Age-related macular degeneration (AMD) traditionally has been a disease synonymous with debilitating central vision loss that too often led to the need for specialty low vision care. Past studies have reported that 78% of patients first diagnosed with this disease present for treatment with irreversible vision loss, including 37% who are legally blind in at least 1 eye.^1,2 As with many chronic diseases, AMD severity is measured on a spectrum, and the sooner doctors, patients, and caregivers are aware of its presence, the sooner everyone can work together to protect against it. 

Risk Factors

A study in 2019 estimated more than 18 million Americans, aged 40 years and over, are living with early-stage AMD, and nearly 1.5 million have late-stage (advanced) AMD.³ As with any sight-threatening condition, the goal is to identify who is at risk and how to mitigate disease progression. Timely, consistent eye care is every adult’s first line of defense in identifying risk factors and instituting treatment plans that are critical in delaying the onset and slowing potential progression. With age being the biggest risk factor for this condition along with family history (genetics) and ethnicity (White) being the nonmodifiable risk factors,⁴ adults should have yearly comprehensive eye examinations to afford their eyecare team the opportunity to fully educate them on the modifiable risks of AMD, which include:

• Smoking,
• High cholesterol,
• Cardiovascular disease,
• Diabetes,
• Obesity,
• Chronic sunlight (ultraviolet [UV]) exposure, and
• Low macular pigment optical density (MPOD).

Primary eyecare physicians must not only educate but also prescribe the appropriate lifestyle modifications and UV protecting eyewear to help patients reduce the risk of converting to and/or progression of early disease. Because smoking is the greatest of modifiable risk factors (2.5 to 4.8 times higher risk),⁵ it is imperative that patients receive and seek out resources to help with smoking cessation. Keeping fit with moderate, consistent exercise (which includes 150 minutes of cardiovascular exercise per week) along with adopting a healthy diet rich in phytonutrients and antioxidants not only is heart healthy but also supports macular health. The Ocular Wellness & Nutrition Society and the American Nutrition Association recommend a Mediterranean diet rich in plant-based foods focusing on a rainbow spectrum of colors, fiber-rich whole grains, healthy fats such as extra virgin olive oil, and a variety of spices and fresh or dried herbs along with nuts and seeds. Healthy animal protein sources such as fish and seafood along with poultry and eggs while limiting red and processed meats and avoiding all sodas, high fructose corn syrup, commercial fruit juice, and ultraprocessed foods is also advantageous.^6,7

Past studies like AREDS (Age-Related Eye Disease Study) and AREDS 2 found that nutritional supplements were beneficial for slowing AMD progression in patients with intermediate stage to advanced stage. It was commonplace for many doctors to wait until patients were in the intermediate stage of AMD before prescribing supplements. Fortunately, many studies since have now shown that supplementing those at risk in early-stage AMD is also beneficial in slowing progression. Carotenoids are pigments found in nature that protect. Of the many carotenoids found in nature, the 2 carotenoids in our food supply that find their way to protect the macula are lutein and zeaxanthin (which also protect the brain). Lutein and zeaxanthin are found in foods like egg yolk, fish, corn, spinach, broccoli, and carrots. Along with a healthy diet, supplementing these carotenoids has been shown not only to improve macular function⁸ in the normal, healthy macula, but also to protect the macula from the damaging effects of blue and UV light.⁹ It is important that primary eyecare providers determine which patients are ideal candidates for carotenoid nutraceuticals and give a recommendation for the best formula to align with clinical needs.

To further identify patients who may be good candidates for nutraceutical supplements, many offices have implemented technologies to measure macular pigment optical density (MPOD). Two of the most used office tests for measurement are heterochromatic flicker photometry (HFP), which directly measures macular pigment at the retinal level, and reflection spectrometry, which measures the level of cartenoids in the skin as a barometer for what macular levels would be. Both methods offer patients and clinicians a snapshot of lutein and zeaxanthin levels patients are up taking from their diet. If measured retinal MPOD is low (less than 50%) and skin reflection scores are below 400, clinicians can counsel their patients on dietary/supplement strategies for improvement to reduce the risk of macular disease. More importantly, it opens the discussion of the importance of how a healthy lifestyle lends itself not only to preservation of vision but also to improvement in cardiovascular and brain health. 

Classification and Diagnosis 

To aid in more timely and accurate diagnoses of AMD, many clinicians have used technology that goes beyond assessing the physical macular structure. The traditional stages of macular degeneration are all based on structural changes in the macula with either cholesterol deposits (drusen) or pigment disruptions. 

Dark adaptation testing now allows for higher-level measurement of macular function. Rod photoreceptors, which provide night vision, are the first to decline as early AMD affects the retina. Dark adaptation testing measures how quickly the eye adapts to going from daylight to darkness (measured as rod intercept time), which studies have shown can detect AMD up to 3 years earlier than traditional structure examination and/or imaging.¹⁰ Delayed dark adaptation time, defined as a rod intercept time of more than 6.50 minutes, is the earliest biomarker for identifying AMD and has added a fourth, new AMD classification to precede the original 3.

Here are the classifications along with symptoms:

• Subclinical AMD: Vision is still intact, and there is no presence of drusen or pigmentary changes, noting delayed dark adaptation time of greater than 6.5 minutes.
• Early AMD: Vision is still good, but night vision problems may be reported, and medium size drusen are present (>63 µm and <125 µm), no pigmentary abnormalities.
• Intermediate AMD: Blur or spot is present in the center of vision with night vision difficulties and decreased contrast sensitivity. Some pigmentary abnormalities may be present and at least 1 druse >125 µm is present.
• Advanced AMD: Vision loss is noticeable due to geographic atrophy (GA), choroidal neovascularization (CNV), or wet AMD.

Although AMD has no cure, with the evolution of anti-VEGF therapy for CNV/wet AMD and novel treatments currently available for GA, there is still hope for slowing down disease progression. Prudent monitoring of those at risk and timely tracking of those who show progression into any of the 4 AMD stages, empowers the astute practitioner to intervene with the appropriate clinical care at the appropriate time to preserve central vision. Here is a comprehensive list of prudent tests for diagnosing/monitoring:

1. Fundus imaging: color fundus photography to visualize the retina and detect abnormalities like drusen or pigmentary changes that can potentially worsen over time.
2. Dark adaptation testing: essential in detecting subclinical AMD by assessing retinal rod function after daylight is simulated on the retina. Studies have shown that a delay in rod intercept time (≥6.5 minutes) is a biomarker (vs a risk factor) for AMD, even in eyes with normal macular structure.
3. Macular pigment optical density testing: assesses the density of macular pigments (lutein and zeaxanthin) in the retina, which play a key role in protecting against oxidative stress and blue light damage, providing insights into the risk of AMD while monitoring the impact of nutritional/lifestyle therapies.
4. Genetic testing: analyzes specific genes (such as the ARMS2 and CFH genes) associated with an increased risk of developing AMD. Aids the practitioner in risk assessment and understanding individual susceptibilities to initiate appropriate treatment plans.
5. Amsler Grid: a simple in-office and take-home test where patients routinely look at a grid to identify any distortions, blurriness, or missing areas in their central vision.
6. Optical coherence tomography (OCT): retinal imaging technique that provides valuable cross-sectional images of the retina, allowing for detailed visualization of retinal layers and fluid accumulation that cannot be seen with traditional fundus imaging.
7. OCT angiography (OCTA): a specialized form of OCT that captures detailed images of blood flow in the retina without the need for dye injection, helping to identify changes in the choroidal and retinal vasculature while monitoring the foveal avascular zone.
8. Visual field testing: assesses central and paracentral vision to determine any loss of visual field that may occur with AMD and can dramatically affect patients’ perception even though central acuity appears intact.
9. Contrast sensitivity testing: evaluates the ability to distinguish between differences in light and dark (contrast), which can be affected in AMD and hallmark of early changes, especially while traditional Snellen acuity is normal.
10. Color vision testing: tracks the function of central cone receptors, because color vision can be impacted in patients with AMD.
11. Autofluorescence imaging: uses natural fluorescence of the retina to identify changes in the retinal pigment epithelium and areas of atrophy affected by accumulation of lipofuscin.
12. Electroretinography: measures the electrical activity of the retina in response to light stimuli, helping to evaluate healthy vs impaired retinal function. Although not commonly used specifically for AMD, it can be valuable as a patient-friendly objective functional test to monitor over time.
13. Home monitoring device: an automated home monitoring device that uses the principles of an Amsler grid-like pattern to help patients detect changes in their vision that can detect dry macular degeneration progression to wet.

Conclusion

The very good news about macular degeneration is with today’s advancements in early detection, patients need not feel powerless when it comes to managing this condition. Early diagnosis leads to early intervention which slows disease progression thus improving visual outcomes. With the ever-increasing numbers of patients currently diagnosed with early AMD, and technology available to identify and treat those with subclinical AMD well before visible structure changes cause the loss of central vision, eyecare professionals and patients can take charge of this condition for a brighter future.OM

References

1. Olsen TW, Feng X, Kasper TJ, Rath PP, Steuer ER. Fluorescein angiographic lesion type frequency in neovascular age-related macular degeneration. Ophthalmology. 2004;111(2):250-255. doi:10.1016/j.ophtha.2003.05.030
2. Cervantes-Castañeda RA, Banin E, Hemo I, Shpigel M, Averbukh E, Chowers I. Lack of benefit of early awareness to age-related macular degeneration. Eye. 2007;22(6):777-781. doi:10.1038/sj.eye.6702691
3. Rein DB, Wittenborn JS, Burke-Conte Z, et al. Prevalence of age-related macular degeneration in the US in 2019. JAMA Ophthalmol. 2022;140(12):1202–1208. doi:10.1001/jamaophthalmol.2022.4401
4. National Eye Institute. Age-related macular degeneration (AMD). Updated June 22, 2021. Accessed February 24, 2026. https://www.nei.nih.gov/learn-about-eye-health/resources-for-health-educators/eye-health-data-and-statistics/age-related-macular-degeneration-amd-data-and-statistics
5. Chakravarthy U, Augood C, Bentham G, et al. Cigarette smoking and age-related macular degeneration in the EUREYE Study. Ophthalmology. 2007;114(6):1157-1163
6. Ocular Wellness and Nutrition Society. Accessed February 24, 2026. https://ocularnutritionsociety.org/
7. American Nutrition Association. Accessed February 24, 2026. theana.org
8. Herman JP, Goudey SJK, Davis RL. Case report of dietary supplements improving macular pigment and visual function. Adv Ophthalmol Vis Syst. 2017;6(1):24-35. DOI: 10.15406/aovs.2017.06.00166
9. Kumar P, Banik SP, Ohia SE, et al. Current insights on the photoprotective mechanism of the macular carotenoids, lutein and zeaxanthin: safety, efficacy and bio-delivery. J Am Nutr Assoc. 2024 Aug;43(6):505-518. doi: 10.1080/27697061.2024.2319090
10. Owsley C, McGwin Jr G, Clark ME, et al. Delayed rod-mediated dark adaptation is a functional biomarker for incident early age-related macular degeneration. Ophthalmology. 2016;123(2):344-351. doi:10.1016/j.ophtha.2015.09.041

Pamela Lowe, OD is owner and director of Professional Eye Care Center, a full-scope primary care office she founded in 1992 on the northwest side of Chicago. She is a Fellow with the American Academy of Optometry, a Diplomate of the American Board of Optometry, and immediate past chair of the American Optometric Association Strategic Communications Committee. Dr. Lowe is also an administrator/medical director for Vision Source Chicagoland.