Neovascular Age‑Related Macular Degeneration (wet AMD)

Overview

Neovascular age‑related macular degeneration (AMD), often called “wet” AMD, is a progressive eye disease that damages the macula—the central portion of the retina responsible for sharp, straight‑ahead vision. Abnormal blood vessels grow under the macula, leak fluid or bleed, and scar the retinal tissue, leading to rapid loss of central vision.

Who it affects: The condition typically appears in people ≥ 50 years old, although it can occur earlier in those with strong genetic predisposition or certain systemic diseases. Women are slightly more likely to develop AMD because they live longer on average, but prevalence is similar between sexes when age‑matched.

Prevalence: According to the U.S. National Eye Institute, ≈ 11 million Americans have some form of AMD, and about 1.2 million (≈ 10 %) have the neovascular (wet) subtype. Worldwide, wet AMD accounts for roughly 15 % of all AMD cases but is responsible for > 80 % of severe vision loss associated with the disease.¹

Symptoms

Symptoms of neovascular AMD can appear suddenly or progress over weeks. Early recognition is vital because prompt treatment can preserve vision.

• Blurred or distorted central vision – straight lines may appear wavy (“metamorphopsia”).
• Dark or empty spot in the center of vision – may make reading or recognizing faces difficult.
• Reduced ability to see colors accurately.
• Difficulty with tasks that require fine detail – e.g., threading a needle, using a smartphone.
• Increased glare or halos around lights, especially at night.
• Rapid vision loss – unlike the slow decline seen in “dry” AMD, wet AMD can cause noticeable worsening within days to weeks.

Causes and Risk Factors

Pathophysiology

In wet AMD, the retinal pigment epithelium (RPE) and Bruch’s membrane become thickened and inflamed. This environment triggers the release of vascular endothelial growth factor (VEGF), a protein that stimulates the growth of new, fragile blood vessels (choroidal neovascularization, CNV) beneath the macula. These vessels leak fluid, blood, and fibrous tissue, disrupting the photoreceptor layer.

Key risk factors

• Age – risk doubles each decade after age 50.
• Genetics – polymorphisms in the CFH, ARMS2, and HTRA1 genes increase susceptibility.²
• Smoking – current smokers have a 2–3‑fold higher risk; risk persists for years after quitting.
• Hypertension & cardiovascular disease – damage to retinal vessels may promote CNV.
• Obesity – high body‑mass index is linked with higher AMD progression rates.
• Diets low in antioxidants (vitamins C, E, lutein, zeaxanthin) and omega‑3 fatty acids.
• Excessive sunlight exposure without UV protection.
• Male sex – modestly higher incidence in some populations.

Diagnosis

Diagnosis is clinical but requires imaging to confirm CNV and guide treatment.

Standard examinations

• Visual acuity test – measures central vision height.
• Amsler grid testing – patients report distortions indicating macular changes.
• Dilated fundus examination – ophthalmologist inspects retina with a slit lamp.

Imaging modalities

• Optical coherence tomography (OCT) – cross‑sectional images show fluid accumulation, retinal thickening, and scar tissue.³
• Fluorescein angiography (FA) – dye injected intravenously highlights leaking vessels.
• Indocyanine green angiography (ICGA) – better visualizes deeper choroidal vessels when FA is inconclusive.
• Fundus autofluorescence (FAF) – helps assess RPE health.

Early detection via routine eye exams (at least once every 1–2 years for people over 50) is essential because treatment success diminishes as scar tissue forms.

Treatment Options

Unlike dry AMD, wet AMD has several effective interventions that can halt or reverse vision loss when started promptly.

Anti‑VEGF intravitreal injections

These are the cornerstone of therapy. Medications bind VEGF, preventing new vessel growth and reducing leakage.

• Aflibercept (Eylea) – administered every 8 weeks after a loading phase.
• Ranibizumab (Lucentis) – monthly or treat‑and‑extend schedule.
• Bevacizumab (Avastin) – off‑label use; cost‑effective, similar efficacy.
• Brolucizumab (Beovu) – newer agent with longer dosing intervals but associated with rare inflammatory reactions.

Most patients require 3–6 initial monthly injections, then a maintenance schedule based on disease activity.

Photodynamic therapy (PDT)

Involves intravenous verteporfin followed by activation with a low‑energy laser. PDT selectively destroys abnormal vessels while sparing surrounding tissue. It is now mostly reserved for cases that are resistant to anti‑VEGF or for polypoidal choroidal vasculopathy.

Laser photocoagulation

Used rarely today because it can damage the overlying retina. It may be considered for well‑defined extrafoveal lesions.

Surgical options

• Vitrectomy – removal of vitreous humor to treat large sub‑retinal hemorrhages.
• Subretinal tissue‑plasminogen activator (tPA) injection – helps dissolve clotted blood.

Lifestyle and adjunctive measures

• AREDS2 supplementation – high‑dose vitamin C, vitamin E, lutein, zeaxanthin, zinc, and copper may slow progression of dry AMD and support overall retinal health.
• Smoking cessation – reduces further vascular damage.
• Blood pressure and lipid control – lowers systemic vascular stress.
• Regular exercise & healthy weight – improves circulation to the retina.

Living with Neovascular Age‑Related Macular Degeneration

Practical daily‑management tips

• Adopt low‑vision aids – magnifying lenses, handheld electronic readers, or screen‑reading software.
• Optimize lighting – use bright, glare‑free illumination; position lamps to avoid shadows.
• Contrast enhancement – wear high‑contrast clothing and use dark‑on‑light or light‑on‑dark apps for reading.
• Regular follow‑up – keep scheduled ophthalmology appointments; many practices schedule OCT scans every 4–8 weeks during the active treatment phase.
• Eye‑protection – wear sunglasses with UV‑400 protection outdoors.
• Medication adherence – never miss an anti‑VEGF injection appointment; discuss any side effects with your eye doctor promptly.
• Driving safety – if central vision is compromised, consider vision‑adaptive driving courses or alternative transportation.

Emotional support

Vision loss can be distressing. Participation in support groups, counseling, or vision‑rehabilitation programs can improve quality of life. Organizations such as the American Macular Degeneration Foundation and the National Federation of the Blind offer resources.

Prevention

While genetics cannot be changed, modifiable risk factors can be addressed to lower the chance of developing wet AMD or slowing its progression.

• Nutrition – eat a Mediterranean‑style diet rich in leafy greens, fatty fish (salmon, sardines), nuts, and colorful vegetables.
• Supplementation – consider AREDS2 formula after consulting your physician.
• Quit smoking – use nicotine‑replacement therapy or counseling programs.
• Control systemic diseases – maintain blood pressure < 130/80 mmHg and LDL < 100 mg/dL.
• Protect eyes from UV and blue light – wear wrap‑around sunglasses; consider blue‑light filtering lenses for prolonged screen time.
• Regular eye exams – early detection of drusen or early dry AMD enables closer monitoring for possible conversion to wet AMD.

Complications

If untreated, neovascular AMD can lead to irreversible visual impairment.

• Geographic atrophy – scarring and loss of RPE cells, causing permanent central blind spot.
• Sub‑retinal fibrosis – scar tissue that permanently distorts the macula.
• Severe central vision loss – inability to read, recognize faces, or perform tasks requiring detail.
• Psychological impact – increased rates of depression and anxiety.
• Increased fall risk – due to reduced visual cues, especially in low‑light environments.

When to Seek Emergency Care

Sources: 1. National Eye Institute, NIH. “Age‑Related Macular Degeneration.” 2023. 2. International AMD Genomics Consortium. “Genetic risk factors for AMD.” *Nat Genet.* 2022. 3. American Academy of Ophthalmology. “Optical Coherence Tomography in AMD.” 2022. 4. Mayo Clinic. “Wet macular degeneration – Treatment.” 2024. 5. AREDS2 Research Group. “Lutein, zeaxanthin, and macular health.” *JAMA Ophthalmol.* 2021. 6. CDC. “Smoking & Vision Loss.” 2024.