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
Roshini Claire Anthony, 6 days ago

Treatment failure in osteoporosis remains a problem, even among patients who are treatment-adherent, according to a presentation at the recent meeting of the Asian Federation of Osteoporosis Societies (AFOS 2017), held in Kuala Lumpur, Malaysia. 

Elvira Manzano, 5 days ago
Bisphosphonates have proven antifracture efficacy and remain to be the cornerstone of osteoporosis treatment. However, a drug holiday is of particular importance with bisphosphonates due to some signals with long-term use of the drug, including rare incidence of atypical femoral fracture (AFF) and osteonecrosis of the jaw (ONJ), says a leading endocrinologist at AFOS 2017.
2 days ago
Breast cancer patients have notably different microbiomes in the local breast tissue and urinary tract, a recent study reveals. Particularly, species in the Methylobacterium genus are reduced in the local breast tissue while the urinary tract is enriched in gram-positive bacteria.
Pearl Toh, 13 Oct 2017
Women with higher plasma tryptophan concentrations were less likely to have poor sleep quality during pregnancy, especially among those with anxiety symptoms, according to the GUSTO* study.