Age-Related Macular Degeneration (ARMD)
โน๏ธ About
- ๐ด ARMD is the leading cause of blindness in the UK and many developed countries.
- ๐ It usually affects both eyes, though progression may differ between them.
- ๐ฌ Risk factors: smoking, ageing, family history, hypertension, prolonged sun exposure without UV protection.
- ๐ฏ ARMD primarily affects central vision, impacting reading, driving, and facial recognition.
๐งฌ Aetiology
- ๐ฌ Dysfunction of the retinal pigment epithelium (RPE) โ degeneration of macular photoreceptors.
- ๐ฑ Advanced disease may involve abnormal new vessel growth beneath the retina (choroidal neovascularization) โ bleeding and scarring.
๐ Types of ARMD
- Dry (atrophic) ARMD ๐ก: 90% of cases. Slow progression, drusen deposits (yellow spots), gradual RPE atrophy โ central vision loss over years.
- Wet (exudative) ARMD ๐ด: 10% of cases but causes most severe vision loss. Abnormal choroidal neovascularization โ leakage/bleeding โ rapid loss. Urgent treatment required.
๐ฉบ Clinical Presentation
- ๐ Central vision blurring: hallmark sign, peripheral vision preserved.
- โฌ Scotomas: dark or blank patches in central vision โ difficulty reading/recognising faces.
- ใฐ๏ธ Metamorphopsia: distortion of straight lines (Amsler grid test useful).
- โจ Drusen: yellow deposits seen on retinal exam, early marker of dry ARMD.
๐ Management
- ๐ฑ Lifestyle: Stop smoking, eat leafy greens + oily fish, control blood pressure.
- ๐ Vitamins: AREDS-2 formula (Vit C, Vit E, lutein, zeaxanthin, zinc, copper) slows dry ARMD progression.
- Wet ARMD treatments:
- ๐ Anti-VEGF injections: e.g., ranibizumab (Lucentis), aflibercept (Eylea). First-line, highly effective if given early.
- ๐ก Photodynamic therapy: verteporfin dye + laser to seal abnormal vessels.
- ๐ฅ Laser therapy: less common; risk of collateral retinal damage.
- ๐ Vision aids: Magnifiers, electronic readers, low-vision support services.
๐ Prognosis
- ๐ก Dry ARMD: slow course; significant central vision loss possible over years. Regular monitoring important.
- ๐ด Wet ARMD: rapid progression without treatment. Early anti-VEGF therapy can stabilise or even improve vision in many patients.
๐ Clinical Pearls
- ๐ก Drusen = early dry ARMD marker โ monitor closely.
- ใฐ๏ธ Distorted lines on Amsler grid = possible wet ARMD โ urgent referral.
- ๐ Anti-VEGF has transformed outcomes; most patients can now maintain vision.
- ๐ฌ Smoking is the most important modifiable risk factor โ always emphasise cessation.
๐ References
Cases โ Age-Related Macular Degeneration (ARMD)
- Case 1 โ Dry ARMD ๐๏ธ: 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 โ Wet ARMD ๐: 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 โ ARMD and driving safety ๐: 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 ๐ฉบ: ARMD is the leading cause of irreversible central vision loss in older adults.
- Dry ARMD: gradual, drusen deposits, no effective cure โ 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.
