Exudative Age‑Related Macular Degeneration (Wet AMD)

Overview

Exudative age‑related macular degeneration (AMD), also called “wet” AMD, is a progressive eye disease that affects the macula—the central part of the retina responsible for sharp, detailed vision. Abnormal blood vessels grow underneath the retina and leak fluid or blood, leading to rapid vision loss if untreated.

• Who it affects: Primarily adults age 60 and older, with a higher prevalence in people of European ancestry, though it can occur in any ethnicity.
• Prevalence: In the United States, about 12 million people have some form of AMD; of these, roughly 10–15 % develop the exudative (wet) type.¹ Globally, AMD is the leading cause of irreversible blindness in adults over 50, accounting for an estimated 8.7 % of visual impairment worldwide.²

Symptoms

Wet AMD can progress quickly—often over weeks—so recognizing early signs is crucial.

• Blurry or distorted central vision – straight lines may appear wavy (metamorphopsia).
• Dark or empty spot in the center of vision – a scotoma that expands over time.
• Difficulty reading or recognizing faces despite otherwise normal peripheral vision.
• Changes in color perception – colors may look washed out.
• Need for brighter light when doing fine‑detail tasks.
• Pain or pressure – rare, but sudden severe eye pain may indicate a complication (e.g., retinal detachment).

Causes and Risk Factors

Pathophysiology

In wet AMD, the retinal pigment epithelium (RPE) and Bruch’s membrane become damaged, prompting the release of vascular endothelial growth factor (VEGF). VEGF stimulates the growth of fragile, leaky choroidal neovascular membranes (CNV) that infiltrate the macula.

Key Risk Factors

• Age: Risk rises sharply after age 60; prevalence doubles each decade thereafter.
• Genetics: Variants in the CFH, ARMS2, and HTRA1 genes increase susceptibility.
• Smoking: Current smokers have a 2–3‑fold higher risk; risk persists years after quitting.
• Race/Ethnicity: Higher rates in White populations; lower in African‑American and Asian groups.
• Cardiovascular disease: Hypertension, hyperlipidemia, and obesity share pathways (VEGF, inflammation) with AMD.
• Diet low in antioxidants (vitamins C/E, lutein, zeaxanthin, omega‑3 fatty acids).
• Excessive sunlight exposure without UV protection.
• High body mass index (BMI) – obesity is linked to increased AMD progression.

Diagnosis

A definitive diagnosis requires a comprehensive eye exam performed by an optometrist or ophthalmologist.

Clinical Examination

• Visual acuity testing – assesses central vision loss.
• Dilated fundus examination – allows direct visualization of drusen, pigment changes, and CNV.

Imaging Tests

• Optical Coherence Tomography (OCT): Provides cross‑sectional images of retinal layers, revealing fluid accumulation and sub‑retinal neovascular tissue. OCT is the primary monitoring tool.³
• Fluorescein Angiography (FA): A dye injected intravenously highlights leaking vessels, confirming CNV activity.
• Indocyanine Green Angiography (ICGA): Useful for detecting polypoidal choroidal vasculopathy, a variant of wet AMD.
• A‑scan or B‑scan ultrasonography: Reserved for cases where media opacity (e.g., cataract) limits visualization.

Treatment Options

Unlike the “dry” form, wet AMD is treatable, and early therapy can preserve or even improve vision.

Anti‑VEGF Intravitreal Injections

• Ranibizumab (Lucentis) – FDA‑approved for AMD; typically 1 month after a loading phase of three monthly injections.
• Aflibercept (Eylea) – Binds VEGF‑A, VEGF‑B, and PlGF; dosing may be every 8 weeks after initial loading.
• Bevacizumab (Avastin) – Off‑label but widely used; cost‑effective.
• Brolucizumab (Beovu) – Longer dosing intervals, but carries a rare risk of intra‑ocular inflammation.

Most patients receive injections every 4–12 weeks, guided by OCT findings.⁴

Photodynamic Therapy (PDT)

Verteporfin‑mediated PDT is reserved for specific lesions (e.g., polypoidal choroidal vasculopathy) and is used in combination with anti‑VEGF agents.

Laser Photocoagulation

Rarely used today because it can cause permanent retinal scarring; limited to well‑defined, extrafoveal lesions.

Lifestyle & Nutritional Adjuncts

• AREDS2 formula: High‑dose antioxidants (vitamin C 500 mg, vitamin E 400 IU, lutein 10 mg, zeaxanthin 2 mg) and zinc 80 mg have shown modest benefit in slowing progression of AMD.⁵
• Smoking cessation, weight management, regular aerobic exercise, and a diet rich in leafy greens, oily fish, and nuts.

Emerging Therapies (clinical trials)

• Gene therapy (e.g., RGX‑314) – delivering a durable anti‑VEGF protein via viral vectors.
• Port delivery systems – refillable ocular implants releasing ranibizumab over months.
• Novel agents targeting complement pathway (e.g., avacincaptad pegol).

Living with Exudative Age‑Related Macular Degeneration

Vision‑Enhancing Strategies

• Magnification devices – handheld magnifiers, stand‑magnifiers, or electronic visual aids.
• High‑contrast, large‑print reading material – use black text on white or yellow background.
• Adaptive lighting – bright, glare‑free task lighting; avoid overhead fluorescent lights.
• Smartphone accessibility tools – screen‑magnifier, voice‑over, and high‑contrast settings.

Rehabilitation & Support

• Low‑Vision Rehabilitation (LVR) programs – certified low‑vision therapists can train patients in the use of assistive technology.
• Support groups – organizations such as the National Eye Institute’s “Low Vision Network” provide peer support.
• Driving evaluation – many states require a vision assessment; consider occupational therapy driving assessments.

Follow‑Up Schedule

After initiating anti‑VEGF therapy, most clinicians schedule OCT‑guided visits every 4–8 weeks initially, then extend intervals if disease remains inactive. Promptly report any new central distortion or sudden vision drop.

Prevention

• Quit smoking – the single most modifiable risk factor.⁶
• Maintain a healthy weight – BMI < 25 kg/m² is associated with slower AMD progression.
• Adopt a Mediterranean‑style diet – rich in leafy greens, fish (omega‑3), nuts, and olive oil.
• Protect eyes from UV and blue light – wear sunglasses with 99‑% UV protection; consider blue‑light filtering lenses for prolonged screen use.
• Regular eye examinations – at least once every 1–2 years after age 60, or more often if you have early AMD changes.
• Consider AREDS2 supplementation if you have intermediate or early AMD (consult your eye doctor).

Complications

• Permanent central vision loss – fibrosis or scar tissue can replace the macular tissue.
• Geographic atrophy – progressive loss of RPE that may follow or coexist with wet AMD.
• Retinal detachment – rare but possible if neovascular tissue leads to traction.
• Elevated intra‑ocular pressure or endophthalmitis – potential injection‑related complications; endophthalmitis can threaten the entire eye if not treated promptly.

When to Seek Emergency Care

References

1. Centers for Disease Control and Prevention. Age‑Related Macular Degeneration Fact Sheet. 2023.
2. World Health Organization. Vision Impairment and Blindness. 2022.
3. Mayo Clinic. Macular Degeneration Diagnosis & Treatment. Updated 2024.
4. American Academy of Ophthalmology. Preferred Practice Pattern: Age‑Related Macular Degeneration. 2023.
5. National Eye Institute (NEI). AREDS2 Study Report. 2020.
6. U.S. Department of Health and Human Services, Office on Smoking and Health. Smoking and Vision Loss. 2022.