As of 2023, age-related macular degeneration (AMD) remains a preventative care disease, in that the best clinical outcomes are achieved by enabling these patients to maintain good vision after an AMD diagnosis. To accomplish this, optometrists must focus on the early and accurate diagnosis and monitoring of dry AMD, and provide comprehensive patient education about the patient’s role in preventing progression to advanced AMD.

Here, I discuss these three action steps.

Early and accurate diagnosis

ODs are the primary care providers in eye care. As such, they manage the majority of dry AMD. To diagnose the condition, early and accurately, they must do the following:

• Perform ophthalmoscopy. This will enable the optometrist to identify the presence of drusen, which can be a diagnostic marker for AMD. It is critical that close attention be given to the dilated macular examination, so that AMD is not overlooked.A study published in 2017 revealed that 25% of eyes deemed normal by the clinician in a primary care setting actually had findings of AMD.¹ What’s more, of those missed, 30% had intermediate AMD.¹ While not all drusen are related to AMD, it’s important to remember that having drusen increases a person’s risk of developing AMD over time.²
• Perform optical coherence tomography (OCT). OCT should be performed on any drusen found during ophthalmoscopy. OCT provides a baseline to monitor for future change, and it can help in identifying subretinal drusenoid deposits (SDD), also known as reticular pseudodrusen. SDDs are extracellular deposits located anterior to the retinal pigment epithelium (RPE) as opposed to typical drusen, which are located beneath the RPE. SDDs carry the highest risk for AMD progression and are a strong independent risk factor for developing late AMD.³ Because of this, it is imperative to identify SDDs, as the presence of them will need more aggressive monitoring.
• Perform functional testing. Use dark adaptation (DA) to aid in the identification of SDDs. SDDs cause severe DA impairment⁴ that typically takes patients >20 minutes to adapt, with studies showing that complete recovery from photobleach can take hours.⁵ If SDDs are not present, DA can also help in confirming or denying AMD, with 90% sensitivity and specificity.⁶Finally, DA can be used to monitor for functional progression of early and intermediate AMD. Like glaucoma, some patients progress faster in function over structure and vice versa. Thus, consistent examination of both is paramount.
• Implement the Beckman Classification system. This stages each AMD patient and aids in management decisions. (See bit.ly/BeckmanClass .) However, all stages of AMD affect more than just macular anatomy.
• Other testing. This includes fundus photography, contrast sensitivity, fundus autofluorescence, microperimetry, genetic testing, carotenoid level (MPOD or skin carotenoid scan), and pattern electroretinography. For their utility, see “Diagnose AMD Early With Protocols,” at bit.ly/OM2110EarlyDiagnosis .

Monitoring for progression to advanced AMD

Catching conversion to advanced AMD (wet AMD or geographic atrophy [GA]) as early as possible allows for the initiation of treatments, such as anti-VEGF injections, photodynamic therapy and complement cascade inhibition, that can continue to preserve vision as AMD progresses.

How often to monitor AMD in-office is based on a patient’s risk of progression to vision loss. At initial diagnosis, timing of follow up is based on family history, patients’ lifestyle, comorbid conditions, stage of AMD diagnosed, and baseline structural and functional test results. I monitor every three months for high concern of progression and every six months for low concern when AMD is diagnosed. I monitor drusen sans AMD yearly.

Once AMD is an established diagnosis, changes to monitoring protocols are based on that individual’s rate of progression — both in anatomic findings and/or functional abnormality. Close monitoring is recommended with changes in drusen volume, changes of hyperreflective foci or hypertransmission defects, or changes to pigment epithelial detachment (PED) size, shape, and content in intermediate AMD.

For patients who have early GA, enlarging the size of these lesions warrants closer monitoring for both visual decline and to continue to monitor for conversion to wet AMD.

A continuous method to monitor for conversion to wet AMD is via the at-home monitoring system ForeseeHome (see foreseehome.com ). The system alerts the optometrist to a statistically significant change in metamorphopsia. The patient is then contacted and scheduled for an urgent dilated exam to determine whether this change is due to conversion.

Patient education

Optometrists must provide comprehensive education to dry AMD patients. Improving patients’ health literacy gives better clinical outcomes.⁷

To accomplish this, ODs should discuss the significance of clinical findings, the progressive nature of AMD, the modifiable risk factors associated with advanced AMD, and the action steps patients can take to mitigate risk.

As a reminder, the modifiable risk factors are body mass index; poor diet; elevated cholesterol levels; hypertension; low MPOD, and smoking. For information on these modifiable risk factors and how to manage patients who have them, see “Managing AMD,” at bit.ly/OM1805AMDfactors .

At the end of the initial diagnosis and education, the patient should understand what stage of AMD they have, the importance of lifestyle modification, in-office and at-home monitoring and good-quality supplementation, if indicated.

On subsequent visits, I recommend discussing the concerns of progression noted with the patient’s own test results.

Having regular exams with AMD patients also gives the opportunity to intervene early with declining vision in the way of increased add powers, tints, discussion of separate glasses for different uses, enhanced lighting conditions, and referral to a low vision specialist.

Making the referral

The importance of early diagnosis and, thus, treatment of wet AMD cannot be overstated. Studies have shown that the visual acuity (VA) at the initial diagnosis of wet AMD is similar at one and two years after beginning anti-VEGF therapy. Having good VA at the time of wet AMD diagnosis results in better long-term outcomes.⁸

Should follow-up testing reveal fibrovascular PED double layer sign, subretinal hyperreflective material, or intraretinal fluid, the patient has likely converted to wet AMD and should, therefore, be referred to a retinal specialist for treatment.

With the recent approvals of therapies for GA, ODs should be laser focused on not overlooking its early development. Referral and treatment should be initiated while VA is still good, as these medications do not reverse damage but slow the progression of the GA lesion, thereby maintaining functional vision for the patient. OM

References

1. Wang JJ, Foran S, Smith W, Mitchell P. Risk of age-related macular degeneration in eyes with macular drusen or hyperpigmentation: the Blue Mountains Eye Study cohort. Arch Ophthalmol. 2003;121(5):658-63. doi: 10.1001/archopht.121.5.658.
2. Neely DC, Bray KJ, Huisingh CE, Clark ME, McGwin G, Owsley C. Prevalence of Undiagnosed Age-Related Macular Degeneration in Primary Eye Care. JAMA Ophthalmol. 2017;135(6):570-575. doi: 10.1001/jamaophthalmol.2017.0830.
3. Zweifel SA, Spaide RF, Curcio CA, Malek G, Imamura Y. Reticular pseudodrusen are subretinal drusenoid deposits. Ophthalmology. 2010;117(2):303-12.e1. doi: 10.1016/j.ophtha.2009.07.014. Epub 2009 Oct 7.
4. Monge M, Araya A, Wu L. Subretinal drusenoid deposits: An update. Taiwan J Ophthalmol. 2022;12(2):138-146.doi: 10.4103/tjo.tjo_18_22.
5. Luu CD, Tan R, Caruso E, Fletcher EL, Lamb TD, Guymer RH. Topographic rod recovery profiles after a prolonged dark adaptation in subjects with reticular pseudodrusen. Ophthalmology Retina. 2018; 2:1206-1217.).
6. Jackson GR, Scott IU, Kim IK, Quillen DA, Iannaccone A, Edwards JG. Diagnostic sensitivity and specificity of dark adaptometry for detection of age-related macular degeneration. Invest Ophthalmol Vis Sci. 2014 10;55(3):1427-31.)
7. McDonald M, Shenkman LJ. Health Literacy and Health Outcomes of Adults in the United States: Implications for Providers. The Internet Journal of Allied Health Sciences and Practice. 2018;16(4).
8. Ho A, Kleinman D, Lum F, et al. Baseline visual acuity at wet AMD diagnosis predicts long-term visual outcomes: an analysis of the IRIS registry. Ophthalmic Surg Lasers Imaging Retina. 2020;51(11):633-639. doi: 10.3928/23258160-20201104-05.

DR. LEGGE has practiced at Wyomissing Optometric Center for 10 years. She practices primary eye care with a special interest in retinal diseases, having earned a certification for advanced retinal studies during her academic and clinical training. Additionally, Dr. Legge is professionally recognized for her expertise in the diagnosis and management of age-related macular degeneration and inherited retina disease.