Age-Related Macular Degeneration (ARMD)
ℹ️ About
- 👴 ARMD is the leading cause of blindness in the UK and many developed countries.
- 👀 It usually affects both eyes, though progression may differ between them.
- 🚬 Risk factors: smoking, ageing, family history, hypertension, prolonged sun exposure without UV protection.
- 🎯 ARMD primarily affects central vision, impacting reading, driving, and facial recognition.
🧬 Aetiology
- 🔬 Dysfunction of the retinal pigment epithelium (RPE) → degeneration of macular photoreceptors.
- 🌱 Advanced disease may involve abnormal new vessel growth beneath the retina (choroidal neovascularization) → bleeding and scarring.
🔄 Types of ARMD
- Dry (atrophic) ARMD 🟡: 90% of cases. Slow progression, drusen deposits (yellow spots), gradual RPE atrophy → central vision loss over years.
- Wet (exudative) ARMD 🔴: 10% of cases but causes most severe vision loss. Abnormal choroidal neovascularization → leakage/bleeding → rapid loss. Urgent treatment required.
🩺 Clinical Presentation
- 📖 Central vision blurring: hallmark sign, peripheral vision preserved.
- ⬛ Scotomas: dark or blank patches in central vision → difficulty reading/recognising faces.
- 〰️ Metamorphopsia: distortion of straight lines (Amsler grid test useful).
- ✨ Drusen: yellow deposits seen on retinal exam, early marker of dry ARMD.
💊 Management
- 🌱 Lifestyle: Stop smoking, eat leafy greens + oily fish, control blood pressure.
- 💊 Vitamins: AREDS-2 formula (Vit C, Vit E, lutein, zeaxanthin, zinc, copper) slows dry ARMD progression.
- Wet ARMD treatments:
- 💉 Anti-VEGF injections: e.g., ranibizumab (Lucentis), aflibercept (Eylea). First-line, highly effective if given early.
- 💡 Photodynamic therapy: verteporfin dye + laser to seal abnormal vessels.
- 🔥 Laser therapy: less common; risk of collateral retinal damage.
- 🔎 Vision aids: Magnifiers, electronic readers, low-vision support services.
📈 Prognosis
- 🟡 Dry ARMD: slow course; significant central vision loss possible over years. Regular monitoring important.
- 🔴 Wet ARMD: rapid progression without treatment. Early anti-VEGF therapy can stabilise or even improve vision in many patients.
🔑 Clinical Pearls
- 🟡 Drusen = early dry ARMD marker → monitor closely.
- 〰️ Distorted lines on Amsler grid = possible wet ARMD → urgent referral.
- 💉 Anti-VEGF has transformed outcomes; most patients can now maintain vision.
- 🚬 Smoking is the most important modifiable risk factor - always emphasise cessation.
📚 References
Cases - Age-Related Macular Degeneration (ARMD)
- Case 1 - Dry ARMD 👁️: A 76-year-old woman reports gradual, painless loss of central vision and difficulty reading small print. Exam: drusen deposits and retinal pigment epithelial changes on fundoscopy. Diagnosis: dry (atrophic) ARMD. Managed with lifestyle advice (stop smoking, diet rich in antioxidants), low-vision aids, and regular monitoring.
- Case 2 - Wet ARMD 🌊: A 72-year-old man presents with sudden distortion of straight lines (metamorphopsia) and rapid central vision loss. Amsler grid: central distortion. OCT: subretinal fluid; fluorescein angiography shows choroidal neovascularisation. Diagnosis: wet (neovascular) ARMD. Managed urgently with intravitreal anti-VEGF injections (ranibizumab/aflibercept).
- Case 3 - ARMD and driving safety 🚗: A 79-year-old woman complains of central scotoma interfering with reading and recognising faces. Visual acuity below DVLA driving threshold. Fundoscopy: extensive drusen with macular scarring. Diagnosis: advanced ARMD affecting quality of life and driving. Managed with referral to low-vision services, occupational therapy, and social support.
Teaching Point 🩺: ARMD is the leading cause of irreversible central vision loss in older adults.
- Dry ARMD: gradual, drusen deposits, no effective cure → lifestyle + monitoring.
- Wet ARMD: rapid progression, choroidal neovascularisation, treat with anti-VEGF injections.
Peripheral vision is usually preserved, so patients rarely go completely blind.
Always assess impact on daily living and driving safety.
