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Symptoms

Gradual loss of central vision, metamorphopsia, Amsler grid changes; may be asymptomatic.

Signs

(See Figures 11.16.1 and 11.16.2.)

Figure 11.16.1: Dry AMD with fine drusen.

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Figure 11.16.2: Dry AMD with soft drusen.

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Critical

Macular drusen, clumps of pigment in the outer retina, and RPE atrophy, almost always in both eyes.

Other

Confluent retinal and choriocapillaris atrophy (e.g., geographic atrophy [GA]), dystrophic calcification.

Differential Diagnosis

Workup

  1. History: Presence of risk factors (e.g., family history, smoking)? See risk factors for loss of vision, 11.17, Neovascular or Exudative (Wet) Age-Related Macular Degeneration.

  2. Amsler grid or preferential hyperacuity perimetry (PHP) testing at home to detect central or paracentral scotoma potentially indicative of neovascular transformation. See Appendix 4, Amsler Grid.

  3. Macular examination with a handheld lens: Look for risk factors for conversion to the exudative form, such as soft drusen or pigment clumping. On OCT, look for reticular pseudodrusen (subretinal drusenoid deposits) as this has been shown to increase risk of conversion to advanced AMD, both neovascular and GA. Look for GA. Look for signs of exudation including edema, SRF, lipid exudation, or hemorrhage (disappearance of drusen may herald the development of CNV).

  4. Baseline and periodic FAF may be useful to monitor for progression of GA.

  5. IVFA or OCT can be useful adjuncts to determine stage of dry AMD and when exudative AMD is suspected based on subjective or objective change in vision or examination findings. Drusen and RPE atrophy are often more visible on IVFA and FAF. OCTA is also a potentially useful diagnostic test as a noninvasive substitute for IVFA or if IVFA is inconclusive, especially with masquerade conditions such as pattern dystrophy or CSCR.

Treatment

NOTE

Beta-carotene (in the original AREDS formula) should be withheld in recent or present smokers because of increased risk of lung cancer. The AREDS2 formulation (with lutein + zeaxanthin) is preferred as it does not contain beta-carotene.

In addition, recommend consumption of dark green leafy vegetables if approved by a primary care physician (intake of vitamin K decreases effectiveness of warfarin) and foods containing high levels of omega-3 fatty acids such as cold-water fatty fish and nuts.

  1. Low-vision aids may benefit patients with bilateral vision loss.

  2. Refer to an internist for management of presumed risk factors: HTN, hypercholesterolemia, smoking cessation, etc.

  3. Those at high risk for progressing to exudative AMD may benefit from home monitoring technology for earlier detection such as the PHP device as well as home OCT. Early detection of CNV increases the likelihood of better visual acuity results after intravitreal anti-VEGF therapy is initiated.

  4. Certain genetic mutations confer an increased risk for AMD (e.g., polymorphisms of complement factor H and ARMS2 genes). This may or may not influence response to treatment and so, at this time, genetic screening in AMD patients is not routinely performed.

Follow-Up

Every 6 to 12 months, watching for signs of the exudative form. Daily use of Amsler grid, PHP device, or home OCT with instructions to return promptly if a change is noted.

REFERENCE

The Age-Related Eye Disease Study 2 (AREDS2) Research Group. Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: The age-related eye disease study 2 (AREDS2) randomized clinical trial. J Am Med Assoc. 2013;309(19):20052015.