age-related%20macular%20degeneration
AGE-RELATED MACULAR DEGENERATION
Age-related macular degeneration is a common, chronic, progressive, degenerative disease that causes central loss of vision due to abnormalities that occurs in the pigment, neural and vascular layers of the macula.
The macular disorder may have one or more of the following:
- Formation of drusen which are localized deposits of extracellular material usually concentrated in the macula
- Abnormalities in the retinal pigment epithelium (eg hypopigmentation or hyperpigmentation)
- Retinal pigment epithelium and choriocapillaris geographic atrophy
- Neovascular (exudative) maculopathy
Decreased central vision and distortion of seeing straight lines are the most common symptoms.

Introduction

  • The macular disorder may have one or more of the following:
    • Formation of drusen which are localized deposits of extracellular material usually concentrated in the macula
    • Abnormalities in the retinal pigment epithelium (eg hypopigmentation or hyperpigmentation)
    • Retinal pigment epithelium (RPE) and choriocapillaris geographic atrophy
    • Neovascular (exudative) maculopathy
  • Leading cause of irreversible vision loss especially in the elderly
  • Decreased central vision and distortion of seeing straight lines (metamorphopsia) are the most common symptoms of age-related macular degeneration (AMD)

Definition

  • Chronic, progressive, degenerative disease that occurs in the pigment, neural and vascular layers of the macula that causes central vision loss

Signs and Symptoms

  • Early stage manifestations:
    • Decline of reading ability in dim light
    • Glare difficulty
    • Dark and light adaptation difficulty (eg the patient wakes up at night and unable to read the clock because of seeing central dark patch in the visual field that disappears within a few minutes as the eye adapts)
    • Needs to use magnifiers and bright light to be able to see as well as the patient used to
    • Gradual progressive central vision loss
  • Late stage manifestations:
    • Metamorphopsia or the patient complains that straight line appearing crooked or wavy that can be confirmed by using Amsler grid
    • Difficulty in reading small sizes of print and then later with larger print and/or words
    • Profound and rapid central vision loss

Risk Factors

  • Increasing age (>50 years old)
  • Genetic factors (eg complement factor H genes)
  • Cigarette smoking history of >20 years
    • Current smokers have 2- to 3-fold risk and there is a dose-relationship with pack years of smoking
  • Diet (eg low intake of antioxidants and zinc, high total fat and trans-fat)
  • Obesity
  • Race
    • While Caucasians are at increased risk compared to African or Hispanic descent, studies fail to show consistent differences in risk between Caucasians and Asians
  • Gender
    • Studies have consistently shown women to be at increased risk
Editor's Recommendations
Most Read Articles
11 days ago
Increased serum levels of C-X-C motif chemokine (CXCL)-11, CXCL-9, CXCL-10 and interferon (IFN)-γ are associated with clinical manifestations of adult-onset Still’s disease (AOSD), reports a new study.
3 days ago
At a recent lunch symposium during the 14th Annual Scientific Meeting of the Malaysian Society of Hypertension, Dr Chow Yok Wai spoke on the importance of patient adherence in the management of hypertension, highlighting the role of combination therapy in improving treatment outcomes.
5 days ago
Myopia is associated with depressive symptoms in Chinese adults, a new population-based study shows.
5 days ago
Chronic obstructive pulmonary disease (COPD) is currently the 10th commonest cause of death in Singapore, with a disease burden of 5.9 percent according to a 2015 population-based survey (EPIC-Asia survey) in Singapore. Pearl Toh spoke with Dr Augustine Tee, chief and senior consultant of the Department of Respiratory and Critical Care Medicine at Changi General Hospital (CGH) in Singapore, on how COPD is often underdetected in the primary care population as symptoms are not specific and diagnosis requires a combination of clinical risk factors, symptoms and spirometry testing.