain things that retina specialists have difficulty offering a patient, such as a refraction, using certain low-vision tools, or evaluations for certain local services. A partnership to help with such patients is critical,” she concludes.