In the first episode of a three-part series, Damon Dierker, OD, FAAO, director of optometric services at Eye Surgeons of Indiana, and Ankur Shah, MD, FASRS, a retina specialist at Retina Partners Midwest at Midwest Eye Institute in Indianapolis, discuss how optometrists and general ophthalmologists can develop practical referral algorithms for patients with geographic atrophy (GA) and collaborate effectively with retina specialists.
Impact of New Treatments
Optometrists and general ophthalmologists are often the first to detect geographic atrophy (GA). The recent FDA approvals of treatments for GA have shifted the approach. In the past, patients were monitored every 6 to 12 months, with no treatment available other than vitamins, which was challenging. Now, while the new treatments provide advantages, they require updates to protocols for patient intake, imaging, consultations, and referrals.
Imaging Protocols
Identifying geographic atrophy (GA) early is crucial, as its symptoms become more apparent as the disease progresses. Dr. Dierker often employs a "wellness OCT" as a screening tool for new patients when there are concerns about retinal disease based on their medical history or age. Optical Coherence Tomography (OCT) provides scans of the macula, outer retina, and the ganglion cell complex (GCC).
In a referral practice setting, patients typically arrive because a problem has already been identified, and the referring optometrist is concerned about progression or unsure whether a retina specialist is needed.
Optical Coherence Tomograph (OCT)
Dr. Dierker critically examines OCT imaging, focusing specifically on the outer retina. Instead of just reviewing the printed reports for patients with significant age-related macular degeneration (AMD), large drusen, or changes in the retinal pigment epithelium (RPE), he scrolls through scans and searches for indicators of incomplete retinal atrophy, hyperreflective foci, and reticular pseudodrusen, which are important biomarkers for disease progression. OCT findings can often precede GA and serve as indicators of the risk of conversion to wet AMD. This adds an additional 15-30 seconds to the evaluation but is helpful identifying features that will modify monitoring intensity and patient education.
Dr. Shah acknowledges that subtle findings may be overlooked on the color printout, and evidence indicates that ellipsoid zone and photoreceptor loss occur before RPE loss. Analyzing the outer retina and RPE by scrolling through the OCT is crucial.
Autofluorescence (AF)
AF has been the standard method used in clinical trials. Dr. Dierker employs it at baseline for AMD patients and as needed thereafter . He notes that AF is particularly helpful for identifying a high risk of progression, especially when hyperautofluorescent borders are observed, which may prompt a referral for treatment.
More recently, Dr. Dierker has been placing greater emphasis on OCT features and the en face infrared/SLO images. He finds these methods more effective for detecting and determining the size and location of early GA lesions than AF alone.
Dr. Shah observes that Optical Coherence Tomography Angiography (OCTA) has decreased the necessity for fluorescein angiography (FA) in cases of AMD. When used alongside OCT, OCTA provides essential information for both wet and dry forms of AMD. This combination is particularly beneficial when there are concerns about early exudative activity beneath a Pigment Epithelial Detachment (PED).
Patient Education and Referral
Dr. Dierker uses color fundus photos and AF to overlay current images on historical images, demonstrating patient progression more easily than with OCT. However, his decision-making is primarily based on the OCT results.
He informs the patient about the structural changes he has observed, specifically noting thinning at the back of the eye, which could lead to vision problems in the future.
Dr. Dierker explains that new injection therapies are now available, and if high-risk features exist or the condition worsens, he will discuss the possibility of referring the patient to a retina specialist, particularly for those who are on the verge of needing treatment.
For very early, small lesions located far from the fovea, where immediate intervention isn't necessary, he assures the patient that they will continue to monitor the situation every 4 to 6 months. He will discuss potential interventions if progression later threatens their vision.
Dr. Shah comments that thorough patient education makes the retina specialist's job easier and more efficient.
Part 2 will focus on specific referral patterns and algorithms.
