Increasing evidence points to the fact that patients with neovascular AMD have a better long-term visual prognosis when treatment with anti-VEGF therapy is initiated soon after or just before development of choroidal neovascularization.1-4 Inherent to that paradigm is early diagnosis. In the following, we present two perspectives on how the entire eye care team can work together to better utilize available imaging technologies to help patients achieve their treatment goals.
Imaging is Crucial for Diagnosing and Following AMD
By Mark R. Barakat, MD
Our clinic regularly provides education about AMD to our local optometric network and other eye care providers, as well as to primary care providers and internists. Given the nature of AMD and how it is managed, a good portion of our education efforts involves discussing the role of imaging.
When it comes to diagnosing and following AMD, we look for changes in imaging features, so obtaining baseline imaging, where feasible, is extremely helpful. OCT and fundus photography are currently used most often in practices. These two modalities form the core of managing AMD, supported by the clinical examination, with findings from all of the above directing the need for more specialized imaging.
OCT findings are crucial for making a diagnosis and for staging the disease (Figure). It is imperative to look for these three findings when examining an OCT:
1. Drusen, appearing as deformations or thickening in the hyperreflective band of the retinal pigment epithelium (RPE), particularly in the Bruch membrane, are perhaps the earliest recognizable sign of AMD. Hard drusen (small hyaline deposits with delimited margins) are considered lower risk than soft drusen (hypo- or
hyperpigmented findings), which are precursors of AMD. Risk of progression varies according to the number,
size, and confluence of the drusen.
2. Continual atrophy of the RPE causes thinning of the retina, which allows the OCT laser to penetrate to
greater depth, thereby depicting a hyperreflective signal from the choroid. Retinal maps may be useful in
confirming areas of thinning and to quantify volume loss, especially in tracking change in these values over
time and in response to treatment.
3. Active neovascular membranes can be identified and characterized on OCT. They appear as
hyperreflective areas on or adjacent to the RPE, almost always in association with retinal edema. Other
hallmark findings associated with a neovascular membrane include RPE detachment (which may be
associated with intraretinal migration of the RPE cells), neurosensorial detachment, intraretinal fluid (dense
particles may be present), and subretinal hemorrhage. Importantly, not all cases of AMD progress to choroidal
Figure. Sample images depicting OCT changes that may be identified in a patient with AMD: atrophy (A), geographic atrophy (B), pigment epithelial detachment (C), sub- and intraretinal fluid (D), and subretinal fluid (E).
The function of any imaging in retinal practice is to support and not replace decision-making. Thus, image findings are used to confirm clinical impressions and to direct follow-up. For example, drusen and RPE changes detected on macular exam are highly suggestive of AMD, but hemorrhages may require angiography to narrow down the differential. Conversely, in many cases, fundus photography is superior to the clinical examination for identifying drusen and may be used to confirm physical findings. Likewise, fundus autofluorescence helps identify the edges of atrophy and its activity, which is easy to overlook on macular exam.
THERE IS NO SUCH THING
AS “TOO EARLY” TO REFER
One of the most frequent topics to come up in our interactions with referral sources is when to refer and how to prepare patients before coming to our clinic.
Take these four factors into consideration when determining rate of referral and patient preparation:
1. Anti-VEGF therapy is highly effective at helping maintain vision and stabilize the disease; however, the rate
of individuals gaining three lines of vision is only about 30 to 40% with monthly treatment.5-7
2. Ultimately, that suggests that earlier treatment is better, and as an eye care community, we have done a tremendous job at early recognition to give us a chance to start an intervention when it can save vision.
3. The best-case scenario is that we may find stable disease that does not require treatment; but even in that case, the patient’s concern has been addressed.
4. Gauge how much information the patient can absorb at the time. There is an art to reading a patient and determining how many details to share. It may not be a good idea to overwhelm someone with safety and efficacy data on anti-VEGF therapy; at the same time, if patients hear about the potential for treatment before coming to our clinic, our education and counseling is much more effective.
5. At a minimum, we encourage referral sources to introduce AREDS vitamins and to recommend the use of the Amsler grid. The former will help slow progression, while the latter helps detect vision changes suggestive of progression—and both help us achieve the goal of early identification and treatment to help save vision.
The Role Of Optometry in Caring for Patients With AMD Continues to Expand
By Nadia Virani, OD
The increasing number of patients affected by AMD, coupled with the growing role of optometry as primary eye care providers, suggests a need for optometrists to become proficient in recognizing signs of the disease and knowing when to refer for specialty care. While not all optometrists will have interest in managing retinal diseases, at a minimum, we should know how to make the diagnosis, how to follow these patients over time, how to counsel patients appropriately, and when to direct patients to specialty care. See Diagnosis and Monitoring sidebar for helpful imaging examples of what to look for in patients with AMD.
Diagnosis and Monitoring
Imaging is additive to the physical examination and patient history in building an overall clinical impression regarding the health of the retina, whether change has occurred, and what the prognosis is for future progression (see Figures 1 through 5 for examples).
Figure 1. Heidelberg Engineering OCT of foveal drusen with subretinal fluid—requires intervention with retinal treatment.
Figure 2. Cirrus OCT of subfoveal drusen (left). Cirrus OCT showing subfoveal drusenoid pigment epithelial defect (right).
Figure 3. Cirrus OCT displaying macular thickness cube of the right and left maculae. The top images show subfoveal drusen. The bottom images show subfoveal drusenoid pigment epithelial defect.
Figure 4. Bilateral Heidelberg Engineering OCT findings. In the right eye (left image), subretinal fluid with mild foveal drusen requires retinal treatment. In the left eye (right image), the macula displays normal variation, with no treatment required.
Figure 5. Heidelberg Engineering OCT displaying punctate drusen.
Monitoring for vision changes between office visits is increasingly important, particularly in light of data showing better long-term outcomes when treatment is initiated when VA is 20/40 or greater.8 We make regular use of the Amsler grid, although more recently, a number of smartphone apps that have a similar function have been released.
Optometrists Are a
Vital Source of Education
Because optometrists have a number of interactions with AMD patients, they have an important role in providing education.
In our clinic, there are a few key messages we want to impart to patients with AMD:
1. What is AMD? AMD is essentially a buildup of proteins and lipids under the retina that may threaten
2. Will you require treatment? About 85% of patients have dry AMD,9 and only a certain percentage of
those patients progress to advanced stages that threaten vision and require treatment.
3. How can you delay or prevent disease progression? There are things patients can do to lower the risk
of progression, including consuming leafy greens, avoiding tobacco use, and being diligent about
4. Take the whole body into consideration. Systemic health also matters. Blood pressure, cholesterol
levels, and blood sugar levels can affect progression.
5. Exceptional advances have been made in treating AMD, if that becomes necessary; we introduce the
topic in the clinic, but don’t get into specifics of treatment, because the treating clinician will make the ultimate determination whether treatment is required and how it will be performed.
6. Low vision services are an option to help patients cope with loss of acuity and function.
The internet can be a wonderful tool for patient research, but in our experience, patients get more relevant information when the eye care team sets the stage. Saying something to the effect of, “here is what you are going to read about, and it may be scary sounding, but that is what we are trying to prevent,” puts the patient at ease and lets him or her be more deliberate about the kind of information they are consuming.
Affecting early treatment in AMD is a matter of teamwork: directing patients to specialty care requires prompt recognition of early signs of the disease. More often than not, the diagnosis is made by a primary eye care specialist. Our patients are truly fortunate to be living in a time where treatment has advanced, where ongoing research offers the promise of new and potentially better therapeutic interventions, and where the increasingly collaborative model of eye care delivery has helped foster greater working relationships between specialties.
1. Wong TY, Chakravarthy U, Klein R, et al. The natural history and prognosis of neovascular age-related macular degeneration: a systematic review of the literature and meta-analysis. Ophthalmology. 2008;115(1):116-126.
2. Ying GS, Huang J, Maguire MG, et al. Baseline predictors for one-year visual outcomes with ranibizumab or bevacizumab for neovascular age-related macular degeneration. Ophthalmology. 2013;120(1):122-129.
3. Maguire MG, Martin DF, Ying GS, et al. Five-year outcomes with anti-vascular endothelial growth factor treatment of neovascular age-related macular degeneration: the comparison of age-related macular degeneration treatments trials. Ophthalmology. 2016;123(8):1751-1761.
4. Rasmussen A, Brandi S, Fuchs J, et al. Visual outcomes in relation to time to treatment in neovascular age-related macular degeneration. Acta Ophthalmol. 2015;93(7):616-620.
5. Rosenfeld PJ, Brown DM, Heier JS, et al; MARINA Study Group. Ranibizumab for neovascular age-related macular degeneration. N Engl J Med. 2006;355(14):1419-1431.
6. Brown DM, Kaiser PK, Michels M, et al ANCHOR Study Group. Ranibizumab versus verteporfin for neovascular age-related macular degeneration. N Engl J Med. 2006 Oct 5;355(14):1432-1444.
7. Heier JS, Brown DM, Chong V, et al, VIEW 1 and VIEW 2 Study Groups. Intravitreal aflibercept (VEGF trap-eye) in wet age-related macular degeneration. Ophthalmology. 2012;119(12):2537-2348.
8. Lee AY, Lee CS, Butt T, et al. UK AMD EMR Users Group Report V: benefits of initiating ranibizumab therapy for neovascular AMD in eyes with vision better than 6/12. The British journal of ophthalmology. 2015;99(8):1045-1050.
9. Jager RD, Mieler WF, Miller JW. Age-related macular degeneration. N Engl J Med. 2008;358(24):2606-2617.