Macular Degeneration, Age-Related

Key Features

Essentials of Diagnosis

• Older age group

• In one or both eyes; acute or chronic deterioration of central vision; distortion or abnormal size of images, sometimes developing acutely

• No pain or redness

• Classified as dry ("atrophic," "geographic") or wet ("neovascular," "exudative") macular degeneration

• Macular abnormalities seen by ophthalmoscopy

General Considerations

• Both dry age-related and wet age-related macular degeneration are progressive and usually bilateral; however, manifestations, prognosis, and management differ

• Although dry age-related macular degeneration is much more common, untreated wet age-related macular degeneration accounts for about 90% of all cases of legal blindness due to age-related macular degeneration

Demographics

• Leading cause of permanent visual loss in the older population

• Prevalence progressively increases over age 50 years (to almost 30% by age 75)

• Occurrence and response to treatment are likely influenced by genetically determined variations, many of which involve the complement pathway

• Other associated factors

  • Sex (slight female predominance)

  • Family history

  • Hypertension

  • Hypercholesterolemia

  • Cardiovascular disease

  • Farsightedness

  • Light iris color

  • Cigarette smoking

Clinical Findings

• Retinal drusen are the hallmark of age-related macular degeneration

  • Hard drusen appear ophthalmoscopically as discrete yellow subretinal deposits

  • Soft drusen are paler and less distinct

  • Large, confluent soft drusen are risk factors for neovascular (wet) age-related macular degeneration

• Vision loss in age-related macular degeneration involves the central field of vision only in most patients

• Peripheral fields, and hence navigational vision, are maintained, except in patients with severe neovascular age-related macular degeneration

• Dry age-related macular degeneration

  • Gradual progressive bilateral visual loss of moderate severity due to geographic atrophy of the

    • Outer retina

    • Retinal pigment epithelium

    • Choriocapillaris, which supplies blood to both the outer retina and the retinal pigment epithelium

• Wet (neovascular) age-related macular degeneration

  • Onset of visual loss is more rapid and more severe than in atrophic degeneration

  • New choroidal vessels grow under either the retina or the retinal pigment epithelial cells, leading to accumulation of exudative fluid, hemorrhage, and fibrosis

  • The two eyes are frequently affected sequentially over a period of a few years

Diagnosis

• On ophthalmoscopic examination, various abnormalities are visualized in the macula

• Fundal photography after intravenous fluorescein (fluorescein angiography) is often required

Treatment

• Dry age-related macular degeneration: No specific treatment

• Wet age-related macular degeneration

  • Rehabilitation including low-vision aids is important

  • VEGF inhibitors, such as ranibizumab, bevacizumab, aflibercept, and brolucizumab can cause regression of choroidal neovascularization with resorption of subretinal fluid and improvement or stabilization of vision; however, brolucizumab has been associated with intraocular inflammation and occlusive retinal vasculitis resulting in irreversible vision loss in some patients

  • Long-term repeated intraocular injections are required and must be administered in the eye clinic several times a year, if not monthly

• No ...