香港醫藥援助會 Project Concern Hong Kong


Aging Macular Degeneration (AMD)

 

Macula - the most important part of the eye

Functions of Macula

  • Located near the centre of the retina
  • Process sharp, clear and straight-ahead vision
  • Identify color of the object
  • Provide us with ability to see

What is Macular Degeneration?
When the macula is damaged, it will result in blurred or loss of vision in the centre of the vision field.


Type of Macular Degeneration

Myopic (Nearsightedness) Macular Degeneration
High myopia will increase the distance between the cornea and the retina.  If the retina is stretched, it will casue the cells in the macula to degenerate.  Such process will cause a blind spot or loss of vision in the centre of the visual field.


Aged-related Macular degeneration (AMD)

A. Dry AMD (80% of the cases of AMD)
  • Degenerating the light-sensitve cells in the macular
  • Central vision impairment
  • Loss of vision in the centre of the vision field
B. Wet AMD 
  • Blind spots in the centre of the visual field
  • Vision distortion

Amsler Grid        Blurred at centre vision




Amsler Grid Testing
  1. Patient holds the grid 30cm away from the face in a well-illuminated space
  2. If the patient is wearing specacles, the tesing should be done with glasses.
  3. Cover one eye with hand and look at the centre dot of the grid
  4. Follow the above steps with the other eye
  5. If any lines look distorted or blurred at the centre of the grid, please seek further medical advice from ophthalmologist.

Cause of Macular Degeneration
  • Aging
  • Inherited disorder of retina
  • Smoking
  • Always expose to strong sunshine
  • High myopia
  • Frequently consume food with high cholesterol level

Prevention of Macular Degeneration
  • Regular eye check-up
  • Protect the eyes from ultraviolet light
  • Quit smoking
  • Healthy diet
  • Healthy lifestyle

Treatment of Macular Degeneration
  • Anti-VEGF: periodic injection of "Anti-VEGF" into the eye to inhibit the fomration of new blood vessels to keep the retina free from leakage.
  • Photodynamic Therapy (PDT): Visudyne (a drug injected intravenously and used to help direct the laser to the affected area) is injected into patient's body.  It uses a specifically-designed laser that produces the low-level, non-thermal light required to activate the drug which results in a selective destruction of the unwanted leaking vessels. 
  • Laser: to seal leaking blood vessels associated with wet AMD with laser



The above information is for reference only.  Please consult opthalmologists for further examination.